Aortic Valve Disease

The aortic valve is responsible for regulating the flow of blood from the left ventricle into the aorta. As time goes by and the valve is subjected to stress, calcium may deposit on the leaflets and cause the valve to become stenotic, or constricted (Fig. 10.3). This process is accelerated by rheumatic fever. The leaflets (cusps) become scarred. Over time, the scar tissue increases, and the valve itself becomes calcified. Aortic valve stenosis is also related to a condition known as a...

Arrhythmias Pacemakers and Defibrillators

Heartbeat now and then, and not all types of irregular heartbeats, or arrhythmias, are necessarily bad. They can range in severity from simply a nuisance to life threatening, especially those that originate from the heart ventricles. In most cases, an arrhythmia is caused by a faulty electrical conduction system, or pacemaker cells, in the heart muscle. Abnormal heart rhythms may interfere with the heart's pumping function and therefore may cause fatigue, lightheadedness, a sensation of...

Managing Arrhythmias

Meissner, M.D., C.M., F.A.C.C, F.A.C.P. Associate Professor of Internal Medicine Cardiac Electrophysiologist and Cardiologist Detroit Medical Center Wayne State University and Assistant Professor of Internal Medicine Cardiac Electrophysiologist and Cardiologist Detroit Medical Center Wayne State University Director, Detroit Medical Center Electrophysiology THE HEART'S PUMPING action, which creates the pulse, is generated by a burst of electrical energy that activates specialized cells...