RADIOWQ

Cardiac enlargement is always significant, but minor degrees may be difficult to detect. The apex beat may be defined as the furthest point of cardiac pulsation downwards and to the left at which the finger is distinctly lifted. It usually lies in the 5^th left intercostals space within the mid-clavicle line. Its position is partly dependent on the shape and size of the chest, and its localization may be difficult or the apex beat to the left is a reliable indication of cardiac enlargement from other caused has been excluded e.g. fibrosis or absorption collapse of the left lung pneumothorax or pleural effusion on the right side. Scoliosis is a common cause of displacement to the left. Enlargement of the heart may be suspected from percussion, but as precision is impossible this method of examination is unreliable. The method is seldom useful except in the diagnosis of emphysema in which the area of cardiac dullness is reduced, or of pericardia effusion in which it is increased. Radiology is the most exact method of detecting general enlargement of the heart or of its individual chambers, but it must be realized that hypertrophy may occur with little radiological evidence of enlargement.