Overview
Restrictive cardiomyopathy is a condition when the heart muscle becomes rigid and less compliant. This increases the difficulty for the blood to fill up the heart in between heartbeats and hence increases blood pressure. This pressure is felt in the lung and patient would experience breathlessness, especially on exertion. The blood that comes out from each contraction of a stiff heart is also less than normal. 

Causes
There are many causes of restrictive cardiomyopathy. Family history of cardiomyopathy can sometimes be found as this condition can be due to misspelling of one or more genes. Infiltrative conditions like amyloidosis or sarcoidosis can sometimes affect the heart and cause stiff heart to occur. 

Symptoms
Symptoms of restrictive cardiomyopathy mimic those in heart failure. They include difficulty in breathing, especially on exertion, fatigue and loss of appetite. Water retention is common and patients frequently complain of both legs swelling and abdominal bloating. Abnormal heart rhythms like atrial fibrillation is frequently seen and this rhythm increases the likelihood of stroke in affected individuals. 

Detection 
This condition is usually diagnosed with imaging studies and echocardiogram is widely used to detect this condition. Sometimes cardiac MRI is needed to better characterize the heart muscle. Rarely a cardiac biopsy, where a small piece of heart muscle is taken for analysis under microscope, is performed. 

Treatment
Treatment is usually aimed at reducing the pressure inside the heart and relieving water retention. Medications include water tablet are usually indispensable. Blood thinners like warfarin decreases the risk of stroke when atrial fibrillation is present. In advanced situations when the heart function is very poor, the patient may require a heart transplant.