2011 Group Project 6 - Revision history

S8600021: Protected "2011 Group Project 6": Protect from student change ([edit=sysop] (indefinite) [move=sysop] (indefinite))

2011-10-13T06:28:00Z

Protected "2011 Group Project 6": Protect from student change ([edit=sysop] (indefinite) [move=sysop] (indefinite))

← Older revision	Revision as of 16:28, 13 October 2011
(No difference)

Z3291317: /* Internal links */

2011-10-13T05:08:55Z

Internal links

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	==Internal links==		==Internal links==

	* ~~Cardiovascular development abnormalities~~		* [http://embryology.med.unsw.edu.au/Notes/heart2.htm#Fallot Cardiovascular development abnormalities] - a page which explains about diferent abnormalities that can arise during Cardiovascular development. Also explains about TOF.
	http://embryology.med.unsw.edu.au/Notes/heart2.htm#Fallot

	* ~~Advanced cardiac embryology~~		* [http://embryology.med.unsw.edu.au/embryology/index.php?title=Advanced_Cardiac_Embryology Advanced cardiac embryology] - a page which describes, at an advanced level, the way the Cardiac system develops during embryogenesis.
	http://embryology.med.unsw.edu.au/embryology/index.php?title=Advanced_Cardiac_Embryology

	* ~~Cardiovascular system development~~		* [http://embryology.med.unsw.edu.au/embryology/index.php?title=Cardiovascular_System_Development Cardiovascular system development] - notes which describes the development of the Cardiovascular system.
	http://embryology.med.unsw.edu.au/embryology/index.php?title=Cardiovascular_System_Development

	* ~~Cardiovascular development lecture~~		* [http://embryology.med.unsw.edu.au/embryology/index.php?title=2009_Lecture_21 Cardiovascular development lecture] - a lecture given by Dr Hill in 2009 in regards to cardiovascular development.
	http://embryology.med.unsw.edu.au/embryology/index.php?title=2009_Lecture_21

	* Heart development ~~lectures showing~~ the genetic influences to anomalies such as TOF		* [http://embryology.med.unsw.edu.au/embryology/index.php?title=Lecture_-_Heart_Development Heart Development] - Heart development lecture delivered in 2011 which shows the genetic influences on cardiac anomalies such as TOF.
	http://embryology.med.unsw.edu.au/embryology/index.php?title=~~Lecture_~~-~~_Heart_Development~~
			* [http://embryology.med.unsw.edu.au/embryology/index.php?title=Cardiovascular_System_-_Movies Cardiovascular System - Movies] - a page which has movies on the development of Cardiovascular system

	==References==		==References==

Z3291317: /* Signs and Symptoms */

2011-10-13T04:55:53Z

Signs and Symptoms

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	''''Tet Spells' and Fatigue'''		''''Tet Spells' and Fatigue'''

	The word [[#Glossary \| '''‘tet spells’''']] is derived from Tetralogy of Fallot, as it is an event experieced by individuals who suffer from TOF. Babies who have TOF can at times enter into these [[#Glossary \| '''‘tet spells’''']], in which there is a sudden drop in oxygen saturation of the blood, causing the baby to turn blue. These [[#Glossary \| '''‘tet spells’''']] become apparent when the baby does certain activities such as crying<ref name= "National Heart Lung and Blood Institute - Signs & Symptoms of TOF"/>. An image portraying a '~~Tet~~ spell' in an infant can be found here: [http://www.nlm.nih.gov/medlineplus/ency/imagepages/18134.htm Cyanotic 'Tet spell']		The word [[#Glossary \| '''‘tet spells’''']] is derived from Tetralogy of Fallot, as it is an event experieced by individuals who suffer from TOF. Babies who have TOF can at times enter into these [[#Glossary \| '''‘tet spells’''']], in which there is a sudden drop in oxygen saturation of the blood, causing the baby to turn blue. These [[#Glossary \| '''‘tet spells’''']] become apparent when the baby does certain activities such as crying<ref name= "National Heart Lung and Blood Institute - Signs & Symptoms of TOF"/>. An image portraying a 'tet spell' in an infant can be found here: [http://www.nlm.nih.gov/medlineplus/ency/imagepages/18134.htm Cyanotic 'Tet spell']

Z3291317: /* Glossary */

2011-10-13T04:48:59Z

Glossary

Z3291317: /* Signs and Symptoms */

2011-10-13T04:20:21Z

Signs and Symptoms

Z3291317: /* Glossary */

2011-10-13T03:58:25Z

Glossary

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	'''Patent Ductus Arteriosus''' - is a congenital condtion that causes the failure of the ductus arteriosus to close		'''Patent Ductus Arteriosus''' - is a congenital condtion that causes the failure of the ductus arteriosus to close

			'''Prostaglandin''' - Refers to a group of fatty acids which are naturally derived. Some of its roles include regulation of acid secretion from the stomach, induce platelet aggregation, control inflammation, lowering of the blood pressure, and many more.

	'''Pulmonary Atresia''' - a form of congenital heart disease in which the pulmonary valve does not form properly		'''Pulmonary Atresia''' - a form of congenital heart disease in which the pulmonary valve does not form properly

Z3291317: /* Signs and Symptoms */

2011-10-13T03:55:36Z

Signs and Symptoms

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	==Signs and Symptoms==		==Signs and Symptoms==
			[[File:Cyanotic baby.jpg\|\|200px\|thumb\|left\|Image of a cyanotic baby]]
			'''Cyanosis'''

	~~'''~~Cyanosis~~'''~~		Normally, red blood cells carry oxygen around the body that is nearly completely saturated with oxygen held by the haemoglobin. When blood loses its oxygen, the colour changes from bright red colour to a colour that is a mix of dark blue and red. This event is known as cyanosis. Cyanosis could occur in situations in which the lungs are compromised due to underlying reasons such as the lungs being infected with chronic obstructive pulmonary disease, pneumonia and exposure to air at high altitudes. In the case of TOF patients, one of the heart defects (i.e. ventricular septal defect, explained further below) allows cyanosis to occur as the blood oxygen concentration is decreased due to the mix of oxygenated and deoxygenated blood in the TOF heart’s ventricles<ref name="Medline Plus - Skin Discoloration">http://www.nlm.nih.gov/medlineplus/ency/article/003215.htm</ref>.

	[[File:Cyanotic baby.jpg\|\|200px\|thumb\|left\|Image of a cyanotic baby]]Normally, red blood cells carry oxygen around the body that is nearly completely saturated with oxygen held by the haemoglobin. When blood loses its oxygen, the colour changes from bright red colour to a colour that is a mix of dark blue and red. This event is known as cyanosis. Cyanosis could occur in situations in which the lungs are compromised due to underlying reasons such as the lungs being infected with chronic obstructive pulmonary disease, pneumonia and exposure to air at high altitudes. In the case of TOF patients, one of the heart defects (i.e. ventricular septal defect, explained further below) allows cyanosis to occur as the blood oxygen concentration is decreased due to the mix of oxygenated and deoxygenated blood in the TOF heart’s ventricles<ref name="Medline Plus - Skin Discoloration">http://www.nlm.nih.gov/medlineplus/ency/article/003215.htm</ref>.

	The most important sign of TOF patients is cyanosis. This is when the lips, fingernails and skin of the patient turns a bluish colour<ref name= "National Heart Lung and Blood Institute - Signs & Symptoms of TOF"><http://www.nhlbi.nih.gov/health/health-topics/topics/tof/signs.html</ref>. Additionally during cyanosis, the mucous membranes of the TOF patient may turn blue. Therefore, the cases where dark-skinned individuals may experience cyanosis, the cyanotic event could be observed by change in colour in the nails and mucous membranes, which include lips, around the eyes and gums <ref name="Medline Plus - Skin Discoloration"/>. Cyanosis is considered to occur due to decreased amounts of oxygenated haemoglobin found within the blood when cyanosis occurs <ref>http://www.ncbi.nlm.nih.gov/books/NBK367/</ref>.		The most important sign of TOF patients is cyanosis. This is when the lips, fingernails and skin of the patient turns a bluish colour<ref name= "National Heart Lung and Blood Institute - Signs & Symptoms of TOF"><http://www.nhlbi.nih.gov/health/health-topics/topics/tof/signs.html</ref>. Additionally during cyanosis, the mucous membranes of the TOF patient may turn blue. Therefore, the cases where dark-skinned individuals may experience cyanosis, the cyanotic event could be observed by change in colour in the nails and mucous membranes, which include lips, around the eyes and gums <ref name="Medline Plus - Skin Discoloration"/>. Cyanosis is considered to occur due to decreased amounts of oxygenated haemoglobin found within the blood when cyanosis occurs <ref>http://www.ncbi.nlm.nih.gov/books/NBK367/</ref>.
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	The word 'Tet spells' is derived from Tetralogy of Fallot, as it is an event experieced by individuals who suffer from TOF. Babies who have TOF can at times enter into these ‘tet spells’, in which there is a sudden drop in oxygen saturation of the blood, causing the baby to turn blue. These 'Tet spells' become apparent when the baby does certain activities such as crying<ref name= "National Heart Lung and Blood Institute - Signs & Symptoms of TOF"/>. An image portraying a 'Tet spell' in an infant can be found here: [http://www.nlm.nih.gov/medlineplus/ency/imagepages/18134.htm Cyanotic 'Tet spell']		The word 'Tet spells' is derived from Tetralogy of Fallot, as it is an event experieced by individuals who suffer from TOF. Babies who have TOF can at times enter into these ‘tet spells’, in which there is a sudden drop in oxygen saturation of the blood, causing the baby to turn blue. These 'Tet spells' become apparent when the baby does certain activities such as crying<ref name= "National Heart Lung and Blood Institute - Signs & Symptoms of TOF"/>. An image portraying a 'Tet spell' in an infant can be found here: [http://www.nlm.nih.gov/medlineplus/ency/imagepages/18134.htm Cyanotic 'Tet spell']


	In addition to experiencing 'Tet spells', the baby could pass out, become unresponsive to their parents calling or touch, develop fatigue and finally have ''dyspnoea''. Furthermore, children with TOF would develop fatigue quickly and possibly pass out, thus surgeons now repair TOF hearts during infancy and not at adult to prevent such events.<ref name= "National Heart Lung and Blood Institute - Signs & Symptoms of TOF"/>		In addition to experiencing 'Tet spells', the baby could pass out, become unresponsive to their parents calling or touch, develop fatigue and finally have ''dyspnoea''. Furthermore, children with TOF would develop fatigue quickly and possibly pass out, thus surgeons now repair TOF hearts during infancy and not at adult to prevent such events.<ref name= "National Heart Lung and Blood Institute - Signs & Symptoms of TOF"/>
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	:3. '''Right Ventricular Outflow Murmur''' – can also have a pansytolic (throughout the systole of the heart beat) murmur if there is a presence of ventricular septal defect found in the heart <ref name="PMID21048055"/>.		:3. '''Right Ventricular Outflow Murmur''' – can also have a pansytolic (throughout the systole of the heart beat) murmur if there is a presence of ventricular septal defect found in the heart <ref name="PMID21048055"/>.

			[[File:Finger-Clubbing.jpg \|thumb\| An example of finger clubbing\|300px]]


	'''Abnormal Growth and Clubbing'''		'''Abnormal Growth and Clubbing'''

	Children with TOF do not grow at the rate of normal children as whilst breastfeeding in infancy, the babies would get tired quicker and during the growth of the infant, normal functionability of the heart and oxygen saturated blood is needed for proper growth <ref name= "National Heart Lung and Blood Institute - Signs & Symptoms of TOF"/>. ~~[[File:Finger-Clubbing.jpg \|thumb\| An example of finger clubbing\|300px]]~~		Children with TOF do not grow at the rate of normal children as whilst breastfeeding in infancy, the babies would get tired quicker and during the growth of the infant, normal functionability of the heart and oxygen saturated blood is needed for proper growth <ref name= "National Heart Lung and Blood Institute - Signs & Symptoms of TOF"/>. TOF children may also have ''''clubbing''''. <ref name= "National Heart Lung and Blood Institute - Signs & Symptoms of TOF"/> This clubbing would be evident as there would be enlargenemt of the bone or the skin around the fingernails of the patient. <ref>http://www.nlm.nih.gov/medlineplus/ency/article/001567.htm</ref>

	TOF children may also have ''''clubbing''''. <ref name= "National Heart Lung and Blood Institute - Signs & Symptoms of TOF"/> This clubbing would be evident as there would be enlargenemt of the bone or the skin around the fingernails of the patient. <ref>http://www.nlm.nih.gov/medlineplus/ency/article/001567.htm</ref>

Z3291317: /* Epidemiology */

2011-10-13T03:50:04Z

Epidemiology

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	Below is a table which shows the incidence rates of TOF in different races<ref><pubmed>12632215</pubmed></ref>:		Below is a table which shows the incidence rates of TOF in different races<ref><pubmed>12632215</pubmed></ref>:

	{\| style="border: solid 1px #a0a0ff" align="center"		{\| style="border: solid 1px #a0a0ff" align="center"
	\|- align="center" style="background:#8eb2ec"		\|- align="center" style="background:#8eb2ec"
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	\|align="center"\| 3.80		\|align="center"\| 3.80
	\|}		\|}


	In regards to genetics, one study showed that in 25% of the cases of TOF there is a microdeletion on Chromosome 22 which has the q11 region within it. Moreover, TOF is associated and frequently diagnosed along side [[#Glossary \| '''Velocardiofacial Syndrome''']] and [[#Glossary \| '''DiGeorge Syndrome''']]. Interestingly, another study showed that there is a rate of 25% in which patients with this 22q11 mutation eventually develop schizophrenia <ref name="PMID19683809"/>.		In regards to genetics, one study showed that in 25% of the cases of TOF there is a microdeletion on Chromosome 22 which has the q11 region within it. Moreover, TOF is associated and frequently diagnosed along side [[#Glossary \| '''Velocardiofacial Syndrome''']] and [[#Glossary \| '''DiGeorge Syndrome''']]. Interestingly, another study showed that there is a rate of 25% in which patients with this 22q11 mutation eventually develop schizophrenia <ref name="PMID19683809"/>.

	Tetralogy of Fallot is also associated with the chromosomal anomalies [[#Glossary \| '''Trisomy''']] 21, 18 and 13, and also associated with [[#Glossary \| '''Alagille Syndrome''']] which has a JAG1 mutation<ref name="PMID20091166"/>. The most frequently associated genetic anomalies with Tetralogy of Fallot is [[#Glossary \| '''Trisomy''']] 21 and 22q11.2 deletion. Furthermore, mutations in the 5q35 section (which codes for NKX2.5) were found in 4% of TOF patients which are classified as non-syndromic TOF<ref name="PMID19948535"><pubmed>19948535</pubmed></ref>.		Tetralogy of Fallot is also associated with the chromosomal anomalies [[#Glossary \| '''Trisomy''']] 21, 18 and 13, and also associated with [[#Glossary \| '''Alagille Syndrome''']] which has a JAG1 mutation<ref name="PMID20091166"/>. The most frequently associated genetic anomalies with Tetralogy of Fallot is [[#Glossary \| '''Trisomy''']] 21 and 22q11.2 deletion. Furthermore, mutations in the 5q35 section (which codes for NKX2.5) were found in 4% of TOF patients which are classified as non-syndromic TOF<ref name="PMID19948535"><pubmed>19948535</pubmed></ref>.


	In respect to clinical features, 35% of patients with TOF have ventricular and atrial [[#Glossary \| '''arrhythmias''']]. A 30 year follow up period of patients with TOF have shown that 6% of them die due to sudden cardiac death <ref name="PMID21048055"/>.		In respect to clinical features, 35% of patients with TOF have ventricular and atrial [[#Glossary \| '''arrhythmias''']]. A 30 year follow up period of patients with TOF have shown that 6% of them die due to sudden cardiac death <ref name="PMID21048055"/>.
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	TOF is treated with surgery (see [[#Treatment/Management \| '''Treatment/Management''']] section below). When this is conducted before the age of six months, there is a low mortality rate associated with it (i.e. 2%). After surgical intervention is conducted, there is a survival rate of 85-90%<ref name="PMID20091166"/>. It is clearly possible that improvements in the surgical field has allowed the reduction in surgical mortality which was 50% in the late 1950’s to 2% with contemporary surgical methods<ref name="PMID21251297"/>. On the other hand, if a TOF patient decides not to correct their condition, there is a 10% chance they will survive till their age is in the 30s and a 3% chance they will survive till their forties or older. Before surgical interventions were possible, TOF patients usually died within the first few years after birth, and it was rather unusual to see a patient who had survived beyond 30 years of age<ref name="PMID19683809"/>.		TOF is treated with surgery (see [[#Treatment/Management \| '''Treatment/Management''']] section below). When this is conducted before the age of six months, there is a low mortality rate associated with it (i.e. 2%). After surgical intervention is conducted, there is a survival rate of 85-90%<ref name="PMID20091166"/>. It is clearly possible that improvements in the surgical field has allowed the reduction in surgical mortality which was 50% in the late 1950’s to 2% with contemporary surgical methods<ref name="PMID21251297"/>. On the other hand, if a TOF patient decides not to correct their condition, there is a 10% chance they will survive till their age is in the 30s and a 3% chance they will survive till their forties or older. Before surgical interventions were possible, TOF patients usually died within the first few years after birth, and it was rather unusual to see a patient who had survived beyond 30 years of age<ref name="PMID19683809"/>.


	In regards to survival statistics, after surgery is conducted to correct TOF there is a <ref><pubmed>16908723</pubmed></ref>:		In regards to survival statistics, after surgery is conducted to correct TOF there is a <ref><pubmed>16908723</pubmed></ref>:
	* 97% chance that the patient will live one year after the surgery		* 97% chance that the patient will live one year after the surgery

Z3291317: /* Contemporary History */

2011-10-13T03:46:37Z

Contemporary History

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	====Contemporary History====		====Contemporary History====

	In '''1938''' there was a dawn in surgical therapy for people with heart defects as Gross and Hubbard closed off the [[#Glossary \| '''patent ductus arteriosus''']] in a girl who was aged 7.<ref name="PMID7888802"><pubmed>7888802</pubmed></ref> [[File:Dr Helen Brooke Taussig.jpg\| thumb \| 180px \| right \| Portrait of Dr. Helen Brooke Taussig]]		In '''1938''' there was a dawn in surgical therapy for people with heart defects as Gross and Hubbard closed off the [[#Glossary \| '''patent ductus arteriosus''']] in a girl who was aged 7.<ref name="PMID7888802"><pubmed>7888802</pubmed></ref> [[File:Dr Helen Brooke Taussig.jpg\| thumb \| 180px \| right \| Portrait of Dr. Helen Brooke Taussig]] Later, it was the work of Helen Taussig with her using a [[#Glossary \| '''fluoroscope''']] which allowed her to determine that children suffering from cyanosis, especially those with TOF, had decreased blood flow to the pulmonary circulation and thus more blood was needed to enter into this circulation. She then put forward a concept that shows the benefits of an [[#Glossary \| '''artificial ductus''']]; as she believed the closing of the patent ductus arteriosis lead to babies having cyanosis and cyanotic spells weeks after the baby was born<ref name="PMID7888802"/>.

	Later, it was the work of Helen Taussig with her using a [[#Glossary \| '''fluoroscope''']] which allowed her to determine that children suffering from cyanosis, especially those with TOF, had decreased blood flow to the pulmonary circulation and thus more blood was needed to enter into this circulation. She then put forward a concept that shows the benefits of an [[#Glossary \| '''artificial ductus''']]; as she believed the closing of the patent ductus arteriosis lead to babies having cyanosis and cyanotic spells weeks after the baby was born<ref name="PMID7888802"/>.

	It was in the morning of '''1943''' in which Taussig explained to [http://www.mc.vanderbilt.edu/diglib/sc_diglib/biopages/ablalock.html Blalock] and [http://www.blackpast.org/?q=aah/thomas-vivien-1910-1985 Thomas] that she believed it would be possible to direct more blood into the pulmonary circulation by conducting surgical methods. It was only a year later in which this belief came into practice as a [[#Glossary \| '''cyanotic congenital heart''']] experienced the first successful treatment due to surgical means. This technique was conducted on another two cases with the same defect and thus due to such success from the surgeries, the concept had received worldwide success.<ref name="PMID7888802"/>		It was in the morning of '''1943''' in which Taussig explained to [http://www.mc.vanderbilt.edu/diglib/sc_diglib/biopages/ablalock.html Blalock] and [http://www.blackpast.org/?q=aah/thomas-vivien-1910-1985 Thomas] that she believed it would be possible to direct more blood into the pulmonary circulation by conducting surgical methods. It was only a year later in which this belief came into practice as a [[#Glossary \| '''cyanotic congenital heart''']] experienced the first successful treatment due to surgical means. This technique was conducted on another two cases with the same defect and thus due to such success from the surgeries, the concept had received worldwide success.<ref name="PMID7888802"/>


	During the '''1950s''', the rise of [[#Glossary \| '''open heart surgery''']] began and the era of closed-heart surgery dominance had ceased. It was also during the '''1950s''' to '''1970s''' that surgeons realised the great variance in the anatomy of TOF, thus they had to work out new surgical techniques to accommodate this variation. Additionally in this period, there was an appreciation by surgeons that whilst conducting such operations in the heart, there needs to be precision in how they conduct their work anatomically. Thus in this 20 year period, there was a number of surgeons who had successfully conducted intracardiac surgeries to infants<ref name="PMID7888802"/>.		During the '''1950s''', the rise of [[#Glossary \| '''open heart surgery''']] began and the era of closed-heart surgery dominance had ceased. It was also during the '''1950s''' to '''1970s''' that surgeons realised the great variance in the anatomy of TOF, thus they had to work out new surgical techniques to accommodate this variation. Additionally in this period, there was an appreciation by surgeons that whilst conducting such operations in the heart, there needs to be precision in how they conduct their work anatomically. Thus in this 20 year period, there was a number of surgeons who had successfully conducted intracardiac surgeries to infants<ref name="PMID7888802"/>.


	During her late years of work, Dr Taussig had hypothesised that [[#Glossary \| '''congenital cardiac defects''']] had arisen from the expression of genetic defects found in the infants. At the time the hypothesis received skepticism, however today studies show us that this idea is quite real <ref name="PMID7888802"/>.		During her late years of work, Dr Taussig had hypothesised that [[#Glossary \| '''congenital cardiac defects''']] had arisen from the expression of genetic defects found in the infants. At the time the hypothesis received skepticism, however today studies show us that this idea is quite real <ref name="PMID7888802"/>.

Z3291317: /* Epidemiology */

2011-10-13T03:41:11Z

Epidemiology

← Older revision		Revision as of 13:41, 13 October 2011
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	In respect to clinical features, 35% of patients with TOF have ventricular and atrial [[#Glossary \| '''arrhythmias''']]. A 30 year follow up period of patients with TOF have shown that 6% of them die due to sudden cardiac death <ref name="PMID21048055"/>.		In respect to clinical features, 35% of patients with TOF have ventricular and atrial [[#Glossary \| '''arrhythmias''']]. A 30 year follow up period of patients with TOF have shown that 6% of them die due to sudden cardiac death <ref name="PMID21048055"/>.

	TOF is treated with surgery (see [[#~~Glossary~~ \| '''Treatment/Management''']] section below). When this is conducted before the age of six months, there is a low mortality rate associated with it (i.e. 2%). After surgical intervention is conducted, there is a survival rate of 85-90%<ref name="PMID20091166"/>. It is clearly possible that improvements in the surgical field has allowed the reduction in surgical mortality which was 50% in the late 1950’s to 2% with contemporary surgical methods<ref name="PMID21251297"/>. On the other hand, if a TOF patient decides not to correct their condition, there is a 10% chance they will survive till their age is in the 30s and a 3% chance they will survive till their forties or older. Before surgical interventions were possible, TOF patients usually died within the first few years after birth, and it was rather unusual to see a patient who had survived beyond 30 years of age<ref name="PMID19683809"/>.		TOF is treated with surgery (see [[#Treatment/Management \| '''Treatment/Management''']] section below). When this is conducted before the age of six months, there is a low mortality rate associated with it (i.e. 2%). After surgical intervention is conducted, there is a survival rate of 85-90%<ref name="PMID20091166"/>. It is clearly possible that improvements in the surgical field has allowed the reduction in surgical mortality which was 50% in the late 1950’s to 2% with contemporary surgical methods<ref name="PMID21251297"/>. On the other hand, if a TOF patient decides not to correct their condition, there is a 10% chance they will survive till their age is in the 30s and a 3% chance they will survive till their forties or older. Before surgical interventions were possible, TOF patients usually died within the first few years after birth, and it was rather unusual to see a patient who had survived beyond 30 years of age<ref name="PMID19683809"/>.

	In regards to survival statistics, after surgery is conducted to correct TOF there is a <ref><pubmed>16908723</pubmed></ref>:		In regards to survival statistics, after surgery is conducted to correct TOF there is a <ref><pubmed>16908723</pubmed></ref>:

← Older revision		Revision as of 13:46, 13 October 2011
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	====Contemporary History====		====Contemporary History====

	In '''1938''' there was a dawn in surgical therapy for people with heart defects as Gross and Hubbard closed off the [[#Glossary \| '''patent ductus arteriosus''']] in a girl who was aged 7.<ref name="PMID7888802"><pubmed>7888802</pubmed></ref> [[File:Dr Helen Brooke Taussig.jpg\| thumb \| 180px \| right \| Portrait of Dr. Helen Brooke Taussig]]		In '''1938''' there was a dawn in surgical therapy for people with heart defects as Gross and Hubbard closed off the [[#Glossary \| '''patent ductus arteriosus''']] in a girl who was aged 7.<ref name="PMID7888802"><pubmed>7888802</pubmed></ref> [[File:Dr Helen Brooke Taussig.jpg\| thumb \| 180px \| right \| Portrait of Dr. Helen Brooke Taussig]] Later, it was the work of Helen Taussig with her using a [[#Glossary \| '''fluoroscope''']] which allowed her to determine that children suffering from cyanosis, especially those with TOF, had decreased blood flow to the pulmonary circulation and thus more blood was needed to enter into this circulation. She then put forward a concept that shows the benefits of an [[#Glossary \| '''artificial ductus''']]; as she believed the closing of the patent ductus arteriosis lead to babies having cyanosis and cyanotic spells weeks after the baby was born<ref name="PMID7888802"/>.

	Later, it was the work of Helen Taussig with her using a [[#Glossary \| '''fluoroscope''']] which allowed her to determine that children suffering from cyanosis, especially those with TOF, had decreased blood flow to the pulmonary circulation and thus more blood was needed to enter into this circulation. She then put forward a concept that shows the benefits of an [[#Glossary \| '''artificial ductus''']]; as she believed the closing of the patent ductus arteriosis lead to babies having cyanosis and cyanotic spells weeks after the baby was born<ref name="PMID7888802"/>.

	It was in the morning of '''1943''' in which Taussig explained to [http://www.mc.vanderbilt.edu/diglib/sc_diglib/biopages/ablalock.html Blalock] and [http://www.blackpast.org/?q=aah/thomas-vivien-1910-1985 Thomas] that she believed it would be possible to direct more blood into the pulmonary circulation by conducting surgical methods. It was only a year later in which this belief came into practice as a [[#Glossary \| '''cyanotic congenital heart''']] experienced the first successful treatment due to surgical means. This technique was conducted on another two cases with the same defect and thus due to such success from the surgeries, the concept had received worldwide success.<ref name="PMID7888802"/>		It was in the morning of '''1943''' in which Taussig explained to [http://www.mc.vanderbilt.edu/diglib/sc_diglib/biopages/ablalock.html Blalock] and [http://www.blackpast.org/?q=aah/thomas-vivien-1910-1985 Thomas] that she believed it would be possible to direct more blood into the pulmonary circulation by conducting surgical methods. It was only a year later in which this belief came into practice as a [[#Glossary \| '''cyanotic congenital heart''']] experienced the first successful treatment due to surgical means. This technique was conducted on another two cases with the same defect and thus due to such success from the surgeries, the concept had received worldwide success.<ref name="PMID7888802"/>


	During the '''1950s''', the rise of [[#Glossary \| '''open heart surgery''']] began and the era of closed-heart surgery dominance had ceased. It was also during the '''1950s''' to '''1970s''' that surgeons realised the great variance in the anatomy of TOF, thus they had to work out new surgical techniques to accommodate this variation. Additionally in this period, there was an appreciation by surgeons that whilst conducting such operations in the heart, there needs to be precision in how they conduct their work anatomically. Thus in this 20 year period, there was a number of surgeons who had successfully conducted intracardiac surgeries to infants<ref name="PMID7888802"/>.		During the '''1950s''', the rise of [[#Glossary \| '''open heart surgery''']] began and the era of closed-heart surgery dominance had ceased. It was also during the '''1950s''' to '''1970s''' that surgeons realised the great variance in the anatomy of TOF, thus they had to work out new surgical techniques to accommodate this variation. Additionally in this period, there was an appreciation by surgeons that whilst conducting such operations in the heart, there needs to be precision in how they conduct their work anatomically. Thus in this 20 year period, there was a number of surgeons who had successfully conducted intracardiac surgeries to infants<ref name="PMID7888802"/>.


	During her late years of work, Dr Taussig had hypothesised that [[#Glossary \| '''congenital cardiac defects''']] had arisen from the expression of genetic defects found in the infants. At the time the hypothesis received skepticism, however today studies show us that this idea is quite real <ref name="PMID7888802"/>.		During her late years of work, Dr Taussig had hypothesised that [[#Glossary \| '''congenital cardiac defects''']] had arisen from the expression of genetic defects found in the infants. At the time the hypothesis received skepticism, however today studies show us that this idea is quite real <ref name="PMID7888802"/>.

← Older revision		Revision as of 14:48, 13 October 2011
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	'''Anomalies''' - something deviating from normal		'''Anomalies''' - something deviating from normal

	'''Arrythmia''' - (dysrhythmia) ~~Abnormal~~ electrical activity of the heart ~~resulting in~~ either a fast, slow, or irregular heart beat.		'''Arrythmia''' - (dysrhythmia) refers to an event where there is abnormal electrical activity of the heart which causes the heart to have either a fast, slow, or irregular heart beat.

	'''Artificial Ductus''' - it is an instrument inserted into blood vessels to create a channel that would allow blood to flow through.		'''Artificial Ductus''' - it is an instrument inserted into blood vessels to create a channel that would allow blood to flow through.

	'''Ascites''' – ~~Excess~~ fluid ~~in the space~~ between the tissues ~~lining~~ the abdomen and abdominal organs (the peritoneal cavity).		'''Ascites''' – a clinical term which refers to increased amounts of fluid between the tissues that line the abdomen and abdominal organs within the peritoneal cavity.

	'''Cardiopulmonary bypass''' - deoxygenated blood returning to the heart is diverted to a machine which oxygenated the lung and then pumps it to the arterial system.		'''Cardiopulmonary bypass''' - deoxygenated blood returning to the heart is diverted to a machine which oxygenated the lung and then pumps it to the arterial system.

	'''Clubbing''' – ~~Changes~~ in ~~the areas~~ under and around the toenails and fingernails~~, and~~ in the nails ~~themselves that may occur with~~ some disorders		'''Clubbing''' – event where there is changes in under and around the toenails and fingernails. Also there is changes in the nails is some disorders.

	'''Congenital''' - a disease/physical abnormality present from birth.		'''Congenital''' - a disease/physical abnormality present from birth.

	'''Conotruncal septation''' – it is the formation of the two great vessels (Aorta and Pulmonary artery) that forms the outflow tracts of the heart		'''Conotruncal septation''' – it is the formation of the two great vessels (Aorta and Pulmonary artery) that forms the outflow tracts of the heart.

	'''Cyanosis''' - Clinical term referring to a blue ~~coloration~~ of the skin and mucous membranes ~~due to the~~ presence of deoxygenated hemoglobin. ~~One cause of cyanosis is cyanotic~~ heart disease.		'''Cyanosis''' - Clinical term referring to a situation where there is a blue colouration of the skin and mucous membranes when there is a presence of deoxygenated hemoglobin. Cyanotic heart disease is one of the causes to this situation.

	'''Cyanotic heart disease''' - Clinical term referring to a congenital heart abnormality (defect) ~~resulting in~~ lack of oxygen ~~that causes~~ cyanosis ~~(a blue coloration of the skin and mucous membranes due to the presence of deoxygenated hemoglobin)~~.		'''Cyanotic heart disease''' - Clinical term referring to a congenital heart abnormality (defect) which causes a lack of oxygen which results in cyanosis.

	'''DiGeorge Syndrome''' - ~~it is~~ a congenital disorder which results from a microdeletion of the 22q11.2 region of Chromosome 22. It is characterised by hypocalcemia, immunodeficiency, and congenital heart disease.		'''DiGeorge Syndrome''' - a congenital disorder which results from a microdeletion of the 22q11.2 region of Chromosome 22. It is characterised by hypocalcemia, immunodeficiency, and congenital heart disease.

	'''Dyspnoea''' – Shortness of breath, difficult or laboured breathing		'''Dyspnoea''' – Shortness of breath, difficult or laboured breathing

	'''Edema/Oedema''' - Swelling caused by the accumulation of abnormally large amounts of fluid in the spaces ~~between~~ the body's cells or in the circulatory system.		'''Edema/Oedema''' - Swelling caused by the accumulation of abnormally large amounts of body fluid in between the spaces os the body's cells or in the circulatory system.

	'''Electrocardiogram''' - it is a diagnostic procedure that detects the electrical activity of the heart.		'''Electrocardiogram''' - it is a diagnostic procedure that detects the electrical activity of the heart.
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	'''Heart Failure''' - condition where the heart is unable to supply blood to the whole body.		'''Heart Failure''' - condition where the heart is unable to supply blood to the whole body.

	'''Hepatomegaly''' – Swelling of the liver beyond its normal size.		'''Hepatomegaly''' – Swelling/enlargement of the liver beyond its anatomical normal size.

	'''Hypertension''' - A medical condition where the pressure within the systemic arteries is raised, causing the heart to work harder than normal.		'''Hypertension''' - A medical condition where the pressure within the systemic arteries is raised, causing the heart to work harder than normal.
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	'''Missense mutation''' – it is a point mutation, whereby a single nucleotide has been changed resulting to a different codon that will lead to the formation of a different amino acid.		'''Missense mutation''' – it is a point mutation, whereby a single nucleotide has been changed resulting to a different codon that will lead to the formation of a different amino acid.

	'''Murmur''' – ~~Blowing~~, whooshing, or rasping ~~sounds heard during a heartbeat~~. The sound is caused by turbulent blood flow through the heart valves or near the heart.		'''Murmur''' – sounds which are heard during a heart beat, which includes sounds of blowing, whooshing or rasping. The sound is caused by turbulent blood flow through the heart valves or near the heart.

	'''Palliative care''' - care that focuses on relieving the suffering of patients rather than treating it.		'''Palliative care''' - care that focuses on relieving the suffering of patients rather than treating it.

	'''Palpitation''' – Unusually or abnormally ~~rapid~~ or ~~violent beating of the heart~~.		'''Palpitation''' – when the heart beats Unusually, abnormally, rapidly or violently.

	'''Patent Ductus Arteriosus''' - is a congenital condtion that causes the failure of the ductus arteriosus to close		'''Patent Ductus Arteriosus''' - is a congenital condtion that causes the failure of the ductus arteriosus to close

	'''Prostaglandin''' - ~~Refers to~~ a group of fatty acids which are naturally derived. Some of its roles include regulation of acid secretion from the stomach, induce platelet aggregation, control inflammation, lowering of the blood pressure, and many more.		'''Prostaglandin''' - a group of fatty acids which are naturally derived. Some of its roles include regulation of acid secretion from the stomach, induce platelet aggregation, control inflammation, lowering of the blood pressure, and many more.

	'''Pulmonary Atresia''' - a form of congenital heart disease in which the pulmonary valve does not form properly		'''Pulmonary Atresia''' - a form of congenital heart disease in which the pulmonary valve does not form properly
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	'''Pulmonary valve insufficiency''' - A condition where the pulmonary valve cannot prevent back flow of blood.		'''Pulmonary valve insufficiency''' - A condition where the pulmonary valve cannot prevent back flow of blood.

	'''Shunt''' – A channel ~~through which~~ blood or other bodily fluid is diverted from its normal path ~~by surgical reconstruction or by a synthetic tube~~.		'''Shunt''' – A channel created surgically either via surgical reconstruction or synthetic tube. It allows blood or other bodily fluid is diverted from its normal path.

	'''Stenosis''' - An abnormal narrowing, usually in relation to a tube. ~~For example,~~ blood vessel, gastrointestinal tract or respiratory tract ~~narrowing~~.		'''Stenosis''' - An abnormal narrowing, usually in relation to a tube. Examples of narrowing or a tube include blood vessel, gastrointestinal tract, respiratory tract, etc.

	'''Stethoscope''' - an instrument used, especially by medical doctors, to hear ausculatory sounds made in the body, generally in the thoracic area.		'''Stethoscope''' - an instrument used, especially by medical doctors, to hear ausculatory sounds made in the body, generally in the thoracic area.

	'''Syncope''' – ~~Brief~~ loss of consciousness associated with transient cerebral anemia, ~~as in~~ heart block, sudden lowering of the blood pressure, etc.; fainting.		'''Syncope''' – an event where there is a brief loss of consciousness which is associated with transient cerebral anemia, heart block, sudden lowering of the blood pressure, etc.; usually results in fainting.

	'''Systolic ejection murmur''' - A heart murmur heard during the contraction phase of the heart.		'''Systolic ejection murmur''' - A heart murmur heard during the contraction phase of the heart.

← Older revision		Revision as of 14:20, 13 October 2011
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	'''Cyanosis'''		'''Cyanosis'''

	Normally, red blood cells carry oxygen around the body that is nearly completely saturated with oxygen held by the haemoglobin. When blood loses its oxygen, the colour changes from bright red colour to a colour that is a mix of dark blue and red. This event is known as cyanosis. Cyanosis could occur in situations in which the lungs are compromised due to underlying reasons such as the lungs being infected with chronic obstructive pulmonary disease, pneumonia and exposure to air at high altitudes. In the case of TOF patients, one of the heart defects (i.e. ventricular septal defect, explained further below) allows cyanosis to occur as the blood oxygen concentration is decreased due to the mix of oxygenated and deoxygenated blood in the TOF heart’s ventricles<ref name="Medline Plus - Skin Discoloration">http://www.nlm.nih.gov/medlineplus/ency/article/003215.htm</ref>.		Normally, red blood cells carry oxygen around the body that is nearly completely saturated with oxygen held by the haemoglobin. When blood loses its oxygen, the colour changes from bright red colour to a colour that is a mix of dark blue and red. This event is known as [[#Glossary \| '''cyanosis''']]. Cyanosis could occur in situations in which the lungs are compromised due to underlying reasons such as the lungs being infected with chronic obstructive pulmonary disease, pneumonia and exposure to air at high altitudes. In the case of TOF patients, one of the heart defects (i.e. ventricular septal defect, explained further below) allows cyanosis to occur as the blood oxygen concentration is decreased due to the mix of oxygenated and deoxygenated blood in the TOF heart’s ventricles<ref name="Medline Plus - Skin Discoloration">http://www.nlm.nih.gov/medlineplus/ency/article/003215.htm</ref>.


	The most important sign of TOF patients is cyanosis. This is when the lips, fingernails and skin of the patient turns a bluish colour<ref name= "National Heart Lung and Blood Institute - Signs & Symptoms of TOF"><http://www.nhlbi.nih.gov/health/health-topics/topics/tof/signs.html</ref>. Additionally during cyanosis, the mucous membranes of the TOF patient may turn blue. Therefore, the cases where dark-skinned individuals may experience cyanosis, the cyanotic event could be observed by change in colour in the nails and mucous membranes, which include lips, around the eyes and gums <ref name="Medline Plus - Skin Discoloration"/>. Cyanosis is considered to occur due to decreased amounts of oxygenated haemoglobin found within the blood when cyanosis occurs <ref>http://www.ncbi.nlm.nih.gov/books/NBK367/</ref>.		The most important sign of TOF patients is [[#Glossary \| '''cyanosis''']]. This is when the lips, fingernails and skin of the patient turns a bluish colour<ref name= "National Heart Lung and Blood Institute - Signs & Symptoms of TOF"><http://www.nhlbi.nih.gov/health/health-topics/topics/tof/signs.html</ref>. Additionally during [[#Glossary \| '''cyanosis''']], the mucous membranes of the TOF patient may turn blue. Therefore, the cases where dark-skinned individuals may experience [[#Glossary \| '''cyanosis''']], the cyanotic event could be observed by change in colour in the nails and mucous membranes, which include lips, around the eyes and gums <ref name="Medline Plus - Skin Discoloration"/>. [[#Glossary \| '''Cyanosis''']] is considered to occur due to decreased amounts of oxygenated haemoglobin found within the blood when cyanosis occurs <ref>http://www.ncbi.nlm.nih.gov/books/NBK367/</ref>.


	''''Tet Spells' and Fatigue'''		''''Tet Spells' and Fatigue'''

	The word '~~Tet spells~~' is derived from Tetralogy of Fallot, as it is an event experieced by individuals who suffer from TOF. Babies who have TOF can at times enter into these ‘tet spells’, in which there is a sudden drop in oxygen saturation of the blood, causing the baby to turn blue. These '~~Tet spells~~' become apparent when the baby does certain activities such as crying<ref name= "National Heart Lung and Blood Institute - Signs & Symptoms of TOF"/>. An image portraying a 'Tet spell' in an infant can be found here: [http://www.nlm.nih.gov/medlineplus/ency/imagepages/18134.htm Cyanotic 'Tet spell']		The word [[#Glossary \| '''‘tet spells’''']] is derived from Tetralogy of Fallot, as it is an event experieced by individuals who suffer from TOF. Babies who have TOF can at times enter into these [[#Glossary \| '''‘tet spells’''']], in which there is a sudden drop in oxygen saturation of the blood, causing the baby to turn blue. These [[#Glossary \| '''‘tet spells’''']] become apparent when the baby does certain activities such as crying<ref name= "National Heart Lung and Blood Institute - Signs & Symptoms of TOF"/>. An image portraying a 'Tet spell' in an infant can be found here: [http://www.nlm.nih.gov/medlineplus/ency/imagepages/18134.htm Cyanotic 'Tet spell']


	In addition to experiencing '~~Tet spells~~', the baby could pass out, become unresponsive to their parents calling or touch, develop fatigue and finally have ''dyspnoea''. Furthermore, children with TOF would develop fatigue quickly and possibly pass out, thus surgeons now repair TOF hearts during infancy and not at adult to prevent such events.<ref name= "National Heart Lung and Blood Institute - Signs & Symptoms of TOF"/>		In addition to experiencing [[#Glossary \| '''‘tet spells’''']], the baby could pass out, become unresponsive to their parents calling or touch, develop fatigue and finally have [[#Glossary \| '''dyspnoea''']]. Furthermore, children with TOF would develop fatigue quickly and possibly pass out, thus surgeons now repair TOF hearts during infancy and not at adult to prevent such events.<ref name= "National Heart Lung and Blood Institute - Signs & Symptoms of TOF"/>


	'''Heart Murmur'''		'''Heart Murmur'''

	Heart murmurs are sound waves which are clearly audible that come from the vascular system or from the heart which have a round range between 20-2000Hz. It is considered to be produced as a consequence of blood flow within the cardiovascular system which is that is turbulent<ref><pubmed>14979389</pubmed></ref>. In the case of Tetralogy of Fallot, a heart murmur is a common sign which occurs due to the defected heart’s abnormal blood flow through it. However it should be mentioned that heart murmur is not a hallmark for congenital heart defects as many hearts of healthy children also have murmurs<ref name= "National Heart Lung and Blood Institute - Signs & Symptoms of TOF"/>. An audio sample of a heart murmur that would be heard in a TOF patient is found in the link below. Also below is a link to the sound of a normal heart beat without murmur and without TOF.		Heart [[#Glossary \| '''murmurs''']] are sound waves which are clearly audible that come from the vascular system or from the heart which have a round range between 20-2000Hz. It is considered to be produced as a consequence of blood flow within the cardiovascular system which is that is turbulent<ref><pubmed>14979389</pubmed></ref>. In the case of Tetralogy of Fallot, a heart [[#Glossary \| '''murmur''']] is a common sign which occurs due to the defected heart’s abnormal blood flow through it. However it should be mentioned that the heart [[#Glossary \| '''murmur''']] is not a hallmark for [[#Glossary \| '''congenital heart defects''']] as many hearts of healthy children also have [[#Glossary \| '''murmurs''']]<ref name= "National Heart Lung and Blood Institute - Signs & Symptoms of TOF"/>. An audio sample of a heart [[#Glossary \| '''murmur''']] that would be heard in a TOF patient is found in the link below. Also below is a link to the sound of a normal heart beat without murmur and without TOF.


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	'''Abnormal Growth and Clubbing'''		'''Abnormal Growth and Clubbing'''

	Children with TOF do not grow at the rate of normal children as whilst breastfeeding in infancy, the babies would get tired quicker and during the growth of the infant, normal functionability of the heart and oxygen saturated blood is needed for proper growth <ref name= "National Heart Lung and Blood Institute - Signs & Symptoms of TOF"/>. TOF children may also have ''''clubbing''''. <ref name= "National Heart Lung and Blood Institute - Signs & Symptoms of TOF"/> This clubbing would be evident as there would be enlargenemt of the bone or the skin around the fingernails of the patient. <ref>http://www.nlm.nih.gov/medlineplus/ency/article/001567.htm</ref>		Children with TOF do not grow at the rate of normal children as whilst breastfeeding in infancy, the babies would get tired quicker and during the growth of the infant, normal functionability of the heart and oxygen saturated blood is needed for proper growth <ref name= "National Heart Lung and Blood Institute - Signs & Symptoms of TOF"/>. TOF children may also have [[#Glossary \| '''clubbing''']]. <ref name= "National Heart Lung and Blood Institute - Signs & Symptoms of TOF"/> This clubbing would be evident as there would be enlargenemt of the bone or the skin around the fingernails of the patient. <ref>http://www.nlm.nih.gov/medlineplus/ency/article/001567.htm</ref>


	'''Cardiac and Visceral Problems'''		'''Cardiac and Visceral Problems'''

	It should also be mentioned that ''pulmonary insufficiency'' symptoms developed from a TOF heart varies in the degree of pulmonary insufficiency found in that individual. Thus the symptoms that could be presented are of a wide range which could from decline in function to palpitations. Moreover, late symptoms could also develop from the insufficiency which includes right heart failure, exertional ~~dyspnea~~, ''syncope'' and palpitations. In an event of which right ventricular failure occurs, signs to indicate it include elevated jugular venous pressure, ''ascites'', ''hepatomegaly'', jugular venous distension and peripheral edema.<ref name="PMID21048055"/>		It should also be mentioned that [[#Glossary \| '''pulmonary insufficiency''']] symptoms developed from a TOF heart varies in the degree of pulmonary insufficiency found in that individual. Thus the symptoms that could be presented are of a wide range which could from decline in function to palpitations. Moreover, late symptoms could also develop from the insufficiency which includes right-sided [[#Glossary \| '''heart failure''']], exertional [[#Glossary \| '''dyspnoea''']], [[#Glossary \| '''syncope''']] and palpitations. In an event of which right ventricular failure occurs, signs to indicate it include elevated jugular venous pressure, [[#Glossary \| '''ascites''']], [[#Glossary \| '''hepatomegaly''']], jugular venous distension and peripheral [[#Glossary \| '''edema''']].<ref name="PMID21048055"/>

	==Genetics/Aetiology==		==Genetics/Aetiology==