Ventricular Tachycardia (VT)

Disease Description

Ventricular tachycardia (VT) is a cardiac rhythm disorder in which the source of the arrhythmia originates in the ventricles rather than in the atria.

Causes of the Disease

Ventricular tachycardia is most commonly associated with serious structural heart disease, including cardiomyopathies, prior myocardial infarction, myocarditis, left ventricular aneurysm, and congenital or acquired heart defects.

VT may also be caused by genetic arrhythmia syndromes, such as Brugada syndrome, long QT syndrome, and short QT syndrome. In some cases, ventricular tachycardia can occur in patients with a structurally normal heart.

Symptoms

During ventricular tachycardia, the heart rate may reach up to 250 beats per minute, preventing adequate filling of the heart chambers. This leads to a rapid drop in blood pressure and loss of consciousness.

A VT episode (paroxysm) is a life-threatening emergency and, in cases of very high heart rate, requires urgent electrical cardioversion.

Ventricular arrhythmias are the most common cause of sudden cardiac death.

Diagnosis

Ventricular tachycardia should be suspected in patients with episodes of rapid palpitations or loss of consciousness. The diagnosis is confirmed by recording VT on a standard ECG or 24-hour (Holter) ECG monitoring.

If arrhythmia episodes cannot be captured non-invasively, an electrophysiological study (EPS) may be performed. During this procedure, VT is intentionally induced in a specialized electrophysiology laboratory to record and analyze the arrhythmia.

Treatment

Treatment of ventricular tachycardia requires a comprehensive approach, including identification and treatment of the underlying cause when possible, prevention of recurrent VT episodes, and protection against sudden cardiac death.

Therapeutic strategies include antiarrhythmic medication, radiofrequency catheter ablation of the VT substrate, and implantation of a cardioverter-defibrillator (ICD) for sudden death prevention.

Treatment Prognosis

Episodes of sustained ventricular tachycardia represent a serious and potentially fatal diagnosis. Rapid VT often degenerates into ventricular fibrillation, a terminal and lethal arrhythmia.

However, advances in medical therapy and interventional electrophysiology have significantly reduced the risk of recurrent episodes. Implantable cardioverter-defibrillators provide reliable protection against sudden cardiac death and greatly improve long-term survival.