Presentation and echocardiographic markers of neonatal hypertensive cardiomyopathy

Systemic hypertension is a rare but important cause of neonatal heart failure. It is critical that this etiology be recognized and distinguished from other causes of myocardial dysfunction in young infants, because diagnostic studies, treatments, and prognoses are quite different.

Between 1991 and 2005, 11 neonates were diagnosed as having neonatal cardiomyopathy and systemic hypertension through retrospective review of the Children's Hospital of Wisconsin database.

All infants in the cohort were found to have systemic hypertension (blood pressure of > 95th percentile for gestational age and weight). Causes included renovascular disease (n = 9), aortic obstruction secondary to thrombus (n = 1), and steroid use (n = 1). Echocardiography was performed at presentation for all patients because of cardiomegaly and/or hypertension. Echocardiographic findings were consistently striking for (1) left ventricular systolic dysfunction without chamber dilation, (2) concentric left ventricular hypertrophy, (3) left atrial dilation, and (4) aortomegaly. No anatomic aortic arch obstruction was identified, but Doppler findings for the descending thoracic aorta were uniformly consistent with elevated systemic vascular resistance. One patient died as a result of overwhelming thrombotic disease; all other patients responded to afterload reduction therapy with normalization of left ventricular systolic function during infancy.

Hypertensive cardiomyopathy can present in neonates with nonspecific symptoms and systemic hypertension. Because sometimes hypertension in infants is ignored or misinterpreted as agitation, echocardiography can provide critical markers of the disease.