Diagnosing and Treating Irregular Heartbeats
EP Studies at Methodist
Electricity flowing through the heart in a regular pattern causes the heart muscle to contract and pump blood and oxygen all over the body. When damaged tissue or other problems disrupt the electrical flow, the heart beats irregularly. This condition is called an arrhythmia.
Traditional tests record only the irregular heartbeats that occur during testing. With these tests, doctors may not obtain the detailed data they need to find the exact source of the problem.
EP studies at Methodist Medical Center of Oak Ridge are changing this situation for many patients in our region. Using sophisticated new technology, a specially trained cardiologist called a cardiac electrophysiologist causes the irregular heartbeats to occur during a test. With information the doctor obtains, he can not only diagnose the source of the irregular heartbeats, but also…
- Determine the effectiveness of certain medications in dealing with a patient’s condition
- Predict a patient’s risk for sudden cardiac death
- Determine whether a patient needs a pacemaker or other device implanted near the heart
An EP study is invasive in that the doctor inserts a small tube called a catheter into a blood vessel and maneuvers the tube into the heart. Once inside the heart, electrodes on the tip of the catheter gather data and pinpoint the damaged area or areas. During this process, the doctor may cause the heart to beat abnormally, administer certain medications or electrical impulses, and determine how well they return the heart to a normal rhythm.
Patients at Methodist are sedated but awake in what’s called “twilight sleep.” Some watch the EP study on monitors, while others sleep. Most procedures last two hours, and patients are discharged in another four to six hours.
Because abnormal heart rhythms are potentially dangerous, EP studies at Methodist are performed by a board-certified electrophysiologist, with assistance from a team of specially trained nurses, technologists, and other healthcare professionals. They perform the test in a well-equipped and controlled environment in order to increase the safety of the procedure.
Treating Irregular Heartbeats
The ideal treatment is the one that corrects an irregular heartbeat in the least invasive way. Consequently, a doctor may initially recommend lifestyle changes and medications. When conservative treatments are not effective, more invasive options may be necessary.
Factors that doctors and patients should discuss before treatment are the nature and severity of the patient’s irregular heartbeat; underlying medical conditions that may affect the patient’s quality of life; medications and treatments that a patient is receiving for other medical problems; and the patient’s age, overall health, and personal and family medical history.
The doctor may recommend implanting an electronic device such as a pacemaker or an ICD, using a burst of energy to destroy small areas where irregular signals begin, or performing surgery.
Small, battery-powered pacemakers are most commonly implanted in patients who have an extremely slow heart rate, rapid and chaotic beating in the upper chambers of the heart, or heart failure. The purpose is to set an appropriate heart rate.
The device, which weighs about one ounce, is implanted below the collarbone. It is pre-programmed before being implanted and can be reprogrammed as necessary afterward.
Patients should tell their doctors that they have a pacemaker before having an MRI. MRIs use powerful magnets that can affect the pacemaker.
Prolonged exposure to electronic security systems at airports and other facilities can cause problems in pacemakers.
Full contact sports can damage pacemakers.
Microwave ovens and cell phones do not affect pacemakers.
Implantable Cardioverter Defibrillator (ICDs)
ICDs are the most successful treatment available for preventing ventricular fibrillation, the major cause of sudden cardiac death. Cardiac arrest, or sudden cardiac death, is not a heart attack. It occurs when a problem with the heart rate prevents the heart from pumping blood throughout the body. A heart attack occurs when blockage in a heart vessel affects blood flow into the heart and causes heart muscle to die.
Only a few patients survived sudden cardiac arrest even 15 years ago. They lost consciousness within seconds and died within minutes. With ICDs, more than 90 percent of patients survive.
The EP specialist at Methodist Medical Center implants an ICD, which is about the size of a pager, below the collarbone. The device continuously monitors heart rate and sends a life-saving electrical jolt if the heart rate becomes dangerously fast. It also can correct a heart rate that is too slow. In some cases, the ICD can be programmed to emit pacing signals to restore a normal heart rate and avoid the need for the electrical jolt.
The purpose of this procedure is to destroy carefully selected tissue or otherwise interrupt inappropriate electrical signals that cause the heart to beat abnormally. During the procedure, a doctor inserts a long, flexible catheter into a vein, guides it to the heart, and delivers radiofrequency energy to the catheter. The energy concentrates heat on the tip of the catheter, creating scar tissue that blocks the inappropriate electrical signals and stabilizes the patient’s heartbeat.
Surgery is occasionally used to treat abnormal heart rhythms, but is more commonly used in patients with heart disease and heart failure. By having these conditions corrected, patients may reduce their risk for having irregular heartbeats.