Ventricular arrhythmia is a term encompassing various forms cardiac rhythm abnormalities originating from the ventricular system. Electrocardiography is used to confirm the diagnosis and the type of arrhythmia, but a detailed morphological and biochemical workup is necessary in order to determine the underlying cause, as most severe forms, such as ventricular fibrillation, can be fatal.
The clinical presentation depends on the underlying subtype of arrhythmia  :
Prompt diagnostic workup is mandatory in defining the exact type of arrhythmia, starting with a thorough physical examination and a detailed patient history that could reveal the presence of comorbidities, use of pro-arrhythmogenic drugs, structural heart disease, or positive family history . A 12-lead electrocardiogram (ECG) should be performed immediately in patients who present with symptoms suggestive of arrhythmia, followed by a transthoracic echocardiogram in order to evaluate cardiac structure and exclude structural heart disease as a possible cause  . ECG findings may include a widened QRS complex (both prolongation and change in shape), ST elevation and inversion of T waves in the case of ventricular tachycardia and fibrillation, while prolonged QT intervals and coving of the ST-segment are seen in long QT syndrome and Brugada syndrome, respectively   . In addition to ECG and echocardiography, laboratory workup should comprise a complete blood count, cardiac markers (troponin, creatine kinase MB, and myoglobin), serum electrolytes (potassium, sodium, magnesium, calcium) and renal function tests, to determine optimal therapy and perform electrolyte correction  . If symptoms appear in childhood, genetic testing to confirm mutations characteristic for Brugada or long QT syndromes is necessary . If the cause of arrhythmia remains unresolved, coronary arteriography, exercise stress testing and cardiac magnetic resonance imaging (MRI) have been suggested as additional diagnostic methods .