Related Experiment Video
Updated: Jul 19, 2026

In Vivo Surface Electrocardiography for Adult Zebrafish
Published on: August 1, 2019
Wide QRS tachycardia: what is the rhythm?
Jonathan Rosman1, Joseph Tawil, Sam Hanon
1Beth Israel Medical Center, University Hospital and Manhattan Campus for the Albert Einstein College of Medicine, New York, NY 10003, USA. jrosman@bethisraelny.org
Abstract:
We report a case of an elderly man who presented to the emergency room complaining of palpitations. Electrocardiogram revealed wide QRS tachycardia with a narrow beat within the tachycardia. Most commonly, a narrow complex beat during a wide complex tachycardia suggests a capture or fusion beat in the setting of ventricular tachycardia. However, there are situations where supraventricular tachycardia can also manifest this way. In our patient a pacemaker interrogation clarified the diagnosis.
Related Concept Videos
Dysrhythmias III: Characteristics of Dysrhythmias
Dysrhythmias II: Classification of Tachyarrhythmias
Dysrhythmias IV: Characteristics of Bradyarrhythmias
Disturbances in Heart Rhythm
Arrhythmias are categorized by their speed, rhythm, and origin. A slow heart...
ECG Interpretation of Arrhythmias I: Sinus Arrhythmias
Types of Arrhythmias
Sinus Node Arrhythmias
Sinus Bradycardia: Originating from the sinoatrial (SA) node, sinus bradycardia involves slower impulses, resulting in a heart rate of less than 60 beats per minute (bpm). Causes include sleep, vagal stimulation, beta-blockers, hypothyroidism, and...
ECG Interpretation of Arrhythmias II: Atrial, Junctional and Ventricular Arrhythmias

