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Aims Direct-current cardioversion is one of the most commonly performed procedures in cardiology. Low-escalating energy shocks are common practice but the optimal energy selection is unknown. We compared maximum-fixed and low-escalating energy shocks for cardioverting atrial fibrillation. Methods and results In a single-centre, single-blinded, randomized trial, we allocated elective atrial fibrillation patients to cardioversion using maximum-fixed (360-360-360 J) or low-escalating (125-150-200 J) biphasic truncated exponential shocks. The primary endpoint was sinus rhythm 1 min after cardioversion. Safety endpoints were any arrhythmia, myocardial injury, skin burns, and patient-reported pain after cardioversion. We randomized 276 patients, and baseline characteristics were well-balanced between groups (mean ± standard deviation age: 68 ± 9 years, male: 72%, atrial fibrillation duration >1 year: 30%). Sinus rhythm 1 min after cardioversion was achieved in 114 of 129 patients (88%) in the maximum-fixed energy group, and in 97 of 147 patients (66%) in the low-escalating energy group (between-group difference; 22 percentage points, 95% confidence interval 13–32, P Conclusion Maximum-fixed energy shocks were more effective compared with low-escalating energy shocks for cardioverting atrial fibrillation. We found no difference in any safety endpoint.

Background Oxygen has long been assumed beneficial for all ill and injured patients. However, hyperoxia may be harmful and aggravate myocardial injury such as that caused by myocardial infarction. We aimed to investigate if hyperoxia increases myocardial injury following direct current cardioversion compared with room air. Methods Patients undergoing elective biphasic cardioversion for atrial fibrillation or atrial flutter were randomized to receive room air or oxygen (10–15 L/min) during the procedure. The primary endpoint was the difference in high-sensitive Troponin I (hs-cTnI) and -T (hs-cTnT) measured 2 hours before and 4 hours after cardioversion. Secondary endpoints were differences in Copeptin and NT-pro-BNP. Results A total of 65 patients were randomized to high-flow oxygen (male: 71%, mean age 66.9 years) and 59 patients to room air (male: 80%, mean age 65.5 years). There was no difference in hs-cTnI between patients treated with oxygen compared to patients treated with room air (P = .09) and no significant difference for hs-cTnT, ratio 1.08 (95% CI: 0.99–1.18) (P = .09). Median hs-cTnI difference before and after cardioversion was 0.1 (interquartile range (IQR): −0.5 to 0.5) ng/L for the high-flow oxygen group and −0.3 (IQR: −1.1 to 0.4) ng/L for the room air group. There was no difference in Copeptin between patients treated with oxygen compared to room air (ratio 1.06 (95% CI: 0.89–1.27) (P = .51) or NT-pro-BNP (difference− 6.0 ng/L (95% CI: −78.5 to 66.6) P = .87). Conclusion Direct current cardioversion of atrial fibrillation/flutter with and without high-flow oxygen supplement was not associated with myocardial injury evaluated by high sensitive myocardial biomarkers.

Background Several different defibrillators are currently used for cardioversion and defibrillation of cardiac arrhythmias. The efficacy of a novel pulsed biphasic ( PB ) waveform has not been compared to other biphasic waveforms. Accordingly, this study aims to compare the efficacy and safety of PB shocks with biphasic truncated exponential ( BTE ) shocks in patients undergoing cardioversion of atrial fibrillation or ‐flutter. Methods and Results This prospective, randomized study included patients admitted for elective direct current cardioversion. Patients were randomized to receive cardioversion using either PB or BTE shocks. We used escalating shocks until sinus rhythm was obtained or to a maximum of 4 shocks. Patients randomized to PB shocks received 90, 120, 150, and 200 J and patients randomized to BTE shocks received 100, 150, 200, and 250 J, as recommended by the manufacturers. In total, 69 patients (51%) received PB shocks and 65 patients (49%) BTE shocks. Successful cardioversion, defined as sinus rhythm 4 hours after cardioversion, was achieved in 43 patients (62%) using PB shocks and in 56 patients (86%) using BTE shocks; ratio 1.4 (95% CI 1.1–1.7) ( P =0.002). There was no difference in safety (ie, myocardial injury judged by changes in high‐sensitive troponin I levels; ratio 1.1) (95% CI 1.0–1.3), P =0.15. The study was terminated prematurely because of an adverse event. Conclusions Cardioversion using a BTE waveform was more effective when compared with a PB waveform. There was no difference in safety between the 2 waveforms, as judged by changes in troponin I levels. Clinical Trial Registration URL : http://www.clinicaltrials.gov . Unique identifier: NCT 02317029.

OBJECTIVES: To investigate, whether renal denervation (RDN) improves arterial stiffness, central blood pressure (C-BP) and heart rate variability (HRV) in patients with treatment resistant hypertension.METHODS: ReSET was a randomized, sham-controlled, double-blinded trial (NCT01459900). RDN was performed by a single experienced operator using the Medtronic unipolar Symplicity Flex(TM) catheter. C-BP, carotid-femoral pulse wave velocity (PWV), and HRV were obtained at baseline and after six months with the SphygmoCor(®)-device.RESULTS: Fifty-three patients (77% of the ReSET-cohort) were included in this substudy. The groups were similar at baseline (SHAM/RDN): n = 27/n = 26; 78/65% males; age 59 ± 9/54 ± 8 years (mean ± SD); systolic brachial BP 158 ± 18/154 ± 17 mmHg; systolic 24-hour ambulatory BP 153 ± 14/151 ± 13 mmHg. Changes in PWV (0.1 ± 1.9 (SHAM) vs. -0.6 ± 1.3 (RDN) m/s), systolic C-BP (-2 ± 17 (SHAM) vs. -8 ± 16 (RDN) mmHg), diastolic C-BP (-2 ± 9 (SHAM) vs. -5 ± 9 (RDN) mmHg), and augmentation index (0.7 ± 7.0 (SHAM) vs. 1.0 ± 7.4 (RDN) %) were not significantly different after six months. Changes in HRV-parameters were also not significantly different. Baseline HRV or PWV did not predict BP-response after RDN.CONCLUSIONS: In a sham-controlled setting, there were no significant effects of RDN on arterial stiffness, C-BP and HRV. Thus, the idea of BP-independent effects of RDN on large arteries and cardiac autonomic activity is not supported.

Background: A recent sham-controlled trial (ReSET) showed no sustained effect of renal denervation (RDN) on 24-hour ambulatory blood pressure (24hA-BP) measurements in patients with treatment resistant hypertension.1 The aim of this substudy was to investigate, whether RDN affects central blood pressure (C-BP) and arterial stiffness independently of brachial artery BP-levels. Methods: ReSET was a randomized, sham-controlled, double-blinded single-center trial. Main inclusion criteria were: daytime systolic 24hA-BP ≥145mmHg following 1 month of stable medication and 2 weeks of compliance registration. RDN was performed by a single experienced operator using the unipolar Medtronic Flex catheter1. C-BP and carotid-femoral pulse wave velocity (PWV) were obtained at baseline and after 6 months with the SphygmoCor®-device. Results: Fifty-three patients (77% of the ReSET cohort) were included in this substudy. The groups were similar at baseline (SHAM/RDN): n=27/n=26; 78/65% males; age 59±9/54±8 years (mean±SD); systolic brachial BP 158±18/154±17 mmHg; systolic 24hA-BP 153±14/151±13 mmHg; systolic C-BP 146±20/143±17 mmHg; diastolic C-BP 92±14/94±10 mmHg; augmentation index (AIx) 26±9/28±13 %; PWV 10.7±2.1/10.1±2.2 m/s. Changes in systolic C-BP (−2±17 (SHAM) vs. −8±16 (RDN) mmHg), diastolic C-BP (−2±9 (SHAM) vs. −5±9 (RDN) mmHg), AIx (0.7±7.0 (SHAM) vs. 1.0±7.4 (RDN) %), and PWV (0.1±1.9 (SHAM) vs. −0.6±1.3 (RDN) m/s) were not significantly different after six months (P>0.13 in all tests). Changes in brachial BP and 24hA-BP were also not significantly different. Conclusions: In a sham-controlled setting, there were no significant effects of RDN on C-BP or arterial stiffness. Thus, the idea of BP-independent effects of RDN on large arteries is not supported.

BACKGROUND: Renal denervation (RDN), treating resistant hypertension, has, in open trial design, been shown to lower blood pressure (BP) dramatically, but this was primarily with respect to office BP.METHOD: We conducted a SHAM-controlled, double-blind, randomized, single-center trial to establish efficacy data based on 24-h ambulatory BP measurements (ABPM). Inclusion criteria were daytime systolic ABPM at least 145 mmHg following 1 month of stable medication and 2 weeks of compliance registration. All RDN procedures were carried out by an experienced operator using the unipolar Medtronic Flex catheter (Medtronic, Santa Rosa, California, USA).RESULTS: We randomized 69 patients with treatment-resistant hypertension to RDN (n = 36) or SHAM (n = 33). Groups were well balanced at baseline. Mean baseline daytime systolic ABPM was 159 ± 12 mmHg (RDN) and 159 ± 14 mmHg (SHAM). Groups had similar reductions in daytime systolic ABPM compared with baseline at 3 months [-6.2 ± 18.8 mmHg (RDN) vs. -6.0 ± 13.5 mmHg (SHAM)] and at 6 months [-6.1 ± 18.9 mmHg (RDN) vs. -4.3 ± 15.1 mmHg (SHAM)]. Mean usage of antihypertensive medication (daily defined doses) at 3 months was equal [6.8 ± 2.7 (RDN) vs. 7.0 ± 2.5 (SHAM)].RDN performed at a single center and by a high-volume operator reduced ABPM to the same level as SHAM treatment and thus confirms the result of the HTN3 trial.CONCLUSION: Further, clinical use of RDN for treatment of resistant hypertension should await positive results from double-blinded, SHAM-controlled trials with multipolar ablation catheters or novel denervation techniques.This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License, where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially. http://creativecommons.org/licenses/by-nc-nd/4.0.

Background: Shock synchronized to the QRS-complex is essential to avoid cardioversion induced ventricular fibrillation. Several defibrillators are used in clinical practice, but little is known about their ability to synchronize shocks in real life use. In a randomized study, comparing two defibrillators, a major adverse event occurred and was related to synchronization failure of one device. Aim: To investigate if shocks are delivered asynchronous during synchronized cardioversion. Methods: A post-hoc analysis of a randomized study enrolling patients admitted for elective cardioversion was performed. Patients were randomized to receive cardioversion by LIFEPAK 20 (Physio-Control Inc., Redmond, WA, USA) or Schiller Defigard 5000 (Schiller AG, Baar, Switzerland). All shocks were delivered with the defibrillators in synchronization modus. Post-hoc, we investigated the ability to synchronize, i.e. the delay between the R-wave and shock delivery, by reviewing electrocardiographic shock recordings. According to the Association for the Advancement of Medical Instrumentation and the American National Standards Institute, a synchronized shock should be delivered within 60 milliseconds after the R-wave. Results: A total of 134 patients were randomized; 65 patients received cardioversion by LIFEPAK 20 (mean age: 67 years, 14% atrial flutter), and 70 patients Schiller Defigard 5000 (mean age: 66 years, 14% atrial flutter). Overall, 138 shocks were delivered by LIFEPAK 20, all of them delayed more than 60 milliseconds (range: 80-200 milliseconds). All LIFEPAK 20 shocks were however delivered between the R-wave and the T-wave upstroke. In total, 193 shocks were delivered by Schiller Defigard 5000. Of these, 169 (88%) shocks were delivered within 60 milliseconds (range: 0-450 milliseconds), 180 (93%) between the R-wave and the T-wave upstroke, and 13 (7%) in the vulnerable part of the T-wave. Two of these shocks resulted in malignant ventricular tachycardia. Conclusion: Synchronized shocks in cardioversions are not uncommonly delivered asynchronous, including in the vulnerable phase of the T-wave. Of these shocks, two resulted in cardioversion induced malignant ventricular tachycardia.

Several different biphasic waveforms are currently in clinical use, but few studies have compared their efficiency. The aim of this study was to compare the efficiency of a biphasic truncated exponential (BTE) waveform with a pulsed biphasic waveform (PBW) in patients undergoing elective