Non-Sustained Ventricular Tachycardia (NSVT)

Introduction

Non-Sustained Ventricular Tachycardia (NSVT) is a type of abnormal heart rhythm (arrhythmia) that originates from the ventricles and lasts less than 30 seconds. It consists of three or more consecutive ventricular beats at a rate of more than 100 beats per minute.

Causes and Risk Factors

NSVT can occur in people with and without structural heart disease. Some common causes include: - Coronary artery disease (CAD) – Affects blood supply to the heart muscle. - Cardiomyopathies – Conditions like hypertrophic cardiomyopathy, dilated cardiomyopathy, and arrhythmogenic right ventricular cardiomyopathy (ARVC). - Electrolyte imbalances – Low potassium, magnesium, or calcium levels. - Congenital heart conditions – Certain inherited syndromes like long QT syndrome or Brugada syndrome. - Medications and stimulants – Some prescription drugs and substances like caffeine or alcohol can trigger NSVT.

Symptoms

NSVT may be asymptomatic or cause symptoms such as: - Palpitations (feeling of rapid or skipping heartbeats) - Dizziness or lightheadedness - Shortness of breath - Chest discomfort - Syncope (fainting) in severe cases

Diagnosis

If NSVT is suspected, the following diagnostic tests may be performed: - Electrocardiogram (ECG) – Captures abnormal rhythms. - Holter or event monitor – Records heart activity over time. - Echocardiogram – Evaluates heart structure and function. - Cardiac MRI – Provides detailed imaging for structural abnormalities. - Stress test – Assesses arrhythmia occurrence during physical exertion. - Electrophysiological study (EPS) – Evaluates electrical pathways in the heart.

Treatment Options

Treatment depends on the underlying cause, presence of symptoms, and risk of sudden cardiac death:

1. Lifestyle Modifications

• Avoid stimulants (caffeine, alcohol, nicotine).
• Maintain electrolyte balance.
• Manage stress and avoid excessive exercise if advised.

2. Medications

• Beta-blockers (e.g., metoprolol) reduce arrhythmia episodes.
• Antiarrhythmic drugs in specific cases (e.g., amiodarone, sotalol).
• Electrolyte supplementation (potassium or magnesium if deficient).

3. Device Therapy

• Implantable Cardioverter Defibrillator (ICD) if there is a high risk of sudden cardiac arrest.

4. Catheter Ablation

• Used in cases of severe or recurrent NSVT caused by an identifiable abnormal focus in the heart.

Prognosis

The impact of NSVT varies depending on heart health. In healthy individuals, NSVT may be benign. However, in patients with structural heart disease, it can increase the risk of serious arrhythmias and require closer management.

Source recommendations

1. American Heart Association Guidelines for Management of 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://pubmed.ncbi.nlm.nih.gov/29097320/
5. https://www.sciencedirect.com/science/article/pii/S2405500X22010945

2. European Society of Cardiology Guidelines on Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death

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://www.ahajournals.org/doi/10.1161/CIR.0000000000000549
4. https://pubmed.ncbi.nlm.nih.gov/36017572/
5. https://www.sciencedirect.com/science/article/pii/S2405500X22010945