Dilated cardiomyopathy (DCM) is a condition in which the heart's ability to pump blood is decreased because the heart's main pumping chamber, the left ventricle, is enlarged and weakened. The right ventricle may also be dilated and dysfunctional. Dilated cardiomyopathy is the third most common cause of heart failure and the most frequent reason for heart transplantation. Many people with dilated cardiomyopathy have no symptoms or only minor symptoms. Other people develop symptoms, which may progress and worsen as heart function worsens. Heart failure symptoms include shortness of breath and fatigue, swelling of the lower extremities, fatigue, weight gain, fainting, Palpitations, Dizziness or lightheadedness. Blood clots can form in the dilated left ventricle as a result of pooling of the blood and when breaks off can lodge in an artery causing stroke.
DCM can be inherited, but it is primarily caused by a variety of other factors like severe coronary artery disease, alcoholism, Thyroid disease, and diabetes, viral infections of the heart and due to drugs that are toxic to the heart. DCM is diagnosed based on medical history, physical exam, blood tests, electrocardiogram, chest X-ray, echocardiogram, exercise stress test, cardiac catheterization, CT scan, and MRI.
Despite so many years of constant denial regarding the prevalence of dilated cardiomyopathy of chagasic origen in Mexico, many primary health care and social security second level hospitals are now reporting from 29% (Poza Rica, Veracruz), through 54% (Tuxtla Gutierrez, Chiapas) and as high as 85% (Salina Cruz, Oaxaca) dilated cardiomyopathies of T. cruzi origin (Guillen et al. 2005, Moreno et al 2001, Olivera et al 2006), complementing the high correlation between mortality due to cardiac insufficiency and estimated mortality due to Chagas disease based on blood donor seroprevalence (p=0.000043, r=98%, Ramsey et al 2003). Many regions are additionally finding higher rates of megaviscera than expected, providing evidence that all chronic phase clinical manifestations observed in South American patients, most of which are infected with T. cruzi type II, are also seen in Mexican patients, principally with T. cruzi type I, and that therefore we should expect no less than 30% evolution of lethal pathology. If this assumption holds true, Mexico has approximately 650,000 chronic cases, currently under hospital or specialty care.
Drug classes used include many types of drugs like Angiotensin-converting enzyme (ACE) inhibitors, Angiotensin II receptor blockers (ARBs), Beta-blockers, Aldosterone antagonists, Cardiac glycosides, Diuretics, Vasodilators, Antiarrhythmics, Human B-type natriuretic peptide, Inotropic agents. Surgical options for patients with disease refractory to medical therapy include Left ventricular assist devices, Cardiac resynchronization therapy, automatic implantable cardioverter-defibrillators, ventricular restoration surgery, heart transplantation.