Ventricular tachycardia (VT) and ventricular fibrillation (VF) are abnormal rapid heart rhythms that originate from the lower heart chambers of the heart. It usually occurs in patients with previous heart attacks or abnormal heart muscle (i.e. cardiomyopathy), though rarely it can also occur in patients with a normal healthy heart.
Depending on the severity, these arrhythmias often cause rapid heart racing, chest pain, shortness of breath, lightheadedness, loss of consciousness, and even sudden death.
Medications may control symptoms and reduce the frequency of these arrhythmias. However, patients often require implantation of a special device called implantable cardioverter defibrillator (ICD), which is capable of delivering an electric shock during a life threatening arrhythmia in order to restore normal rhythm.
Sometimes, in patients who do not respond well to medications and have frequent shocks from VT, a specialized cardiac ablation procedure may be recommended. This procedure is intended to target the rhythm abnormalities as well as scar tissue from where they arise in order to decrease the amount of these life threatening arrhythmias.