Atrial macroreentry tachycardia in patients without obvious structural heart disease or previous cardiac surgical or catheter intervention: characterization of arrhythmogenic substrates, reentry circuits, and results of catheter ablation.
BACKGROUND
Atrial macroreentry tachycardia (AMRT) in patients without obvious structural heart disease or previous surgical or catheter intervention has not been characterized in detail.


RESULTS
Electroanatomical mapping and ablation of right or left AMRT were performed in 33 patients. Right atrial central conduction obstacle was formed by an electrically silent area (ESA) in 15 (68%) patients and by a line of double potentials (DPs) in seven (32%) patients. Left atrial ESAs were found in all 11 patients with the left AMRT. Reentry circuit was reconstructed in 19 (86%) patients with right AMRT and seven (64%) patients with left AMRT. Of the ESA-related right AMRT, eight (50%) were double-loop reentry circuits utilizing a narrow critical isthmus within the ESA and eight (50%) were single-loop reentry circuits with a critical isthmus bounded by ESA and either ostium of the vena cava. Single-loop DP-related AMRTs had the critical isthmus between the DP line and the ostium of the inferior vena cava (IVC). Left AMRTs included a variety of single-, double-, or triple-loop reentry circuits and their critical isthmuses. During the 37 +/- 15 month follow-up, atrial tachyarrhythmia-free clinical outcome was achieved in 21 (95%) patients (18 patients, 82%, without antiarrhythmic drugs) with the right AMRT and in nine (82%) patients (six patients, 55%, without antiarrhythmic drugs) with the left AMRT.


CONCLUSIONS
The majority of right and left AMRTs were related to the presence of ESA. Ablation can be successful with a favorable risk of atrial tachyarrhythmia recurrence.
Fiala
Martin
M
Department of Cardiology, Heart Center, Hospital Podlesí a.s., Trinec, Czech Republic. martin.fiala@nempodlesi.cz
Chovancík
Jan
J
Neuwirth
Radek
R
Nevralová
Renáta
R
Jiravský
Otakar
O
Sknouril
Libor
L
Dorda
Miloslav
M
Januska
Jaroslav
J
Vodzinská
Alexandra
A
Cerný
Jindrich
J
Nykl
Igor
I
Branny
Marian
M
D000368:Aged; D018780:Body Surface Potential Mapping; D006328:Cardiac Catheterization; D017115:Catheter Ablation; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology* / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D013612:Tachycardia, Ectopic Atrial / Q000150:complications / Q000503:physiopathology* / Q000601:surgery*; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000150:complications / Q000503:physiopathology