Talk:Cardiovascular System - Heart Rate Development

2010

Embryology of the conduction system for the electrophysiologist

Indian Pacing Electrophysiol J. 2010 Aug 15;10(8):329-38.

Mirzoyev S, McLeod CJ, Asirvatham SJ.

Mayo Medical School. Abstract

It is critical for interventional electrophysiologists to thoroughly appreciate the topographic and developmental anatomy of the heart and its conduction system. Not only is understanding cardiac anatomy important to prevent complications from collateral damage and to help guide catheter placement, but developmental anatomy allows a deeper appreciation of the arrhythmogenic substrate. In this article, we briefly review the relevant stages of cardiac development for electrophysiologists. The potential location of normal and abnormal conduction patterns resulting from heterogeneous developmental origin is discussed.

PMID: 20811536 http://www.ncbi.nlm.nih.gov/pubmed/20811536

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2922875/?tool=pubmed

Evaluation of the embryonic and foetal heart rate at 6(+0) to 11(+6) weeks of gestation] Hamela-Olkowska A, Wiech K, Jalinik K, Zaryjewski D, Kornatowski L, Dangel J. Ginekol Pol. 2009 Mar;80(3):188-92. Polish. PMID: 19382610

"RESULTS: FHR varied between 47 and 192 bpm (mean 154 +/- 26 bpm). At 6 weeks, mean EHR was 116 +/- 21 bpm, then slowly increased, reaching mean 172 +/- 9 bpm at 10 weeks. At 11 weeks the mean FHR achieved the level of 165 +/- 7 bpm. The difference was statistically significant. The r-correlation ratio between FHR and the gestational week was 0.58. In case of 7 embryos (2.75%) at 6.1 to 8.1 weeks of gestation slow FHR was noted (< 100 bpm). The scan performed 7-10 days later revealed miscarriages in all cases. CONCLUSIONS: EHR and FHR in the first trimester depends on gestational week. It increases since 6 to 9 weeks and decreases after 10 weeks. The highest values of FHR are observed between 9 and 10 weeks of gestation. The risk of early pregnancy loss increases significantly in case of detecting slow FHR. FHR can be checked by M-mode methods using any kind of ultrasound machine."