Ventricular Tachycardia (VT): Symptoms, Diagnosis and Treatment
What is ventricular tachycardia?
Ventricular tachycardia is a rapid heart rhythm originating in the ventricles, the lower chambers of the heart. It may impair the heart's ability to pump blood effectively. Some episodes stop spontaneously, while sustained episodes may cause fainting, circulatory collapse or cardiac arrest.
What symptoms can occur?
- A sudden rapid heartbeat or palpitations.
- Dizziness, near-fainting or fainting.
- Shortness of breath.
- Chest pain or pressure.
- Severe weakness, low blood pressure or loss of consciousness.
A short episode may cause few symptoms. The absence of severe symptoms does not establish that a ventricular rhythm is harmless.
What causes VT?
VT may occur in people with previous myocardial infarction and myocardial scarring, coronary artery disease, heart failure, dilated or hypertrophic cardiomyopathy, myocarditis and certain inherited electrical disorders. Electrolyte abnormalities and some medicines may also contribute.
VT can also occur without detectable structural heart disease. This is often called idiopathic VT, and its assessment and outlook differ from VT arising in a scarred heart.
What are the main types?
Nonsustained and sustained VT
Nonsustained VT stops spontaneously within 30 seconds. Sustained VT lasts at least 30 seconds or requires earlier termination because of circulatory instability. The duration alone does not determine the complete risk assessment.
Monomorphic and polymorphic VT
Monomorphic VT has a similar QRS appearance from beat to beat. Polymorphic VT has changing QRS appearances. Torsades de pointes is a particular form of polymorphic VT associated with a prolonged QT interval; not all polymorphic VT is torsades.
How is VT diagnosed?
An ECG recorded during the episode is particularly valuable. Holter and longer recordings may detect intermittent episodes. Echocardiography assesses heart structure and pumping function. Blood tests evaluate electrolytes and other contributing factors.
Cardiac MRI may identify scar or inflammation. Coronary assessment, an electrophysiological study and genetic evaluation may be needed in selected patients, depending on the suspected cause and family history.
How is VT treated?
Emergency treatment
VT with serious circulatory instability may require immediate electrical treatment. A pulseless patient requires emergency resuscitation and defibrillation. Call 112 immediately if someone collapses and is not breathing normally; follow the emergency dispatcher's instructions.
Medication and treatment of the cause
Antiarrhythmic medicines and beta blockers may be used according to the rhythm and underlying disease. Ischaemia, electrolyte abnormalities and other reversible contributors should be treated.
Catheter ablation
Ablation aims to identify and treat the focus or circuit responsible for VT. It may be appropriate for selected idiopathic VT and recurrent scar-related VT. Its role and expected success depend on the underlying mechanism.
Implantable cardioverter-defibrillator (ICD)
An ICD detects and treats life-threatening ventricular rhythms. It may be recommended for selected patients with previous dangerous ventricular arrhythmias or a sufficiently high future risk. Not every person with a short VT episode needs an ICD.
Can VT recur?
Yes. Recurrence depends on the cause, heart function and response to treatment. Regular follow-up, medication adherence and device checks when applicable are important. Exercise advice should be individualised.
Assoc. Prof. Sezen Bağlan Uzunget, MD — Cardiologist
This information is educational. Diagnosis, risk assessment and treatment require individual specialist evaluation.
Türkçe: Ventriküler Taşikardi