What is Ventricular Tachycardia?
Tachycardia is a heart rate higher than 100 beats per minute. A normal resting heart rate is 60 to 100 beats per minute. Ventricular tachycardia starts in the heart’s lower chambers. Most patients who have ventricular tachycardia have a heart rate that is 170 beats per minute or more.
What Causes Ventricular Tachycardia?
Your heart rate is controlled by electrical signals that move across the heart muscle. When something goes wrong and signals are sent too quickly, it can cause tachycardia. Most patients with ventricular tachycardia have another heart problem, such as coronary artery disease, high blood pressure, an enlarged heart (cardiomyopathy) or heart valve disease. The condition can also develop after a heart attack (myocardial infarction) or heart surgery because of scar tissue that forms on the heart. Other, non-heart-related causes of ventricular tachycardia include some medications, an imbalance in electrolytes (the minerals that control heart rhythm), too much caffeine or alcohol, recreational drugs, exercise, and certain genetically transmitted conditions. Sometimes the cause is unknown. You are also more likely to have ventricular tachycardia as you get older or if you have a family history of heart rhythm disorders.
What are the symptoms of ventricular tachycardia?
During an episode of ventricular tachycardia, the heart is beating so fast that the blood pressure drops so the heart cannot pump enough oxygen to every part of the body, and this is what causes symptoms. Although some people with ventricular tachycardia do not experience any symptoms, the most common symptoms are dizziness, lightheadedness, palpitations, shortness of breath or chest pain. When the heart rate is extremely high or the ventricular tachycardia persists for more than a few seconds, it can cause fainting, unconsciousness or cardiac arrest and death. If you experience unexplained fainting, dizziness, lightheadedness, shortness of breath or palpitations, you should be evaluated for possible ventricular tachycardia. Chest pain, difficulty breathing and a rapid pulse are urgent symptoms of a potentially fatal ventricular tachycardia, and you must seek emergency help immediately to avoid the risk of cardiac arrest and death.
How is ventricular tachycardia diagnosed?
You will also have testing to determine if you have ventricular tachycardia. The most common test used to diagnose ventricular tachycardia is an electrocardiogram (ECG/EKG).
An EKG records your heart’s electrical activity. Electrodes are placed on your chest and arms to record the heart’s rhythm, and the pattern prints on graph paper. Your cardiologist may also want to track your heart rhythm at home with a 24 h holter EKG .
Your cardiologist may refer you to a specialist to electrophysiology testing. During the test, catheters are inserted through the veins at the groin and placed directly in the heart. The electrical activity in different parts of the heart is recorded so your doctor can see where the electrical problem starts.
What treatments are available?
These treatments may improve or prevent the abnormal heart rhythm from returning. In emergency situations, CPR, electrical defibrillation and IV medications may be needed to slow the heart rate.
Nonemergency treatment usually includes radiofrequency catheter ablation (RCA) or an implantable cardioverter defibrillator (ICD).
Medications to slow the heart rate is another treatment option for patients with ventricular tachycardia. These drugs can be effective but are associated with some serious, potentially fatal side effects, and they are not used as much as they were in the past.
It is important to keep your appointments for regular follow-up visits. Your cardiologist will want to see how you’re doing, make sure your treatment is working and talk about any symptoms or changes you’ve had.