Cardiomyopathy

Symptoms:

shortness of breath
decreasing ability to tolerate physical exertion
chest pain - also known as "angina," consists of a feeling of sharp, unrelenting pressure the middle of the chest (more common in ischemic cardiomyopathy)
fainting - especially after activity; temporary and brief loss of consciousness
light-headedness - especially after activity
dizziness
palpitations - the sensation of feeling the heart beat
high blood pressure

Additional symptoms that may occur:

swelling of legs, ankles, or other portion of the body
abdominal swelling or enlargement (liquid in the abdomen is called "ascites")
low amount of urine during daytime
need to urinate at night
fatigue
change in mental status
decreased alertness
difficulty concentrating
cough - may be caused by extra liquid accumulating in the lungs, secondary to heart failure
loss of appetite
deconditioning may occur as a consequence of the other symptoms, leading to a reduction in the heart's muscle mass

Signs and tests:

Examination may reveal an irregular heartbeat. Heart sounds and breath sounds may be abnormal. Additionally, there may be other signs of heart failure.

Decreased heart function and heart enlargement may appear in these tests:

Coronary Angiography: This is the study of the coronary arteries (the vessels providing blood to the heart muscle). The angiography is done by introducing a small tube through an artery in the groin area and advancing it to the heart, then injecting an X-ray dye to visualize the coronary arteries.
Echocardiogram and ultrasound examination of the heart.
Chest X-ray.
Chest CT scan.
MRI of chest.
ECG: May show enlargement, evidence of a previous heart attack, ischemic changes (abnormalities seen with a lack of blood flow to the heart), arrhythmias (abnormal heart rhythms) or other abnormalities.
Rarely, a heart biopsy may be needed to rule out other disorders.

Certain lab tests may be used to rule out other disorders and to assess the condition of the heart:

CBC (Complete Blood Count). Red and white blood cells are counted, as well as platelets.
Coronary Risk Profile: The patient's risk factors for coronary disease are evaluated. Risk factors include, but are not limited to, cigarette smoking, lipid profile (particularly cholesterol level), high blood pressure, diabetes, alcoholism, and physical inactivity.
Blood Chemistries: CBC, lipid profile (cholesterol test), and cardiac enzymes.
Cardiac Enzymes: (CPK isoenzymes, CK-MB, LDH isoenzymes).