Lesional tachycardias related to mitral valve surgery.
OBJECTIVE
The purpose of this study was to define the anatomic distribution of electrically abnormal atrial tissue and mechanisms of atrial tachycardia (AT) after mitral valve (MV) surgery.


BACKGROUND
Atrial tachycardia is a well-recognized long-term complication of MV surgery. Because atrial incisions from repair of congenital heart defects provide a substrate for re-entrant arrhythmias in the late postoperative setting, we hypothesized that atriotomies or cannulation sites during MV surgery also contributed to postoperative arrhythmias.


METHODS
In 10 patients with prior MV surgery, electroanatomic maps were constructed of 11 tachycardias (6 right atrium [RA], 4 left atrium [LA] and 1 biatrial). Activation and voltage maps were used to identify areas of low voltage, double potentials and conduction block.


RESULTS
Lesions were present in the lateral wall of the RA (six of seven maps) and in the LA along the septum adjacent to the right pulmonary veins (four of five maps). In 8 of 10 patients, these findings corresponded to atrial incisions or cannulation sites. Arrhythmia mechanisms were identified for 9 of 11 tachycardias. A macro-re-entrant circuit was mapped in six cases, three involving lesions in the lateral wall of the RA and three involving the LA septum and right pulmonary veins. In three of these cases figure-of-eight re-entry was demonstrated, and in the other three a single macro-re-entrant circuit was observed. In three other cases, a focal origin was identified adjacent to abnormal tissue in the RA (two cases) or within a pulmonary vein (one case).


CONCLUSIONS
Surgical incisions for MV surgery provide a substrate for atrial arrhythmias. Both macro-re-entrant and focal mechanisms contribute to AT after MV surgery.
Markowitz
Steven M
SM
Division of Cardiology, The New York Hospital-Cornell University Medical Center, New York, New York 10021, USA.
Brodman
Richard F
RF
Stein
Kenneth M
KM
Mittal
Suneet
S
Slotwiner
David J
DJ
Iwai
Sei
S
Das
Mithilesh K
MK
Lerman
Bruce B
BB
D000368:Aged; D018780:Body Surface Potential Mapping; D006348:Cardiac Surgical Procedures / Q000009:adverse effects* / Q000379:methods; D017115:Catheter Ablation; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006325:Heart Atria / Q000503:physiopathology; D006329:Heart Conduction System / Q000503:physiopathology; D006349:Heart Valve Diseases / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000601:surgery*; D013610:Tachycardia / Q000209:etiology* / Q000503:physiopathology*