Ventricular Tachycardia
What is Ventricular Tachycardia?
Ventricular tachycardia is an abnormally fast, but usually regular, heartbeat that originates in a ventricle (lower chamber of the heart). A ventricular tachycardia is a type of ventricular arrhythmia.
Ventricular tachycardia can be nonsustained, which means it lasts for fewer than 30 seconds, or sustained, which means it lasts for more than 30 seconds.
Is Ventricular Tachycardia Dangerous?
Ventricular tachycardia disrupts the normal beating of the heart. It can be life threatening, leading to complete collapse requiring resuscitation and electrical shock to the chest. There are some specific types of ventricular tachycardia, however, that occur in patients that are shown after extensive evaluation not to have significant abnormalities of the heart. In many of these situations, ventricular tachycardia is not felt to be life-threatening. This distinction is critical to make.
What Causes Ventricular Tachycardia?
Ventricular tachycardia is caused by abnormal impulses in the heart. Some people who experience ventricular tachycardia have some type of heart disease, such as prior heart attack or myocardial infarction, cardiomyopathy, valvular heart disease or myocarditis.
Some forms of ventricular tachycardia occur as the result of genetic abnormalities.
Occasionally, abnormal blood chemistry or medications cause ventricular tachycardia.
What are the Symptoms of Ventricular Tachycardia?
Ventricular tachycardia may be associated with one or more of the following symptoms:
- Palpitations (a rapid heartbeat)
- Chest discomfort
- Shortness of breath
- Lightheadedness
- Dizziness
- Fainting
Some patients have minimal or no symptoms. Symptoms can start and stop suddenly. Patients may still have a life-threatening arrhythmia even if they have minimal or no symptoms.
How are Patients with Ventricular Tachycardia Evaluated?
The Stanford Cardiac Arrhythmia Service provides comprehensive evaluation of patients with ventricular tachycardia. Most patients receive by their local physician or at Stanford imaging studies such as an echocardiogram, stress test, and sometimes cardiac catheterization with coronary angiography (dye test of the arteries to the heart). Selected patients may need to have cardiac MRI or cardiac CT scans to delineate any heart abnormalities. Some patients felt to have a genetic origin of the ventricular tachycardia may be offered genetic evaluation. In such cases, family members including children are also evaluated.
How is Ventricular Tachycardia and Treated?
The Stanford Cardiac Arrhythmia Service provides a wide range of state-of-the-art diagnostic and therapeutic approaches to the management of patients with arrhythmias such as ventricular tachycardia. Patients felt to have life-threatening ventricular tachycardia, often but not always in the presence of specific heart abnormalities, may require implantation of a special pacemaker-like device called an implantable cardioverter-defibrillator or ICD. This device is implanted in the upper chest and involves insertion of special wires or leads into the vein under the collar bone. These wires or leads are then advanced into the heart and connected to the device. This device waits until a life-threatening ventricular arrhythmia to occur and will provide fast electrical signals (pacing) or an electrical shock to the heart to rapidly return the rhythm to normal. Some patients may still experience some dizziness or even pass out while other patients are not aware of the ventricular tachycardia if it is terminated by the rapid pacing. Some patients with frequent episodes of ventricular tachycardia or ventricular tachycardia resulting in severe symptoms such as passing out may require medications. As an alternative to medications or in conjunction with medications, physicians may recommend the patient to have a procedure called catheter ablation of ventricular tachycardia to minimize the number of episodes of ventricular tachycardia, particularly in the patient with more than ICD shock. In catheter ablation, the focus or position within the heart that are responsible for the ventricular tachycardia is targeted and the cells responsible are destroyed by delivering energy using small plastic tubes inserted into the arteries in the groin or leg without the need for open heart surgery. The Stanford Arrhythmia Service have an internationally recognized expertise in these procedures.
Learn more about arrhythmias.