Case Presentation: A 55-year-old male admitted with a diagnosis of pulmonary embolism and complaints of several episodes of intermittent palpitations was referred for cardiac evaluation for supraventricular tachycardia. Family history was significant for heart failure in the father who required an implantable defibrillator and a brother who died in his 50s due to refusal of therapy. Physical examination was unrevealing. Electrocardiogram showed SVT with aberrancy and telemetry showed short episodes of paroxysmal atrial fibrillation. Transthoracic echocardiogram (TTE) showed left ventricular (LV) ejection fraction of 35% with prominent trabeculae in apical and lateral walls. He was managed with metoprolol and warfarin with plans for further outpatient work-up. Holter-monitoring revealed multiple runs of non-sustained ventricular tachycardia. He was subsequently readmitted with complains of palpitations, lightheadedness and fatigue on minimal exertion. Repeat TTE with contrast showed prominent trabeculae in the apical and lateral walls with Doppler evidence of color flow in the intertrabecular recesses suggestive of left ventricular non-compaction cardiomyopathy (LVNCC). Subsequent cardiac magnetic resonance imaging (cMRI) showed trabeculated to compact myocardium ratio of 3.5. Pharmacological stress testing was negative for inducible ischemia. He was medically optimized on lisinopril, metoprolol and warfarin. He received an implantable cardioverter defibrillator and was discharged. His first degree relatives were recommended TTE screening.
Discussion: Isolated LVNCC is rare primary genetic cardiomyopathy with echocardiographic prevalence of 0.014-1.3%. LVNCC, characterized by prominent trabeculae, deep intertrabecular recesses, and myocardial thickening in two distinct layers (compacted and non-compacted), is thought to be due to intra-uterine arrest of myocardial compaction. Common presentations include heart failure, atrial and ventricular arrhythmias and thromboembolic events. Multiple diagnostic criteria have been proposed, with the most common being a thickened LV wall consisting of two layers: a thin compacted epicardial layer; and a markedly thickened endocardial layer with numerous prominent trabeculations and deep recesses. Maximum ratio of non-compacted to compacted myocardium >2:1 at end-systole in the TTE parasternal short-axis view in apical and lateral walls has been well validated as a diagnostic criterion, although non-compacted to compacted myocardial thickness of > 2.3 in diastole in the long axis views on cMRI remains the most widely accepted criterion.
Conclusions: LVNCC is associated with high morbidity and mortality, with symptomatic presentation, LV dilatation and LV systolic dysfunction serving as mortality predictors. Management involves prevention and treatment of complications such as thromboembolism, heart failure and arrhythmias using standard guidelines.
To cite this abstract:Nawaz M, Vallabhajosyula S, Bansal O, Tantoush H, Mooss A. Isolated Left Ventricular Non-Compaction Cardiomyopathy in Adults. Abstract published at Hospital Medicine 2015, March 29-April 1, National Harbor, Md. Abstract 632. Journal of Hospital Medicine. 2015; 10 (suppl 2). https://www.shmabstracts.com/abstract/isolated-left-ventricular-non-compaction-cardiomyopathy-in-adults/. Accessed March 28, 2020.