AP19-00416 Abstract View

Methods : A 54-year old male had symptoms of shortness of breath for 3 years. Four months ago, he was diagnosed as severe aortic valve stenosis with heart failure, and trans-thoracic echocardiography showed enlarged left ventricular end-diastolic diameter(LVEDD) of 70mm and reduced left ventricular ejection fraction (LVEF) less than 40%. Because the baseline ECG showed atrial fibrillation and complete LBBB with a QRS duration of 186ms (Figure 1), the ventricular dyssynchronization caused by LBBB might contribute to the impaired LV function. During the procedure of aortic valve replacement, an epicardial lead was implanted on lateral wall of left ventricle in case of the requirement of implant of cardiac resynchronization therapy (CRT). After 4 months of optimal medical therapy, no significant improvement was observed in cardiac function, with further reduced LVEF of 29% and enlarged LVEDD of 75mm. The patient was indicated for implantation of CRT. During the procedure, LBBAP was attempted by using trans-septal protocol after placement of defibrillation lead. Although LBBAP did not completely correct LBBB, a relatively narrow paced QRS was achieved. The LBBAP lead was plugged into the atrial port since the patient had chronic atrial fibrillation, and the AV delay was set as 30 ms. Two-dimensional mechanical dispersion (defined as time to peak strain delay, PSD) was analyzed on three different pacing modes (LBBAP optimized BiV, LBBAP only, and BiV) for evaluating LV synchrony. ECG and echocardiography were evaluated 6-month follow-up.