This Holter monitor strip of a 5-year-old showing atrial<unk> . This person was eventually diagnosed with<unk> . There are no specific diagnostic criteria for<unk> , and it can be difficult to diagnose for a number of reasons. First, in patients presenting with both<unk>  and cardiomyopathy, it can be difficult to distinguish which is the causative agent. Additionally, it can occur in patients with or without underlying structural heart disease. Previously normal left ventricular ejection fraction or left ventricular systolic dysfunction out of proportion to a patient’s underlying cardiac disease can be important clues to possible<unk> . The diagnosis of<unk>  is made after excluding other causes of cardiomyopathy and observing resolution of the left ventricular systolic dysfunction with treatment of the<unk> . Specific tests that can be used in the diagnosis and monitoring of<unk>  include: * electrocardiography (EKG) * Continuous cardiac rhythm monitoring (e.g. Holter monitor) * echocardiography * Radionuclide imaging * Endomyocardial biopsy * Cardiac magnetic resonance imaging (CMR) * N-terminal pro-B-type natriuretic peptide (NT-pro BNP) Cardiac rhythm monitors can be used to diagnose tachyarrhythmias. The most common modality used is an EKG. A continuous rhythm monitor such as a Holter monitor can be used to characterize the frequency of a tachyarrhythmia over a longer period of time. Additionally, some patients may not present to the clinical setting in an abnormal rhythm, and continuous rhythm monitor can be useful to determine if an arrhythmia is present over a longer duration of time. To assess cardiac structure and function, echocardiography is the most commonly available and utilized modality. In addition to decreased left ventricular ejection fraction, studies indicate that patients with<unk>  may have a smaller left ventricular end-diastolic dimension compared to patients with idiopathic dilated cardiomyopathy. Radionuclide imaging can be used as a non-invasive test to detect myocardial ischemia. Cardiac MRI has also been used to evaluate patients with possible<unk> . Late-gadolinium enhancement on cardiac MRI indicates the presence of fibrosis and scarring, and may be evidence of cardiomyopathy not due to<unk> . A decline in serial NT-pro BNP with control of tachyarrhythmia indicates reversibility of the cardiomyopathy, which would also suggest<unk> . People with<unk>  display distinct changes in endomyocardial biopsies.<unk>  is associated with the infiltration of CD68+ macrophages into the myocardium while CD3+ T-cells are very rare. Furthermore, patients with<unk>  display significant fibrosis due to collagen deposition. The distribution of mitochondria has found to be altered as well, with an enrichment at the intercalated discs (EMID-sign).<unk>  is likely underdiagnosed due to attribution of the tachyarrhythmia to the cardiomyopathy. Poor control of the tachyarrhythmia can result in worsening of heart failure symptoms and cardiomyopathy. Therefore, it is important to aggressively treat the tachyarrhythmia and monitor patients for resolution of left ventricular systolic dysfunction in cases of suspected<unk> .
Tachycardia-induced cardiomyopathy
Alcoholic cardiomyopathy
Coxsackievirus-induced cardiomyopathy
Arrhythmogenic cardiomyopathy
Uremic pericarditis
Ischemic cardiomyopathy
Viral cardiomyopathy
Diabetic cardiomyopathy