What are the clinical findings of aortic stenosis in older adults?

Clinical Findings of Aortic Stenosis in Older Adults

The classic clinical triad of severe aortic stenosis consists of a loud (grade 4/6 or louder), late-peaking systolic ejection murmur radiating to the carotids; a single or paradoxically split second heart sound (S2); and delayed, diminished carotid upstroke (pulsus parvus et tardus). 1

Cardinal Auscultatory Findings

Systolic Murmur Characteristics:

• The murmur is harsh, crescendo-decrescendo (diamond-shaped), best heard at the right upper sternal border with radiation to the carotid arteries 1
• Midsystolic timing, starting shortly after S1 when left ventricular pressure rises sufficiently to eject blood across the narrowed valve 1
• In severe disease, the murmur is typically grade 4/6 or louder and late-peaking, with the peak of the systolic murmur delayed in 98% of patients 1, 2
• May radiate to the apex in elderly patients, potentially causing diagnostic confusion 3

Critical Second Heart Sound Changes:

• Valve calcification and immobility prevent normal rapid, forceful closure of the aortic valve leaflets, resulting in diminished or absent A2 1
• As stenosis progresses from mild to severe, the aortic valve becomes increasingly rigid and immobile, progressively dampening the closure sound 1
• In severe aortic stenosis, A2 may become so soft that a single S2 is heard, or paradoxical (reverse) splitting may occur 1
• An abnormal second heart sound is an independent predictor of significant aortic stenosis; conversely, a normally split second heart sound reliably excludes severe AS 3, 4

Peripheral Vascular Findings

Carotid Pulse Abnormalities:

• Delayed and diminished carotid upstroke (pulsus parvus et tardus) is characteristic of severe disease 1
• Important caveat: Age-related vascular changes can mask the classic carotid upstroke in elderly patients, leading to missed or delayed recognition 3

Electrocardiographic Findings

• Most patients (84%) have increased QRS amplitude indicating left ventricular hypertrophy 2
• Electrocardiographic left ventricular hypertrophy with strain pattern is more common in patients with significant AS 4
• LV hypertrophy with strain is an independent predictor of significant stenosis 4

Echocardiographic and Radiographic Findings

Valve Morphology:

• All patients have echodense valves 2
• Severe echocardiographic aortic valve calcification is more frequent in significant AS 4
• Aortic valve calcification shown by x-ray in 76% of elderly patients, and in all but one by cineradiography 2

Left Ventricular Changes:

• Echocardiography shows increased left ventricular wall thickness in 90% of patients with definable myocardial borders 2
• Increased LV wall thickness is more common in patients with significant AS 4

Symptomatic Presentation

Classic Symptom Triad:

• Angina pectoris (77% of patients) 2
• Dyspnea (74% of patients) 2
• Exertional vertigo or syncope (46% of patients) 2

Critical Limitation in Older Adults:

• Symptoms do NOT reliably predict severity of aortic stenosis in adults 4
• Prevalence of symptoms and functional class are similar between significant and nonsignificant AS 4
• Elderly patients often attribute exertional dyspnea, fatigue, or syncope to normal aging, contributing to underestimation of disease severity 3
• Angina pectoris is related to coronary artery disease (present in 24% with angina history) but not to severity of AS 4
• Dyspnea is only related to age, not AS severity 4
• Syncope/effort dizziness is more frequent in women but not predictive of AS severity 4

Hemodynamic and Exercise Findings

• Inadequate blood pressure increase in response to exercise occurs in 82% of patients 2
• Prolonged left ventricular ejection time is characteristic of severe AS, though a normal value does not exclude the diagnosis 2

Structural Cardiac Consequences

• Progressive LV pressure overload leads to concentric hypertrophy, diastolic dysfunction, reduced coronary reserve, myocardial ischemia, and eventually depressed contractility 3
• Late-diagnosed patients present with advanced diastolic dysfunction and may already have irreversible LV systolic dysfunction 3
• These changes often become irreversible by the time symptoms emerge 3

Etiology in Older Adults

• In Europe and North America, calcific AS represents by far the most frequent etiology 5
• Tricuspid valves predominate in the elderly (>75 years), while bicuspid valves are more common in younger patients (age <65 years) 5
• Coexistent aortic regurgitation is found in 85% of cases, but severe regurgitation in only 1% 2

Key Diagnostic Pitfalls

• The murmur may be soft or absent in elderly patients with severe AS, particularly when cardiac output is reduced 3
• About 25% of patients have exercise test results at variance with NYHA classification 2
• The absence of a single symptom or non-invasive sign does not exclude severe aortic stenosis when most other findings point to severe disease 2
• Coronary artery disease cannot be excluded without selective coronary angiography, as 31% of patients without angina also have coronary disease 4