A Novel Cardiac MRI Protocol To Guide Successful Cardiac Resynchronization Therapy Implantation

Cardiac MRI (CMR) is recognized as an important imaging modality for assessing patients with heart failure. With improved segmentation and image registration tools, data acquired using CMR can help with planning and intraprocedural guidance as well as with defining etiology of heart failure and ventricular function. Here, we describe a successful CRT implantation where segmented CMR images were registered with the fluoroscopic images during the procedure to guide device implantation. A 23-year-old man with a history of repair of hemianomalous pulmonary venous drainage and biventricular noncompaction (Figure 1A and B) presented with a 3-month history of reduced exercise tolerance and peripheral edema. Despite optimal medical therapy, he remained in New York Heart Association class 3. His ECG showed sinus rhythm with a PR interval of 154 milliseconds (ms), QRS duration of 134 ms, and left bundle branch block (LBBB) morphology. Transthoracic echocardiography showed a dilated left ventricle with severe global impairment, an ejection fraction of 23%, and an end-systolic volume of 141 mL. The patient had significant intraventricular dyssynchrony, with 3D echo assessment giving a systolic dyssynchrony index (SDI) of 16.7%. A CMR examination was performed to assess cardiac function and …