What is the location of the point of maximal impulse (PMI)?

What is the location of the point of maximal impulse (PMI)?

• A. 4th or 5th intercostal space, 7-9 cm from the sternum
• B. 2nd intercostal space at the left sternal border
• C. 6th intercostal space at the midclavicular line
• D. 8th intercostal space along the left midaxillary line

Answer: (A)

The apical impulse, or point of maximal impulse (PMI), reflects the apex of the left ventricle during systole. In a normal adult, the impulse is felt best at the left fifth intercostal space along the midclavicular line, about 7–9 cm from the sternum. This position corresponds to where the left ventricle taps the chest wall with the strongest thrust. Occasionally the PMI can be at the 4th intercostal space, but the distance from the sternum remains around 7–9 cm, making a location in the left 4th/5th interspaces near the midclavicular line the best description. The other sites listed correspond to different cardiac areas or are too lateral or too low to be the apical impulse: the second intercostal space at the left sternal border is the aortic area; the 6th intercostal space at the midclavicular line is lower than the apex; the left midaxillary line at the 8th intercostal space is far from the apex.

The apical impulse, or point of maximal impulse (PMI), reflects the apex of the left ventricle during systole. In a normal adult, the impulse is felt best at the left fifth intercostal space along the midclavicular line, about 7–9 cm from the sternum. This position corresponds to where the left ventricle taps the chest wall with the strongest thrust.

Occasionally the PMI can be at the 4th intercostal space, but the distance from the sternum remains around 7–9 cm, making a location in the left 4th/5th interspaces near the midclavicular line the best description. The other sites listed correspond to different cardiac areas or are too lateral or too low to be the apical impulse: the second intercostal space at the left sternal border is the aortic area; the 6th intercostal space at the midclavicular line is lower than the apex; the left midaxillary line at the 8th intercostal space is far from the apex.