HYPERTROPHIC CARDIOMYOPATHY

The condition was first recognised in the 1950's and has been known by the names Hypertrophic Obstructive Cardiomyopathy (HOCM), Idiopathic Hypertrophic Sub-aortic Stenosis (IHSS) and Muscular Sub-aortic Stenosis but the term Hypertrophic Cardiomyopathy (HCM) is now generally used.

HCM is an inherited condition which, in the majority of affected people, does not limit the quality and duration of life. It is a disorder of the heart consisting of excessive growth of the muscle, which may begin before birth when the fetal heart is developing. The natural history is characterised by slow progression of symptoms but a significant incidence of sudden death. Symptoms of chest pain, dizziness, loss of consciousness, palpitation and breathlessness can occur but some affected persons do not experience symptoms. Irregularity of the heartbeat can lead to palpitations but usually is only detected during ECG monitoring. Treatment is usually by drug therapy but surgery may be indicated where the thickening of the muscle causes obstruction to the outflow tract of the heart. Risk stratification to identify an affected individual's potential risk of sudden death is an important part of medical management to ensure appropriate preventative measures are taken. If the condition is diagnosed, intense competitive exercise should be avoided. Special monitoring during anaesthesia is required.

If the condition is diagnosed, violent exercise, prolonged standing in hot conditions and very hot baths/showers should be avoided. Special monitoring during anaesthesia is required.

Inheritance patterns
Autosomal dominant. Family screening is strongly recommended. Research shows 1 in 500 people are affected in the UK

Prenatal diagnosis
None.

DILATED CARDIOMYOPATHY

Dilated cardiomyopathy is a condition which was first recognised in the 1950s. It is characterised by dilation and impaired pumping function of the main chambers of the heart. The onset of the condition is genetically determined in the majority of patients. It may be triggered by viral infection, pregnancy, or excessive alcohol abuse. Symptoms of heart failure, in particular breathlessness and fatigue, are the usual presenting feature. Natural history is usually progressive though there have been recent improvements in the treatment of heart failure including newer drugs and the possibility of transplantation.

Inheritance patterns
Dilated cardiomyopathy is an autosomal dominant condition with incomplete penetrance and family screening is recommended. The condition is familial in at least fifty per cent of cases.

Prenatal diagnosis
Not Applicable

Medical text written November 1994 by Professor W J McKenna. Last updated October 2004 by Professor W J McKenna, Clinical Director, Heart Hospital, London, UK.

CARDIOMYOPATHY ASSOCIATION

Cardiomyopathy Association
Unit 10
Chiltern Court
Asheridge Road
Chesham
HP5 2PX
Tel: 01494 791224
Tel: 0800 018 1024 Helpline
Fax: 01494 797199
e-mail: info@cardiomyopathy.org
Web: http://www.cardiomyopathy.org

The Association is a National Registered Charity No. 803262, established in 1989. It offers: advice and information for individuals and families; linking families where possible; raising awareness among doctors, nurses, health professionals, educational institutions and the general public; and a regional contact network. It publishes a quarterly newsletter and has a wide range of information available, details on request. The Association has approximately 2,000 members.

Group details last updated March 2007.

Further support for young people with Hypertrophic Cardiomyopathy is available from CRY - Cardiac Risk in the Young (see entry, Heart Defects)

Support for bereaved families of adults who have died as a result of Cardiomyopathy is provided by the Sudden Adult Death Trust (SADS UK) (see entry, Heart Defects)