**Question:** ECG features of Athlete's Heart include all of the following except-

A. Increased P waves
B. Increased QRS duration
C. Wide QRS complex
D. Flattened T waves

**Core Concept:** Athlete's Heart is a physiological cardiac adaptation to regular physical exercise, characterized by structural and functional changes. The electrocardiogram (ECG) can show specific changes reflecting these adaptations.

**Why the Correct Answer is Right:** The correct answer (D) is "Flattened T waves" because flattened T waves are not a typical ECG finding in athletes. Flattened T waves are usually associated with ischemia or hypokalemia, conditions that are less likely in an athlete with a normal exercise capacity.

**Why Each Wrong Option is Incorrect:**

A. Increased P waves (Option A) are typically observed in conditions like pulmonary hypertension, atrial enlargement, or atrial fibrosis, which are uncommon in athletes due to their exercise-induced adaptation.

B. Increased QRS duration (Option B) is seen in conditions like first-degree atrioventricular block, prolonged QT interval, or conduction abnormalities. These are less likely in athletes due to their adaptations from regular exercise.

C. Wide QRS complex (Option C) is commonly seen in conditions like bundle branch block, conduction abnormalities, or hypertrophic cardiomyopathy. These are less likely in athletes due to their exercise-induced adaptations.

**Clinical Pearl:**

Understanding ECG changes in Athlete's Heart helps differentiate between physiological adaptations and pathologic conditions. It is essential for diagnosing and managing athletes with ECG abnormalities, ensuring appropriate treatment and preventing misdiagnosis of potentially life-threatening cardiac conditions.

**Correct Answer:** D. Flattened T waves