system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
Mechanism of action of epinephrine in cardiopulmonary resuscitation is -
assistant
The correct answer is  Ans. is 'b i.e., Increase S.A. node activity "Epinephrine speeds the hea by accelerating the slow depolarization of SA nodal cells that takes place during diastole, i.e., during phase 4 of the action potential. Consequently, the transmembrane potential of the pacemaker cells rises more rapidly to the threshold level of action potential initiation. The amplitude the action potential and the maximal rate of depolarization (phase 0) also are increased."