Dr. M.J. Bazos, MD. Patient Handout

About Your Diagnosis

This condition often comes on suddenly (paroxysmal) and causes a rapid heartbeat (tachycardia) from abnormal electrical signals within the atria. The atria are above the ventricles, their position is often referred to as supraventricular; therefore, this condition may be called paroxysmal supraventricular tachycardia (PSVT). The abnormal signals produce an abnormal heart rhythm called an arrhythmia. These signals begin as the result of heart disease such as mitral valve disorders, problems with the walls of the atria, or preexcitation syndromes (when the ventricles are stimulated to contract too early and too often). About half of patients with PSVT have no heart disease and simply generate abnormal signals because of other conditions, such as thyroid disease. Nicotine from smoking, caffeine, or stress may cause this condition.

Living With Your Diagnosis
You may notice the rapid heartbeat because it often occurs at rest and may cause shortness of breath or chest pain. Attacks may last from a few seconds to several weeks. You may have to urinate frequently during prolonged attacks because the increased heart rate increases blood flow through the kidneys. Attacks may occur almost daily or may happen only a few times ever. You can try to stop the attack by gently massaging the carotid artery in the neck for a few seconds, straining as if lifting a heavy object, or placing a cold, wet towel on your face for a few minutes. Have your doctor show you how to do this before you try it on your own.

The doctor can detect the rapid pulse and can read the rapid rate on an electrocardiogram (ECG). If the maneuvers used to slow the heart rate do not work, medications are used. Medications are often given in a hospital to allow monitoring of the heart. Digoxin helps control the rate and efficiency of contraction of the ventricles. Digoxin levels in the blood have to be measured periodically. Verapamil or beta-blocker medications may be used, especially by patients with hypertension (high blood pressure). These drugs may cause low blood pressure or a slowed heart rate and make exercise difficult. They may cause fainting, lightheadedness, or fatigue. Hearts with PSVT not controlled with medicines may have to be electrically shocked back to normal (cardioversion). The main complications of PSVT are related to the excess work done by the heart. This eventually puts a strain on the heart and cause it to work less efficiently (heart failure). For persons with heart disease, this may be a strain that the heart cannot handle. Prolonged symptoms of a rapid heartbeat, chest pain, shortness of breath, or feeling faint necessitate immediate attention.

The DOs
•Stop smoking.
•Reduce stress in your life.
•Exercise, but do not start unless advised by your doctor.
•Start a healthful diet for your heart that includes low-fat and low-cholesterol foods.

The DON’Ts
•Do not ignore worsening symptoms.

When to Call Your Doctor
•If you have any reactions to your medications.
•If you have chest pain, shortness of breath, fainting, or rapid heartbeat that affects your ability to rest.