Case Presentation: A 60-year-old African American man with diabetes presented with progressive dyspnea on exertion and swelling of lower extremities for 3 months. He reported a decline in his previously unlimited exercise tolerance to 1 block and paroxysmal nocturnal dyspnea, with no chest pain or palpitations. He denied any toxic habits and his family history was unknown. On exam patient had BP 123/87, HR 110, RR 18, SpO2 98% on room air, jugular venous distention, a S3 gallop, clear lungs, and +2 bilateral lower extremity pitting edema. Labs were significant for BNP of 870, while troponins, TSH, HIV, ANA, iron and lipid panels were unremarkable. EKG revealed sinus tachycardia with PVCs. Chest x-ray showed borderline cardiomegaly. Echocardiogram revealed left ventricle at upper limit of normal size with an ejection fraction of 10%, and very prominent apical trabeculations. Cardiac catheterization revealed non-obstructive coronary disease, and patient was classified with non-ischemic cardiomyopathy due to left ventricular non-compaction (LVNC). The patient was aggressively diuresed, and a beta blocker and ACE inhibitor were initiated. He was discharged with cardiology follow up with plans for genetic screening and evaluation for AICD placement.
Discussion: LVNC is a cardiomyopathy characterized by an altered myocardium with two layers: one thickened with prominent trabeculations and deep recesses, and one thinner compacted epicardial layer. LVNC is hypothesized to be caused by an arrest in compaction of the endomyocardial fiber meshwork during embryogenesis, although cases in which LVNC appears acquired later in life have also been reported. Prevalence is estimated at up to 3-4% of CHF patients, and is more common in males and African Americans. There is a genetic predisposition for this condition which may be familial or sporadic.
LVNC may present at any age, with a spectrum of clinical manifestations including cardiac arrhythmia, sudden cardiac arrest, stroke and other thromboembolism, or most commonly with heart failure as in our case. Echocardiography is the initial diagnostic tool to identify LVNC, with criteria including the detection of distinct trabeculated and compacted myocardial layers, followed by cardiac MRI if results are equivocal.
Treatment is dictated by a patient’s clinical presentation. Patients with heart failure from LVNC should be given standard heart failure medications. LVNC patients should also receive ICD placement according to indications for other cardiomyopathy, but due to increased risk of malignant arrhythmias, surveillance with routine holter monitoring has been advocated. Moreover, LVNC patients remain at greater risk for systemic thromboembolism; patients with a prior embolic event or known LV clot require anticoagulation, and those with atrial fibrillation, EF<40%, or elevated CHADS2-VASc scores should also be considered for treatment. Finally, cardiac screening is recommended for first degree relatives due to risk of familial recurrence, as early detection may improve prognosis.
Conclusions: LVNC is a relatively rare cardiomyopathy which may present with significant arrhythmias, systemic embolizations, and heart failure. It is increasingly diagnosed with improved cardiac imaging techniques, and hospitalists should be familiar with this disease entity and consideration in treatment apart from other cardiomyopathies, including need to screen for initiation of anticoagulation given elevated embolic risk and patient counseling regarding family screening.