Reentry EXPLAINED: Electrophysiology, Mechanisms & Unidirectional Block (Beginner’s Guide)

⚡ Reentry Arrhythmias: Electrophysiology, Mechanisms & Unidirectional Block Explained Reentry is a key mechanism of many cardiac arrhythmias, including AVNRT, AVRT, atrial flutter, and ventricular tachycardia. But what exactly causes reentrant circuits, and how do factors like unidirectional block and excitable gap contribute? In this video, we break down the electrophysiology of reentry arrhythmias, covering anatomical and functional reentry mechanisms, and discuss their clinical significance for medical students, USMLE prep, and cardiology professionals. What You’ll Learn in This Video: ✔️ What is Reentry? Electrophysiological basis of arrhythmias ✔️ Anatomical vs. Functional Reentry: Key differences and clinical examples ✔️ Unidirectional Block & Excitable Gap: How they enable reentrant circuits ✔️ Common Reentrant Arrhythmias: AVNRT, AVRT, Atrial Flutter, WPW Syndrome ✔️ Antiarrhythmic Drugs & Reentry: Class I & III drug effects on refractory periods ✔️ High-yield mnemonics & USMLE exam pearls ⏰ Timestamps for Easy Navigation: 00:00 Introduction 00:25 Normal impulse propagation 01:25 Reentry ring model 02:05 3 basic electrophysiological properties. Unidirectional block. 03:21 Wavelength and excitable gap 06:28 Slow conduction 09:02 Impedance match 09:17 Safety factor for conduction 12:39 Post-repolarization refractoriness 14:34 Anisotropic conduction (uniform and non-uniform) 17:02 Unidirectional conduction block types 19:39 Premature contraction as requirement for reentry initiation 23:46 Recovery of excitability in reentry circuit (Effective refractory period) 24:41 Reentry classification (anatomical and functional) 25:44 Leading circle reentry 💡 Engage With Us: Question for You: Which reentrant arrhythmia do you find most difficult to understand? Drop your thoughts in the comments! Don’t forget to like 👍 this video, subscribe 🔔 to the channel, and share this with fellow students & professionals! Our telegram channel with ECG and other useful stuff https://t.me/foxterRier_med #usmle #step1 #step2 #medicine #pathology #physiology #education #medicalschool #pharmacology #biochemistry #highyield #lab #ecg #cardiology #cardiology #electrophysiology #reentry #unidirectional block#anisotropy