Wednesday, May 28, 2008


The heart is a moving structure and is deep in our chest cavity, making it difficult to get a picture of. Fortunately, the echocardiogram was invented and is a good and convenient tool to examine the function and structure of the heart. The echocardiogram is made up of a machine which contains the computing chip or the brains and a probe which is attached to the machine and which is the “eye” of the machine through which the image of the heart is obtained.

The echocardiogram uses sound waves and the principle of reflection of sound very much like that of a train moving in relation to a person. When the train is approaching you, the sound of the whistle gets louder and when it moves away, the the sound gets softer. The sound waves that are reflected off the heart are then processed by powerful computers in the echo machine to reconstruct an image of the moving heart. Because the pulses of sound released by the probe of the echo machine are in rapid pulses, the heart can be viewed in real-time motion.

The echocardiogram is useful for determining the heart function, the valve function and is able to measure the pressures in the various chambers of the heart. It can be use to measure the dimensions of all the structures in the heart and the major blood vessels that are attached to the heart. It can also be combined with an exercise stress test to look for blockages in the blood vessels of the heart.

Going for an echo study is relatively easy. There is no need for any fasting prior to the study. It is a non-invasive procedure. The patient is required to remove his shirt and don on an examination gown to protect his or her modesty. Then ECG electrodes are applied to the chest wall. The patient is then required to lie down on a special couch with his face and body turned to the left. A small cut-out hole in the couch is opened up to allow for better access to the left side of the body. The sonographer will then apply some gel to the probe and place the probe on various positions on the chest to obtain the various views of the heart. The whole study will take about 30 minutes to complete.

After the echo study, the all the electrodes and gel will be removed form the chest and the patient can proceed to change back into his own clothing.

Dr Kenneth Ng
MBBS (Singapore), MRCP (UK), M Med (Int Med), FAMS
Consultant Cardiologist
Novena Medical Centre
Novena Heart Centre