Diagnosis and investigations

Dilated cardiomyopathy

Involves excluding other causes of heart failure.

The tests used may include: -

• Electrocardiogram (ECG),
• 24 hour ambulatory ECG (Holter Monitor) - this is when electrodes are attached to the chest wall and also attached to a small monitor worn at waist level which, over a 24 hour period, continually records the electrical activity of the heart. This record is interpreted by a Specialist and any abnormal cardiac activity is evaluated,
• Exercise test,
• Echocardiogram,
• Blood tests,
• Magnetic Resonance Imaging (MRI) scan,
• Chest X-ray.

Hypertrophic Cardiomyopathy

• Chest X ray,
• ECG - shows enlargement of the left ventricle and other abnormalities,
• Echocardiogram which shows an image of the heart in action (and will show the hypertrophy),
• ECG recording, while moving about (ambulatory) and possibly an exercise test.

Physical examination will show a "jerky" pulse, a palpably enlarged heart, heart murmurs and an extra heart sound.

Hypertrophic cardiomyopathy is the most common cause of sudden death among young people and athletes.

Restrictive Cardiomyopathy ("Infiltrative")

• Chest x ray (may show congestion in the lungs, and the heart size may be normal or enlarged),
• ECG (may show non- specific abnormalities in electrical activity),
• Echocardiography (may demonstrate impaired filling of the ventricles),
• Cardiac catheterisation (to measure pressures in the heart chambers),
• MRI scan to show structure of the heart,
• Biopsy of the heart muscle.

Arrhythmogenic Right Ventriclular Cardiomyopathy (ARVC)

• ECG,
• Ambulatory ECG (Holter monitor),
• Possibly exercise test,
• Echocardiogram,
• MRI scan.

Also - Electrophysiological Studies (EPS) may be done, with a view to ablation of abnormal foci of electrical activity if arrhythmia is a problem.

The condition may be associated with a leaking of the Tricuspid Valve, which is in the right side of the heart. This can lead to right heart failure.