The Effect Of Rhabdomyomas On Underlying Cardiomyopathy: A Case Report

ABSTRACT

Case Presentation Term male infant born to SARS-CoV-2 positive mother with infant testing negative. ECG for perinatal bradycardia revealed ventricular pre-excitation. Echocardiogram showed asymmetric LV hypertrophy with prominent trabeculations, subaortic narrowing with no pressure gradient, and normal biventricular systolic function. Rapid increase in RV pressure estimates and NT-proBNP in first week if life concerning for diastolic dysfunction. Anti-arrhythmic therapy initiated for SVT with subsequent resolution. Later, developed progressive LV dilation and systolic dysfunction. Myocardium showed regions resembling non-compaction and others concerning for infiltrative process. Cardiac MRI showed no obvious tumors, but rhabdomyomas could not be ruled out given similar appearance to myocardium. Due to worsening heart failure, everolimus therapy initiated to target potential rhabdomyomas while awaiting genetic testing for tuberous sclerosis. Subaortic narrowing and LV hypertrophy improved within days, and LV appearance became more consistent with non-compaction. Genetic testing revealed a TSC2 gene variant consistent with tuberous sclerosis. Systolic function improved, and patient discharged on afterload reduction. Echocardiogram 6 months post-discharge shows continued LV dilation and mild systolic dysfunction. Discussion(s) Although outflow obstruction and arrhythmias are common with cardiac rhabdomyomas and can cause dysfunction, our patient developed progressive dysfunction in the absence of outflow tract gradient or prolonged arrhythmia. As rhabdomyomas subsided, it became clearer that he had an underlying cardiomyopathy. We suspect that rhabdomyomas in the setting of abnormal myocardium led to abnormalities in myocardial contractility and compliance causing combined systolic and diastolic dysfunction. After complete resolution of rhabdomyomas, cardiac function has improved. However, he continues to have ventricular dilation and mild dysfunction attributable to cardiomyopathy. It is unlikely that mother's SARS-CoV-2 infection played a role as infant tested negative and clinical picture was not consistent with myocarditis.