Ventricular tachycardia
Make an Appointment
Talk to DoctorOverview
Ventricular tachycardia (VT or V–tach) is a serious cardiac arrhythmia originating from the ventricles, the heart’s lower chambers. It’s characterized by abnormally fast heart rhythms which disrupt normal heart function and can lead to significant health risks if not managed effectively.
This condition triggers a heart rate that exceeds 100 beats per minute, far above the normal resting rate of 60 to 100 beats. The rapid pace can prevent the heart from filling adequately with blood, diminishing its ability to supply oxygen–rich blood to the body. Symptoms of this insufficient blood flow include lowered blood pressure, shortness of breath, dizziness, and in severe cases, loss of consciousness. While brief episodes of VT might not be harmful, sustained instances lasting more than a few seconds can become life–threatening and may lead to sudden cardiac arrest.
Treating ventricular tachycardia involves several strategies aimed at controlling the heart rate and restoring normal rhythm. Medications may be prescribed to manage the arrhythmia, while immediate cases may require cardioversion—delivering a shock to the heart. In certain scenarios, catheter–based procedures or surgery might be necessary to correct the underlying heart rhythm disturbances and prevent future episodes.
Symptoms
Ventricular tachycardia, or VT, occurs when the heart beats very fast and may not effectively pump blood to the body. This can lead to organs not receiving enough oxygen. Symptoms during VT may include:
- Chest discomfort
- Dizziness
- rapid heartbeat
- Lightheadedness
- Shortness of breath
VT can be brief, lasting less than 30 seconds and resolving on its own—this is known as nonsustained VT, which often causes no symptoms. However, if VT persists for longer, it is referred to as sustained VT and can be more serious, potentially leading to:
- Fainting spells
- Loss of consciousness
- Cardiac arrest, which may result in death.
It’s crucial to consult a doctor promptly if you or your child experiences any unusual heart symptoms to determine the cause. Some cases may require immediate medical attention.
In the event of the following symptoms, call emergency services right away:
- Persistent chest pain lasting more than a few minutes
- Difficulty breathing
- Sudden fainting or loss of consciousness
Causes
Ventricular tachycardia is a condition where the lower parts of your heart, called ventricles, beat very fast. Because they’re beating too quickly, they can’t fill up with blood properly between each beat. This happens when unusual electrical signals in the ventricles interrupt the heart’s normal rhythm, which is typically controlled by something called the sinoatrial node.
Potential causes of ventricular tachycardia include:
Heart-related causes:
- Coronary artery disease: When the heart’s arteries are blocked, usually by a buildup of fat, cholesterol and other substances.
- Heart failure: The heart can’t pump blood effectively.
- Myocarditis: Inflammation of the heart muscle.
- Cardiomyopathy (Enlarged Heart): A condition where the heart is bigger and weaker.
- Heart valve disease: Problems with the valves that control blood flow in the heart.
- Past heart problems: Including a previous heart attack or surgery that left scar tissue.
Non-Heart Related Causes:
- Medications: Some can disrupt heart rhythms.
- Electrolyte Imbalance: Minerals that control heart rhythm are off balance.
- Substances: Too much caffeine, alcohol, or the use of recreational drugs.
- Exercise: Sometimes intense physical activity can trigger it.
In some cases, doctors can’t find the cause.
Risk factors
The risk of ventricular tachycardia can increase due to various factors that strain the heart or harm heart tissue. To reduce this risk, individuals can make lifestyle changes and receive appropriate medical treatment for the following conditions and situations:
- Prior history of heart disease.
- Family history of heart rhythm abnormalities.
- Coronary artery disease.
- Myocarditis.
- Heart failure.
- Enlarged heart (cardiomyopathy).
- Heart valve disease.
- Previous heart attack (myocardial infarction) or heart surgery.
- Adverse effects of medications.
- Severe imbalances in electrolytes.
- Use of stimulant drugs like cocaine or methamphetamine.
- A familial history of tachycardia or other heart rhythm disorders can increase an individual’s susceptibility to developing ventricular tachycardia.
Diagnosis
To diagnose ventricular tachycardia (VT) and determine its underlying causes, healthcare providers rely on a variety of tests and procedures. These diagnostic measures include:
- Electrocardiogram (ECG or EKG): The common electrocardiogram (ECG or EKG) test involves the placement of small electrodes on the chest and arms to detect and record the heart’s electrical activity. ECGs are instrumental in providing valuable insights into the specific type of tachycardia a person may have and can also reveal potential underlying heart–related problems.
Additional ECG options:
-
- Holter monitor: This portable ECG device tracks heart activity over 24 hours or longer, capturing data during daily activities.
- Event monitor: Similar to a Holter monitor but worn for up to 30 days or until you experience symptoms; it may automatically record arrhythmias.
- Implantable loop recorder: A wire–free implantable device placed under the skin, continuously monitoring heart rhythm for up to three years.
- Heart (cardiac) imaging: These imaging tests assess the heart’s structure and function, especially when arrhythmias are present:
-
- Chest X–ray: Offers insights into heart and lung conditions, including enlarged heart.
- Echocardiogram: Uses sound waves to create moving images, identifying blood flow issues and valve problems.
- Cardiac magnetic resonance imaging (MRI): Provides dynamic images of blood flow in the heart.
- Cardiac computed tomography (CT) scan: Combines X–ray images to create detailed cross–sectional views.
- Coronary angiogram: Evaluates coronary artery blockages through contrast dye and special X–rays.
- Stress tests: May accompany some imaging exams, monitoring heart activity while you exercise or receive medication to simulate exercise.
- Electrophysiological (EP) test and cardiac Mapping: An electrophysiological (EP) study, also known as an EP test, serves to confirm the diagnosis of ventricular tachycardia (VT) while precisely pinpointing the origin of the arrhythmia. This procedure involves the insertion of catheters equipped with electrodes through a blood vessel, typically in the groin area, to meticulously map the electrical signals within the heart.
- Tilt Table Test: A tilt table test is employed to gain insight into the relationship between tachycardia and fainting episodes. During this procedure, heart rate and blood pressure are continuously monitored while the patient lies flat on a table. Subsequently, the table is cautiously tilted to simulate an upright position, allowing healthcare providers to observe the responses of both the heart and the nervous system that regulates it as they adapt to these positional changes.
In cases of VT, quick diagnosis is crucial, as it can be a medical emergency. The specific tests used depend on your symptoms, medical history, and the healthcare provider’s judgment. Early diagnosis enables timely treatment and management of VT and any underlying heart issues.
Treatment
Treatment for ventricular tachycardia aims to both lower an already rapid pulse and stop it from happening again in the future. common treatment options include medication, surgery, and procedures. Treatment also includes managing any disorder that causes the condition.
Sustained VT which lasts for more than 30 seconds, frequently requires urgent medical attention because it occasionally results in rapid cardiac death.
- Medications: Anti–arrhythmic medications can lower the heart rate and work to keep its rhythm regular. It may be taken along with other heart medications, such as calcium channel blockers and beta blockers. Anti–arrhythmic drugs may be prescribed intravenously or orally.
- Cardioversion: Cardioversion involves the use of electric shocks delivered to the heart via chest–mounted electrodes to restore a regular heart rhythm. This procedure can also be performed while taking medicine or by employing an automated external defibrillator (AED) to deliver an electric shock to the heart. Cardioversion is performed in situations of emergency or rapid heart rates, such as sustained ventricular tachycardia.
- Surgery or other procedures: To prevent or control periods of ventricular tachycardia, nonemergency treatment options include:
- Catheter ablation: When an additional abnormal electrical pathway is the cause of the rapid heartbeat, catheter ablation is recommended. During the procedure, thin tubes or catheters are inserted through a groin artery to reach the heart. Electrodes on the catheter tip use heat or cold to create small scars in the heart, which correct irregular electrical signals and restore a normal heart rhythm.
- Implantable cardioverter–defibrillator (ICD): The heart’s rhythm is monitored and managed by this small device. When it notices a ventricular tachycardia event, it immediately sends an electrical signal to restore the heart’s regular rhythm. This is often prescribed to people with high risk of developing ventricular tachycardia or ventricular fibrillation.
- Pacemaker: The pacemaker sends an electrical pulse to help reset the heart’s rhythm when it notices an abnormal heartbeat. This compact device is implanted beneath the skin in the chest region through a surgical procedure.
- Maze procedure: This treatment involves creating a maze–like pattern of scar tissue to obstruct errant electrical signals that lead to certain forms of tachycardia. The signals from the heart cannot travel through scar tissue. Small incisions are made in the top portion of the heart during the procedure.
- Open–heart surgery: Surgery is often only performed when all other therapeutic options have failed or when it is necessary to treat another heart condition. This may be performed to block a second electrical route that is causing tachycardia.
