Mid-ventricular hypertrophic obstructive cardiomyopathy complicated by an apical aneurysm, presenting as ventricular tachycardia

Mid-ventricular obstructive hypertrophic cardiomyopathy with apical aneurysm: An important subtype of arrhythmogenic cardiomyopathy

Mid-ventricular obstructive hypertrophic cardiomyopathy (MVOHCM) is an uncommon type of HCM. LV apical aneurysms are present in more than 20% MVOHCM cases and has been identified as an independent predictor of potentially lethal arrhythmic events, including non-sustained or sustained ventricular tachycardia (VT), and ventricular fibrillation (VF), as well as SCD. Although the pathogenesis of LVA remains unknown, but it has been suggested that apical aneurysm may be secondary to the increased after-load and high apical pressure arising from significant pressure gradient of the midventricular obstruction. The scarred rim of the aneurysm and the adjacent areas of LV myocardial fibrosis and consequent apical oxygen-demand mismatch may be responsible for the formation of apical aneurysm. Recent electrophysiologic studies have demonstrated that the aneurysmal rim forms the primary culprit arrhythmogenic substrate for generation of monomorphic ventricular tachycardia leading to SCD, but the clinical significance of the size of aneurysm in relation to SCD remains unsettled. We summarized the clinical features of the patients with MVOHCM and apical aneurysms. Appropriate therapeutic interventions include ICD implantation, and early surgical intervention for gradient relief may be undertaken to relief the MVO.

Left ventricular aneurysms in hypertrophic cardiomyopathy with midventricular obstruction: A systematic review of literature

BACKGROUND

Hypertrophic cardiomyopathy (HCM) with or without left ventricular apical aneurysm (LVA) had been studied in the past. Midventricular obstruction associated with HCM and LVA is a unique entity that has not been distinguished previously as a separate phenotypic disease in HCM patients.

METHODS

A systematic review of Pubmed and Google Scholar was conducted from inception until September 2017 for all observational studies conducted on HCM with midventricular obstruction and LVA.

RESULTS

A total of 94 patients from 39 studies were included in our analysis. The mean age of the patients was 58.05 ± 11.76 years with 59.6% being males. The most common electrocardiographic finding was T wave inversion occurring in 13.8% of the cases followed by ST elevation (9.5%). Maximal left ventricle (LV) wall thickness was reported 18.89 ± 5.19 mm on transthoracic echocardiography and paradoxical jet flow was detected in 29.8% of patients. Beta-blockers (58.5%) were the most common drug therapy at baseline and amiodarone (10.6%) was the most common antiarrhythmic used for ventricular tachycardia (VT). The most common complication, VT, occurred in 39.3% of cases and the incidence of all-cause mortality was 13.8 % over 16 ± 20.1 months follow-up. Implantable cardioverter defibrillator (ICD) was used in 37.2% of patients; 25.7% of patients with ICD received appropriate shock therapy.

CONCLUSION

HCM with LVA and midventricular obstruction is a unique entity that appears to be associated with high incidence of morbidity and mortality. Thus, early diagnosis and therapeutic intervention is recommended for management of this condition.