Hydrogen inhalation: in vivo rat genotoxicity tests.

Preclinical and clinical studies have shown that molecular hydrogen (H2) has anti-oxidant, anti-inflammatory, and anti-apoptotic properties. Safety data are available in the literature and acute toxicity has been tested in isolated cells and laboratory animals. We have evaluates the genotoxicity of H2 in vivo in rats after 72 h exposure, following the International Council for Harmonization guidelines ICH S2 (R1). The study was conducted on three groups of male Wistar rats: a negative control group, a positive control group receiving methyl methanesulfonate, and a H2-treated group receiving a 3.1% H2 gas mixture for 72 h. Alkaline comet, formamidopyrimidine DNA glycosylase (Fpg)-modified comet and bone marrow micronucleus assays were performed. H2 exposure increased neither comet-tail DNA intensity (DNA damage) nor frequency of "hedgehogs" in blood, liver, lungs, or bronchoalveolar lavage fluid. No increase in Fpg-sensitive sites in lungs, no induction of micronucleus formation, and no imbalance of immature erythrocyte to total erythrocyte ratio (IME%) was observed in rats exposed to H2. The ICH S2 (R1) test-battery revealed no in vivo genotoxicity in Wistar rats after 72 h inhalation of a mixture containing 3.1% H2.

Mitral valve perforation after left lateral accessory pathway ablation: a case report.

BACKGROUND: Radiofrequency catheter ablation is considered to be a relatively safe procedure. This is an unusual case report in which severe mitral regurgitation was occurred after left lateral accessory pathway radiofrequency catheter ablation. CASE PRESENTATION: A 15-year-old man without structural heart disease was referred for ablation of a left lateral accessory pathway. He was a rugby player who had lived with Wolff-Parkinson-White syndrome since 2017. In 2017, two failed extensive radiofrequency catheter ablations of a left lateral accessory pathway had been performed in another center. In June 2018, he underwent a third radiofrequency catheter ablation of a left lateral accessory pathway using an anterograde transseptal approach with an early recurrence one month later. A successful fourth procedure was performed in August 2018 using a retrograde aortic approach. Three months later, the patient presented to the hospital with atypical chest pain and dyspnea on exertion. Transthoracic echocardiography revealed severe mitral regurgitation caused by a perforation of the posterior leaflet. Given the symptoms and the severity of the mitral valve regurgitation, the decision was taken to proceed with surgical intervention. Posterior mitral leaflet perforation was confirmed intraoperatively. The patient underwent video-assisted mitral valve repair via Minithoracotomy approach. CONCLUSION: This case demonstrates a very rare complication of Wolff-Parkinson-White radiofrequency ablation.

European experience with a first totally leadless cardiac resynchronization therapy pacemaker system.

AIMS: Totally leadless cardiac resynchronization therapy (CRT) can be delivered with a combination of Micra and WiSE-CRT systems. We describe the technical feasibility and first insights into the safety and efficacy of this combination in European experience. METHODS AND RESULTS: Patients enrolled had indication for both Micra and WiSE-CRT systems because of heart failure related to high burden of pacing by a Micra necessitating system upgrade or inability to implant a conventional CRT system because of infectious or anatomical conditions. The endpoints of the study were technical success of WiSE-CRT implantation with right ventricle-synchonized CRT delivery, acute QRS duration reduction, and freedom from procedure-related major adverse events. All eight WiSE-CRT devices were able to detect the Micra pacing output and to be trained to deliver synchronous LV endocardial pacing. Acute QRS reduction following WiSE-CRT implantation was observed in all eight patients (mean QRS 204.38 ± 30.26 vs. 137.5 ± 24.75 mS, P = 0.012). Seven patients reached 6 months of follow-up. At 6 months after WiSE-CRT implantation, there was a significant increase in LV ejection fraction (28.43 ± 8.01% vs. 39.71 ± 11.89%; P = 0.018) but no evidence of LV reverse remodelling or improvement in New York Heart Association class. CONCLUSION: The Micra and the WiSE-CRT systems can successfully operate together to deliver total leadless CRT to a patient. Moreover, the WiSE-CRT system provides the only means to upgrade the large population of Micra patients to CRT capability without replacing the Micra. The range of application of this combination could broaden in the future with the upcoming developments of leadless cardiac pacing.

The effects of fasting on heart rate variability in hypertensive patients.

Heart rate variability (HRV) is an independent indicator of increased mortality in patients with myocardial infarction and congestive heart failure. The effects of fasting on the HRV are not known in hypertensive patients. Therefore, studying the effects of Ramadan fasting on hypertensive patients' HRV seems reasonable to address. We conducted a prospective study including 20 hypertensive patients with sinus rhythm. HRV was determined twice by ambulatory 24-hour Holter recordings at fasting during and after Ramadan. Subjects mean age was 55 ± 11.8 years. Sex-ratio was 1.5. When two groups compared, statistically significant differences were found in terms of SDNN (113 ± 71 vs 140 ± 38, p = 0.001), SDANN (109.7 ± 45 vs 134.8 ± 48.3, p = 0.008), T power (2368.7 ± 121.3 vs 3660.5 ± 170.9, p = 0.03) and LF (552.2 ± 31.3 vs 903.7 ± 48.9, p < 0.0001) values. HRV parameters were found to be decreased in Ramadan. Thus, Ramadan fasting enhances the activity of the sympathetic system in hypertensive patients.

Right ventricular systolic echocardiographic parameters in dilated cardiomyopathy and prognosis.

BACKGROUND: Right ventricular (RV) dysfunction is associated with poor prognosis in patients with non-ischemic dilated cardiomyopathy. Several RV echocardiographic parameters have been proposed as sensitive markers to detect patients at risk. OBJECTIVE: To compare the predictive value of echographic parameters of RV systolic function for adverse outcomes in patients with non-ischemic dilated cardiomyopathy. METHODS:    Forty patients with non-ischemic dilated cardiomyopathy were included. Right ventricular systolic function assessed by Doppler echocardiography standard (RV fractional area change, Tei index, TAPSE and dp/dt), tissue Doppler (peak systolic velocity (Sa)) and Strain 2D of the RV. The primary endpoint was the occurrence of a major cardiovascular event. The follow-up extended for 6.2 months ± 2,49. RESULTS: Eighteen patients reached the primary endpoint. TAPSE (HR 0.86 [0.74-0.99], p=0.04), Sa (HR 0.77 [0.62-0.95], p=0.01), Tei index (HR 1.06 [1.01-1.12], p=0.02) and strain of the lateral wall of the RV (HR 1.13 [1.04-1.23], p=0.004) were found to be independent predictors of major cardiovascular event. The cut-off thresholds for TAPSE, Sa, Tei index and strain of the lateral wall of th RV, defined using ROC curves were respectively 12,5mm ; 8,5cm/s ; 0,55 et -12. CONCLUSION: TAPSE, Sa, Tei index and strain of the lateral wall of the RV are independent predictors of major cardiovascular event in non ischemic dilated cardiomyopathy.