Ventricular Tachycardia (VT)

Introduction

Ventricular tachycardia (VT) is a type of fast heart rhythm (tachyarrhythmia) that originates from the ventricles, the lower chambers of the heart. It is defined as a heart rate exceeding 100 beats per minute (bpm), typically with at least three consecutive ventricular beats.

Causes

VT can occur due to various underlying conditions, including: - Coronary artery disease (CAD) – Reduced blood flow to the heart can cause irritability in the ventricular muscles. - Myocardial infarction (heart attack) – Scarring from past heart attacks can create electrical instability. - Heart failure – Structural and functional abnormalities increase the risk of VT. - Electrolyte imbalances – Abnormal levels of potassium, magnesium, or calcium can trigger VT. - Congenital heart disease – Some inherited heart conditions increase susceptibility to VT (e.g., Long QT syndrome, Brugada syndrome). - Drug toxicity – Certain medications or illicit drugs can provoke ventricular arrhythmias.

Symptoms

Symptoms of VT may vary, but can include: - Palpitations (rapid heartbeat) - Dizziness or lightheadedness - Shortness of breath - Chest pain - Syncope (fainting) in severe cases - Sudden cardiac arrest in extreme cases

Diagnosis

Diagnosis of VT typically involves: - Electrocardiogram (ECG) – The primary tool for identifying VT characteristics. - Holter monitoring – Continuous ECG tracing to detect intermittent VT episodes. - Electrophysiological study (EPS) – Invasive testing to map heart electrical activity. - Echocardiography & MRI – Used to assess heart structure and function. - Blood tests – Evaluate electrolyte imbalances and underlying metabolic disorders.

Treatment

The treatment approach depends on the severity and underlying cause of VT: - Acute management: - Hemodynamically unstable VT – Immediate electrical cardioversion is required. - Stable VT – Antiarrhythmic medications such as amiodarone , lidocaine , or procainamide . - Long-term management: - Implantable cardioverter-defibrillator (ICD) to prevent sudden cardiac arrest. - Catheter ablation to eliminate arrhythmogenic foci. - Lifestyle modifications , including controlling hypertension, diabetes, and avoiding triggers like stimulants or excessive alcohol.

Prognosis

The outlook for VT depends on the underlying heart condition and treatment effectiveness. Ventricular tachycardia in a structurally normal heart may carry a good prognosis, while VT associated with significant heart disease poses a higher risk and requires careful management.

Source recommendations

1. American Heart Association (AHA) Guidelines on Ventricular Arrhythmias

1. https://www.ahajournals.org/doi/10.1161/CIR.0000000000000549
2. https://www.heart.org/en/health-topics/arrhythmia/about-arrhythmia/tachycardia--fast-heart-rate
3. https://www.ahajournals.org/doi/10.1161/CIR.0000000000001193
4. https://www.heart.org/en/health-topics/arrhythmia/about-arrhythmia/ventricular-fibrillation
5. https://pubmed.ncbi.nlm.nih.gov/29097320/

2. European Society of Cardiology (ESC) Guidelines for the Management of Patients with Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death

1. https://pubmed.ncbi.nlm.nih.gov/36017572/
2. https://www.escardio.org/Guidelines/Clinical-Practice-Guidelines/Ventricular-Arrhythmias-and-the-Prevention-of-Sudden-Cardiac-Death
3. https://academic.oup.com/eurheartj/article/43/40/3997/6675633
4. https://pubmed.ncbi.nlm.nih.gov/26320108/
5. https://academic.oup.com/eurheartj/article/36/41/2793/2293363