Mark K. Friedberg, MD

Patterns and Clinical Significance of Electro-mechanical Dyssynchrony in Pediatric Dilated Cardiomyopathy
Hospital for Sick Children, Toronto, Canada
Mark K. Friedberg, MD – $44,550

Dilated cardiomyopathy (DCM) is a serious illness, which can cause premature death or lead to a heart transplant. This study will identify abnormal muscle contraction in DCM to understand which children can be treated with new therapies that have helped adults with DCM. Children with DCM may have a slow spread of the heart's electrical signal in the heart muscle causing different parts of the heart to squeeze at different times, rather than all together, thereby interfering with the heart's ability to pump and fill with blood. Stimulating the left and right heart chambers with an electrical signal (pacemaker) to make them squeeze at the same time (cardiac resynchronization therapy, CRT) improves the heart's pumping action and has been shown to improve life quality and life expectancy in adults with heart failure. At this time, it is unknown whether CRT will help children with heart failure from DCM. In the proposed study ultrasound (sound waves) techniques will be used on 60 children with DCM to analyze the squeeze and relaxation of different parts of the heart muscle. The study will look at how abnormal heart muscle motion affects the heart's function and whether this causes some patients to do poorly. This information will allow us to better understand which children with DCM may benefit from CRT. This study will also gather data from DCM muscle samples to investigate how different genes cause injury when the heart's motion is abnormal.