Ventricular tachyarrhythmia is an umbrella term for fast heart rhythms that start in the ventricles rather than the atria. These arrhythmias are usually secondary to structural problems of the heart. One could argue that ventricular tachyarrhythmias are the most dangerous of the arrhythmias as they are life threatening, unlike most other supraventricular tachycardias. Patients with heart failure and those who have previously experienced heart attacks may have a higher risk of ventricular tachycardia. Typically, these patients will develop scarring in the heart that can lead to this group of conditions. It is often in this scarred area of the ventricle that the tachycardia is initiated.
Ventricular tachycardias can be both regular and irregular but in all cases represent a fast heartbeat – usually greater than 100 beats per minute. In some cases, ventricular tachycardia can cause sudden cardiac death unless early treatment is pursued.
How we diagnose ventricular tachycardia
Much like other arrhythmias of the heart, we use a combination of diagnostic tools starting with an EKG and then using Holter or event monitors as necessary. A specialized electrophysiologist with experience is required to ensure that the proper diagnosis is made, and the condition is not confused with a supraventricular tachycardia which is far less concerning.
Antiarrhythmic medication to reduce the severity and occurrence of ventricular tachycardias can be an important first step, but antiarrhythmics can also create secondary arrhythmias. As a result, most patients who have had life threatening ventricular tachycardias should be fitted with an ICD or implantable cardioverter defibrillator. Patients who are at high risk of life-threatening ventricular tachycardia because of lower ventricular function should also benefit from this device.
As mentioned above, an implantable cardioverter defibrillator is a prudent course of action for anyone with structural heart disease who is also at risk of life-threatening ventricular tachycardia. The ICD works much like an external defibrillator in that when it detects an irregular heartbeat, it shocks the patient back into normal rhythm. In the case of ventricular tachycardia, this can be truly lifesaving.
Cardiac catheter ablation is also an option for patients who have experienced life-threatening ventricular tachycardia. With improvements in the technology associated with cardiac catheter ablation we are better able to differentiate between super ventricular tachycardias and ventricular tachycardias allowing for proper treatment and long-term positive results. While an ablation can be very successful, there is always the possibility that the ventricular tachycardia will return in a different area.