The Effect of Chloroquine, Hydroxychloroquine and Azithromycin on the Corrected QT Interval in Patients with SARS-CoV-2 Infection

Background - The novel SARs-CoV-2 coronavirus is responsible for the global COVID-19 pandemic. Small studies have shown a potential benefit of chloroquine/hydroxychloroquine ± azithromycin for the treatment of COVID-19. Use of these medications alone, or in combination, can lead to a prolongation of the QT interval, possibly increasing the risk of Torsade de pointes (TdP) and sudden cardiac death. Methods - Hospitalized patients treated with chloroquine/hydroxychloroquine ± azithromycin from March 1st through the 23rd at three hospitals within the Northwell Health system were included in this prospective, observational study. Serial assessments of the QT interval were performed. The primary outcome was QT prolongation resulting in TdP. Secondary outcomes included QT prolongation, the need to prematurely discontinue any of the medications due to QT prolongation and arrhythmogenic death. Results - Two hundred one patients were treated for COVID-19 with chloroquine/hydroxychloroquine. Ten patients (5.0%) received chloroquine, 191 (95.0%) received hydroxychloroquine and 119 (59.2%) also received azithromycin. The primary outcome of TdP was not observed in the entire population. Baseline QTc intervals did not differ between patients treated with chloroquine/hydroxychloroquine (monotherapy group) vs. those treated with combination group (chloroquine/hydroxychloroquine and azithromycin) (440.6 ± 24.9 ms vs. 439.9 ± 24.7 ms, p =0.834). The maximum QTc during treatment was significantly longer in the combination group vs the monotherapy group (470.4 ± 45.0 ms vs. 453.3 ± 37.0 ms, p = 0.004). Seven patients (3.5%) required discontinuation of these medications due to QTc prolongation. No arrhythmogenic deaths were reported. Conclusions - In the largest reported cohort of COVID-19 patients to date treated with chloroquine/hydroxychloroquine {plus minus} azithromycin, no instances of TdP or arrhythmogenic death were reported. Although use of these medications resulted in QT prolongation, clinicians seldomly needed to discontinue therapy. Further study of the need for QT interval monitoring is needed before final recommendations can be made

Conduction patterns of idiopathic arrhythmias from the endocardium and epicardium of outflow tracts: New insights with noninvasive electroanatomic mapping.

BACKGROUND: Idiopathic arrhythmias commonly arise from the septal right ventricular outflow tract (RVOT), sinuses of Valsalva (SoV), and great cardiac vein (GCV). Predicting the exact site of origin is important for preparation for catheter ablation. OBJECTIVE: The purpose of this study was to examine the diagnostic value of noninvasive electroanatomic mapping (NIEAM) to differentiate between septal RVOT, SoV, and GCV origin and compare it to that of 12-lead electrocardiography (ECG). METHODS: NIEAM maps (CardioInsight, Medtronic) were generated during spontaneous ventricular premature depolarizations (VPDs) and threshold pacing from septal RVOT, SoV, and GCV. Origin prediction using NIEAM was compared to algorithmic ECG criteria (maximal deflection index; V RESULTS: Sixty NIEAMs (18 spontaneous VPDs and 42 pace-maps) from 31 patients (age 56 ± 16 years) were analyzed. NIEAM showed distinct conduction patterns, best visualized at the base of the heart: septal RVOT VPDs propagate toward the tricuspid annulus, depolarizing the septum from inferior to superior; SoV VPDs engage the superior septum early; and GCV VPDs move laterally along the mitral annulus, depolarizing the heart from left to right. Activation of the lateral mitral annulus \u3e60.50 ms and the superior basal septum CONCLUSION: Arrhythmias arising from the outflow tracts follow distinct propagation patterns depending on the origin. A 2-step algorithm using activation timing by NIEAM yields 100% diagnostic accuracy in predicting origin

Early recurrence of atrial fibrillation after pulmonary vein isolation: a comparative analysis between cryogenic and contact force radiofrequency ablation

© 2019, Springer Science+Business Media, LLC, part of Springer Nature. Background: Early recurrence (ER) of atrial fibrillation (AF) within 90 days post-ablation is observed in up to 50% of patients and has been attributed to transient inflammation. The importance of ER in current era of pulmonary vein isolation (PVI) with cryoballoon ablation (CBA) and contact-force catheter radiofrequency ablation (cfRFA) has not been clearly reported. In addition, it is not known whether there are differences between types of ablation energy used during PVI. Methods: Study population was drawn from a prospective multicenter database of AF ablation. Consecutive patients undergoing first-time ablation with PVI alone, using either second-generation CBA or cfRFA catheters were included. Patients were followed at 0.5, 3, 6, and 12 months to assess recurrence. Predictors of late recurrence (LR), defined as recurrence outside the blanking period, were assessed by Cox proportional hazards regression models. Freedom from LR was calculated and compared between two groups using the Kaplan-Meier method and log-rank test. Results: Study cohort included 300 patients (1:1 CBA:RFA, age 63.6 ± 10.3 years, 67% male). There were no baseline characteristic differences between the CBA and cfRFA groups. ER occurred in 23.3% and 16.7% of patients in the CBA and cfRFA groups, respectively (p = 0.149). One-year freedom from LR was similar for both groups (72.7% CBA vs. 78% cfRFA, p = 0.287). Fifty-two patients (25 CBA and 27 cfRFA) underwent repeat ablation and no difference in durability of PVI was found. ER was the only common independent predictor of LR for either group and for the entire cohort (HR 2.3). Conclusions: In our series of AF ablation using second-generation cryoballoon and contact-force RFA catheters, recurrence in the “blanking period” is seen in 20% and remains predictive of late recurrence irrespective of the energy used