Restrictive cardiomyopathy is a rare disease in which the heart muscle becomes stiff and cannot relax normally during activity, so the ventricles (lower chambers) do not receive enough blood that is then pumped to other organs. Because the ventricles cannot relax normally, the blood is sent back (upstream) in the bloodstream.
Restrictive cardiomyopathy is rare in Europe, USA and Canada. Other forms of cardiomyopathy also include dilated cardiomyopathy, in which the heart muscle is weakened, stretched, or hypertrophic cardiomyopathy, in which the heart muscle is thickened, voluminous (by increasing the volume and weight of cardiac muscle fibers).
Restrictive cardiomyopathy – Causes
In most cases, the etiology is unknown (idiopathic restrictive cardiomyopathy). Among the known causes of restrictive cardiomyopathy, we include:
Cardiac amyloidosis – abnormal deposition of proteinaceous material in the cardiac muscle tissue;
Hemochromatosis – abnormal deposition of iron in the heart muscle;
Sarcoidosis – a chronic disease characterized by the formation and deposition in various organs and tissues of inflammatory masses nodules (granulomas).
These inflammatory formations are found also in the lungs and heart.
Granulomas affect normal structure and function of the organs concerned:
Radiotherapy and chemotherapy – used to treat various types of cancer, carcinoid syndrome;
Loeffler syndrome (hypereosinophilic syndrome) and endomyocardial fibrosis – diseases in which eosinophil’s (white blood cell type of the line) causes tissue fibrosis by the immune mechanism;
Genetic factors – especially in the case of hereditary (inherited) such as Gaucher disease or Fabry (disease caused by hereditary disorder of metabolism).
Restrictive cardiomyopathy – Symptoms
The symptoms of restrictive cardiomyopathy are usually the same ones that occur in heart failure and include:
Increases in weight due to salt and water retention (edema), which occur mainly in the feet, ankles and legs, bilateral;
Increase in volume of the abdomen, associated with pain, discomfort due to fluid accumulation (ascites) and reflux of blood to the liver;
Dyspnea (difficulty breathing) occurring during daily physical activities;
Dry painful, cough occur mainly in supine (horizontal) and can awaken the patient at night due to impending feeling of suffocation (paroxysmal nocturnal dyspnea);
Dizziness, fatigue (weakness) and even fainting or syncope (fainting with temporary loss of consciousness);
Palpitations (irregular heartbeats);
Nocturia (need to urinate during the night).
Restrictive cardiomyopathy may be complicated by acute heart failure due to accumulation of fluid in the lungs (pulmonary congestion). Pulmonary edema is a medical emergency that requires proper treatment. Symptoms develop quickly and include:
Severe dyspnea (choking);
Tachycardia (irregular heartbeats high frequency);
Cough with sputum lining, sparkling pink shade;
Acute heart failure must be distinguished from chronic heart failure and may be triggered by:
Consumption of large amounts of liquid;
high salt diet;
No treatment or incorrect ineffective treatment;
Paroxysmal tachycardia (rapid heartbeat sudden onset);
Myocardial infarction (AMI);
In addition to acute heart failure, restrictive cardiomyopathy may have other serious complications including:
A blood clot that forms in the heart and can be mobilized into sanguine circulation. Such a clot (embolus) can stop and thus block a small container located in different organs:
Brain and thus cause a cerebrovascular accident;
The heart, causing myocardial infarction;
Lungs, the occurrence of acute pulmonary embolism;
Peripheral tissues and organs, causing various areas infarction;
Arrhythmia (disturbance of the normal heart rhythm), especially atrial fibrillation;
Sudden cardiac death.
Restrictive cardiomyopathy – Investigations
History and personal medical history is important in the diagnosis of restrictive cardiomyopathy. Family medical history and description of symptoms manifest are also important.
Clinical examination, especially in the heart and lung auscultation with a stethoscope can identify the following:
Unusual heartbeats, heart murmur or superimposed noise (cardiac gallop), which signals the walls or heart valve damage. Accumulation of fluid in the lungs is signaled by the appearance of bilateral basal rales (noise, murmurs lung characteristic).
Swelling of the lower limbs;
Hepatojugular reflux (jugular vein pulsations).
Some cardiologists recommend regular reviews for elderly who have symptoms of heart failure, but heart size cvasinormal. New studies show that the disease is much more common than previously thought, among people over 60 years. The symptoms of restrictive cardiomyopathy are more easily treated if early diagnosis.
It is important to remember that the disease can occur at any age. A fair and detailed clinical examination can determine a possible etiology, namely, sarcoidosis (detection of nodular formations in the heart and other tissues and organs) or hemochromatosis (excess of iron in various organs).
Echocardiogram – a filling too fast and failure of the ventricles (the lower chambers of the heart) is a diagnostic sign of restrictive cardiomyopathy.
Electrocardiogram – ECG may suggest a possible injury to the heart or, in some cases, the diagnostic value may be etiologically (highlighting myocardial infarction or cardiac amyloidosis).
Cardio-pulmonary radiography – an X-ray examination may reveal the shape and size of the heart and fluid buildup in the lungs. In restrictive cardiomyopathy, the atria (upper chambers of the heart) may appear enlarged although overall heart size is normal.
Magnetic resonance imaging (MRI) and computed tomography (CT)
There are two imaging methods successfully used in evaluating restrictive cardiomyopathy. The major benefit of these methods is that they can differentiate restrictive cardiomyopathy of restrictive pericarditis (inflammation, fibrosis leaf that surrounds the heart). If the pericardium is thickened, symptoms may be due to constrictive pericarditis rather than restrictive cardiomyopathy.
Angiography and cardiac catheterization – Cardiac catheterization can make differential diagnosis between restrictive pericarditis and restrictive cardiomyopathy.
Other diagnostic procedures including biopsy is done during cardiac catheterization and can confirm the etiological diagnosis of restrictive cardiomyopathy, where hemochromatosis or amyloidosis.