RESUMEN
Biventricular pacing has demonstrated improvement in cardiac functions in treating congestive cardiac failure patients. Recent trials have proven the clinical and functional benefits of cardiac resynchronization therapy in severe heart failure and intraventricular cardiac delays, mainly left bundle branch block. Biventricular pacing improves the exercise tolerance, quality of life, systolic heart function, reduces hospitalization and slows progression of the disease. A 54-year-old lady, a known case of dilated cardiomyopathy, was on biventricular pacing since 2 years. She presented in emergency with sudden deterioration of dyspnea to NYHA class III/IV. When investigated, the coronary sinus lead was found displaced; thus, left ventricle (LV) was not getting paced. After multiple failures to reposition the coronary sinus lead, it was decided to surgically place the epicardial lead for LV pacing under general anesthesia. Lateral thoracotomy was done and LV pacing lead was placed at different sites with simultaneous monitoring of cardiac output (CO) and stroke volume (SV) by transesophageal echocardiography (TEE). Baseline CO and SV were 1.9 l/min and 19.48 ml respectively and increased at different sites of pacing at LV, the best CO and SV were 4.2 l/min and 42.39 ml respectively on lateral surface. Intraoperative TEE can calculate beat to beat stroke volume and thus CO and helps to choose optimal site for placement of epicardial pacing lead.