From the Guidelines
Sustained ventricular (V) tachycardia (VT) is defined as a life-threatening arrhythmia characterized by a rapid, abnormal heart rhythm originating in the ventricles, with a duration of more than 30 seconds or requiring termination due to hemodynamic compromise in less than 30 seconds 1.
Key Characteristics
- A heart rate exceeding 100 bpm (cycle length less than 600 ms)
- Three or more consecutive complexes in duration emanating from the ventricles
- Can be further classified as monomorphic or polymorphic based on the QRS morphology 1.
Clinical Considerations
In clinical practice, sustained VT is often treated with anti-arrhythmic medications and may require cardioversion or defibrillation if the patient is hemodynamically unstable.
- The classification of VT is crucial in determining the appropriate treatment approach, with sustained VT requiring prompt attention to prevent serious complications 1.
- A thorough understanding of the definition and characteristics of sustained VT is essential for accurate diagnosis and effective management in real-life clinical practice.
From the FDA Drug Label
1 INDICATIONS & USAGE Amiodarone hydrochloride injection is indicated for initiation of treatment and prophylaxis of frequently recurring ventricular fibrillation (VF) and hemodynamically unstable ventricular tachycardia (VT) in patients refractory to other therapy.
The definition of sustained ventricular (V) tachycardia (VT) is not explicitly provided in the drug labels.
- The labels mention hemodynamically unstable ventricular tachycardia (VT), but do not define sustained VT.
- The labels also mention recurrent VT, but do not provide a definition for sustained VT 2, 2. The FDA drug label does not answer the question.
From the Research
Definition of Sustained Ventricular Tachycardia
- Sustained ventricular tachycardia (VT) is a potentially life-threatening arrhythmia characterized by a ventricular rhythm with a QRS >120 milliseconds (ms) and >100 beats-per-minute (BPM) in the absence of an aberrant conduction 3.
- It is classified as sustained when lasting >30 seconds 3, 4.
- The term "sustained" implies a duration of over 30 seconds or poor haemodynamic tolerance 4.
Key Characteristics
- Ventricular tachycardia is a ventricular rhythm with a rapid heart rate 3.
- It can be monomorphic or polymorphic, and can be caused by various factors such as coronary artery disease, cardiomyopathy, or electrical abnormalities in the heart 5, 6, 7.
- Sustained VT can lead to hemodynamic instability and even cardiac arrest if left untreated 5, 6, 7.