Clinical Dilemma: Recurrent Syncope With Isolated Left Ventricle Non-Compaction Cardiomyopathy and Preserved Ejection Fraction, a Case Report and Review of the Literature

Abstract

Left ventricle non-compaction cardiomyopathy (LVNC) is an uncommon disorder characterized by the persistence of fetal myocardium of prominent trabecular meshwork, deep intertrabecular recesses, systolic dysfunction and left ventricular dilatation. It is thought to be caused by the arrest of normal endomyocardial morphogenesis. Here we present a case of a 27-year-old Caucasian female without past medical history who was presented to the emergency department because of syncope while she was working out. On further questioning, she relates that she has been having recurrent syncope for the last 9 years but she did not seek medical attention. Echocardiography and cardiac magnetic resonance imaging confirmed the diagnosis of LVNC and also showed a preserved ejection fraction. Implantable loop recorder showed recurrent non-sustained ventricular tachycardia. Although data were limited, an implantable cardioverter-defibrillator was prophylactically implanted because of the individual's high sudden cardiac death risk.

Left Ventricular Noncompaction as a Rare Cause of Syncope

“…The prevalence of LVNC has been estimated to vary from 0.01% to 1.3% in patients referred for echocardiography. However, recent studies show that it may be seen in as high as 3%-4% of patients with heart failure [3][4][5].…”

“…This is thought to result from premature cessation of the compaction of the loosely interwoven meshwork of myocardial fibers during endomyocardial morphogenesis, a process that occurs between 12-18 weeks of fetal life, beginning at the base of the left ventricle and progressing toward the apex. This process of trabeculation appears to involve the release of neuregulin growth factors from the endocardium and may also involve angiogenetic factors, such as vascular endothelial growth factor and angiopoietin-1 [4][5][6][7][8].…”

“…However, they are thought to be significantly more common than in the general population, particularly in those who have already developed heart failure (a potent trigger for malignant arrhythmias). Furthermore, recurrent syncope in LVNC may be predictive for eventual SCD [1,[4][5][6][7]12].…”

“…Asymptomatic patients generally carry a favorable prognosis. Predictors of increased mortality include increased age, neuromuscular disorders, severe arrhythmias, New York Heart Association (NYHA) class III/IV heart failure, exertional syncope related to ventricular arrhythmias, permanent atrial fibrillation, bundlebranch block, left ventricular dilatation/dysfunction, and thromboembolic events [5][6][7][8][9]14,15].…”

“…ICD may be considered for the management of ventricular arrhythmias. ICDs are often indicated in cases of aborted cardiac arrest, sustained ventricular tachycardia, exertional syncope related to ventricular arrhythmias, family history of SCD, or severely impaired left ventricular ejection fraction [ 2 , 5 - 8 ].…”