How to Recognize Tachycardia Rhythms | AHA ACLS 2025 | ECG Interpretation

Can you distinguish the major tachycardia rhythms seen in ACLS? In this episode of The Healthcare Simulationist, we use clear ECG tracings, interval measurements, and interactive visual highlights to recognize six important tachycardia patterns based on the 2025 AHA ACLS framework. Rather than memorizing ECG pictures, we use a systematic approach: Rate → Regular or irregular → Narrow or wide QRS → P waves or atrial activity → Relationship to the QRS In this episode, we cover: Sinus Tachycardia A fast, regular sinus rhythm with a clear P wave before every QRS and a constant PR interval. Regular Narrow-Complex Tachycardia A rapid, regular rhythm with narrow QRS complexes. P waves may be difficult to identify, hidden within the QRS or T wave, or appear differently from normal sinus P waves. Atrial Fibrillation with Rapid Ventricular Response No organized P waves and continuously changing R-R intervals—the classic irregularly irregular rhythm. Atrial Flutter Organized repetitive atrial activity with characteristic flutter waves. The video demonstrates a clear 2:1 conduction example and highlights the flutter waves directly on the ECG. Monomorphic Ventricular Tachycardia A fast, wide-complex rhythm with essentially the same QRS morphology from beat to beat. Remember: Wide + Fast + Regular + Uniform Polymorphic Ventricular Tachycardia A wide, rapid ventricular rhythm in which the QRS morphology changes from beat to beat. Remember: Monomorphic = one repeated morphology Polymorphic = changing morphology The 2025 AHA ACLS approach uses a QRS duration of 0.12 second or greater when identifying a wide-complex tachycardia. ━━━━━━━━━━━━━━━━━━━━ CHAPTERS 00:00 Introduction — How to Approach Tachycardia 00:18 Sinus Tachycardia 01:20 Regular Narrow-Complex Tachycardia 02:10 Atrial Fibrillation with RVR 02:52 Atrial Flutter 03:40 Monomorphic Ventricular Tachycardia 04:35 Polymorphic Ventricular Tachycardia 05:12 Six-Rhythm Review 06:32 Subscribe • Like • Comment ━━━━━━━━━━━━━━━━━━━━ REFERENCES American Heart Association. (2025). Advanced Cardiovascular Life Support Precourse Self-Assessment: Rhythm Identification. American Heart Association. (2025). Adult Tachyarrhythmia With a Pulse Algorithm. American Heart Association. (2025). 2025 Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care: Adult Advanced Life Support. ━━━━━━━━━━━━━━━━━━━━ EDUCATIONAL DISCLAIMER This video is intended for healthcare education and ECG rhythm-recognition practice. It does not replace formal ACLS training, institutional protocols, clinical judgment, or official American Heart Association course materials. The Healthcare Simulationist is an independent educational channel and is not affiliated with or endorsed by the American Heart Association. If this episode helped you understand tachycardia rhythms, please LIKE, COMMENT, SHARE, and SUBSCRIBE for more ECG, ACLS, and healthcare simulation content. The Healthcare Simulationist Making healthcare education visual, practical, and memorable. #ACLS #Tachycardia #ECG #AHA2025 #ECGInterpretation The AHA’s current precourse rhythm material includes sinus tachycardia, narrow-complex tachycardia, atrial fibrillation, atrial flutter, monomorphic VT, and polymorphic VT among the rhythms ACLS learners should recognize.