Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content +++ KEY FEATURES +++ ESSENTIALS OF DIAGNOSIS ++ Remote history of residence in rural Central or South America ECG evidence of conduction system disease, especially right bundle branch block and left anterior fascicular block, and ST-segment elevation suggesting ventricular aneurysm Premature ventricular contractions and nonsustained ventricular tachycardia (VT) Echocardiographic evidence of an apical left ventricular aneurysm Positive serology for Trypanosoma cruzi +++ GENERAL CONSIDERATIONS ++ Caused by the protozoan T. cruzi Most common cause of cardiomyopathy in South and Central America Three phases of Chagas’ disease: acute, indeterminate, and chronic Pericarditis-myocarditis may develop in the acute phase with variable signs of cardiac failure that often resolve Patients are asymptomatic during the indeterminate phase, which lasts 10–30 years Thirty percent of patients in the indeterminate phase eventually develop chronic heart failure Cardiomyopathy occurs in the chronic phase of T. cruzi infection +++ CLINICAL PRESENTATION +++ SYMPTOMS AND SIGNS ++ Remote history of residence in South or Central America Fatigue Palpitations Dizziness and syncope Stokes-Adams attacks due to arrhythmias Chest pain Dyspnea Dysphasia in patients with megaesophagus Severe constipation and abdominal discomfort in patients with megacolon +++ PHYSICAL EXAM FINDINGS ++ Tachypnea Tachycardia Hypotension Elevated jugular venous pressure Pulmonary rales Diffuse, sustained apical impulse Wide splitting of S2 due to right bundle branch block Systolic murmurs of mitral and tricuspid insufficiency S3 and S4 Hepatomegaly and pulsatile liver Abdominal ascites Peripheral edema Signs of thromboemboli phenomenon +++ DIFFERENTIAL DIAGNOSIS ++ Coronary artery disease Dilated cardiomyopathy Isolated conduction system disease Other causes of ventricular arrhythmias +++ DIAGNOSTIC EVALUATION +++ LABORATORY TESTS ++ Laboratory findings are nonspecific CBC demonstrates leukocytosis with an absolute increase in lymphocyte count Serologic tests for T. cruzi +++ ELECTROCARDIOGRAPHY ++ Sinus rhythm or sinus bradycardia Atrial fibrillation VT First- to third-degree atrioventricular (AV) block Right bundle branch block Left anterior fascicular block +++ IMAGING STUDIES ++ Chest x-ray: variable degrees of cardiomegaly, pulmonary vascular redistribution, and pulmonary edema Echocardiography: variable ventricular dilatation and reduced systolic function; a ventricular apical aneurysm may be present; mural thrombi may be present; mitral and tricuspid regurgitation are often present +++ DIAGNOSTIC PROCEDURES ++ Cardiac catheterization and angiography: can exclude coronary artery disease Electrophysiologic study: indicated in selected cases to assess sinus node function and AV conduction in symptomatic patients; may be useful in patients with sustained VT to determine prognosis and select the appropriate antiarrhythmic therapy +++ TREATMENT +++ CARDIOLOGY REFERRAL ++ Heart failure Arrhythmias +++ HOSPITALIZATION CRITERIA ++ Decompensated heart failure Syncope Thromboembolic events and stroke Arrhythmias... Your Access profile is currently affiliated with [InstitutionA] and is in the process of switching affiliations to [InstitutionB]. Please select how you would like to proceed. Keep the current affiliation with [InstitutionA] and continue with the Access profile sign in process Switch affiliation to [InstitutionB] and continue with the Access profile sign in process Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Error: Incorrect UserName or Password Username Error: Please enter User Name Password Error: Please enter Password Sign in Forgot Password? Forgot Username? Sign in via OpenAthens Sign in via Shibboleth You already have access! Please proceed to your institution's subscription. Create a free profile for additional features.