Two dimensional echocardiography-a new technique in clinical practice.

With the advent of 2 dimensional echocardiography (2D echo), non-invasive cardiac diagnosis has been made more refined and reliable, especially when combined with the M mode echocardiographic presentation of the heart. For the last decade M mode echocardiography (M mode echo) has been the mainstay of non-invasive cardiac diagnosis, but M mode echo presents certain limitations, namely it shows only an ice-pick view of the heart and many structures such as the pulmonary valve, and tricuspid valve and the interatria septa are difficult to see. Other limitations include seeing the heart In an unfamiliar anatomy, although this can be overcome with training. On the other hand 2D echo offers an anatomy of the heart that is more familiar to the practising cardiologist and the greater visual impact of the heart's image makes diagnosis and measurements of certain parameters of the heart reliable and easier than M mode echo. It has therefore been the OpInIOn of many cardiologists that 2D echo is superior to the conventional M mode echo, though the two methods should be viewed as complimentary to each other (Kotler et at, 1980). 2D echo operates on the same principle as M mode echo, but the sound beams are made to travel back and forth through an angle ranging fron 30 0 to 80 0 depending on the machines available. The returning sound waves are picked up by the transducer and shows the heart in real time two dimensional images. It is not the purpose of this paper to present the technical details of ultrasound machines involved which are amply given in the literature, and to which some references are given here (Bom et at, 1973; von Ramm and Thurstone, 1976).