Collapse and Chest Pain

Clinical Vignette

An elderly man presents with episodes of syncope and angina. He has been referred to the cardiovascular clinic with worsening symptoms of shortness of breath. Please examine his cardiovascular system.

Positive Findings

  • Pulse: Slow-rising, low-volume pulse.
  • Blood Pressure: Narrow pulse pressure.
  • Apex Beat: Heaving, located in the fifth intercostal space.
  • Aortic Area:
    • Palpable systolic thrill over the right second intercostal space.
    • Auscultation: Ejection systolic murmur best heard in the aortic area, radiating to the carotids. The murmur has a crescendo-decrescendo quality, peaking mid-systole and loudest in expiration with the patient leaning forward.
    • Soft or absent A2, and presence of S4.

Relevant Negative Findings

  • No signs of congestive cardiac failure, such as bibasal crackles, peripheral oedema, or raised JVP.
  • No evidence of endocarditis (e.g. splinter haemorrhages, Janeway lesions, Osler nodes).

What is the most likely diagnosis?

The likely diagnosis is severe aortic stenosis, given the characteristic murmur radiating to the carotids, slow-rising pulse, and a soft or absent second heart sound.

What is your differential diagnosis?

  1. Aortic Sclerosis: Similar auscultation findings but with a normal A2 and no carotid radiation. Generally, has no haemodynamic significance.
  2. Hypertrophic Cardiomyopathy (HOCM): Associated with a jerky pulse, double apical impulse, and murmur loudest at the left sternal edge that increases with Valsalva manoeuvre.
  3. Pulmonary Stenosis: Murmur is louder with inspiration and radiates to the left clavicle.

How would you investigate this patient?

1. Electrocardiogram (ECG):

  • Likely to show left ventricular hypertrophy (LVH) and possible left axis deviation. Presence of conduction abnormalities, such as left bundle branch block (LBBB), may indicate disease progression.
  1. Chest X-ray (CXR):
  • May show calcification of the aortic valve, post-stenotic dilatation of the ascending aorta, and possibly left atrial enlargement.
  1. Transthoracic Echocardiogram (TTE):
  • The diagnostic standard for confirming AS. TTE will assess valve morphology, measure the aortic valve area (AVA), and evaluate transvalvular pressure gradients. Severe AS is indicated by:
  • AVA <1.0 cm²
  • Peak velocity >4.0 m/s
  • Mean pressure gradient >40 mmHg
  1. Cardiac Catheterisation:
  • Indicated to evaluate for concurrent coronary artery disease in those being considered for valve replacement.
  1. Other Tests:
  • Dobutamine stress echocardiography may be useful in patients with low-gradient AS and reduced left ventricular function to distinguish between true severe AS and pseudo-severe AS.

How would you manage this patient?

  1. Symptomatic Management:
  • Aortic Valve Replacement (AVR): Indicated for symptomatic severe AS (especially with syncope, angina, or dyspnoea). This procedure improves survival and quality of life.
  • Transcatheter Aortic Valve Implantation (TAVI): Indicated for patients at high or prohibitive surgical risk. It is increasingly used and has shown mortality benefit in patients who are ineligible for open surgery.
  • Balloon Aortic Valvuloplasty: Rarely used, except as a bridge to AVR or TAVI in haemodynamically unstable patients.
  1. Medical Management:
  • Avoidance of Preload-Reducing Medications: Drugs like ACE inhibitors, nitrates, and diuretics should be used with caution as they can exacerbate the low output state in severe AS.
  • Heart Failure Management: If heart failure develops, use diuretics cautiously. Beta-blockers and ACE inhibitors may be beneficial but should also be used with care.
  1. Monitoring:
  • Regular Follow-Up: Asymptomatic patients with severe AS should be monitored closely with regular TTE to assess disease progression.
  • Exercise Testing: May be considered in asymptomatic patients to unmask any functional limitation or abnormal blood pressure response, which would be an indication for AVR even in the absence of symptoms.
  1. Endocarditis Prophylaxis:
  • Recommended only for those with prosthetic valves or a history of endocarditis.

Viva Questions

  1. What are the common causes of aortic stenosis?
  • Calcific degeneration (most common in the elderly), bicuspid aortic valve (typically presents earlier), and less commonly, rheumatic heart disease.
  1. When should aortic valve replacement be considered?

In symptomatic severe AS or asymptomatic patients with:

  • Decreased left ventricular ejection fraction (<50%),
  • Severe AS with abnormal exercise test,
  • Rapid progression of AS severity,
  • Evidence of LV dysfunction.
  1. How do you differentiate severe AS from aortic sclerosis?
  • Severe AS often presents with a low-volume, slow-rising pulse, narrow pulse pressure, and absent A2. In contrast, aortic sclerosis has a normal A2 and pulse character, with no hemodynamic significance.
  1. What complications are associated with severe aortic stenosis?
  • Heart failure, syncope, angina, sudden cardiac death, and, in some cases, embolic events.
  • Heyde syndrome is a known association between aortic stenosis and angiodysplasia of the colon with microangiopathic haemolytic anaemia.
  1. What role does TAVI play in the management of AS?
  • TAVI is an option for patients with severe AS who are at high or inoperable risk for surgical AVR. It can improve survival and quality of life in such patients, although it carries risks such as stroke and vascular complications.