Ventricular tachycardia is a fast heart rate, anything over the normal 100 beats per minute, which starts in the lower chambers of the heart, the ventricles. It causes the ventricles to contract before they have had a chance to completely fill with blood, impairing blood flow to the body.
Premature Ventricular Contractions (PVCs) are single beats originating from the lower chambers. Any time there is more than 3 beats in succession this is defined as ventricular tachycardia.
Most of the time ventricular tachycardia occurs in people with underlying heart abnormalities. Sometimes in can occur in structurally normal hearts. In these patients the origin is usually the right ventricular outflow tract (RVOT). The route the blood flows from the right ventricle to the lungs. In other patiens, such as those who have had a heart attack, the scar from the heart attack creates a milieu of intact heart muscle and scar that predisposes to VT.
Ventricular Tachycardia (VT) and Premature Ventricular Contractions (PVCs)
This is a serious disorder and requires prompt treatment. It may evolve into the ventricular fibrillation. In this life-threatening condition, the ventricles quiver, pumping very little blood out of the heart. Ventricular fibrillation is the primary cause of sudden cardiac death. If normal rhythm is not restored within 3-5 minutes, the heart and brain will be damaged, and the patient will die. Ventricular tachycardia and ventricular fibrillation can be converted into normal rhythm with a controlled electrical shock from a defibrillator.
Regular treatment of ventricular tachycardia include medications to slow the heart rate. High-risk patients are treated with an implantable cardioverter-defibrillator (ICD). [Learn more]
Catheter ablation is the treatment of choice in patients with RVOT VT. Catheter ablation can be used in patients with scar to prevent receiving numerous shocks from an ICD.
Ablation of ventricular tachycardia in a patient with an old heart attack. The target for ablation are islands of live tissue within the scar. These islands cause a circuit for the ventricular tachycardia. The ablation electrically isolates these live islands of live tissue within the scar from healhty tissue.