Diagnosing Heart Rhythm Disorders
Early detection and treatment are key in preventing death or disability from certain heart rhythm disorders. Rhythm disorders may be diagnosed by careful examination of the symptoms (palpitations, fainting spells, lightheadedness, dizziness, rapid heart action, etc.) and several diagnostic tests, including:
- Electrocardiogram (ECG or EKG): An electrocardiogram is a graphical record of the electrical activity of the heart. A normal ECG, in most cases, rules out the presence of other cardiac diseases. An abnormal ECG indicates the presence of a cardiac disease and further investigations are performed. An ECG can be beneficial in detecting the disease and sometimes even the extent of the disease.
- Stress test: A stress test involves taking an ECG before, during and after a treadmill workout to detect cardiac disease and/or damage, including the extent of coronary artery disease. However, false positive results are possible with stress tests.
- Echocardiogram (heart ultrasound): This diagnostic technique is an excellent tool to provide details of the cardiac structures – vessels, valves, and muscle. Echocardiography is a non-invasive exam in which images are acquired and viewed in real time without the use of radiation. Echocardiography is often useful in studying the beating heart and provides some information on functional abnormalities of the heart wall, valves and blood vessels. Echocardiography with Doppler is used to measure blood flow across valves, across septal defects (shunts), extent of regurgitations, etc. Color flow mapping capability is extremely useful in the detection of shunts. Abnormal operation of the valves can be detected by studying the opening and closing function versus normal valve function. Echocardiography may also be used to study congenital heart defects such as a septal defect (a hole in the wall that separates the two chambers of the heart).
- Tilt table study: This study is typically performed to determine the cause of fainting spells. The patient is secured on a special table, an intravenous line is drawn, and the patient is quickly titled upright. Blood pressure, heart rate, and other factors are monitored for abnormal readings.
- Electrophysiology (EP) study: This study involves inserting a catheter in a vein or artery in the groin and guiding it to the heart using angiography for guidance. The heart’s electrical activity is then monitored in multiple places using sophisticated in-vivo EKG leads to help diagnose tachycardias or bradycardias. Electrophysiology studies are also useful before surgery to help plan implantation of pacemaker or cardioverter defibrillator.
Treating Heart Rhythm Disorders
The treatment of heart rhythm disorders depends on the type of disorder and its severity. Many abnormal heart rhythms may be treated by dietary and lifestyle changes such as not smoking, reducing caffeine intake, limiting alcohol intake, avoiding decongestants, and minimizing stress. Drug therapy may also be necessary.