Cardiac Resynchronization Therapy

A healthy heart pumps blood through the body evenly and synchronously supplying the body with oxygen and nutrients. The right and left ventricles pump blood into the body’s circulatory system & the heart’s pumping motions are controlled by electric pulses that are distributed synchronously through the ventricles’ left and right bundle branches. They contract at the same time with every distributed excitation. When electrical conduction is blocked in the left bundle branch, it is referred to as a left bundle branch block, where the left bundle branch is blocked and the electrical stimulus is not passed on. For example, an electrical pulse first passes into the right ventricle, then the left ventricle with a delay. The delayed excitation in the ventricles causes uneven pumping motions in the heart, pumping force decreases, and the heart muscle becomes weaker. A device for cardiac resynchronization or CRT can restore an even balance between the two ventricles. The device is implanted through a small incision below the collarbone and connected to the heart with three leads. The atrial lead allows the CRT device to monitor the atrial rate & the device responds with electric pulses that are conducted into the ventricles simultaneously by the ventricular leads. The obstruction in the left bundle branch is bypassed and the pumping motion is synchronized; improving the cardiac output and quality of life in patients.