Match each diagnostic investigation used in the evaluation of dilated cardiomyopathy (DCM) with its characteristic finding or purpose: Investigations: - Electrocardiogram (ECG) - Chest radiograph - Echocardiogram - Polymerase chain reaction (PCR) Findings / Purposes: - Detection of a viral origin in suspected myocarditis - Chamber dilation and poor contractility - Cardiomegaly and pulmonary congestion - Atrial enlargement and nonspecific T-wave abnormalities

Each test contributes different information. **ECG** may show atrial enlargement, ventricular hypertrophy, or nonspecific T-wave changes. **Chest radiography** demonstrates cardiomegaly and may show congestion or pleural effusions. **Echocardiography** assesses dilation and contractility, while **PCR** may help detect viral origin. **Key takeaway:** DCM evaluation combines electrical, radiographic, structural, and selected molecular assessment.\n\n**Glossary:** **ECG**: Electrocardiogram. **PCR**: Polymerase chain reaction, a method used to detect genetic material.