Ventricular Tachycardia (VT)

Introduction

Ventricular tachycardia (VT) is a fast and potentially life-threatening heart rhythm that originates from the ventricles. It is characterized by a heart rate of more than 100 beats per minute and often presents in patients with underlying heart disease.

Causes

VT can be triggered by several conditions, including:

• Coronary artery disease (CAD) – Reduced blood flow to the heart muscle.
• Previous myocardial infarction (heart attack) – Scar tissue formation can lead to abnormal electrical signals.
• Cardiomyopathies – Structural disorders of the heart muscle.
• Electrolyte imbalances – Low levels of potassium or magnesium can predispose to VT.
• Medication side effects – Certain drugs, including some antiarrhythmic medications, can induce VT.
• Inherited arrhythmia syndromes – Conditions like Long QT syndrome or Brugada syndrome can lead to VT episodes.

Symptoms

The symptoms of VT vary depending on its duration and the person’s underlying health:

• Palpitations (fast, pounding sensation in the chest)
• Dizziness or lightheadedness
• Shortness of breath
• Chest pain
• Loss of consciousness (syncope) – Prolonged VT can result in fainting due to insufficient blood flow.
• Cardiac arrest – In some cases, VT can degenerate into ventricular fibrillation, leading to sudden cardiac death.

Diagnosis

VT is diagnosed using:

• Electrocardiogram (ECG) – VT is identified by a wide QRS complex tachycardia (>120 ms).
• Holter monitoring – A portable ECG device used to capture intermittent arrhythmias.
• Echocardiography – To assess structural heart disease.
• Electrophysiology study (EPS) – To map abnormal electrical pathways in the heart.
• Blood tests – To check for electrolyte imbalances or heart disease markers.

Treatment

Treatment depends on the urgency and the underlying cause of VT:

Acute Treatment (for life-threatening VT episodes)

• Cardioversion (electric shock therapy) – Used if the patient is unstable.
• IV antiarrhythmic drugs – Medications such as amiodarone or lidocaine can terminate VT.

Chronic Treatment (Long-Term Management)

• Beta-blockers – Reduce episodes of VT in certain conditions.
• Implantable Cardioverter Defibrillator (ICD) – A device implanted in high-risk patients to detect and stop VT.
• Catheter ablation – A minimally invasive procedure to remove abnormal electrical pathways.
• Lifestyle modifications – Proper electrolyte management, avoiding triggers, and controlling conditions like hypertension and diabetes.

Conclusion

VT is a serious condition that requires timely diagnosis and appropriate management. Patients with heart conditions should undergo regular check-ups to minimize the risk of life-threatening arrhythmias.

Further Reading

For professional guidance, refer to the following clinical guidelines:

Source recommendations

1. American Heart Association (AHA) Guidelines for the Management of Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death

1. https://www.ahajournals.org/doi/10.1161/CIR.0000000000000549
2. https://pubmed.ncbi.nlm.nih.gov/29097320/
3. https://www.sciencedirect.com/science/article/pii/S2405500X22010945
4. https://pubmed.ncbi.nlm.nih.gov/29084733/
5. https://www.hrsonline.org/guidance/clinical-resources/2017-ahaacchrs-guideline-management-patients-ventricular-arrhythmias-and-prevention-sudden-cardiac

2. European Society of Cardiology (ESC) Guidelines for the Management of Patients with Ventricular Arrhythmias

1. https://www.escardio.org/Guidelines/Clinical-Practice-Guidelines/Ventricular-Arrhythmias-and-the-Prevention-of-Sudden-Cardiac-Death
2. https://academic.oup.com/eurheartj/article/43/40/3997/6675633
3. https://pubmed.ncbi.nlm.nih.gov/36017572/
4. https://www.acc.org/Latest-in-Cardiology/ten-points-to-remember/2022/09/02/14/23/2022-ESC-Guidelines-for-VAs-ESC-2022
5. https://pubmed.ncbi.nlm.nih.gov/26320108/