Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content +++ KEY FEATURES +++ ESSENTIALS OF DIAGNOSIS ++ Typical dilated cardiomyopathy with reduced systolic function Atrial or ventricular tachycardia or frequent ventricular ectopy (>10,000 to 25,000 premature ventricular contractions per 24 hours) +++ GENERAL CONSIDERATIONS ++ Atrial tachyarrhythmias with persistently elevated ventricular rates (120–180 bpm) can lead to progressive left ventricle dilatation and systolic dysfunction The cardiomyopathy develops slowly (over months or longer) The mechanism of tachycardia cardiomyopathy is poorly understood, but it can be created in animals by rapid atrial and ventricular pacing The hallmark of disease is partial or complete reversibility once the arrhythmia is controlled +++ CLINICAL PRESENTATION +++ SYMPTOMS AND SIGNS ++ Typical symptoms of chronic heart failure, such as exertional dyspnea, exercise intolerance, chest discomfort, orthopnea, paroxysmal nocturnal dyspnea, and weight gain There is no specific heart rate cutoff that predisposes to cardiomyopathy +++ PHYSICAL EXAM FINDINGS ++ Typical findings of chronic heart failure, such as elevated jugular venous pressure, extra heart sounds (S3 or S4), pulmonary rales, peripheral edema Supraventricular tachycardia, ventricular tachycardia, or frequent ventricular ectopy +++ DIFFERENTIAL DIAGNOSIS ++ Dilated cardiomyopathy of another etiology should be suspected if left ventricular function does not improve with control or termination of the tachyarrhythmia +++ DIAGNOSTIC EVALUATION +++ LABORATORY TESTS ++ Electrolytes, creatinine, brain natriuretic peptide +++ IMAGING STUDIES ++ Chest x-ray – Pulmonary edema with cardiomegaly Echocardiography – Dilated, hypokinetic left ventricle – Functional mitral regurgitation, tricuspid regurgitation, and mildly elevated pulmonary pressures on Doppler +++ DIAGNOSTIC PROCEDURES ++ Coronary angiography may be necessary in some cases to exclude other causes of heart failure and coronary artery disease +++ TREATMENT +++ CARDIOLOGY REFERRAL ++ Suspected tachycardia cardiomyopathy +++ HOSPITALIZATION CRITERIA ++ Decompensated heart failure +++ MEDICATIONS ++ Pharmacologic therapy to eliminate or control the arrhythmia Pharmacologic therapy to prevent the arrhythmia Guideline-directed medical therapy for chronic heart failure +++ THERAPEUTIC PROCEDURES ++ Cardioversion of ventricular tachycardia, atrial fibrillation, or atrial flutter Catheter ablation of tachyarrhythmia +++ MONITORING ++ ECG in hospital as appropriate +++ DIET AND ACTIVITY ++ Low-sodium diet Restricted activity until problem corrected +++ ONGOING MANAGEMENT +++ HOSPITAL DISCHARGE CRITERIA ++ Resolution of heart failure Successful ablation +++ FOLLOW-UP ++ Depends on therapy +++ COMPLICATIONS ++ Death, cardiac arrest Pulmonary edema Antiarrhythmic drug toxicity Complications surrounding catheter ... 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? Download the Access App: iOS | Android 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.