Talk:Paper - A congenital anomaly of the heart - truncus arteriosus communis (1927)

A CONGENITAL ANOMALY OF THE HEART: TRUNCUS ARTERIOSUS COMMUNIS*

H. M. ZnowErwan, M.D.

(From the Depariment of Pathology, Brady Memorial Laboratory, Yale University School of Medicine, New Haven, Conn.)

In view of the infrequent occurrence of the congenital anomaly of the heart, truncus arteriosus communis, it seems desirable to report a case of this kind which occurred during the past year on the Pathology service of the New Haven Hospital. Moreover, several unusual features make this case particularly interesting; namely, the age of the patient, the unusual blood supply to the lungs and the apparent lack of previous cardiac symptoms. No complete review of the literature is attempted, for Dr. Abbott has done this in a recent article 1 in which a summary of the literature and other sources of study reveal but twenty-three cases of this anomaly. The case history given below is that of the oldest patient presenting a truncus arteriosus communis to come to necropsy. Vierordt reported one dying at sixteen and another at nineteen years of age. Crisp’s patient lived to twelve years. The other patients in this series died in early childhood or infancy.

The embryologic factors responsible for cardiac malformations are discussed in detail by Abbott and Shanly,? and, therefore, will not be repeated here. The arteries supplying the lungs in this case, one to each lobe, appear to be derivatives of the branchial arches of the fetus.

REporT OF CASE

History: A fairly well developed and well nourished black male, aged 25 years, was brought to the New Haven Hospital in an unconscious condition as the result of an automobile accident. On admission the patient had a contusion and laceration over the left eye. The pulse was 68 per minute and the blood pressure 140 systolic and 74 diastolic. A regular irregularity of the heart, ap

• Received for publication July 5, 1927.

617 618 ZIMMERMAN

parently of long standing, was noted. A “machinery” murmur was heard over the sternum. Respirations were slow and labored. The pupils were active and equal, and there was bleeding into the posterior pharynx. The patient did not regain consciousness and died four hours after admission. A history of previous cardiac symptoms was not obtained.

Necropsy: The examination was performed eleven hours after death. Only the findings bearing on the subject are here included. The body is fairly well developed and nourished and weighs 47.7 kilograms. The finger nails have a decided double curvature, but there is no clubbing of the phalanges. As the chest plate is removed it is noted that the heart’s transverse diameter is unusually great and that the diameter from base to apex is relatively short. No pulmonary artery is seen in situ, and so the heart and lungs, together with the aorta as far as the bifurcation of the common iliac arteries are removed en masse.

The heart is large and very firm, and is estimated to weigh over 500 gm. The apex is broad and not very well defined. The epicardium is smooth and glistening but for a gray elevated plaque 3 cm. in diameter on the anterior surface near the base. A moderate amount of subepicardial fat is present along the course of the coronary arteries. The auricular appendages nearly surround the common truncus arteriosus (Fig. I, T. A.), which arises from the left side of the base of the heart. No evidence whatever is present of a pulmonary artery or of a ductus arteriosus. The ascending portion of the truncus is wide, and a short distance beyond its junction with the transverse portion gives rise to the right innominate, left common carotid and left subclavian arteries in the normal manner. Just beyond this latter vessel the truncus narrowed perceptibly, and here, from the right lower surface of the arch of the truncus, arises a vessel (Fig. I, 1) which courses beneath the arch toward the left and enters the upper lobe of the left lung. At its origin from the truncus this vessel measures 6 mm. in diameter. One and one-half centimeters beyond this, from the right side of the truncus, another vessel (Fig. I, 2) arises, measuring 8 mm. in diameter at its origin. This vessel passes transversely in front of the trachea, just above the bifurcation, to enter the upper lobe of the right lung. This vessel bifurcates just before it enters the lung. One centimeter beyond this CONGENITAL ANOMALY OF HEART 619

vessel, and arising from the same side of the truncus, a small artery (Fig. II, 3) 2 mm. in diameter, passes transversely behind the lower portion of the trachea to enter the middle lobe of the right lung. Here also, from the under surface of the arch of the truncus, arises an artery (Fig. I, 4) 4 mm. in diameter passing obliquely downward to supply the lower lobe of the right lung. One centimeter beyond this last vessel, and from the left side of the beginning of the descending portion of the truncus, arises an artery (Fig. II, 5) 12 mm. in diameter, which passes horizontally toward the left to enter the lower lobe of the left lung. Just before it enters the lung this vessel also bifurcates. At this level the truncus, which follows the normal course of the thoracic and abdominal aortae and gives rise to the arteries usually derived from these vessels, measures 4.5 cm. in circumference.

The cavity of the right atrium is approximately three times the size of the left. The foramen ovale is closed. The valves of the inferior vena cava and coronary sinus are well formed. Two left pulmonary veins open by a short common trunk into the very small left auricle and two similar veins from the right lung also unite a short distance from the lung to enter this auricle.

The left ventricular wall measures 15 mm. in thickness, and the right wall at a corresponding level measures 12 mm. The interventricular septum averages 20 mm. in thickness. The capacity of the left ventricle is at least three times that of the right. The endocardium of all four chambers is everywhere smooth and glistening. The papillary muscles of both ventricles are greatly hypertrophied and the columnae carneae stand out as thick cords from the ventricular walls. The tricuspid valve is delicate and velamentous and the chordae tendineae insert well beyond the free edge of the valve. Two chordae arise from the muscular interventricular septum below and in front of the septal defect and insert into adjacent parts of the anterior and median cusps of this valve. This interventricular defect measures 1.5 cm. in diameter and readily permits the insertion of one finger. It is situated between the upper border of the ventricular septum and the lower surface of the semilunar valves of the common truncus. Its anterior, posterior and lower limits are formed by the anterior and posterior walls and the muscular septum respectively. Above, it is bounded by a valve-like structure which 620 ZIMMERMAN

is the remains of the pars membranacea. This membranous structure is inserted above between the anterior and the right posterior cusps of the common truncus. Below it is attached to the medial cusp of the tricuspid valve by a structure resembling a chorda tendinea. Its vertical position serves to partially narrow the interventricular defect. This ventricle lacks a well marked conus arteriosus, the space between the anterior heart wall, the anterior cusp of the tricuspid valve and the right side of the remains of the pars membranacea being quite shallow.

The large truncus arteriosus arises chiefly from the left ventricle, only about one-fourth of the lumen over-riding the interventricular defect. The semilunar cusps guarding the orifice of the truncus are three in number and very large, and the sinuses of Valsalva are all very deep, readily allowing the insertion of the end of the thumb. This valve measures 8 cm. in circumference. The sinus of Valsalva behind the anterior cusp is deeply funnel-shaped. The right and left coronaries arise rather high up in the anterior and in the left posterior sinuses, respectively. No evidence whatever of the septum aortopulmonale is present, and a slight puckering of the wall of the truncus 4 cm. above the truncal valve is the only evidence of a probable ductus Botalli. The base of the truncus has a few irregularly shaped yellow arteriosclerotic subintimal plaques.

The mitral valve is delicate and velamentous and the chordae tendineae insert well beyond the free edge. From the above description of the heart, it is seen that the venous blood of the right ventricle mixed with the arterial blood of the left ventricle at each ventricular systole, for the only pathway of escape for the blood in the right ventricle is through the interventricular defect into the common truncus, which received simultaneously the blood from the left ventricle.

The following anatomic diagnoses are made after a complete necropsy:

Primary: Contusions and lacerations of the face and body; extradural hemorrhage (following rupture of middle meningeal artery).

Subsidiary: Common truncus arteriosus persistens and interventricular septal defect; apical pulmonary scar; pleural and peritoneal adhesions. CONGENITAL ANOMALY OF HEART 621

REFERENCES

. Abbott, M. E., Osler and McCrae. Modern Medicine, 1927, Ed. 3, iv, 707.

. Abbott, M. E., and Shanly, E. Internat. A.M. Museums Bull., 1922, No. 8, 188, DESCRIPTION OF PLATES

PLATE 159 Fic. 1. Anterior view of heart showing common truncus and origin of pulmonary arteries to upper lobes of lungs.

Fic. 2. Posterior view of heart showing common truncus and origin of pulmonary arteries to lower lobes of lungs. AMERICAN JOURNAL OF PATHOLOGY.

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PLATE 159

A.11I90) ANTERIOR VIEW OF HEART SHOWING COMMON TRUNCUS AND ORIGIN OF PULMONARY ARTERIES TO UPPER LOBES OF LUNGS. @

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A 1190 POSTERIOR VIEW OF HEART SHOWING COMMON TRUNCUS AND ORIGIN OF PULMONARY ARTERIES TO LOWER LOBES OF LUNGS

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Fic. 3. Longitudinal section of heart showing common truncus arteriosus and interventricular septal defect. AMERICAN JOURNAL oF PaTHotocy. Vor. III PLATE 160

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A.1i90 LONGITUDINAL SECTION OF HEART SHOWING COMMON TRUNCUS ARTERIOSUS AND INTERVENTRICULAR SEPTAL DEFECT.

Congenital Anomaly of Heart