Getting the right beat
Every pump needs a power source ... and the heart is no exception. Serving as a type of electrical relay station inside the body,
our hearts pump about 72 times per minute, totaling more than 100,000 heartbeats each day. Even as we sleep, the heart continues to keep pace, pumping about 1,900 gallons of oxygen-rich blood through the arteries every 24 hours!
Millions of Americans have hearts that beat irregularly due to disturbances in the heart's electrical system. Heart rhythm disorders—or arrhythmias—can cause the heart to pump less effectively. While they often do not require medical treatment, they can cause serious side effects, and in some cases, life-threatening complications such as stroke and heart failure.
Many arrhythmias have no known cause. However, a number of factors can contribute to them, including heart disease, high blood pressure, diabetes, smoking, excessive use of alcohol or caffeine, drug abuse, certain medications, stress and age of 65 years and above.
irregular heartbeat
Documenting the cause of an erratic heartbeat is sometimes difficult because arrhythmias can occur at irregular intervals. However, a number of tests are available:
- Electrocardiogram (EKG)
This standard test uses electrodes placed on different parts of the body to read and record electrical impulses as they move through the heart. A doctor can tell a lot about the heart and its rhythm by studying the wavelike images produced in this test. One limitation is that the test lasts only a few seconds. If an episode of arrhythmia doesn’t occur during the test, the exact source of the problem cannot be identified. - Holter monitor
To check for an arrhythmia that isn’t found during an EKG, you can wear a small, portable EKG monitor. The Holter monitor can record 24-48 hours of electric signals, after which you return the recorder to your doctor for analysis. - Event recorder or monitor
This mall device—which you keep at home for a month or two—allows you to record an irregular heartbeat as it happens. This may be particularly helpful if you have relatively infrequent and brief episodes of irregular heartbeats. - Treadmill
You may walk and run on a treadmill or ride a stationary bicycle while your heart rate and rhythm are checked. - Echocardiogram
Ultrasound waves show the heart’s size, structure and motion. - Esophageal electrophysiologic procedure
A soft, flexible plastic tube is inserted through your nostril into the esophagus to make an ECG. Because the esophagus is close to the heart’s upper chambers, an ECG recording taken there gives more exact information than a regular ECG. - Electrophysiologic study
Thin tubes called electrode catheters are inserted into blood vessels in the groin, neck, leg or arm and threaded into the heart to measure how the electrical system is working. Electric impulses are then applied to the heart to make it beat rapidly or irregularly and the heart’s response helps identify slow or fast heart rates that could be life-threatening.
An early diagnosis is very important to reduce the risk of permanent damage and additional heart dysfunction. Diagnosis is done through noninvasive tests such as an electrocardiogram (EKG) or through more invasive testing like an electrophysiology study.
And, with technological advances, a relatively new specialist called an electrophysiologist now focuses on treating heart rhythm problems. Procedures include everything from pacemakers and implantable cardioverter defibrillators (ICDs) to radiofrequency ablations and valve repairs.
Procedures used to treat abnormal heartbeats
With advances in the field of cardiology, a new specialist—an electrophysiologist—is now repairing heart rhythms. Procedures include the following:
Pacemakers are electronic devices typically implanted under the skin in the upper chest to treat patients with abnormally slow heartbeats. Used since the 1960s, pacemakers may function continuously and stimulate the heart at a fixed rate, or may be programmed to episodically stimulate the heart when a long pause between heartbeats is detected.
Implantable cardioverter defibrillators (ICDs) deliver a shock to restore normal heart rhythm to correct abnormally fast and dangerous heartbeats originating in the heart’s lower pumping chambers (ventricles). The battery-operated ICD is typically implanted under the skin in the upper chest to constantly monitor the heart rate and rhythm. It acts like a small computer, programmed by the physician to check the heart’s electrical signals and deliver electrical energy when it detects an abnormal rhythm. The ICD’s memory stores information about each incident and notes what treatment was delivered and the treatment’s success.
Biventricular defibrillators treat both ventricles of the heart and often provide both shock and pacing capabilities to help synchronize heart rhythm.
Radiofrequency catheter ablation is a minimally invasive procedure performed by cardiac electrophysiologists, in which one or more catheters with specialized tips are threaded through the blood vessels to the heart. The catheters are used to map the heart’s electrical impulses from within to either zap the tissue with electronic radiofrequency waves or freeze very small areas of heart tissue that are the source of the arrhythmia.
The The Maze procedure for patients with atrial fibrillation is usually performed in conjunction with other needed cardiac surgery such as coronary artery bypass or mitral valve repair. This open-heart procedure is named for its original concept of applying incisions in a maze-like pattern within the atria (the heart’s upper chambers) to clock the abnormal electrical circuits that trigger atrial fibrillation. Today, new tissue ablation technologies (such as lasers, ultrasound and cryotherapy) and minimally invasive surgical instruments are reducing the size and complexity of incisions required.
Diagnostic studies in which a catheter, normally inserted into the body through the patient’s femoral artery near the top of the leg, is guided to a patient’s heart “to unamask rhythm disorders” that could cause life-threatening problems.
Too fast or too slow?
Whether your heartbeat is too slow, too fast or irregular, experienced electrophysiologists understand that proper treatment and diagnosis is essential to good health.
To diagnose either tachycardia or bradycardia, the physician will usually order an EKG to record the electrical activity of the heart.
- Tachycardia—or rapid heartbeat—can produce palpitations, rapid heart action, chest pain, dizziness, lightheadedness, fainting or near fainting if the heart beats too fast to circulate blood effectively. It occurs when the heart beats in a regular rhythm, but more than 100 times a minute. Since there is not enough time between beats for the heart to fill properly with blood, the body gets less oxygen and nutrients than it needs to function properly.
When rapid heart beating starts in the ventricles—called ventricular tachycardia—it can interfere with the heart’s ability to pump enough blood to the brain and other vital organs. This dangerous arrhythmia can change without warning into the most serious heart rhythm disturbance—ventricular fibrillation. In this, the lower chambers quiver and the heart can’t pump any blood. Collapse and sudden cardiac death follow unless medical help is provided immediately.
If treated in time, ventricular tachycardia and ventricular fibrillation can be treated by using an electronic device called an implantable cardioverter defibrillator (see below). Rapid heart beating can be controlled with medications or by identifying and destroying the focus of rhythm disturbances.
Blood clots can form during atrial fibrillation, a disorder found in 2.2 million Americans. In atrial fibrillation, the atria quiver instead of beating effectively. Blood isn’t pumped completely out of them when the heart beats, so the blood pools and clots.
If part of a blood clot in the atria leaves the heart and lodges in an artery in the brain (or leading to it), a stroke results. About 15 percent of strokes occur in people with atrial fibrillation. - Bradycardia occurs when the heart beats too slowly, less than 60 beats per minute, starving the body of oxygen and nutrients.
Bradycardia doesn’t usually require treatment unless there are prolonged or repeated symptoms such as fatigue, dizziness, lightheadedness, fainting or near-fainting spells. These symptoms are usually due to insufficient blood flow to the brain. Elderly people are more prone to problems with a slow heart rate. These symptoms can be treated and, in certain cases, can be corrected by implanting an electronic pacemaker under the skin to speed up the heart rhythm when the heart rate becomes too slow.
EP program expands
Since opening in 1995, the Electrophysiology (EP) Lab at Sacred Heart Medical Center & Children's Hospital has grown into one of the busiest arrhythmia programs in the region for both adults and children.
And it just got busier with the recent opening of a third state-of-the-art EP lab to serve a fast-growing demand for patients needing pacemakers, defibrillators and other heart procedures.
The new $2.5 million, 950-square-foot lab is equipped with 3-D X-ray cameras. In addition, a new computerized mapping system captures high quality images through technology similar to that used by global positioning systems.
Each lab includes a large procedure room and a smaller room partitioned off with a leaded glass wall where technicians operate specialized computers and monitor the procedures. 
Cardiologists perform procedures in the EP labs through a puncture in the skin rather than through an incision. This reduces both the pain patients suffer and the length of time they spend in the hospital (usually just one night).
With three labs now open, the EP department expects to exceed 5,000 procedures this year.
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