Vol. 42 | No. 1 Supplement | January-June 2014 Suppl. Back

Open Access

Inducible Focal Atrial Tachycardia of Coronary Sinus Origin Masquerading as Ventricular Tachycardia

Edgar Wilson G. Timbol, Giselle G. Gervacio
Jun 2014 DOI 10.69944/pjc.6b3817b183

Abstract

CASE: This is the case of a 35-year old male physician presenting with a 12-year history of palpitations despite oral metoprolol. He had reversible left hemiparesis with right hemispheric lacunar infarctions on computerized tomography scan. The 12-lead electrocardiogram (ECG) recorded during an episode of palpitations revealed wide QRS (0.16 s) tachycardia (heart rate=214 beats per minute) with left bundle branch block (LBBB) QRS morphology; no identifiable P waves; QS pattern in leads V1 to V4; RS pattern in leads V5 and V6; and a QRS axis at -1300. There were no AV dissociation; fusion and captured beats; and precordial QRS concordance. Electrophysiology studies (EPS) were performed. During programmed electrical stimulation (PES) at the right ventricular apex, sustained narrow QRS (0.10 s) tachycardia (168 bpm) was induced. Examination of the intracardiac atrial (A) and ventricular (V) electrograms during the tachycardia revealed a 1:1 AV relationship; closer A electrogram to the preceding A electrogram than the following V electrogram producing a short RP tachycardia (<70 ms); variable VA intervals; VAAV response during ventricular overdrive maneuver, and termination of the tachycardia at the V electrogram. The above EP parameters favored a diagnosis of focal atrial tachycardia (FAT) over re-entrant supraventricular tachycardia (SVT). The earliest activation site of the induced SVT was recorded near the ostium of the coronary sinus (CS 9 and 10) which coincided with the findings on 3D mapping. 

DIAGNOSIS:  FAT with acceleration-dependent functional LBBB based on a mechanism of triggered automaticity arising from the coronary sinus ostium. 

TREATMENT AND OUTCOME: Radiofrequency ablation was applied on the identified arrhythymogenic atrial focus and effectively restored sinus rhythm and rendered the FAT non-inducible.

References
  1. Bonow RO, Mann DL, Zipes DP, Libby P. Braunwald’s Heart Disease: A Textbook of Cardiovascular Medicine, 2011
  2. Bhima Shankar PR, Muralidharan TR. Succesful Radiofrequency Ablation of Atrial Tachycardia Arising From Within the Coronary Venous Sinus. Indian Pacing Electrophysiol J 2010;10:228-232.
  3. Pekka Raatikainen MJ, Huikuri HV. Successful catheter ablation of focal atrial tachycardia from the non-coronary aortic cusp. Europace 2007;9:216–219. 
  4. Blomström-Lundqvist C, Scheinman MM. ACC/AHA/ESC guidelines for the management of patients with supraventricular arrhythmias developed in collaboration with NASPE-Heart Rhythm Society. J Am Coll Cardiol 2003;42:1493-531. 
  5. Zipes DP, Douglas P. Atrial Fibrillation: A tachycardia-induced Atrial Cardiomyopathy. Circulation 1997;95:572-576. 
  6. Medi C. Tachycardia-Mediated Cardiomyopathy Secondary to Focal Atrial Tachycardia: Long-Term Outcome After Catheter Ablation. J Am Coll Cardiol 2009;53:1791-1797.
License

Open Access This article is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License, which permits use, share — copy and redistribute the material in any medium or format, adapt — remix, transform, and build upon the material, as long as you give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use. You may not use the material for commercial purposes. If you remix, transform, or build upon the material, you must distribute your contributions under the same license as the original. You may not apply legal terms or technological measures that legally restrict others from doing anything the license permits. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit https://creativecommons.org/licenses/by-nc-sa/4.0/.