Cardiac resynchronization therapy in left ventricular hypertrabeculation/non-compaction and myopathy

Little is known how patients with left ventricular hypertrabeculation/non-compaction (LVHT) and heart failure respond to cardiac resynchronization therapy (CRT).

Included in this retrospective study were 8/102 patients (3 female, age range 43-78 years), in whom LVHT was diagnosed and in whom a CRT system was implanted. All eight patients were investigated neurologically and in seven of them a myopathy was found. The mean follow-up after CRT implantation was 39 (4-68) months. All patients improved by one or more New York Heart Association (NYHA) classes, and two by two NYHA classes. The left ventricular end-diastolic diameter decreased by < or =5% in 2 patients, by 6-10% in 3 patients, by 12% in 1 patient, and by >30% in 2 patients. The left ventricular systolic function, as assessed by the fractional shortening, did not change in 2 patients, increased by 10% in 2 patients, by 59% in 1 patient, doubled in 2 patients, and showed a five-fold increase in 1 patient. Two patients died during follow-up.

CRT by biventricular pacing in LVHT, heart failure, and myopathy leads to improvement in functional capacity in all patients and improvement of systolic function in half of the patients. The weak response of LVHT patients to CRT may be due to inappropriate selection or comorbidities, in particular, neuromuscular disorders.