(FIT)-Module 1, Workshop 1: Electrocardiographic/Electrophysiologic Correlation-Tomaselli Case 5 Answer

Video Transcription

Video Summary

The correct answer, B, highlights adenosine's activation of A1 receptors and its cardiac effects. Adenosine makes the maximal diastolic potential more negative, slows phase IV diastolic depolarization, and shortens the action potential duration. Unlike other agents like ranolazine or amiodarone, adenosine has direct effects via G-protein coupled receptors and opens potassium channels, causing hyperpolarization and reduced action potential duration. It also exhibits anti-adrenergic effects, inhibiting calcium currents to shorten atrial action potentials. Adenosine’s effects can be potentiated by dipyridamole or inhibited by methylxanthines, requiring careful consideration during administration.

Keywords

adenosine

A1 receptors

cardiac effects

action potential

G-protein coupled receptors