Apical hypertrophic cardiomyopathy

Apical hypertrophic cardiomyopathy (AHCM) (also known as Yamaguchi syndrome) is a rare form of hypertrophic cardiomyopathy which usually involves the apex of the left ventricle and rarely involves the right ventricular apex or both apices.

Historically, this condition was thought to be confined to the Japanese population but it is also found in other populations. Of all HCM patients in Japan the prevalence of AHCM was 15-25% (cf. US ~ 3%).

Over half of patients with AHCM are thought to be asymptomatic but the most common presenting symptom is chest pain, followed by palpitations, dyspnoea and syncope. It may also manifest as morbid events such as atrial fibrillation, myocardial infarction, embolic events, ventricular fibrillation and/or congestive heart failure.

Giant negative T waves at ECG.

"Spade-like" view of the left ventricle may sometimes be present 6.

It is frequently sporadic. An autosomal dominant inheritance has been reported in a few families where a sarcoma gene mutation (E101K mutation in the alpha-cardiac actin gene) has been identified 1.

Some publications divide this into 3 subtypes

  • pure focal: considered most common
  • pure diffuse
  • mixed

Compared with other variants of HCM, the prognosis of AHCM is relatively benign. The overall mortality rate of AHCM patients has been reported around 10.5% and cardiovascular mortality around 1.9% after a follow-up of 13.6 ± 8.3 years 1.

The syndrome and its echocardiographic appearances were first described in 1979 by H Yamaguchi.

Possible differential considerations include


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Article information

rID: 56622
System: Cardiac
Synonyms or Alternate Spellings:
  • Yamaguchi syndrome
  • AHCM
  • Apical hypertrophic cardiomyopathy (ACHM)
  • ApHCM

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