Development of the sinus venosus myocardium from the posterior second heart field : implications for sinoatrial and atrioventricular mode development

Abstract

While the embryonic heart is developing and maturing towards its four-chambered form, the cardiac conduction system (CCS) is developing as well. The CCS will provide the heart with the required wiring system to ensure the properly orchestrated contraction of the myocardial chambers. In both the young and adult population rhythm disturbances or cardiac arrhythmias can occur. Electrophysiological studies have shown that these events do not occur randomly in the heart but rather at anatomical predilection sites. This thesis presents our results on the morphological as well as electrophysiological changes that occur during heart development, specifically in the developing sinoatrial and atrioventricular node. By studying the developmental changes we aim to increase our knowledge on the mechanism underlying arrhythmias.