Resynchronization Therapy

Cardiac resynchronization therapy (CRT) is achieved by implanting a biventricular pace-maker (BiV) into patients suffering from con-gestive heart failure secondary to a dilated cardio-myopathy. Congestive heart failure patients are first treated with standard heart failure drug ther-apy; however, if this therapy is not sufficient and the patients meet specific criteria, they can be se-lected for CRT. This therapy can create vast car-diac and symptomatic improvements in a relatively short time. This case report discusses the characteristics of a dilated cardiomyopathy before and after CRT and the associated cardiac improvements. Sonography continues to play an important role in diagnosing dilated cardio-myopathies, as well as congestive heart failure, and monitoring the progression after treatment. Key words: cardiac resynchronization therapy, cardiomyopathy, congestive heart failure, sonography Case Report A woman in her mid-40s presented to her cardi-ologist with prominent shortness of breath, chest tightness, and dizzy spells associated with nausea, vomiting, and abdominal pain. She was found to have cardiomegaly on a previous chest x-ray. An electrocardiogram and Bio-Z (CardioDynamics, The ICG Company, San Diego, CA) were obtained and showed sinus rhythm at a rate of 98 beats per minute (bpm) with a left bundle branch block and a QRS duration of 138 ms. The Bio-Z showed a low cardiac index with elevated systemic vascular re-sistance and normal thoracic fluid content. An echocardiogram was performed using American Society of Echocardiography guidelines using