Overview of First and Second-Degree Atrioventricular (AV) Block Core Characteristics · 1st-Degree: Fixed PR >200ms; 1:1 conduction. · Mobitz I: PR lengthens → QRS drop. · Mobitz II: Fixed PR; sudden QRS drop. Clinical Significance · 1st-Degree & Mobitz I: Often benign; monitor. · Mobitz II: Infranodal; high-risk for progression → pacemaker assessment. #AVBlock #HeartBlock #Cardiology #ECG #EKG #MedEd #MedicalEducation #CardioEd #HeartRhythm #Wenckebach #Mobitz | Abdallah Othman

First-Degree AV Block:🔍 A fixed delay in conduction at the AV node. Not a blockage, but a slowdown. 🔹 Diagnostic ECG Criteria ▸PR Interval: >200 ms (≥ 1 large box). ▸Rhythm: Regular sinus. ▸Conduction: 1:1 (Every P → QRS). ▸Constancy: Fixed PR interval. 💡 Clinical Pearls ▸Often Benign: Asymptomatic; common with high vagal tone, athletes, or medications (BB, NDHP-CCB, digoxin). ▸Context Matters: Assess for underlying heart disease, ischemia, or electrolytes. New onset in acute settings require

First Degree AV Block - EKG (ECG) Interpretation