Early repolarization pattern as a predictor of atrial fibrillation recurrence following radiofrequency pulmonary vein isolation

Relationship between pre-procedural non-ischemic ST-segment depression and the clinical outcomes after catheter ablation in persistent atrial fibrillation patients

BACKGROUND

ST-segment depression suggests the presence of coronary artery disease (CAD) during sinus rhythm, but the clinical significance, including the outcomes after catheter ablation (CA), in atrial fibrillation (AF) patients remain unknown.

METHODS

The present study included persistent AF (PerAF) patients from the Osaka Rosai Atrial Fibrillation ablation (ORAF) registry who underwent an initial ablation and had no history of CAD. We assigned the patients based on the presence of ST-segment depression before CA and evaluated the impact of relevant factors on ST-segment depression and the relationship between ST-segment depression, including leads locations (anterior leads, inferior leads, and lateral leads) or depression type (upsloping, horizontal, and downsloping) or the degree of ST-segment depression and late recurrence of AF (LRAF).

RESULTS

This study population included a total of 551 patients of whom 189 had ST-segment depression. The median follow-up duration was 397 days and LRAF occurred in 195 patients. By multiple regression analysis, diabetes mellitus, hemoglobin, brain natriuretic peptide, left ventricular ejection fraction, and left atrial diameter were significant determinants of ST-segment depression before CA. Kaplan-Meier analysis demonstrated that the patients with ST-segment depression had a significantly greater risk of LRAF than those without (p < 0.001). Multivariate Cox proportional hazards analysis showed ST-segment depression was independently and significantly associated with a higher risk of LRAF (p < 0.001). The patients with ST-segment depression ≥0.15 mV had a significantly higher risk of LRAF than those with ST-segment depression ≥0.15 mV (p < 0.001). No significant differences among the ST-segment depression lead locations and ST-segment depression type were observed.

CONCLUSION

Non-ischemic ST-segment depression during AF rhythm was significantly associated with LRAF post CA in PerAF patients.

Evaluation of Atrial Electromechanical Delay and Left Atrial Phasic Function in Individuals with Electrocardiographic Early Repolarization Pattern

BACKGROUND

Atrial electromechanical delay (EMD) and left atrial (LA) phasic function have been demonstrated to be predictors for the development of atrial fibrillation (AF). In the present study, we aimed to evaluate atrial EMD and LA phasic function in individuals with electrocardiographic early repolarization pattern (ERP).

METHODS

Eighty consecutive individuals with ERP and 40 age- and gender-matched control subjects without ERP were compared in this cross-sectional study. Atrial electromechanical coupling (Pa') was measured from lateral mitral annulus (Pa'_lateral), septal mitral annulus (Pa'_septal), and lateral tricuspid annulus (Pa'_tricuspid) using tissue Doppler echocardiography to calculate intra- and inter-atrial EMD. LA maximal volume, LA minimal volume, and LA volume before atrial contraction were calculated using the biplane area-length method to assess LA phasic function.

RESULTS

LA diameter, LA volume index, Pa'_lateral, Pa'_septal, Pa'_tricuspid electrical activity and intra-left atrial EMD were significantly increased in the ERP patients. Mitral lateral, septal, tricuspid lateral annular tissue Doppler s' and e' waves were significantly decreased in the ERP patients. There were no significant difference between the groups in terms of interatrial EMD, intra-right atrial EMD, LA total emptying volume and LA total emptying fraction indicating LA reservoir function, LA passive emptying volume and LA passive emptying fraction indicating LA conduit function, LA active emptying volume and LA active emptying fraction indicating LA pump function.

CONCLUSIONS

Left atrial EMD parameters are affected in individuals with ERP, but LA phasic functions are not affected. Further prospective studies are needed to clarify whether individuals with ERP have an increased susceptibility to AF.

Impact of Baseline Right Bundle Branch Block on Outcomes After Pulmonary Vein Isolation in Patients With Atrial Fibrillation

Right bundle branch block (RBBB) is one of the most frequent alterations of the electrocardiogram. Several studies have shown that RBBB is a risk factor of cardiovascular diseases. However, the clinical outcomes after pulmonary vein isolation (PVI) in patients with RBBB remain unclear. We enrolled consecutive atrial fibrillation (AF) patients who underwent PVI from the Osaka Rosai Atrial Fibrillation (ORAF) registry. We excluded patients with other wide QRS morphologies (left bundle branch block, ventricular pacing, and unclassified intraventricular conduction disturbances) and divided them into 2 groups: RBBB (QRS duration ≥120msec) and No-RBBB (QRS duration <120) groups. We compared the incidence of late recurrence of AF and/or atrial tachycardia (AT) (LRAF) between the 2 groups using a propensity score-matched analysis and evaluated the risk of LRAF using Cox regression model. We finally analyzed 671 consecutive AF patients. The RBBB group consisted of 50 patients (7.5%) and the No-RBBB group of 621 patients. Median follow-up duration was 734 [496, 1,049] days. Hypertension and diabetes mellitus were significantly higher in RBBB group than No-RBBB group. Among the 46 matched patients pairs, Kaplan-Meier analysis demonstrated that RBBB group had a significantly greater risk of LRAF than the No-RBBB group (p = 0.046). The Cox regression model revealed significantly higher risks of LRAF (HR, 2.30; 95% CI, 1.00 to 5.33; p=0.044) in RBBB group compared with No-RBBB group. Non-PV AF triggers were significantly higher in RBBB group than No-RBBB group (p = 0.048). In conclusion, RBBB can be an important predictor of LRAF after PVI.

Early repolarization pattern as a predictor of atrial fibrillation recurrence following radiofrequency pulmonary vein isolation

BACKGROUND

Early repolarization patterns (ERP) have been found to be associated with poor cardiovascular end points. We aimed to evaluate the ERP prevalence among patients with structurally normal hearts undergoing radiofrequency (RF) pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (AF) ablation and its association with the AF recurrence.

METHODS

All consecutive patients who underwent RF-PVI as index procedure for paroxysmal AF in our center were evaluated.

EXCLUSION CRITERIA

structural heart disease, ongoing use of Class I/III antiarrhythmics, complete-bundle-branch-block. Lateral (I, aVL, V₅ -V₆ ), inferior (II, III, aVF), or infero-lateral (both) ERP were defined in baseline ECG as horizontal/downsloping J-point elevation ≥1 mm in two consecutive leads with QRS slurring/notching. Documented episodes of AF lasting ≥30 s were considered recurrence.

RESULTS

Of 701 cases, 434 patients (305 males, 58 ± 11 years) were included for analysis. ERP observed in 67 patients (15.4%) (Infero-lateral n = 26, inferior n = 23, lateral n = 18) which were significantly younger, demonstrating longer PR-interval and lower heart rates. At a mean follow-up of 22.1 ± 9.7 months, AF recurrences were found in 107 patients (24.6%). In middle-aged patients (≥40-<60 years; n = 206, 79% male), those with an infero-lateral ERP had higher recurrence compared with the ones without (56.3% vs. 19%; p = 0.002). Infero-lateral ERP was significantly predicting recurrence (HR 2.42, 95% CI 1.21-4.82; p = 0.01).

CONCLUSION

Early repolarization patterns was more prevalent in our AF population than in the general population. Infero-lateral ERP in baseline ECG might predict AF recurrence in the follow-up after RF-PVI in middle-aged patients.