Combined implantation of dual-chamber ICD and optimizer through a persistent left superior vena cava

Cardiac contractility modulation (CCM) is a relatively new treatment for patients with an advanced heart failure having reduced left ventricular ejection fraction (LVEF), which is particularly indicated in patients with a sinus rhythm, narrow QRS complex, and 25%–35% LVEF (1). Studies have demonstrated improvements in NYHA class, quality of life, and exercise capacity (2–5)