Ventricular Fibrillation vs Ventricular Tachycardia

Introduction

Ventricular fibrillation (VF) and ventricular tachycardia (VT) are life-threatening heart rhythm disorders that originate in the ventricles of the heart. Both conditions cause the heart to beat abnormally, reducing the heart’s ability to pump blood effectively. However, they have distinct characteristics, causes, and treatments.

What is Ventricular Tachycardia (VT)?

Ventricular tachycardia is a fast but organized heart rhythm that originates in the ventricles. It is defined as a heart rate greater than 100 beats per minute and can be sustained (lasting more than 30 seconds) or non-sustained (shorter episodes).

Causes of VT:

• Coronary artery disease (CAD)
• Previous heart attack (myocardial infarction)
• Structural heart disease (e.g., cardiomyopathy)
• Electrolyte imbalances (e.g., low potassium or magnesium)
• Side effects of certain medications

Symptoms of VT:

• Palpitations
• Dizziness or fainting
• Shortness of breath
• Chest pain
• Cardiac arrest in severe cases

Treatment for VT:

• Stable VT: Managed with antiarrhythmic drugs (e.g., amiodarone, lidocaine) or electrical cardioversion.
• Unstable VT: Requires immediate electrical cardioversion or defibrillation.
• Recurrent VT: May require an implantable cardioverter-defibrillator (ICD) or catheter ablation.

What is Ventricular Fibrillation (VF)?

Ventricular fibrillation is a chaotic and disorganized electrical activity in the ventricles, leading to ineffective heart contractions and no significant blood flow. Without rapid intervention, VF leads to sudden cardiac death.

Causes of VF:

• Acute myocardial infarction (heart attack)
• Severe electrolyte imbalances
• Drug toxicity (e.g., cocaine, methamphetamine)
• Electric shock
• Severe heart failure

Symptoms of VF:

• Sudden loss of consciousness (fainting)
• No pulse or breathing
• Cyanosis (bluish skin discoloration)
• Death within minutes if untreated

Treatment for VF:

• Immediate defibrillation is the most effective treatment.
• CPR (cardiopulmonary resuscitation) until defibrillation is available.
• Advanced cardiac life support (ACLS) including epinephrine and amiodarone.
• Implantable cardioverter-defibrillator (ICD) for prevention in high-risk patients.

Key Differences Between VT and VF:

Conclusion

VT and VF are serious conditions requiring rapid intervention. While VT can sometimes be stable and treated with medications, VF requires immediate defibrillation to prevent sudden cardiac death. If you or someone you know has risk factors for these conditions, seeking medical attention and following preventive strategies such as ICD implantation and medication management may be life-saving.

Source recommendations

1. American Heart Association 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://cpr.heart.org/en/resuscitation-science/cpr-and-ecc-guidelines/algorithms
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 Guidelines on 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://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