ECG of normal sinus RYTHHMS -- On an ECG, a normal sinus rhythm is characterized by a heart rate between 60-100 bpm, a regular rhythm, a P wave preceding each QRS complex, and a normal PR interval. •Rhythm: The heart beats regularly, with consistent intervals between each beat. •Heart Rate: The heart rate falls within the normal range of 60 to 100 beats per minute (bpm). •P Wave: A P wave should be present before each QRS complex. The P wave should be upright in leads I and II, and inverted in l

Sinus Rhythm & Core Variations · Normal Sinus Rhythm (NSR): The physiological standard. Regular rhythm (60-100 bpm), with a normal P wave preceding each narrow QRS complex. · Sinus Tachycardia: >100 bpm. A normal physiological response to demand (e.g., exercise) or a sign of pathology (e.g., fever, anemia). · Sinus Bradycardia: