Ventricular tachycardia is a heart rhythm disorder caused by impaired electrical activity in the lower chambers of the heart (ventricles).In this condition, the abnormal electric signals in the ventricles cause the heart to beat abnormally fast. The normal heart rate is 60-100 beats / minute. In ventricular tachycardia, the heart beat rises above 100 beats per minute. If this condition is left untreated, it may get worse and lead to ventricular fibrillation. In ventricular tachycardia, the heart beats fast but in regular rhythm whereas, in ventricular fibrillation, it beats fast and irregularly. In some people, this condition may last for a short duration and cause no symptoms, however, in some people, it may last for longer duration and cause symptoms such as dizziness, lightheadedness or loss of consciousness.
SIGNS AND SYMPTOMS
The following are the signs and symptoms of ventricular tachycardia:
- Palpitations(being aware of your heartbeat)
- Dizziness or lightheadedness
- Near-fainting or fainting
- Weak pulse or no pulse
- Chest pain or pressure
- Shortness of breath
In this condition, the heart beat is so fast that the ventricles cannot effectively pump oxygenated blood to the rest of the body.
CAUSES AND RISK FACTORS
Ventricular tachycardia is caused by disturbance in the electric impulses controlling the ventricular activity. The various factors which may cause disturbance in ventricular activity include:
- Congenital heart diseases
- Coronary artery disease
- Connective tissue disorder such as sarcoidosis
- Structural heart disease like cardiomyopathy
- Electrolyte imbalance, responsible for conducting electrical impulses
- Drug abuse, such as cocaine
- Medication side effects
- Family history
Idiopathic ventricular tachycardia: In this type, the exact cause of ventricular tachycardia can’t be determined.
The complications are based on the severity of condition and presence of other heart diseases. The following are the some of the possible complications of ventricular tachycardia:
- Heart failure, inability of the heart to pump enough blood
- Frequent unconsciousness
- Sudden death due to cardiac arrest
The doctor would take a detailed history of the patient, check the heart rate and check for other signs of impaired cardiac function. The following tests help in confirming the diagnosis of ventricular tachycardia and to assess heart function:
Electrocardiogram: In this test, the doctor would place small sensors on chest and arms of the patient, which would record the electrical activity of the heart.
Cardiac imaging: This technique is used to examine the heart and obtain following information:
- Structural abnormalities of heart responsible for arrhythmia.
- Presence of obstruction of blood flow to the heart.
- Other abnormalities of heart contributing to ventricular tachycardia.
- Echocardiogram (echo): This test uses sound waves to detect abnormalities in heart valves and heart muscles that may cause ventricular tachycardia.
- Magnetic resonance imaging (MRI): This imaging test uses sound waves and magnetic fields to obtain detailed and clear images of the heart. This is helpful in assessing any structural abnormalities which may contribute to ventricular tachycardia.
- Computerized tomography (CT): In this test, series of X-rays are used to obtain cross-sectional images of heart. This test is also useful to detect structural abnormalities of heart.
- Coronary angiogram: The doctor injects a dye in blood and then uses X-rays to view the blood flow through the coronary arteries. This test is helpful in detecting blockagesand other structural abnormalities which may cause blood flow obstruction in heart and blood vessels.
- Chest X-ray: This test helps to obtain images of the heart and lungs. It is a painless procedure.
- Stress test: The doctor places electrodes on the chest and record the heart behavior during stress caused by exercise, usually by walking on treadmill.
- Electrophysiological test: This test is used to confirm the diagnosis of abnormalities related to heart circulation. The doctor inserts a thin flexible tube, which bears electrodes at its tips, into an access point usually groin or neck.
The treatment of ventricular tachycardia is based on type of arrhythmia and severity of tachycardia.
Immediate treatment involves restoring normal heart rate by defibrillation, cardioversion and medications.
- Defibrillation: This process involves administration of controlled electric shock to stop fibrillation of the heart and bring back the heart rhythm to normal. The medical professional can recognize signs of cardiac arrest and perform defibrillation with the automated external defibrillator (AED) in a hospital setting.
- Cardioversion: This technique aims to restore regular rhythm of the heart with the help of electrical impulses.
- Medications: The doctor will give anti-arrhythmic medication which brings back the heart rhythm to normal.
- Surgery: The doctor may recommend an open-heart surgery to treat the cases in which the blood vessels supplying the heart muscles are blocked (atherosclerosis)
Ventricular tachycardia can be prevented by:
- Taking prescribed anti-arrythmic drugs regularly
- Avoiding stimulants such as nicotine
- Visiting cardiologist on a regular basis
- Practicing yoga/exercises daily
- Quitting alcohol consumption
- Maintaining healthy body weight
- Following a healthy diet