All You Should Know about Echocardiography
Echocardiography is a powerful diagnostic tool used in the current practice of cardiology, where high pitched sound waves are used to assess the structure and the function of the heart. The basic principles of echocardiography is the same as ultrasound scanning where high pitched sound frequencies are emitted from an ultrasound probe and the reflections are recorded using a sensor in the same device. It has many advantages over the traditional imaging techniques as it is safe, non-invasive and painless yet being quite sensitive and specific (accurate) as a diagnostic tool.
Echocardiography can be performed with either the probe lying over the body wall of the thorax (trans-thoracic) or the probe lying in the oeasophagus (trans-oesophagial). Trans-thoracic echocardiography can be carried out using five windows as shown in the illustration.
a. Left para-sternal
b. Apical
c. Subcostal
d. Suprasternal
e. Right para-sternal
Different views can be obtained from each window (e.g.- 2 chamber view, 4 chamber view and 5 chamber view from the apical window). In addition, there are different modes of study (e.g.- two dimensional or cross sectional, three dimensional, motion or M mode and colour Doppler studies). Two dimensional echocardiography is useful to study the anatomy of the heart as well as ventricular and valvular movements. It is also useful to position the patients for more advanced modes of echocardiography. Three dimensional echocardiography is useful in the assessment of ventricular volumes and the mass as well as the valvular function. Motion mode times the events in the cardiac cycle. Doppler studies integrate the Doppler’s principles to study the motion and show the flow of blood as well as the ventricular movements.
The patient is asked to lie on left side with the left arm flexed at shoulder. Different probes are used to match with the body composition and the built of individual patients. Probes producing waves with low frequencies are capable of providing a better resolution but the penetration is less. Therefore, they can be used in lean individuals. In contrast, high frequency probes are to be used on obese individuals as the penetration is more at the expense of the resolution.
Different views can be obtained from each window (e.g.- 2 chamber view, 4 chamber view and 5 chamber view from the apical window). In addition, there are different modes of study (e.g.- two dimensional or cross sectional, three dimensional, motion or M mode and colour Doppler studies). Two dimensional echocardiography is useful to study the anatomy of the heart as well as ventricular and valvular movements. It is also useful to position the patients for more advanced modes of echocardiography. Three dimensional echocardiography is useful in the assessment of ventricular volumes and the mass as well as the valvular function. Motion mode times the events in the cardiac cycle. Doppler studies integrate the Doppler’s principles to study the motion and show the flow of blood as well as the ventricular movements.
The patient is asked to lie on left side with the left arm flexed at shoulder. Different probes are used to match with the body composition and the built of individual patients. Probes producing waves with low frequencies are capable of providing a better resolution but the penetration is less. Therefore, they can be used in lean individuals. In contrast, high frequency probes are to be used on obese individuals as the penetration is more at the expense of the resolution.