Electrophysiology Explained: From Resting Potential to Electrical Chaos

In this episode of Paging Dr. Samir, we take the next step from transport and gradients into electrophysiology—the rules that determine when cells fire, when they stay silent, and when electrical systems fail without warning. Dr. Samir breaks down resting membrane potential, thresholds, action potentials, repolarization, and refractory periods as clinical decision points rather than abstract waveforms.

Using real bedside scenarios including hyperkalemia, ischemia, wide-complex tachycardia, and sudden collapse, this episode explains why arrhythmias are usually symptoms of an unstable electrical substrate, not the primary problem. You’ll learn how electrolyte abnormalities, ischemia, and drugs alter ion channel availability, slow conduction, promote reentry, and create lethal instability.

This episode reframes electrophysiology as timing, recovery, and control—showing why calcium stabilizes membranes, why sodium channels matter more than heart rate, and why treating rhythm without fixing the substrate can make things worse. If electrophysiology has ever felt intimidating, this episode makes it predictable, usable, and clinically relevant.

Clinical electrophysiology explained through resting membrane potential, action potentials, ion channels, electrolytes, arrhythmias, and real bedside decision-making.