Echocardiogram
The echocardiogram is an ultrasound of the heart. Using standard ultrasound techniques, two-dimensional slices of the heart can be imaged. An echocardiogram is a painless procedure that uses sound waves and a computer to look at your beating heart. A device called a transducer sends high-frequency sound waves into your chest. The sound waves bounce (echo) off your heart. A computer uses the echoes to create a moving picture of the heart. Echocardiogram works well for most patients and allows doctors to see the heart beating and to visualize many of the structures of the heart.
Cardiac stress test
A cardiac stress test is performed to evaluate the ability of arterial blood flow to the left ventricular heart muscle, to increase with exercise, as compared to resting blood flow rates, and some indication of overall physical fitness. The test is not capable of detecting the presence/absence of the atheroma lesions of atherosclerosis, thus usually misses disease which most commonly produces future angina or heart attack events. Also, it is not designed to evaluate the presence or influences of emotional stresses, even though these probably play a role in heart attacks. The stress test is used to check both overall physical exercise capacity and is generally able to detect high grade, 75% or greater stenosis of the coronary arteries supplying the cardiac muscle.
Electrocardiogram (ECG or EKG)
Electrocardiogram (ECG or EKG) is a painless process that records the heart's electrical activity. Small metal electrodes are placed on the person's wrists, ankles and chest. The electrical signals travel from the electrodes through wires to the EKG machine, which transforms the signals into patterns or waves. Different waves represent different areas of your heart through which electrical currents flow. These current cause the heart muscles to contract and relax. The P wave represents the current in the upper chambers of the heart (atria); the QRS complex represents current in the lower heart chambers (ventricles); and the T wave represents the heart's brief "rest period" as it recharges electrically (repolarizes) between heartbeats.
