**Question:** The most common rhythm disturbance during early post-operative period is –

A. Atrial fibrillation
B. Ventricular tachycardia
C. Bradycardia
D. Ventricular fibrillation

**Core Concept:**
Understanding the common rhythm disturbances in the postoperative period is crucial for early diagnosis and management. These disturbances can be categorized into bradycardia, tachycardia, and asystole. Bradycardia is characterized by a heart rate below 60 beats per minute, while tachycardia refers to a heart rate above 100 beats per minute. Asystole is a complete absence of cardiac activity.

**Why the Correct Answer is Right:**
Atrial fibrillation (AF) is the most common rhythm disturbance following surgery, particularly in the early postoperative period. AF occurs when the atria quiver instead of contracting effectively, leading to an irregular heart rate. This can cause poor blood flow to vital organs and increase the risk of stroke and heart failure.

**Why Each Wrong Option is Incorrect:**
- Ventricular tachycardia (VT) is an inappropriate response to stress, and it is not the most common rhythm disturbance in the postoperative period. It is characterized by rapid ventricular contractions without a discernible P wave, which is not the case in atrial fibrillation.
- Ventricular fibrillation (VF) is a life-threatening cardiac arrest characterized by rapid, chaotic contractions of the ventricles. It is not the most common rhythm disturbance in the postoperative period.
- Bradycardia is a low heart rate, but it is not the most common rhythm disturbance in the postoperative period. Bradycardia can be caused by various factors, including anesthesia, pain, and hypothermia, but it is not the most common rhythm disturbance in this context.

**Clinical Pearl:**
Postoperative atrial fibrillation often resolves spontaneously without complications, and, in some cases, it may be managed with rate control using medications like beta-blockers or rate control agents like digoxin. In severe cases, electrical cardioversion or catheter ablation may be required. Early recognition and appropriate management of postoperative atrial fibrillation can significantly improve patient outcomes and reduce complications.