What does a sustained, heaving, or diffuse pulse indicate?

Understanding Sustained, Heaving, or Diffuse Pulse

A sustained, heaving, or diffuse pulse refers to a forceful, prolonged apical impulse that is displaced laterally and occupies a larger area than normal, indicating left ventricular hypertrophy, dilation, or volume overload from conditions like aortic regurgitation or heart failure.

Physical Examination Characteristics

The term describes specific palpable qualities of the cardiac impulse:

• Sustained impulse: The apical beat persists throughout systole rather than being brief and tapping, characteristic of left ventricular hypertrophy from pressure overload (hypertension, aortic stenosis) 1

• Heaving impulse: A forceful, lifting quality felt over a broad area, typically indicating left ventricular volume overload from conditions like aortic regurgitation or dilated cardiomyopathy 2

• Diffuse impulse: The point of maximal impulse (PMI) is displaced laterally beyond the midclavicular line and occupies more than one intercostal space, suggesting left ventricular dilation 1, 3

Clinical Significance and Associated Conditions

Volume Overload States

Aortic regurgitation produces the classic combination of a heaving, diffuse apical impulse with bounding peripheral pulses due to wide pulse pressure and increased stroke volume 2. The physical findings reflect:

• Systolic hypertension with wide pulse pressure causing the bounding quality 2
• Progressive left ventricular dilation from chronic volume overload 2
• Combined pressure and volume overload leading to the sustained, forceful character 2

Heart Failure and Cardiomyopathy

A diffuse, sustained impulse indicates:

• Left ventricular dysfunction with chamber dilation in dilated cardiomyopathy 4
• Decompensated heart failure with elevated filling pressures 4
• The impulse may be accompanied by palpable S3 or S4 gallops, which can sometimes be felt as a double impulse 5

Distinguishing from Normal Variants

Key Differentiating Features

The normal apical impulse is brief, tapping, localized to one intercostal space, and located at or medial to the midclavicular line in the 5th intercostal space 1. Abnormal characteristics include:

• Location: Displaced beyond midclavicular line or below 5th intercostal space 1, 3
• Duration: Sustained throughout systole rather than brief 1
• Area: Occupying more than 2-3 cm diameter or multiple intercostal spaces 1
• Quality: Forceful, heaving, or lifting rather than gentle tapping 2

Associated Physical Examination Findings

Concurrent Signs to Assess

When detecting an abnormal apical impulse, systematically evaluate:

• Jugular venous distention, peripheral edema, and pulmonary rales suggest heart failure with elevated filling pressures 4
• Cardiac murmurs: Aortic regurgitation (diastolic), mitral regurgitation (systolic), or aortic stenosis (systolic) may explain the impulse character 4
• Gallop sounds: S3 indicates volume overload and heart failure; S4 suggests hypertrophy and decreased compliance 5
• Peripheral pulses: Bounding pulses with wide pulse pressure point to aortic regurgitation 2

Special Examination Techniques

In patients with increased anteroposterior chest diameter or emphysema, palpate over the xiphoid or epigastric area where the impulse may be more readily detected 5. This technique prevents missing important findings in patients with altered chest anatomy.

Clinical Implications for Risk Stratification

Prognostic Significance

The presence of a sustained, heaving, or diffuse impulse indicates:

• Structural heart disease requiring echocardiographic evaluation to assess left ventricular size, function, and valvular abnormalities 1, 3
• Increased risk for ventricular arrhythmias in patients with dilated cardiomyopathy and reduced ejection fraction 4
• Need for guideline-directed medical therapy including ACE inhibitors and beta-blockers for heart failure 4

When to Escalate Care

Urgent evaluation is warranted when the abnormal impulse is accompanied by syncope, severe dyspnea, or signs of acute decompensation 1. These patients require:

• Immediate 12-lead ECG to identify arrhythmias or ischemia 1
• Echocardiography to quantify ventricular function and identify structural abnormalities 1, 3
• Assessment for acute heart failure requiring diuresis or vasodilator therapy 6

Common Pitfalls to Avoid

• Do not dismiss a displaced or abnormal impulse in obese patients—use alternative examination positions (left lateral decubitus) or imaging 3
• Recognize that the impulse quality changes with body position—examine in both supine and left lateral positions for complete assessment 1
• Avoid confusing a palpable S4 (presystolic) with a split first heart sound—the S4 disappears with firm stethoscope pressure 5