5th July 2026

Diagnosis

History and physical examination 

• • Patients may describe chest pain, dyspnoea, palpitations, and/or syncope, in relation to exercise or dehydration. 
  • A three-generation family history is important to identify family members with HCM or who have experienced a sudden, unexpected death. 
  • Physical examination may reveal a jerky carotid pulse, and a harsh ejection systolic murmur is heard loudest at the left sternal edge in patients with associated LVOTO. The intensity of the murmur increases with manoeuvres that reduce preload, such as the Valsalva manoeuvre and standing from the squatting position. By contrast, those without LVOTO may have a normal physical examination. 
  • Clinical signs: 

• systolic ejection murmur may be noted with a crescendo-decrescendo pattern at the apex, during the Valsalva manoeuvre or when standing from a squatting position

• left sternal border pansystolic murmur of mitral regurgitation at the apex
• S4 gallop may be noted or a jugular venous pulse with a prominent ‘a’ wave

Investigations

Genetic Testing

• Genetic testing: where wall thickness of ≥15mm in one or more left ventricular myocardial segments is present, unexplained by loading conditions, in a patient whose age of onset is less than 60. Otherwise, unexplained increased LV wall thickness of ≥13mm in one or more LV myocardial segments in those patients with a first-degree relative with unequivocal disease (ideally with LV hypertrophy of ≥15 mm).
• Genetic testing may not be appropriate for adults with wall thickness ≥15 mm not solely explained by loading conditions, especially if clinical and imaging features (e.g., asymmetric hypertrophy, specific wall thickness ratios) provide a clear diagnosis. It also may not be appropriate in cases with characteristic apical hypertrophy that does not meet the full criteria for apical HCM (apical hypertrophic cardiomyopathy diagnostic wall thickness cut-off of ≥15mm, with spade‐like configuration and apical obliteration).