J-Shaped Association Between QTc Interval Duration and the Risk of Atrial Fibrillation

Abstract Background/Introduction The majority of beta thalassemia major (β-TM) patients suffer from cardiac disorders, while a significant proportion of them die suddenly. Twelve-lead and signal-averaged electrocardiography are simple, inexpensive, readily available tools for identifying an unfavorable arrhythmiological substrate by detecting the presence of arrhythmias, conduction abnormalities and late potentials (LPs) in these patients. Methods 47 β-TM patients and 30 healthy controls were submitted to twelve-lead and signal-averaged electrocardiography. Basal rhythm, heart rate, PR interval duration, QRS complex duration and morphology, QTc interval duration and prevalence of LPs were recorded. Results β-TM patients demonstrated a more prolonged PR segment (167.74 msec vs. 147.07 msec) (p=0.043), a higher prevalence of PR prolongation (21.05% vs. 0%) (p=0.013) and a higher prevalence of LPs (18/47, 38.3% vs. 2/30, 6.7%) (p=0.002) compared with controls. In particular, every single SAECG parameter significantly differed among patients compared with controls. Among patients, left ventricular ejection fraction was marginally lower and QTc more prolonged among LPs positive subgroup compared with LPs negative subgroup. The prevalence of atrial fibrillation among b-TM patients was estimated at 10.64%. Conclusions β-TM patients have a higher prevalence of a prolonged PR segment, atrial fibrillation and LPs. Twelve-lead and SAECG performance was feasible in all subjects and constitutes a readily available tool for assessing myocardial electrophysiological alterations in this patient group, that could have significant impact on survival and quality of life with timely application of appropriate treatment. Funding Acknowledgement Type of funding source: None

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ASSOCIATION BETWEEN QTC INTERVAL DURATION AND THE RISK OF ARRHYTHMIA RECURRENCE AFTER CATHER ABLATION OF PAROXYSMAL ATRIAL FIBRILLATION

Journal of the American College of Cardiology ◽

10.1016/s0735-1097(15)60419-3 ◽

2015 ◽

Vol 65 (10) ◽

pp. A419

Author(s):

Xiao-Yan Wu ◽

Nian Liu ◽

Rong Bai ◽

Song-Nan Li ◽

Xin Du ◽

...

Keyword(s):

Atrial Fibrillation ◽

Paroxysmal Atrial Fibrillation ◽

Qtc Interval ◽

Interval Duration

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Changes of QT interval in the acute phase after pulmonary vein isolation for paroxysmal atrial fibrillation

European Heart Journal ◽

10.1093/ehjci/ehaa946.0414 ◽

2020 ◽

Vol 41 (Supplement_2) ◽

Author(s):

A Chikata ◽

T Kato ◽

K Ududa ◽

S Fujita ◽

K Otowa ◽

...

Keyword(s):

Atrial Fibrillation ◽

Pulmonary Vein ◽

Female Patient ◽

Pulmonary Vein Isolation ◽

Acute Phase ◽

Paroxysmal Atrial Fibrillation ◽

Qt Interval ◽

Qt Prolongation ◽

Qtc Interval ◽

The Impact

Abstract Introduction Pulmonary vein isolation (PVI) affects ganglionated plexi (GP) around the atrium, leading to a modification of the intrinsic cardiac autonomic system (ANS). In animal models, GP ablation has a potential risk of QT prolongation and ventricular arrhythmias. However, the impact of PVI on QT intervals in humans remains unclear. Purpose This study aims to evaluate the Impact of PVI on QT interval in patients with paroxysmal atrial fibrillation. Methods We analyzed consecutive 117 PAF patients for their first PVI procedures. 12-lead ECG was evaluated at baseline, 4 hr, day 1, 1 month, and 3 months after ablation. Only patients with sinus rhythm on 12-lead ECG at each evaluation point without antiarrhythmic drugs were included. Results Heart rate significantly increased at 4 hr, day 1, and 1 month. Raw QT interval prolonged at 4 hr (417.1±41.6 ms, P<0.001) but shortened at day 1 (376.4±34.1 ms, P<0.001), 1 month (382.2±31.5 ms, P<0.001), and 3 months (385.1±32.8 ms, P<0.001) compared to baseline (391.6±31.4 ms). Bazett- and Fridericia- corrected QTc intervals significantly prolonged at 4hr (Bazett: 430.8±27.9 ms, P<0.001; Fridericia: 425.8±27.4 ms, P<0.001), day1 (Bazett: 434.8±22.3 ms, P<0.001; Fridericia: 414.1±23.7 ms, P<0.001), 1M (Bazett: 434.8±22.3 ms, P<0.001; Fridericia: 408.2±21.0 ms, P<0.05), and 3M (Bazett: 420.1±21.8 ms, P<0.001; Fridericia: 407.8±21.1 ms, P<0.05) compared to baseline (Bazett: 404.9±25.2 ms; Fridericia: 400.0±22.6 ms). On the other hand, Framingham- and Hodges- corrected QTc interval significantly prolonged only at 4hr (Framingham: 424.1±26.6 ms, P<0.001; Hodges: 426.8±28.4 ms, P<0.001) and at day1 (Framingham: 412.3±29.3 ms, P<0.01; Hodges: 410.6±40.2 ms, P<0.05) compared to baseline (Framingham: 399.2±22.7 ms; Hodges: 400.7±22.8 ms). At 4 hr after ablation, raw QT and QTc of all formulas significantly prolonged than baseline. Raw QT and QTc prolongation at 4hr after ablation were more frequently observed in female patients. Multiple regression analysis revealed that female patient is a significant predictor of raw QT and QTc interval prolongation of all formulas 4hr after PVI. Conclusions Raw QT and QTc prolonged after PVI, especially in the acute phase. Female patient is a risk factor for QT prolongation in the acute phase after PVI. Funding Acknowledgement Type of funding source: None

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