PR interval in ECG denotes: (A) Isovolumetric contraction of ventricle, (B) Insovolumetric relaxation of heart, (C) Atrial contraction, (D) None
Answer is C. Ans. (c) Atrial contractionRef: Ganong, 25th ed/p.525PR interval#From the onset of P wave to the beginning of QRS complex#Duration - 0.12 to 0.20 sec#Denotes atrial contraction and Atrioventricular (AV) conduction time