Common heart tests and why they’re done

October 30, 2012 By Joshua Rock, D.O.

Whether you go for a physical or already see a cardiologist, chances are your doctor may order a test to check how well your heart is working. Among the most common cardiac tests are electrocardiogram, echocardiogram and stress test. Each test helps to detect certain types of cardiac disease.

Electrocardiogram (EKG). This is probably the most routine and commonly performed study. The EKG is a simple cardiac test that involves applying 10 sticky electrodes to the chest, arms, and legs. These electrodes record a “snapshot” of the heart's electrical activity. The study, including preparation, takes less than 10 minutes and provides vital information about cardiac structure and electrical conduction. If the heart's “wires” develop problems or scar with age, the electrical impulse may be blocked as it tries to travel through the heart. Symptoms would include fatigue, light headedness, fainting spells, lethargy, and shortness of breath. An EKG can be interpreted by most physicians, though advanced analysis is reserved for the cardiologist.

Echocardiogram. Commonly referred to as an “echo,” this study is a cardiac ultrasound that uses a probe to look at the heart. An echo is a wonderful tool used to evaluate overall function of the heart muscle (left ventricular ejection fraction) and heart valves. It can easily identify narrowed or leaky valves. This study can also indicate information about blood pressure inside the lungs, fluid around the heart and evidence of a prior heart attack. Symptoms associated with valve abnormalities or a weakened heart muscle are vast and include shortness of breath, fatigue, fainting spells, fluid accumulation in legs/ankles and palpitations. In preparation for the study, which takes about 20-25 minutes to complete, a small amount of ultrasound jelly is placed on one's chest. The images should only be interpreted by a cardiologist.

Stress test. Stress testing was designed to detect coronary artery disease (CAD) triggered by buildup of cholesterol plaque in coronary artery walls. CAD symptoms include chest pain upon exertion (angina), shortness of breath, fatigue and abdominal discomfort. Over time, these plaques obstruct or clog blood flow to the heart muscle, starving the heart of blood during times of physical stress, as when heart rate increases during exercise. A stress test has two parts – the stress and imaging components. The stress portion can be performed through exercise, either on a treadmill (most common) or bicycle, or chemically. Chemical stress tests involve an injection of a medicine that mimics exercise by increasing blood flow in the coronary arteries. The imaging portion -- how we indirectly detect blockages in the artery -- can be done through EKG, echocardiogram or nuclear imaging. Depending on the type of stress test it may take between 15 minutes and 3 hours. Tests can be interpreted by cardiologists or radiologists (for nuclear stress test).

One of the beauties of cardiology is availability of varied cardiac tests to make a diagnosis and start early treatment. Nevertheless, no matter how advanced the tests are they're only as good as you showing up. So make sure to see your physician on a regular basis. If s/he recommends a cardiac test, don't put it off. It could mean early diagnosis, early treatment, and a longer, happier life!

Dr. Joshua Rock is a member of The Hospital of Central Connecticut (HOCC) medical staff. For referrals to HOCC physicians, please contact our free Need-A-Physician referral service by phone at 800.321.6244 or online.