While a few seconds may not result in problems, longer periods are dangerous. Short periods may occur without symptoms or present with lightheadedness, palpitations, or chest pain.<unk>  may turn into<unk>  fibrillation and can result in cardiac arrest.
Ventricular tachycardia
Artificial cardiac pacemaker
Sinus arrhythmia
Electrocardiography
Junctional tachycardia
Supraventricular tachycardia
Torsades de pointes
Tachycardia