Is the pulsating sensation in the abdomen from an abdominal aortic aneurysm (AAA) constant or intermittent?

Pulsating Sensation in AAA: Constant or Intermittent

The pulsating sensation from an abdominal aortic aneurysm can be either constant or intermittent, according to the European Society of Cardiology guidelines. 1

Clinical Presentation

The 2014 ESC Guidelines explicitly describe that large AAAs may present with "constant or intermittent abdominal pain or discomfort, a pulsating feeling in the abdomen, or feeling of fullness after minimal food intake." 1 This directly addresses your question—the pulsation is not necessarily always present and can vary in its perception.

Why the Variability Occurs

Several factors explain why the pulsating sensation may be intermittent rather than constant:

• Patient position and body habitus affect the ability to perceive aortic pulsations, as transmission of the pulse can vary based on adjacent anatomical structures 2
• Blood pressure fluctuations throughout the day alter the intensity of pulsation, given the aorta's role in responding to pressure changes via baroreceptors 1
• Abdominal distension or bowel gas can intermittently obscure the sensation of pulsation 2
• The patient's awareness and attention to the sensation naturally varies, making it seem intermittent even when physically present 1

Critical Clinical Pitfall

Do not dismiss a pulsatile abdominal mass simply because the pulsation is intermittent rather than constant. 1 The presence of a pulsatile mass on physical examination has near 100% specificity for AAA when detected, regardless of whether the patient reports constant or intermittent symptoms. 3

Immediate Action Required

When a pulsatile abdominal mass is identified—whether constant or intermittent—ultrasound is the definitive first-line diagnostic test with sensitivity and specificity approaching 100%. 3 This imaging should be performed rapidly to distinguish normal aortic pulsation from true AAA. 3 In 42% of cases presenting with pulsating abdominal mass, no AAA is found, but ultrasound definitively resolves the question. 2

Additional Symptoms to Assess

Beyond the pulsation pattern, inquire specifically about:

• Deep, aching, or throbbing abdominal pain that may spread to the back, buttocks, groin, or legs 1
• Feeling of fullness after minimal food intake, which suggests mass effect from a large AAA 1
• Risk factors including age >65 years, male sex, smoking history, and family history of AAA 4, 5