An EKG is a standard method of evaluating a patient with<unk> .  It can help to determine the cause, severity, and the specific chamber which is affected.  A q wave would indicate an area of muscle death accounting for the enlargement, and ST elevation may suggest a myocardial infarction, myocarditis or pericarditis.
Cardiomegaly electrocardiogram
Wide complex tachycardia physical examination
Ventricular tachycardia physical examination
Cardiomegaly echocardiography or ultrasound
Supraventricular tachycardia physical examination
Cardiomegaly chest x ray
Cardiomegaly other diagnostic studies
Left ventricular hypertrophy electrocardiogram