ECG
Sinus tachycardia
Low voltages
Prolonged QTc
AV block
ST elevations (Usually >1 vessel distribution)
Elevated troponin
Echocardiography
Decreased LVEF
Global hypokinesis
Regional wall motion abnormalities
Contrast MR
Nuclear Study
Widespread uptake indicating myocyte necrosis
Viral titres
Endocardial biopsy: Gold standard, but rarely used
Sinus tachycardia
Low voltages
Prolonged QTc
AV block
ST elevations (Usually >1 vessel distribution)
Decreased LVEF
Global hypokinesis
Regional wall motion abnormalities
Widespread uptake indicating myocyte necrosis
Myocarditis
Consider other causes of CHF
Endocarditis
Acute coronary syndromes 
Constrictive pericarditis
STEMI
Pericarditis
Non-STEMI