In normals, chest wall movement is felt only in the apical area, usually in the fifth intercostal space at the mid clavicular line.
With left ventricular hypertrophy, but not appreciable dilation, the impulse remains normally located, but is often enlarged.
With left ventricular dilation, the apical impulse is inferolaterally displaced and enlarged. For example, it may be in the sixth intercostal space at the anterior or mid axillary line.
With localized left ventricular dyskinesia from ischemic heart disease, an impulse may be felt superior to the normal apical location. This location can vary according to the site of the underlying myocardial dyskinesia. Such precordial movements are termed ectopic impulses.
With right ventricular hypertrophy or dilation, a movement of the mid-to-lower left parasternal area can occur.
A dilated pulmonary artery from, for example, pulmonary hypertension, can cause an impulse in the second left intercostal space.
A dilated ascending aorta may be felt at the upper right parasternal area. This is now rare, but can occur in a patient with an ascending aortic aneurysm.