Our patient's chest wall movement is normal - normal in location, normal in size, normal in contour. Location: midclavicular line, 5th interspace; small, dime-sized - that's what you feel when that normal left ventricle just taps up against the chest wall and then pulls away. Contour: just an early systolic tap, nothing sustained throughout systole. Our patient's chest wall movement is normal.
Let's review it again, and watch the tip of the cotton swab, and remember the utility of timing this very early systolic impulse with the carotid vessel. When you do that, you clearly can see that it just barely precedes the carotid. Normal apical impulse - location, size, contour.
Location and Size
Chest wall movement may occur in several locations. Normally, it is felt only in the apical area, located in the fifth intercostal space at the mid-clavicular line.
When the left ventricle is hypertrophied but not appreciably dilated the impulse may remain normally located, however, it is often larger.
When the left ventricle is dilated, the apical impulse is inferolaterally displaced. For example, it may be felt in the sixth intercostal space at the anterior axillary line.
With localized left ventricular dyskinesis from ischemic heart disease, an impulse may be felt superior and medial to the normal apical location. This location is called the ectopic area.
With right ventricular hypertrophy or dilatation, an impulse may be felt at the mid-to-lower left parasternal area.
A dilated pulmonary artery, such as occurs with pulmonary hypertension, may be felt at the upper left parasternal area.
A dilated aorta at times may be felt at the upper right parasternal area. This can occur in a patient with an aortic aneurysm.
Abnormal impulses
We have discussed the normal apical impulse, and one must know the normal baseline to judge the pathologic. To evaluate the pathologic chest wall movement, one must know just a bit more, that is, the impulse may not be displaced in location, but if the ventricle is hypertrophied, you may have a sustained impulse. In addition, in the normal location or elsewhere, occasionally there is diastolic movement due to filling sounds that can actually move the chest wall during diastole. When the ventricle is enlarged, dilated, in contrast to pure hypertrophy, the impulse may be inferolaterally displaced in the 6th and 7th interspace, out here at the anterior axillary line, and sometimes, to pick up these apical impulses, it's best to put the patient in the left lateral decubitus position, have them hold their breath for just a moment - by the way, hold yours also, so you know when they might just need an extra breath - and then you feel the impulse so clearly in that position because the left ventricle, in the left lateral decubitus position, is just against the chest wall.