Ventricular Tachycardia is represented by all, Except:
**Ventricular Tachycardia (VT) Core Concept**
Ventricular tachycardia is a life-threatening cardiac arrhythmia characterized by a rapid heart rate originating from the ventricles. It often results from abnormal electrical activity in the heart, disrupting the normal sequence of ventricular depolarization.
**Why the Correct Answer is Right**
Ventricular tachycardia is typically represented by a heart rate of more than 100 beats per minute, with a narrow QRS complex on an electrocardiogram (ECG). The arrhythmia often presents with a regular rhythm and a rate that is usually between 150-250 beats per minute. The underlying mechanism involves re-entry circuits within the ventricles, leading to a sustained and potentially fatal arrhythmia.
**Why Each Wrong Option is Incorrect**
**Option A:**
This option is incorrect as it is not a characteristic of ventricular tachycardia. Atrioventricular (AV) dissociation occurs when the atria and ventricles beat independently, often seen in ventricular fibrillation or pulseless electrical activity.
**Option B:**
This option is incorrect as it is a characteristic of ventricular fibrillation, not ventricular tachycardia. Ventricular fibrillation is a chaotic and disorganized electrical activity in the ventricles, often resulting in a pulseless and unresponsive patient.
**Option C:**
This option is incorrect as it is not a characteristic of ventricular tachycardia. A wide QRS complex is typically seen in ventricular fibrillation, ventricular tachycardia with a left bundle branch block, or pre-excitation syndromes such as Wolff-Parkinson-White syndrome.
**Clinical Pearl / High-Yield Fact**
It is essential to differentiate ventricular tachycardia from ventricular fibrillation as the management strategies differ. Ventricular tachycardia can be treated with cardioversion or medications, whereas ventricular fibrillation requires immediate defibrillation.
**Correct Answer: D.**