Which ventricular tachycardia is dangerous?

The treatment of ventricular arrhythmias remains a major challenge in cardiology. Several very helpful pieces of information can be obtained from the clinical history. The left ventricular function and the hemodynamic effects of a ventricular tachycardia are the two main factors affecting survival. Therefore, if a patient with sustained ventricular tachycardia presents with syncope or cardiac arrest, or if his functional class for dyspnea is III-IV (NYHA classification), he is a candidate for an implantable defibrillator while otherwise medical therapy is advised.