Aortic Stenosis Nursing Guide

Aortic Stenosis — Overview

Aortic stenosis (AS) is narrowing of the aortic valve orifice, obstructing left ventricular outflow. It is the most common valvular heart disease in developed and GCC countries, predominantly affecting elderly patients.

Causes

Cause	Age Group	Notes
Calcific/degenerative AS	>60 years — MOST COMMON	Age-related calcium deposition on normal tricuspid valve
Bicuspid aortic valve (BAV)	Adults 40–60 years	Congenital — 1–2% population; accelerated calcification; associated with aortic coarctation
Rheumatic fever	Any age	More common in developing countries; associated with mitral valve disease; important in GCC expat populations from South Asia/East Africa

Pathophysiology

AS → LV outflow obstruction → LV hypertrophy (concentric) → increased myocardial oxygen demand
Progressive → LV failure → reduced cardiac output
Fixed low cardiac output → syncope on exertion, angina (supply/demand mismatch), dyspnoea (HF)

Classic Triad of Symptoms

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Dyspnoea (HF)

Mean survival: ~2 years

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Syncope (exertional)

Mean survival: ~3 years

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Angina (exertional)

Mean survival: ~5 years

Mnemonic SAD: Syncope, Angina, Dyspnoea. When symptoms develop, prognosis worsens markedly — prompt valve replacement is indicated. The onset of heart failure (dyspnoea) carries the worst prognosis.

Severity Classification (Echocardiography)

Severity	AVA (cm²)	Mean Gradient (mmHg)	Peak Velocity (m/s)
Mild	>1.5	<20	<3.0
Moderate	1.0–1.5	20–40	3.0–4.0
Severe	<1.0	>40	>4.0
Very severe	<0.6	>60	>5.0

Aortic valve area (AVA) <1.0 cm² = severe AS. Normal AVA: 3–4 cm².

Aortic Stenosis Murmur

Type: Ejection systolic murmur (crescendo-decrescendo)
Location: Right upper sternal edge (aortic area, 2nd intercostal space, right)
Radiation: To the carotid arteries (neck)
Timing: Systolic (between S1 and S2)
Character: Harsh, rough

Associated findings in severe AS:
• Slow rising (pulsus parvus et tardus) pulse
• Narrow pulse pressure
• Soft/absent A2 (aortic component of S2 — calcified valve doesn't close crisply)
• S4 gallop (LV hypertrophy)
• Displaced apex beat (LV hypertrophy, later LV dilation)

Investigations

Investigation	Findings
Echocardiogram	Gold standard: AVA, mean gradient, peak velocity, LV function, degree of calcification
ECG	LVH (tall R in V5/V6, deep S in V1/V2), LBBB (in advanced)
CXR	Aortic knuckle calcification, post-stenotic aortic dilatation, cardiomegaly (late)
Coronary angiogram	Before valve surgery — assess for concurrent CAD (40% of AS patients have significant CAD)

Treatment

There is NO effective medical therapy to slow AS progression. Statins, ACE inhibitors, and calcium channel blockers do NOT halt calcification. Management is watchful waiting until intervention criteria are met.

Medical Management (Conservative)

Diuretics for fluid overload (caution — reduce preload)
Rate control (β-blockers) for concurrent AF — cautiously
AVOID vasodilators (nitrates, ACE inhibitors) — fixed obstruction → vasodilation causes severe hypotension and syncope
Antibiotic prophylaxis for dental procedures is no longer routinely recommended (NICE guidelines) unless prosthetic valve or previous endocarditis

Valve Replacement — Indications for Intervention

Severe AS + symptoms (angina/syncope/HF) — CLASS I indication
Severe AS + LVEF <50%
Severe AS undergoing other cardiac surgery
Very severe AS (mean gradient >60 mmHg) even if asymptomatic

SAVR vs TAVI

Feature	SAVR (Surgical Aortic Valve Replacement)	TAVI (Transcatheter Aortic Valve Implantation)
Approach	Open heart surgery — sternotomy	Minimally invasive — catheter via femoral artery or trans-apical
Indication	Younger patients (<65–70 yrs), low surgical risk, bicuspid valve	Elderly (≥75 yrs), high/intermediate surgical risk
Recovery	5–7 days hospital; weeks recovery	2–3 days; earlier ambulation
Valve durability	Mechanical (lifelong) or bioprosthetic (15–20 yrs)	Bioprosthetic (durability evolving, ~10–15 yrs)
Anticoagulation	Mechanical: warfarin lifelong; Bioprosthetic: aspirin only	Antiplatelet therapy (aspirin ± clopidogrel)

Post-TAVI Nursing Care

Femoral access site monitoring (haematoma, pseudo-aneurysm, bleeding)
Cardiac monitoring — conduction disturbances (LBBB, complete heart block — may need pacemaker in 10–15%)
Stroke risk — neurological assessment hourly post-procedure
Dual antiplatelet therapy compliance education
Echo at follow-up to check valve position and function

MCQ Practice — Aortic Stenosis

Q1. A 78-year-old man has a harsh ejection systolic murmur radiating to the carotid arteries, slow-rising pulse, and exertional syncope. What is the most likely diagnosis?

A) Mitral regurgitation

B) Hypertrophic obstructive cardiomyopathy (HOCM)

C) Severe aortic stenosis

D) Aortic regurgitation

✅ C — Ejection systolic murmur (right upper sternal edge, radiating to carotids) + slow-rising pulse + exertional syncope = classic severe aortic stenosis. Valve replacement is indicated urgently — syncope from AS has ~3-year mean survival without intervention.

Q2. Which drug class should be AVOIDED in patients with severe aortic stenosis?

A) Beta-blockers (cautious use)

B) Vasodilators (GTN, ACE inhibitors, calcium channel blockers)

C) Diuretics (low dose)

D) Digoxin (for concurrent AF)

✅ B — Vasodilators cause severe hypotension in AS because the fixed obstruction prevents compensatory increase in cardiac output. Peripheral vasodilation → reduced afterload → but cardiac output cannot increase to compensate → BP drops. GTN and ACE inhibitors are therefore dangerous in severe AS.

Q3. What echocardiographic finding defines SEVERE aortic stenosis?

A) Aortic valve area >1.5 cm²

B) Mean gradient <20 mmHg

C) Aortic valve area <1.0 cm² AND mean gradient >40 mmHg

D) Peak velocity <3.0 m/s

✅ C — Severe AS: AVA <1.0 cm² + mean gradient >40 mmHg + peak velocity >4.0 m/s. Normal valve area is 3–4 cm². Mild AS: >1.5 cm², moderate: 1.0–1.5 cm². Intervention is indicated in severe AS with symptoms or LV dysfunction.

Q4. TAVI (transcatheter aortic valve implantation) is preferred over SAVR for which patient group?

A) Young patients (35–50 years) with bicuspid aortic valve

B) All patients with severe AS regardless of age

C) Elderly patients (≥75 years) with high or intermediate surgical risk

D) Patients with LVEF <20% requiring emergency surgery

✅ C — TAVI is preferred for elderly (≥75) or high surgical risk patients. It avoids sternotomy, has faster recovery, and outcomes are equivalent to SAVR in this group. SAVR is preferred in younger patients (better durability, bicuspid valves, concurrent coronary bypass needs). Decision made by Heart Team (cardiologist + cardiac surgeon).

Aortic Stenosis — Nursing Guide