Restrictive Cardiomyopathy refers to heart disorders in which the walls of the heart tissue become stiff thereby inhibiting normal pumping of blood. It is an uncommon type of Cardiomyopathy, or a heart disorder which damages the walls of the heart. The cause of onset of this disorder may be not be determined.
Restrictive Cardiomyopathy causes the walls of the ventricles (lower chambers of the heart) to become stiff. The walls of the heart need not become thicker or enlarged but their flexibility decreases. This impairs the pumping action of the heart. Lesser blood is pumped and with lesser pressure. As a result, lesser blood reaches the other vital organs such as the liver and the brain, affecting their function as well.
Restrictive Cardiomyopathy may either be caused by either changes in the makeup of the heart muscle or by the accumulation of abnormal substances in the heart muscle. Fibrosis, which causes the replacement of heart muscle tissue with tougher fibrous tissues, can stiffen the heart walls. Scarring of the heart muscle by exposure to radiation, during cancer treatment, builds up scar tissue in the heart walls, hardening it in the process. Diseases of the endocardium (thin tissue covering the heart walls) such as endomyocardial fibrosis and Loeffler’s syndrome may also cause this disorder.
Restrictive Cardiomyopathy may also occur due to the undesired accumulation of materials in the walls of the heart. Amyloidosis is the buildup of a protein called amyloid in the heart walls. For people with excess iron in their body, Hemochromatosis causes the storage of iron in the heart walls, thereby stiffening it. Hypereosinophilic syndrome causes the infiltration of eosinophils into the heart tissue and subsequent buildup. People having sarcoidosis may develop small lesions or granulomas in the heart walls which contain inflammatory white blood cells. All these types of material accumulations can decrease the flexibility of the heart and affect its pumping.
Various symptoms of Restrictive Cardiomyopathy include:
- Shortness of breath
- General feeling of tiredness and weakness
- Intolerance to exercise
- Feeling your heartbeat
- Fluid accumulation in the abdomen
- Swelling in the legs and feet
- Irregularities in heart rhythm
Diagnosis of restrictive Cardiomyopathy is made with the help of an Echocardiogram which uses sound waves to project a picture of the heart. Doctors can then analyze the size and performance of important structures of the heart. Magnetic resonance Imaging or MRI can spot unusual changes in the texture of the heart muscle due to possible accumulation of amyloid or iron. The diagnosis can be confirmed by performing a heart catheterization during which a catheter is inserted into the heart through an artery, which can check the blood pressures in the heart as well as the volume of the blood being pumped. If needed, it can also remove a sample of heart tissue for further investigation or biopsy.
Patients suffering from Restrictive Cardiomyopathy have poor prognosis. Even if the condition is recognized early and treatment is begun, damage once done to the heart cannot be reversed. The emphasis of treatment is to relieve the symptoms and give the patient a better quality of life. Treatment involves the correction of cardiac rhythm disturbances, prevention of blood clots, reducing the workload of the heart etc. However, there is no effective cure for restrictive Cardiomyopathy as drugs used normally to treat heart disorders create complications for this condition.
Symptoms such as swelling can be controlled by administering diuretics but it may also reduce the blood input into the heart thereby worsening the condition. Similarly, drugs such as angiotensin-converting enzyme inhibitors which lower the workload of the heart can also lead to undesirably low blood pressures.
However, the treatment of the disorder causing restrictive Cardiomyopathy can aid in halting the disease. For example, patients with iron overload in their bloodstream, which eventually ends up in the heart walls, may be advised to remove some of their blood at intervals. For patients with high risk of heart failure, a heart transplant may be considered. Early detection and diagnosis of Restrictive Cardiomyopathy is the only way of preventing or at least controlling the disease. Timely consultation with a physician is advised if any of the symptoms of the disease are noticed.