Recurrent sustained ventricular tachycardia, hypertrophic cardiomyopathy, and apical aneurysm: Electroanatomic map–guided surgical ablation and left ventricular restoration

Abstract

FIGURE 1. Electroanatomic voltage map of the left ventricle during sinus rhythm in anteroposterior (A) and posteroanterior (B) views (EnSite NavX system; St JudeMedical, Inc, St Paul, Minn). Areas with voltage amplitude greater than 1.5 mV are purple. Amplitudes less than 1.5 mV are, in decreasing order, blue, light blue, yellow, orange, red, and gray. The apical chamber is largely a low-voltage area. In the posteroanterior view, the scarred lesion apicolateral wall is gray. Pace mapping detected the critical CLINICAL SUMMARY A 73-year-old woman with a history of midventricular HCM and LV apical aneurysm received an implantable cardioverter-defibrillator (ICD) for recurrent sustained monomorphic VT. She continued to have frequent recurrence of sustained VT, resulting in refractory cardiogenic shock despite pharmacologic therapy with amiodarone and b-blockers. At admission, an electrocardiogram showed sustained monomorphic VT with a cycle length of 380 ms. VT was terminated by electrical cardioversion, and VT frequency decreased with amiodarone. Transthoracic echocardiography demonstrated asymmetric LV hypertrophy with a midventricular obstruction and a 40 3 47-mm dyskinetic apical aneurysm. Coronary angiography showed no significant stenosis. Electroanatomic endocardial and epicardial voltage mapping of the LV, performed with the EnSite NavX system (St Jude Medical, Inc, St Paul, Minn), revealed an area of low voltage and scar corresponding to the aneurysm (Figure 1, A and B). A pace map identical to the clinical VT wave was obtained at the rim of apical aneurysm, which was presumed to be the critical slow conduction zone that caused the reentry of VT (Figure 2). The operation was conducted through a median sternotomy under conventional cardiopulmonary bypass.