Reverse electrical remodeling of the ventricles following successful restoration of sinus rhythm in patients with persistent atrial fibrillation

Withdrawal of oral anticoagulants 3 months after successful radiofrequency catheter ablation in patients with atrial fibrillation: A meta-analysis

BACKGROUND

The best anticoagulation therapy for atrial fibrillation (AF) after radiofrequency catheter ablation (RFCA) remains a challenge.

METHODS

A systematic search of PubMed, Ovid, and Cochrane Library was conducted identifying at clinical trials which evaluated the differences between thromboembolism (TE) and hemorrhage in an off-oral anticoagulants (OACs) treatment group (the observation group) and an on-OACs treatment group (the control group), at 3 months after successful RFCA. Meta-analysis was performed using RevMan 5.3 software, and the fixed effect model was used as a relevant statistical model. χ² test and I² were used to test for the presence of heterogeneity. Subgroup analysis and sensitivity analysis were also performed.

RESULTS

The results showed no significant differences between two groups in TE (relative risk [RR] 0.82, 95% confidence interval [CI], 0.51-1.33, P = 0.42), and only mild heterogeneity (P = 0.22, I²  = 29%). No significant differences in TE between two subgroups were found according to < 3 years and ≥ 3 years follow-up analyses (RR 0.58, 95% CI, 0.26-1.28, P = 0.18; RR 1.00, 95% CI, 0.54-1.85, P = 1.00). Furthermore, there was a lower risk of TE in the observation subgroup (< 60 years) compared to the control group (RR 0.31, 95% CI, 0.12-0.78, P = 0.01). Also, there were no significant differences in TE between two subgroups (≥ 60 years, RR 1.24, 95% CI, 0.67-2.28, P = 0.49). The risk of hemorrhage in the observation group was significantly lower compared to the control group (RR 0.05, 95%CI, 0.02-0.14, P < 0.00001).

CONCLUSIONS

The withdrawal of OACs 3 months after successful radiofrequency catheter ablation for patients with AF may be safe and feasible. It needs to be tested by randomized controlled trial.

The application of root mean square electrocardiography (RMS ECG) for the detection of acquired and congenital long QT syndrome

BACKGROUND

Precise measurement of the QT interval is often hampered by difficulty determining the end of the low amplitude T wave. Root mean square electrocardiography (RMS ECG) provides a novel alternative measure of ventricular repolarization. Experimental data have shown that the interval between the RMS ECG QRS and T wave peaks (RTPK) closely reflects the mean ventricular action potential duration while the RMS T wave width (TW) tracks the dispersion of repolarization timing. Here, we tested the precision of RMS ECG to assess ventricular repolarization in humans in the setting of drug-induced and congenital Long QT Syndrome (LQTS).

METHODS

RMS ECG signals were derived from high-resolution 24 hour Holter monitor recordings from 68 subjects after receiving placebo and moxifloxacin and from standard 12 lead ECGs obtained in 97 subjects with LQTS and 97 age- and sex-matched controls. RTPK, QTRMS and RMS TW intervals were automatically measured using custom software and compared to traditional QT measures using lead II.

RESULTS

All measures of repolarization were prolonged during moxifloxacin administration and in LQTS subjects, but the variance of RMS intervals was significantly smaller than traditional lead II measurements. TW was prolonged during moxifloxacin and in subjects with LQT-2, but not LQT-1 or LQT-3.

CONCLUSION

These data validate the application of RMS ECG for the detection of drug-induced and congenital LQTS. RMS ECG measurements are more precise than the current standard of care lead II measurements.