The authors present the unique case of an 8-month-old baby diagnosed with severe left ventricular failure of unknown etiology. Due to a lack of organ availability for this age, a mechanical assist device and assessment for cardiac transplantation were not offered. Subsequent comprehensive echocardiographic dyssynchrony assessment and the presence of left bundle branch block were suggestive of response to cardiac resynchronization therapy. Dual-chamber epicardial pacing was initiated, resulting in prompt marked clinical and echocardiographic improvement, which continued until complete normalization of cardiac function. The pacing system was safely turned off 6 months after its implantation. In conclusion, cardiac resynchronization therapy should be considered as a treatment option even in infancy, regardless of the etiology of disease and/or patient age.
Cardiac resynchronization therapy (CRT) in the pediatric population has thus far not been followed extensively enough to provide concrete positive data, as has been done in adult patients with heart failure. However, several case studies have indicated that CRT produces similar, if not better, results in children. Not only has CRT become established as a bridge to transplantation, but in some cases, patients have been removed from transplantation lists because of significantly improved cardiac function and clinical presentation. Several criteria have been described to predict the response to CRT in the adult population.
We report the case of a small male infant who presented with severe heart failure of unknown etiology and was placed on the cardiac transplantation list within days of admission. We used biventricular resynchronization therapy as a bridge to rapid recovery to near normal cardiac function.
Case Presentation
An 8-month-old baby was addressed with severe heart failure and a 2-week history of increasing shortness of breath, coughing, and sweating with feeding. Clinical examination revealed weight in the 0.4th percentile. He was tachypneic and tachycardic, with a respiratory rate ranging from 60 to 80 breaths/min and a heart rate ranging from 160 to 180 beats/min. There were bilateral rales, no obvious cardiac murmurs, and moderate hepatomegaly. Electrocardiography ( Figure 1 A) showed sinus rhythm with broad QRS complexes and a pattern of complete left bundle branch block. Chest radiography showed important cardiomegaly with hilar enlargement and interstitial edema. The patient was admitted to intensive care with respiratory and inotropic support.
Echocardiography demonstrated normal cardiac connections; a dilated, globular left ventricle; severely impaired biventricular systolic function, with a left ventricular ejection fraction of 18%; and severe mitral regurgitation. Ventricular dyssynchrony was assessed and revealed the presence of septal–to–posterior wall motion delay of 214 ms ( Figure 2 A), preejection septal flash documented on color-coded tissue M-mode echocardiography ( Figure 2 B), presystolic mitral regurgitation ( Figure 2 C), and a shortened filling time of 30% of the RR interval ( Figure 2 D). Interventricular delay was 50 ms, and the 12-segment dyssynchrony index was 110 ms, calculated using 2-dimensional strain in 12 segments ( Videos 1A and 1B ).
