In recent years, new technology has been developed for patients with both advanced heart failure and mechanical “dyssynchrony.” Dyssynchrony
Dyssynchrony occurs when the right side of the heart beats out of step with the left side of the heart as identified on electrocardiogram (ECG) or echocardiogram. These devices consist of a pacemaker or an ICD connected to three wires which are placed in the right atrium, right ventricle, and coronary sinus—a large vein behind the left ventricle (see diagram). By pacing from three distinct locations “in synchrony” the weakened heart can often beat more effectively resulting in improved quality of life and length of life. The surgical techniques and potential complications are similar to conventional pacemaker or ICD insertions albeit higher due to the added complexity of placing the special third wire on the left side of the heart. Johns Hopkins has played an important role in the development of resynchronization therapy for the treatment of heart failure patients. | 
