Observe the shape of the anterior chest wall, noting any abnormality or scars (figure 45). Asymmetry of the parasternal costal areas may indicate underlying right ventricular or left ventricular hypertrophy. The apex beat is the lowest and outermost point at which the cardiac pulse may be felt; it may be visible in thin subjects.
The normal apex is located in the fifth intercostal space, in the midclavicular line. In order to locate it, place the flat of your hand just below the nipple in both males and females (figure 46). In the female, lift the breast to observe and palpate the appropriate area: a mitral valvotomy scar is easily missed if this observation is not made. Note the position of the apex beat, by counting down from the second costal cartilage (opposite the manubriosternal joint).
Displacement of the apex beat may be due to movement of the mediastinum (check for the position of the trachea if this is suspected) or true cardiac enlargement. The left ventricle normally produces the apex beat and, when the ventricle is hypertrophied, the beat is forceful and may extend outwards towards the axilla. This hyperdynamic pulse of left ventricular hypertrophy, is in contrast to the hyperkinetic and rather sustained impulse characteristic of volume overload. The latter may occur in heart failure, and mitral and aortic regurgitation.