In some stages of the disease, the ability to perform physical activity may be limited by breathlessness and / or fatigue. Most individuals have only a mild limitation to exercise, but occasionally the limitation can be severe and a minority may struggle with even modest exertion.

Chest pain or tightness in the chest is a common symptom. It is usually triggered by exertion and relieved by rest, but the pain can also occur at rest and can last a long time. The cause is usually attributed to insufficient oxygen being supplied to the myocardium (ischemia).

In Cardiomyopathy the main coronary arteries are usually normal, although congenital anomalies are rarely observed and, after the age of 40, it is possible to have an obstruction of a coronary vessel. In most patients with Cardiomyopathy the flow necessary to convey oxygen and nutrients to the cells, can be reduced, and insufficient, especially when the heart makes an effort or when the heart accelerates a lot (over 130-150 beats per minute).

Palpitations are an uncomfortable sensation of an irregular heartbeat (arrhythmia) that everyone can occasionally feel. However, in some cases, palpitations can have a sudden onset, be very fast, and be associated with sweating, shortness of breath, a feeling of loss of balance, or fainting.

The presence of a significant arrhythmia must be ascertained with dynamic ECG (Holter) by a cardiologist and treated appropriately.

People can sometimes feel dizzy and rarely fall unconscious (Syncope). This can happen during exercise or at rest, with no apparent clear trigger.

The reasons for these episodes are not always immediately evident and their documentation can be difficult, if occasional. They may be due to an irregular heartbeat, or a sudden drop in blood pressure. Episodes of dizziness and any fainting must be reported immediately to the cardiologist, who will decide on subsequent investigations.