Related Experiment Video
Updated: Jun 20, 2026

Non-fluoroscopic Catheter Tracking for Fluoroscopy Reduction in Interventional Electrophysiology
Published on: May 26, 2015
2:1 left to right interatrial block and other effects of ibutilide during non-isthmus-dependent atrial flutter
Peter E Zambito1, Eugen C Palma
1Arrhythmia Service, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, New York 10461, USA.
Abstract:
The effects of ibutilide on non-isthmus-dependent atrial flutter (NIDAFL) and the left atrium are not completely known. We describe a case report of 2:1 left to right interatrial block as a result of ibutilide during NIDAFL. This is a 68-year-old man with history of right atrial flutter ablation who presented with recurrence of atrial flutter and underwent a diagnostic electrophysiology study. A 20-pole catheter with 2-10-mm spacing was used spanning the cavotricuspid isthmus to the midcoronary sinus. Morphology of the flutter waves and atrial activation sequence was recorded. Ibutilide was given to terminate the atrial flutter. During administration, 2:1 left-to-right interatrial block was seen. In addition, the cycle length of the flutter prolonged, yet the activation sequence did not change. Ibutilide terminated the flutter. During sinus rhythm, interatrial block was not seen. This case report illustrates an example of 2:1 left to right interatrial conduction block because of ibutilide during a non-isthmus-dependent atrial flutter.
Related Concept Videos
Dysrhythmias IV: Characteristics of Bradyarrhythmias
Antiarrhythmic Drugs: Class III Agents as Potassium Channel Blockers
ECG Interpretation of Arrhythmias II: Atrial, Junctional and Ventricular Arrhythmias
Antiarrhythmic Drugs: Class II Agents as β-Adrenergic Blockers
Antiarrhythmic Drugs: Class IV Agents as Calcium Channel Blockers
Verapamil, a calcium channel blocker, inhibits calcium movement across myocardial cell membranes and vascular smooth muscle. This results in the dilation of coronary and...
Disturbances in Heart Rhythm
Arrhythmias are categorized by their speed, rhythm, and origin. A slow heart...

