QTc Interval Prolongation Predicts Arrhythmia Recurrence After Catheter Ablation of Atrial Fibrillation in Patients With Hypertrophic Cardiomyopathy.
BACKGROUND
In hypertrophic cardiomyopathy (HCM) patients complicated with atrial fibrillation (AF), catheter ablation has been recommended as a treatment option. Meanwhile, prolongation of QTc interval has been linked to an increased AF incidence in the general population and to poor outcomes in HCM patients. However, whether QTc prolongation predicts arrhythmia recurrence after AF ablation in the HCM population remains unknown.


RESULTS
Thirty-nine HCM patients undergoing primary AF ablation were enrolled. The ablation strategy included bilateral pulmonary vein isolation (PVI) for paroxysmal AF (n=27) and PVI plus left atrial roof, mitral isthmus and tricuspid isthmus linear ablations for persistent AF (n=12). Pre-procedural QTc was corrected by using the Bazett's formula. At a 14.8-month follow up, 23 patients experienced atrial tachyarrhythmia recurrence. Recurrent patients had longer QTc than non-recurrent patients (461.0±28.8 ms vs. 434.3±18.2 ms, P=0.002). QTc and left atrial diameter (LAD) were independent predictors of recurrence. The cut-off value of QTc 448 ms predicted arrhythmia recurrence with a sensitivity of 73.9% and a specificity of 81.2%. A combination of LAD and QTc (global chi-squared=13.209) was better than LAD alone (global chi-squared=6.888) or QTc alone (global chi-squared=8.977) in predicting arrhythmia recurrence after AF ablation in HCM patients.


CONCLUSIONS
QTc prolongation is an independent predictor of arrhythmia recurrence in HCM patients undergoing AF ablation, and might be useful for identifying those patients likely to have a better outcome following the procedure.
Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University.
Song-Nan
SN
Wen
Nian
N
Liu
Song-Nan
SN
Li
Xiao-Yan
XY
Wu
Mohamed
M
Salim
Jun-Ping
JP
Kang
Man
M
Ning
Jia-Hui
JH
Wu
Yan-Fei
YF
Ruan
Rong-Hui
RH
Yu
De-Yong
DY
Long
Ri-Bo
RB
Tang
Cai-Hua
CH
Sang
Chen-Xi
CX
Jiang
Rong
R
Bai
Xin
X
Du
Jian-Zeng
JZ
Dong
Xiao-Hui
XH
Liu
Chang-Sheng
CS
Ma
D000328:Adult; D000368:Aged; D001281:Atrial Fibrillation / Q000453:epidemiology / Q000503:physiopathology / Q000601:surgery; D002312:Cardiomyopathy, Hypertrophic / Q000453:epidemiology / Q000503:physiopathology / Q000601:surgery; D017115:Catheter Ablation; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012008:Recurrence; D013610:Tachycardia / Q000453:epidemiology / Q000209:etiology / Q000503:physiopathology