michael s
(Michael S)
#1
48 How should I investigate a patient with
hypertrophic cardiomyopathy (HCM)?
Krishna Prasad
The first step in the investigation of a patient with hypertrophic
cardiomyopathy (HCM) is to establish the diagnosis and determine
whether the case is sporadic or familial.
History
The investigation should begin with the taking of a detailed history.
This should include the construction of a family tree with at least
three generations.
The clinical examination
This should be aimed specifically at excluding other causes of
hypertrophy such as aortic stenosis or hypertension.
Descriptive investigations
Electrocardiography. In the majority of patients, the 12-lead electro-
cardiogram (ECG) shows abnormalities such as voltage criteria
for left ventricular hypertrophy (LVH), minor intraventricular
conduction defects or bundle branch blocks. Only rarely (<5% of
cases) is the ECG completely normal.
Echocardiography. The mainstay of diagnosis is the echocardio-
graphic demonstration of left ventricular hypertrophy (LVH),
with either the interventricular septum or the free wall measuring
15mm. A very detailed study by an experienced operator is
often necessary as hypertrophy may involve any part of LV. It is
important to note that for adults with family history of HCM,
modified diagnostic criteria apply.
Investigations to identify risk factors of sudden death
The recognised risk factors are family history of sudden deaths,
recurrent syncope, non-sustained ventricular tachycardia and an
