Pouched mitral isthmus is associated with incomplete linear block in atrial fibrillation patients with mechanical mitral valve replacement.
BACKGROUND
Previous studies have described the impact of mitral isthmus (MI) anatomy on the likelihood of achieving MI linear block in patients with native mitral valves (NMV) who underwent atrial fibrillation (AF) ablation. However, none have investigated that issue in AF patients with mechanical mitral valve replacements (MMVR).


RESULTS
Twenty-nine consecutive patients who developed symptomatic persistent AF post-MMVR and referred for ablation were enrolled. Twenty-nine patients with NMV who underwent ablation of persistent AF during the same period were matched. With preprocedural cardiac computed tomographic imaging, MI anatomical features of all the participants were analyzed. Pouched MI was observed in 19 (65.5%) MMVR patients versus to 6 (20.7%) controls (P = 0.001). Bidirectional linear block across MI was achieved in 21 (72.4%) MMVR patients and 22 (75.9%) in the controls (P = 0.764). In the multivariable analysis, pouched MI was an independent predictor of incomplete MI block.


CONCLUSIONS
Pouched MI accounts for the majority of AF patients with MMVR and may be associated with incomplete bidirectional linear block of MI.
Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China.
Wen-Ning
WN
Deng
Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China.|Department of Cardiology, Henan Provincial People's Hospital, Zhengzhou, Henan, China.
K E
KE
Chen
Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China.
Rong
R
Bai
Department of Cardiology, Shanxi Dayi Hospital, Taiyuan, Shanxi, China.
Zhi-Jun
ZJ
Zhang
Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China.
Song-Nan
SN
Li
Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China.
Zhao-Ying
ZY
Wen
Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China.
Chen
C
Zhang
Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China.
Rong-Hui
RH
Yu
Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China.
De-Yong
DY
Long
Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China.
Ri-Bo
RB
Tang
Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China.
Cai-Hua
CH
Sang
Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China.
Nian
N
Liu
Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China.
Xue-Yuan
XY
Guo
Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China.
Xiao-Yan
XY
Wu
Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China.
Jun-Gang
JG
Nie
Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China.
Xin
X
Du
Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China.
Jian-Zeng
JZ
Dong
Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China.
Chang-Sheng
CS
Ma
D000368:Aged; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology / Q000601:surgery*; D016022:Case-Control Studies; D017115:Catheter Ablation; D016009:Chi-Square Distribution; D018572:Disease-Free Survival; D005260:Female; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects* / Q000295:instrumentation*; D006801:Humans; D053208:Kaplan-Meier Estimate; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D061330:Multidetector Computed Tomography; D015999:Multivariate Analysis; D011446:Prospective Studies; D011474:Prosthesis Design; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome
atrial fibrillation; catheter ablation; left atrial flutter; mechanical mitral valve; mitral isthmus