Biventricular pacemaker is a special pacemaker, which is used to synchronize the contractions of the left ventricle with the right ventricle, to improve the ejection fraction in patients with severe and moderately severe symptoms of heart failure.
Ejection fraction is a measure of blood that is pumped out by the left ventricle of the heart and is expressed in percentage. A normal ejection fraction usually lies between 50% and 70%. A patient with heart failure has a low ejection fraction, hampering the blood supply to various parts of the body and leads to symptoms of heart failure that include shortness of breath, dry cough, swelling of the ankles and legs, weight gain, increased urination, fatigue and rapid or irregular heart-beat.
Biventricular implantation is considered in heart failure patients with:
- Severe or moderately-severe heart failure symptoms
- Delayed electrical activation of the heart
- Either a risk or history of cardiac arrest
- On long-term medications for heart failure
Similar to a standard pacemaker, a biventricular pacemaker can be implanted either by an endocardial (transvenous) approach or an epicardial approach. However, a biventricular pacemaker usually has three leads, one is guided to the right ventricle, one to the left ventricle and the third (which is not always present) is guided to the right atrium. The lead in the left ventricle is guided through the coronary sinus.
When the heart rate drops below the rate set with the pacemaker, it senses the drop and transmits electrical impulses to the left as well as the right ventricle to contract simultaneously, improving the ejection fraction and the cardiac function. The lead placed in the right atrium helps the heart to function in a more balanced way.
Biventricular pacemaker implantation is also called cardiac synchronization therapy and is only a part of any comprehensive heart failure management program. Medications, life style changes and regular follow up with a cardiac specialist are all crucial for managing the symptoms and improving the quality of life in heart failure patients.
Baylor All Saints
Mid Cities EP