Heart Care Info - Heart Disease Prevention & Treatment

Developmentally Regulated SCN5A Splice Variant Potentiates Dysfunction of a Novel Mutation Associated with Severe Fetal Arrhythmia

LL Murphy, AJ Moon-Grady, BF Cuneo, RT Wakai... - Heart Rhythm, 2011 - Elsevier Background Congenital long-QT syndrome (LQTS) may present during fetal development and can be life-threatening. The molecular mechanism for the unusual early onset of LQTS during fetal development is unknown. Objective We sought to elucidate the molecular ...

Figure 1. Fetal Doppler echocardiogram and magnetocardiogram. A: Pulsed-wave Doppler of the fetal aorta at 20 weeks' gestation. Normal conducted beats (red arrows) are interrupted by frequent premature beats and 2 3 beat runs of tachycardia with a variable cycle length (white arrows). The flow velocity is maintained during the short runs of tachycardia, suggesting that stroke volume is only slightly diminished. B: Signal-averaged butterfly plot determined by using fetal magnetocardiography during sinus rhythm at 206/7 weeks' gestation, illustrating T-wave alternans, a corrected QT interval of 604 ms, normal PR interval, and a QRS duration that was slightly prolonged for age (0.69 ms). C: Representative rhythm trace obtained by fetal magnetocardiography at 206/7 weeks' gestation. Arrows indicate sinus beats interrupted by 2 episodes of nonsustained polymorphic ventricular (V) tachycardia with varying cycle length (400 200 ms). D: Pulsed-wave Doppler of the middle cerebral artery at 22 weeks' gestation illustrating fetal arrhythmia. At this time, the fetus was severely hydropic with very poor systolic function (not shown). The tracing shows the onset of a sustained period (>3500 ms) of ventricular tachycardia (white arrows), initiated by a premature beat. During the tachycardia, there is a decreased stroke volume as evidenced by the extremely low velocity Doppler signals. The tachycardia cycle length was 480 to 210 ms.