Right ventricular apical (RVA) pacing can induce left ventricular (LV) dyssynchrony and dysfunction. In this article, we describe the prevalence, clinical characteristics, and outcome in a subset of patients with unrecognized LV apical akinetic aneurysmatic area associated with permanent RVA pacing as potential causes of heart failure (HF) and/or ventricular tachyarrhythmias (VT).We retrospectively studied 220 patients with permanent RVA pacing and no pre-existing structural heart disease in our follow-up clinic for high-degree atrioventricular block. Patients who presented with new-onset HF, chest pain, or VT following RVA pacing were evaluated by echocardiogram and cardiac catheterization. RVA pacing-induced LV apical akinetic aneurysmatic area was diagnosed in the absence of significant coronary artery disease by left ventriculogram. After a mean 8.8 ± 6.3 years, eight patients (3.6%) had LV apical akinetic aneurysmatic area. Of those with LV apical akinetic aneurysmatic area, four patients presented with or died of VT. There was no evidence of LV apical akinetic aneurysmatic area on echocardiogram or left ventriculogram in the remaining 212 patients. The four patients with LV apical akinetic aneurysmatic area and HF underwent cardiac resynchronization therapy: in all cases LV ejection fraction improved (from 33 ± 6 to 47 ± 10%, P = 0.03), and LV apical akinetic aneurysmatic area resolved in two.Permanent RVA pacing for high-degree atrioventricular block is associated with LV apical akinetic aneurysmatic area. This condition was associated with a high incidence of VT and cardiovascular complication, but was possibly reversible with cardiac resynchronization therapy.