Apical impulse is the outermost and downward movement of maximum cardiac impulse. It is located in the 5th intercostal space medial to the midclavicular line on left side in majority of the children, ft is a brief outward impulse due to recoil of the effects of the heart blood. The three points to be noted about it are its (1) Site, (2) Area of occupation and (3) Amplitude.
In a young infant or a child up to 4 years of age, the apex beat is normally in the fourth intercostal space either at or inside the midclavicular line. Many physicians use the term point of maximum cardiac impulse (PMT).
When the left ventricle is dilated the apex beat is displaced downward and inferiorly and may be hyperactive.
An indistinct apex is found in association with right ventricular hypertrophy.
Left ventricle is enlarged in volume overloaded diseases like MR, AR, VSD, PDA, dilated cardiomyopathy and also in afterload diseases like aortic stenosis, coarctation of aorta and hypertension.
Cyanotic heart diseases in which left ventricle is enlarged, like tricuspid atresia.
Right ventricular enlargement seen in acyanotic heart diseases like ASD and mitral stenosis (acquired) and cyanotic heart disease like Fallot’s tetralogy, TAPVR.
Biventricular enlargement is seen in acyanotic like VSD, and cyanotic heart diseases like TGA, and truncus arteriosus.
No ventricular enlargement is seen in Ebstein’s anomaly.
