Echo-cardiogram test
Echocardiogram is nothing but cardiac ultrasonography. In this sophisticated technique sound waves are used for direct visualization of heart. Doctors can see or scan the heart in a screen, which is almost like television screen. So echocardiogram is the technique of ultrasound imaging of the living heart using ultrasound waves to image various structures within the heart. It is a noninvasive procedure so patient does not feel any pain during echocardiography. Not only the doctor, but also the patient can see his heart movement in the television screen during the procedure. This technique provides detailed anatomical information on cardiac chambers, valves, holes in the heart, abnormal fluid collection around the heart and abnormal intracardiac masses such as tumors, blood clot and infective material. In this procedure a hand-held transducer housing the ultrasound crystal is applied to the patient’s anterior (front) chest wall. Through this, a beam of ultrasound waves is transmitted into the patient’s heart and the returning echoes are then converted into images which are displayed on a video monitor to be recorded on tape in real-time for easy play-back and hard-copy print-out. Doctor can take multiple two dimensional pictures of heart in different positions during the procedure. Doppler echocardiography is used along with the two dimensional echocardiography for detecting flow direction, for measuring blood flow velocity and pressure gradient. Now a day, through colour Doppler imaging, doctor can see the actual blood flow in and around the heart. Obstruction of the values and any trivial leaking can also be demonstrated by colour flow imaging. Heart can also be scanned by using transesophageal echocardiography. Here, the ultrasound crystal is mounted at the tip of an endoscope which is similar to that used by gastroenterologists for studying the stomach and intestines. This tube is introduced through the patient’s mouth in to the esophagus (food-pipe) which lies immediately behind the heart. This technique is usually used when conventional transthoracic (through external chest wall) images are technically suboptimal or inadequate for definitive interpretation.
In patients with coronary heart disease echocardiography usually detect left ventricular wall motion abnormality. In a patient with history of previous heart attack, echo can demonstrate that the wall affected previously either is not moving at all or contracting sub normally. So this procedure is an excellent diagnostic tool for assessing left ventricular function (heart pump function). But in patients with only angina pectoris with out any previous heart attack echo may not show any abnormality. So a normal echo study does not exclude the possibility of significant block in coronary circulation. But newer technique which is called tress echo can detect angina pectoris by stressing the heart and simultaneously real time imaging of heart function. Echocardiography can also document blood clot (solidified blood) inside heart. Now a day’s bed side echocardiography is used to diagnose heart attack at a very early stage when ECG interpretation gives equivocal result.
