Healthy Heart Rhythms

Taking a pulse on healthy heart rhythms
By Teresa Menendez, MD, FACC, FHRS, CCDS

Millions of people experience irregular heartbeats, called arrhythmias, at some point in their lives. Most often, they are harmless and happen in healthy people free of heart disease. However, some abnormal rhythms can indicate life-threatening conditions. Fortunately, advances in medicine and technology – including implanted cardiac devices which monitor and regulate rhythms, as well as minimally invasive procedures such as ablation which destroy unhealthy tissues – are saving lives every day. 

The heart’s pumping action or heartbeat is guided by a complicated internal electrical system.  Abnormal heart rhythms – too fast, too slow or erratic – are short circuits in that system. The prevention, diagnosis and treatment of arrhythmia all focus on closely tracking those rhythms and correcting them when necessary. 

Prevention
As always, the best medicine is prevention.  You can significantly lower your risk by making healthy lifestyle choices. Exercise regularly, maintain a healthy weight and eat a healthy diet with plenty of vegetables, fruits, and other vitamin-rich foods.  Stop smoking.  Avoid or limit caffeine and alcohol. Seek ways to manage stress. If you have a previously diagnosed condition like high blood pressure or high cholesterol, please take your medicines. 

Diagnosis
The best way to track your own heart rhythm is to listen to your heart (apical pulse) with a store-bought stethoscope, available at most pharmacies for lessthan $30.  It’s far more accurate than taking your pulse with your fingers (radial pulse). A normal resting heart rate for adults ranges from 60 to 100 beats a minute. The beat should be regular. You should take your pulse for a full minute.  If your pulse is too low or high or irregular, see your primary care physician, who can run a series of tests to more closely measure and monitor your heart and do further workup.  Your doctor may refer you to a cardiologist that specializes in clinical cardiac electrophysiology for further diagnosis and possible treatment. 

The heart has four chambers: two atria on top and two ventricles on the bottom which pump your blood. Arrhythmia can happen in either place. The most common conditions:

• Atrial Fibrillation. More than two million people in the U.S. have this condition, where the heartbeat is irregular and rapid due to disorganized electrical signals. The upper chamber may beat as often as 300 times a minute, about four times faster than normal. Though AFib isn't usually life threatening, it can lead to constant fatigue and other problems like congestive heart failure and stroke.
• Ventricular Tachycardia. This life-threatening arrhythmia is usually seen with other heart disease, but also can happen in people with normal hearts. Because VT can lead to ventricular fibrillation and a cardiac arrest, it requires aggressive treatment. 
• Ventricular Fibrillation. Cardiac arrest caused by this electrical malfunction is responsible for at least 50 percent of all cardiac deaths. It’s not the same as a heart attack, which is a circulatory or “plumbing” problem. In VF, the heartbeat is fast and chaotic, causing the lower chamber to quiver. It usually happens without warning and stops the heart from beating effectively.

Treatment
Treatments of arrhythmia vary, depending on the nature and severity. Lifestyle changes and a wide variety of medications are highly effective in treating most forms.  Every year brings advances in implanted electronic devices which correct and regulate rhythms. They include implanted cardioverter defibrillators (ICD), which continuously monitor the heart, serve as pacemakers and deliver life-saving shocks if necessary; they are 99 percent effective in stopping life-threatening abnormal heart rhythms. One of the most effective and widely used treatment procedures for arrhythmias is catheter ablation, where one or more flexible, thin tubes are guided into the blood vessels and to the heart muscle. A burst of energy heats and destroys very small areas of tissue that cause the abnormal electrical signals.

For more information, visit the Heart Rhythm Society site www.hrsonline.org

Teresa Menendez, MD, FACC, FHRS, CCDS is Director of the Electrophysiology Lab at Berkshire Medical Center.