Heritability for indices for cardiac contractility in ambulatory recordings

Introduction: Overactivity of the sympathetic nervous system (SNS) plays a pivotal role in the development of cardiovascular disease. This involvement suggests that the genetic susceptibility to adverse cardiovascular events may derive in part from individual differences in SNS activity. Methods and Results: To establish a genetic contribution to SNS activity, we measured sympathetic effects on cardiac contractility in 755 healthy adult twins and their singleton siblings. The preejection period (PEP) and the ratio of PEP to the left ventricular ejection time (PEP/LVET ratio) were derived from... Mehr ...