Topics in Clinical Cardiac Electrophysiology

By Lawrence E Widman, MD, PhD
Friday, March 30, 2018

The human heart is a wonderful machine, but sometimes it develops problems. The major plumbing problems are well known: heart attacks, tight valves, leaky valves and weakness of the muscle in its walls.

But the heart also has an electrical system, and its specialists are called cardiac electrophysiologists. In this article, I would like to discuss three of the common electrical problems that can develop in the heart and what can be done to help restore the patient to as vigorous and healthy a life as possible.

The first problem is atrial fibrillation. This rhythm arises in the upper chambers of the heart and often results in an irregular pulse that can be either too fast or too slow. Even when the pulse is normal, people with this rhythm just don’t “feel right.” The risk of getting it is increased by obstructive sleep apnea (OSA) and is reduced with effective treatment of OSA. The most important risk of atrial fibrillation is stroke, and this risk can be halved by anticoagulation. There are also treatments that can cure atrial fibrillation in many patients. When it cannot be cured, the heart rate can almost always be controlled satisfactorily.

The second problem is a slow heart beat, or chronotropic incompetence. In this rhythm, the natural pacemaker of the heart simply goes too slowly for the amount of exercise the person is trying to do. It begins very slowly, over a period of years, and often patients think they are just getting old. It is remarkable how many people say, after receiving a permanent pacemaker, that they feel 10 years younger! That’s because their hearts are now able to beat as fast as they did 10 years before.

The third problem is high risk for sudden death due to one of the abnormally fast heart rhythms that can kill within minutes. Most commonly, this situation is due to damage to the muscle of the heart severe enough to cause shortness of breath and fatigue. There is a well-proven treatment, an implantable cardioverter-defibrillator (ICD), that can control the risk of sudden cardiac death with a pretty low risk of side effects. For some reason, in the United States, many patients who could benefit from ICD treatment do not receive one. The magic number is a left ventricular ejection fraction (LVEF) of 35 percent or less.

It is important to remember that many people with the above conditions, and other problems with the electrical system of the heart, can lead active and fulfilling lives. In fact, after treatment, many of these people feel as good as they ever have.

If you would like to discuss these or related issues, please feel free to call my office at 210-615-9500.