What is the apical impulse (point of maximal impulse)?

From the Guidelines

The apical impulse is a palpable pulsation felt on the chest wall where the apex of the heart makes contact with the chest, typically located in the fifth intercostal space, about 7-9 cm from the midsternal line (at the midclavicular line) in adults, as described in the 2017 AHA/ACC key data elements and definitions for ambulatory electronic health records in pediatric and congenital cardiology 1. The apical impulse represents the point of maximum impulse (PMI) created when the left ventricle contracts during systole, pushing against the chest wall.

• Key characteristics of a normal apical impulse include:
  • Discrete and localized
  • Brief, lasting less than two-thirds of systole
  • Typically felt at the midclavicular line in the fifth intercostal space When examining a patient, you can locate the apical impulse by placing your fingertips gently on the left side of the chest in the area where the heartbeat is expected to be felt. Changes in the location, size, duration, or intensity of the apical impulse can provide valuable diagnostic information about cardiac conditions such as cardiomegaly (enlarged heart), ventricular hypertrophy, or heart failure, as noted in the study 1. For example, a displaced apical impulse that is felt lateral to the midclavicular line may indicate left ventricular enlargement, while a sustained, forceful impulse might suggest left ventricular hypertrophy.

From the Research

Definition and Location of Apical Impulse

• The apical impulse, also known as the point of maximal impulse (PMI), is the point on the chest where the apical beat of the heart can be felt most strongly 2.
• It is typically located at the fifth intercostal space, mid-clavicular line, and is usually associated with the apex of the left ventricle.

Clinical Significance of Apical Impulse

• The apical impulse is an important clinical sign used to assess cardiac function and diagnose various heart conditions, including cardiomyopathy and heart failure 3, 4.
• An abnormal apical impulse can indicate conditions such as left ventricular hypertrophy, cardiomyopathy, or heart failure 5, 2.

Diagnostic Techniques for Evaluating Apical Impulse

• Echocardiography is a commonly used imaging modality to evaluate the apical impulse and assess cardiac function 5, 6.
• Cardiac magnetic resonance imaging (CMR) is also used to evaluate cardiac anatomy and function, including the apical impulse 3, 4.