Diaphragm movement sensor for phrenic nerve monitoring during cryoballoon procedures: the first clinical evaluation.

Background and aims: Right phrenic nerve palsy is the most frequent complication of cryoballoon procedures. The SMARTFREEZE™ console (Boston Scientific, St. Paul, MN, USA) has integrated a new tool for diaphragm monitoring-the Diaphragm Movement Sensor; however, it has not been evaluated in clinical practice. We aimed to assess the diagnostic performance of the Diaphragm Movement Sensor based on compound motor action potential data recorded simultaneously. Methods: Thirty consecutive patients (mean age 63.2 ± 10.2 years) were included. We simultaneously recorded the compound motor action potential and the Diaphragm Movement Sensor during cryoapplications in the right pulmonary veins. The right phrenic nerve was paced at 60 per minute, 12 V and 2.9 ms. Compound motor action potential monitoring with a 30% decrease cutoff for the diagnosis of phrenic nerve threatening was considered the gold standard. The Diaphragm Movement Sensor decrease threshold was also set at 30%. Results: Considering compound motor action potential monitoring, phrenic nerve threatening occurred 11 times (in seven patients) among 84 cryoapplications (13.1%) at the right pulmonary veins. The sensitivity and specificity of the Diaphragm Movement Sensor were, respectively, 33% (95% CI: 7%-70%) and 49% (95% CI: 38%-61%; P < 0.001). The predictive positive and negative values for the Diaphragm Movement Sensor were, respectively, 7% (95% CI: 2%-20%) and 86% (95% CI: 72%-95%). The Diaphragm Movement Sensor gave an erroneous diagnosis in 44/84 cryoapplications (52.4%). Conclusions: The diagnostic performance of the Diaphragm Movement Sensor is low, and the relevance of its use in clinical practice may be debated.

Cardiovascular Safety of Hydroxychloroquine-Azithromycin in 424 COVID-19 Patients.

Background and Objectives: Hydroxychloroquine (HCQ) combined with azithromycin (AZM) has been widely administered to patients with COVID-19 despite scientific controversies. In particular, the potential of prolong cardiac repolarization when using this combination has been discussed. Materials and Methods: We report a pragmatic and simple safety approach which we implemented among the first patients treated for COVID-19 in our center in early 2020. Treatment contraindications were the presence of severe structural or electrical heart disease, baseline corrected QT interval (QTc) > 500 ms, hypokalemia, or other drugs prolonging QTc that could not be interrupted. Electrocardiogram and QTc was evaluated at admission and re-evaluated after 48 h of the initial prescription. Results: Among the 424 consecutive adult patients (mean age 46.3 ± 16.1 years; 216 women), 21.5% patients were followed in conventional wards and 78.5% in a day-care unit. A total of 11 patients (2.6%) had contraindications to the HCQ-AZ combination. In the remaining 413 treated patients, there were no arrhythmic events in any patient during the 10-day treatment regimen. QTc was slightly but statistically significantly prolonged by 3.75 ± 25.4 ms after 2 days of treatment (p = 0.003). QTc prolongation was particularly observed in female outpatients <65 years old without cardiovascular disease. Ten patients (2.4%) developed QTc prolongation > 60 ms, and none had QTc > 500 ms. Conclusions: This report does not aim to contribute to knowledge of the efficacy of treating COVID-19 with HCQ-AZ. However, it shows that a simple initial assessment of patient medical history, electrocardiogram (ECG), and kalemia identifies contraindicated patients and enables the safe treatment of COVID-19 patients with HCQ-AZ. QT-prolonging anti-infective drugs can be used safely in acute life-threatening infections, provided that a strict protocol and close collaboration between infectious disease specialists and rhythmologists are applied.

Adenosine and Adenosine Receptors: Advances in Atrial Fibrillation.

Atrial fibrillation (AF) is the most common arrhythmia in the world. Because the key to developing innovative therapies that limit the onset and the progression of AF is to fully understand the underlying molecular mechanisms of AF, the aim of the present narrative review is to report the most recent advances in the potential role of the adenosinergic system in the pathophysiology of AF. After a comprehensive approach describing adenosinergic system signaling and the mechanisms of the initiation and maintenance of AF, we address the interactions of the adenosinergic system's signaling with AF. Indeed, adenosine release can activate four G-coupled membrane receptors, named A1, A2A, A2B and A3. Activation of the A2A receptors can promote the occurrence of delayed depolarization, while activation of the A1 receptors can shorten the action potential's duration and induce the resting membrane's potential hyperpolarization, which promote pulmonary vein firing, stabilize the AF rotors and allow for functional reentry. Moreover, the A2B receptors have been associated with atrial fibrosis homeostasis. Finally, the adenosinergic system can modulate the autonomous nervous system and is associated with AF risk factors. A question remains regarding adenosine release and the adenosine receptors' activation and whether this would be a cause or consequence of AF.

Predicting outcome after cardiac resynchronisation therapy defibrillator implantation: the cardiac resynchronisation therapy defibrillator Futility score.

BACKGROUND: Risk-benefit for cardiac resynchronisation therapy (CRT) defibrillator (CRT-D) over CRT pacemaker remains a matter of debate. We aimed to identify patients with a poor outcome within 1 year of CRT-D implantation, and to develop a CRT-D Futility score. METHODS: Based on an administrative hospital-discharge database, all consecutive patients treated with prophylactic CRT-D implantation in France (2010-2019) were included. A prediction model was derived and validated for 1-year all-cause death after CRT-D implantation (considered as futility) by using split-sample validation. RESULTS: Among 23 029 patients (mean age 68±10 years; 4873 (21.2%) women), 7016 deaths were recorded (yearly incidence rate 7.2%), of which 1604 (22.8%) occurred within 1 year of CRT-D implantation. In the derivation cohort (n=11 514), the final logistic regression model included-as main predictors of futility-older age, diabetes, mitral regurgitation, aortic stenosis, history of hospitalisation with heart failure, history of pulmonary oedema, atrial fibrillation, renal disease, liver disease, undernutrition and anaemia. Area under the curve for the CRT-D Futility score was 0.716 (95% CI: 0.698 to 0.734) in the derivation cohort and 0.692 (0.673 to 0.710) in the validation cohort. The Hosmer-Lemeshow test had a p-value of 0.57 suggesting accurate calibration. The CRT-D Futility score outperformed the Goldenberg and EAARN scores for identifying futility. Based on the CRT-D Futility score, 15.9% of these patients were categorised at high risk (predicted futility of 16.6%). CONCLUSIONS: The CRT-D Futility score, established from a large nationwide cohort of patients treated with CRT-D, may be a relevant tool for optimising healthcare decision-making.

Diaphragmatic CMAP Monitoring During Cryoballoon Procedures: Surface vs. Hepatic Recording Comparison and Limitations of This Approach.

BACKGROUND: Compound motor action potential (CMAP) monitoring is a common method used to prevent right phrenic nerve palsy during cryoballoon ablation for atrial fibrillation. OBJECTIVE: We compared recordings simultaneously obtained with surface and hepatic electrodes. METHODS: We included 114 consecutive patients (mean age 61.7 ± 10.9 years) admitted to our department for cryoballoon ablation. CMAP was monitored simultaneously with a hepatic catheter and a modified lead I ECG, whilst right phrenic nerve was paced before (stage 1) and during (stage 2) the right-sided freezes. If phrenic threat was detected with hepatic recordings (CMAP amplitude drop >30%) the application was discontinued with forced deflation. RESULTS: The ratio of CMAP/QRS was 4.63 (2.67-9.46) for hepatic and 0.76 (0.55-1.14) for surface (p < 0.0001). Signal coefficients of variation during stage 1 were 3.92% (2.48-6.74) and 4.10% (2.85-5.96) (p = 0.2177), respectively. Uninterpretable signals were more frequent on surface (median 10 vs. 0; p < 0.0001). For the 14 phrenic threats, the CMAP amplitude dropped by 35.61 ± 8.27% on hepatic signal and by 33.42 ± 11.58% concomitantly on surface (p = 0.5417). Our main limitation was to achieve to obtain stable phrenic capture (57%). CMAP monitoring was not reliable because of pacing instability in 15 patients (13.16%). A palsy occurred in 4 patients (3.51%) because cryoapplication was halted too late. CONCLUSION: Both methods are feasible with the same signal stability and amplitude drop precocity during phrenic threats. Clarity and legibility are significantly better with hepatic recording (sharper signals, less far-field QRS). The two main limitations were pacing instability and delay between 30% CMAP decrease and cryoapplication discontinuation.

Advantages and disadvantages of drug challenge during electrophysiological study in patients with new left bundle branch block after transaortic valve implantation.

AIMS: Electrophysiological study (EPS) is recommended in case of new-onset persistent left bundle branch block (NOP-LBBB) after transaortic valve implantation (TAVI) to identify patients at high risk of delayed atrioventricular block (D-AVB). We evaluated the added value of drug challenge, after normal baseline EPS, to predict D-AVB in such patients. METHODS: We conducted a comparative single-centre study of two successive periods, during which we used baseline EPS alone (first period) or drug challenge in case of normal baseline EPS (second period), for patients with NOP-LBBB after TAVI. The primary endpoint was a composite of pacemaker use, documented D-AVB, cardiac syncope, sudden death, or delayed pacemaker implantation. RESULTS: Among 736 patients with TAVI implantation between January 2016 and September 2019, 64 with NOP-LBBB were included. During the first period, 4/22 (18.2%) presented with a positive baseline EPS. After a mean (standard deviation [SD]) of 15.6 (8.3) months, 7/22 (31.8%) reached the primary endpoint. During the second period, 19/42 (45.2%) presented with a positive EPS. After a mean (SD) of 12.8 (3.5) months, 8/42 (19.0%) reached the primary endpoint. There was a tendency to increased sensitivity (42.9-87.5%; P = 0.12) and negative predictive value (77.8-95.7%; P = 0.15) of the EPS, respectively during the first to the second period. However, the specificity decreased (93.3-64.7%; P = 0.04). CONCLUSION: Diagnostic yield improved with drug challenge in case of normal baseline EPS. However, the decrease in specificity led to a high rate of unnecessary pacemaker implantation.

A2 Adenosine Receptor Subtypes Overproduction in Atria of Perioperative Atrial Fibrillation Patients Undergoing Cardiac Surgery: A Pilot Study.

Objective: Although atrial fibrillation is a common cardiac arrhythmia in humans, the mechanism that leads to the onset of this condition is poorly elucidated. Adenosine is suspected to be implicated in the trigger of atrial fibrillation (AF) through the activation of its membrane receptors, mainly adenosine receptor (AR) subtypes A1R and A2R. In this study, we compared blood adenosine concentration (BAC), and A1R, A2AR, and A2BR production in right (RA) and left atrium (LA), and on peripheral blood mononuclear cells (PBMCs) in patients with underlying structural heart disease undergoing cardiac surgery with or without peri-operative AF (PeOpAF). Methods: The study group consisted of 39 patients (30 men and 9 women, mean age, range 65 [40-82] years) undergoing cardiac surgery and 20 healthy patients (8 women and 12 men; mean age, range 60 [39-72] years) as controls were included. Among patients, 15 exhibited PeOpAF. Results: Blood adenosine concentration was higher in patients with PeOpAF than others. A2AR and A2BR production was higher in PBMCs of patients compared with controls and was higher in PeOpAF patients than other patients. In LA and RA, the production of A2AR and A2BR was higher in patients with PeOpAF than in other patients. Both A2AR and A2BR production were higher in LA vs. RA. A1R production was unchanged in all situations. Finally, we observed a correlation between A1R, A2AR, and A2BR production evaluated on PBMCs and those evaluated in LA and RA. Conclusions: Perioperative AF was associated with high BAC and high A2AR and A2BR expression, especially in the LA, after cardiac surgery in patients with underlying structural heart disease. Whether these increases the favor in triggering the AF in this patient population needs further investigation.

Smartwatch Electrocardiogram and Artificial Intelligence for Assessing Cardiac-Rhythm Safety of Drug Therapy in the COVID-19 Pandemic. The QT-logs study.

BACKGROUND: QTc interval monitoring, for the prevention of drug-induced arrhythmias is necessary, especially in the context of coronavirus disease 2019 (COVID-19). For the provision of widespread use, surrogates for 12­lead ECG QTc assessment may be useful. This prospective observational study compared QTc duration assessed by artificial intelligence (AI-QTc) (Cardiologs®, Paris, France) on smartwatch single­lead electrocardiograms (SW-ECGs) with those measured on 12­lead ECGs, in patients with early stage COVID-19 treated with a hydroxychloroquine-azithromycin regimen. METHODS: Consecutive patients with COVID-19 who needed hydroxychloroquine-azithromycin therapy, received a smartwatch (Withings Move ECG®, Withings, France). At baseline, day-6 and day-10, a 12­lead ECG was recorded, and a SW-ECG was transmitted thereafter. Throughout the drug regimen, a SW-ECG was transmitted every morning at rest. Agreement between manual QTc measurement on a 12­lead ECG and AI-QTc on the corresponding SW-ECG was assessed by the Bland-Altman method. RESULTS: 85 patients (30 men, mean age 38.3 ± 12.2 years) were included in the study. Fair agreement between manual and AI-QTc values was observed, particularly at day-10, where the delay between the 12­lead ECG and the SW-ECG was the shortest (-2.6 ± 64.7 min): 407 ± 26 ms on the 12­lead ECG vs 407 ± 22 ms on SW-ECG, bias -1 ms, limits of agreement -46 ms to +45 ms; the difference between the two measures was <50 ms in 98.2% of patients. CONCLUSION: In real-world epidemic conditions, AI-QTc duration measured by SW-ECG is in fair agreement with manual measurements on 12­lead ECGs. Following further validation, AI-assisted SW-ECGs may be suitable for QTc interval monitoring. REGISTRATION: ClinicalTrial.govNCT04371744.

Seasonal variations in cardiac implantable electronic device infections.

Infections of cardiac implantable electronic devices (CIEDs) have increased over the past decade. However, the impact of the climate on CIED infections is unknown. To determine whether there is a seasonal variation in CIED infections. In this single-center observational study, retrospective analysis of prospectively collected data was performed. Timone Hospital in Marseille (south-east France) is a tertiary care institution and the regional reference center for management of CIED infections. All consecutive patients with CIED extractions for infectious reasons were included over a 12-year period. We noted the mean temperature (°C), precipitation (mm) and the incidence of CIED infections over this period. Among 612 patients [mean (standard deviation) age, 72.4 (13.0) years; 74.0% male], 238 had endocarditis alone (38.9%), 249 had pocket infection alone (40.7%), and 125 had both (20.4%). We found bacterial documentation in 428 patients (70.0%), commensal in 245 (40.0%). The incidence of CIED infections was positively associated with high temperature (regression coefficient = 0.075; P = 0.01) and precipitation (regression coefficient = 0.022; P < 0.01). Seasonal variation was specific of pocket infections, whether they were associated with endocarditis or not. Subgroups with infection seasonality were: women, elderly people (> 75 years), late CIED infection and skin commensal bacterial infections. We found a seasonal variation in pocket infections, whether associated with endocarditis or not. Infections were associated with elevated temperatures and precipitation. Therefore, specific prevention strategy should be discussed in high-risk patients.

Device-Related Thrombus After Left Atrial Appendage Occlusion With the Amulet Device.

BACKGROUND: Left atrial appendage occlusion (LAAO) is increasingly used for stroke prevention in patients with atrial fibrillation who are considered unsuitable for a lifelong oral anticoagulant regimen. Recently, a single-centre study reported device-related thrombus formation in 16.7% of patients treated with the second-generation Amulet device (St. Jude Medical, St. Paul, MN, USA), presenting a potential major safety concern. As "real-world" data on device-related thrombus formation following LAAO with the Amulet occluder are scarce, we aimed to evaluate this outcome in a retrospective registry. METHODS: Clinical and tranosesophageal echocardiography data after LAAO with the Amulet in consecutive patients from three centres were collated. RESULTS: Among 38 patients (mean age 75.8 years), mean (standard deviation) CHA2DS2-VASc and HAS-BLED scores were 4.4 (1.2) and 3.4 (0.9), respectively. All patients underwent successful device placement without procedure-related adverse events. The antithrombotic regimen at discharge consisted of dual antiplatelet therapy (DAPT) in 27 patients (71.1%), single antiplatelet therapy in 10 patients (26.3%), and no antithrombotic therapy in one patient (2.6%). Device-related thrombus was observed in one patient (2.6%) despite DAPT regimen. The outcome of this patient was uncomplicated after adjustment of oral anticoagulant therapy. No patients presented with a thromboembolic event following LAAO during a mean (standard deviation) follow-up of 15 (5) months. CONCLUSIONS: In this retrospective study, device-related thrombus formation with the second-generation Amulet device was rare and occurred at a rate similar to that of the previous device. Importantly, no patient experienced a device-related thromboembolic event during follow-up. Larger real-life studies are required to confirm the safety profile of this increasingly used device.

Adenosine plasma level in patients with paroxysmal or persistent atrial fibrillation and normal heart during ablation procedure and/or cardioversion.

The mechanism of atrial fibrillation (AF) in patients with normal heart remains unclear. While exogenous adenosine can trigger AF, nothing is known about the behavior of endogenous adenosine plasma level (APL) at the onset of AF and during ablation procedure. Ninety-one patients (68 with paroxysmal AF: 40 males, 66 ± 16 years; 23 with persistent AF: 14 males, 69 ± 11 years) and 18 controls were included. Among paroxysmal patients: i) medical therapy alone was performed in 45 cases and ablation procedure in 23. AF was spontaneously resolutive in 6 cases; ii) 23 underwent ablation procedure and blood was collected simultaneously in a brachial vein and in the left atrium; 17 were spontaneously in sinus rhythm while 6 were in sinus rhythm after direct current cardioversion. Among persistent patients: i) in 17 patients, blood samples were collected in a brachial vein before and after direct current cardioversion; ii) in 6 patients, blood samples were collected simultaneously in a brachial vein and in left atrium before and after cardioversion during ablation procedure. CV-APL was higher in patients with persistent AF vs patients with paroxysmal AF (median [range]: 0.9[0.6-1.1] vs 0.7[0.4-1.1] µM; p < 0.001). In patients with paroxysmal AF, LA-APL increased during the AF episode (0.95[0.85-1.4] vs 2.7[1.5-7] µM; p = 0.03) and normalized in sinus rhythm after DCCV. In patients with persistent AF, LA-APL was higher than CV-APL (1.2[0.7-1.8] vs 0.9[0.6-1.1] µM; p < 0.001), and both normalized in sinus rhythm (CV-APL: 0.8[0.6-1.1] vs 0.75[0.4-1] µM; p = 0.03), (LA-APL: 1.95[1.3-3] vs 1[0.5-1.15] µM; p = 0.03). The occurrence of AF is associated with a strong increase of APL in the atrium. The cause of this increase needs further investigations.

High-density mapping for catheter ablation of premature ventricular complexes originating from left ventricular papillary muscles: A case series.

PURPOSE: Ablation of premature ventricular complexes (PVCs) originating from left-sided papillary muscles is challenging. We tested a new approach by performing high-density mapping of PVC. METHODS AND RESULTS: We used a 20-pole deflectable spiral catheter during ablation procedures in four consecutive patients. Three presented with mitral valve prolapse, one with dilated cardiomyopathy. PVC burden was 24 ± 13%. The procedures lasted 182 ± 55.4 minutes, including 10 ± 3.2 minutes of radiofrequency. In all patients, mapping evidenced internal primary activation relative to the left ventricle shell (mean distance 21.3 ± 5.1 mm). Endocavitary prematurity was -38.3 ± 4.8 ms. Primary ablation success was achieved for all patients. CONCLUSIONS: High-density mapping of the papillary muscles in the left ventricle using a spiral catheter may be feasible. We identified the PVC foci away from the left ventricular shell. This consolidates the assumption for the origin of these ectopic beats at the junction between the chordae tendineae and the papillary muscles.

Device-Related Thrombosis After Percutaneous Left Atrial Appendage Occlusion for Atrial Fibrillation.

BACKGROUND: Transcatheter left atrial appendage (LAA) occlusion is an alternative strategy for stroke prevention in patients with atrial fibrillation (AF). OBJECTIVES: This study sought to determine the incidence, predictors, and prognosis of thrombus formation on devices in patients with AF who were treated with LAA closure. METHODS: The study retrospectively analyzed data from patients treated with 2 LAA closure devices seen in 8 centers in France from February 2012 to January 2017. RESULTS: A total of 469 consecutive patients with AF underwent LAA closure (272 Watchman devices [Atritech, Boston Scientific, Natick, Massachusetts] and 197 Amplatzer devices [St. Jude Medical, Minneapolis, Minnesota]). Mean follow-up was 13 ± 13 months, during which 339 (72.3%) patients underwent LAA imaging at least once. There were 98 major adverse events (26 thrombi on devices, 19 ischemic strokes, 2 transient ischemic attacks, 18 major hemorrhages, 33 deaths) recorded in 89 patients. The incidence of device-related thrombus in patients with LAA imaging was 7.2% per year. Older age (hazard ratio [HR]: 1.07 per 1-year increase; 95% confidence interval [CI]: 1.01 to 1.14; p = 0.02) and history of stroke (HR: 3.68; 95% CI: 1.17 to 11.62; p = 0.03) were predictors of thrombus formation on the devices, whereas dual antiplatelet therapy (HR: 0.10; 95% CI: 0.01 to 0.76; p = 0.03) and oral anticoagulation at discharge (HR: 0.26; 95% CI: 0.09 to 0.77; p = 0.02) were protective factors. Thrombus on the device (HR: 4.39; 95% CI: 1.05 to 18.43; p = 0.04) and vascular disease (HR: 5.03; 95% CI: 1.39 to 18.23; p = 0.01) were independent predictors of ischemic strokes and transient ischemic attacks during follow-up. CONCLUSIONS: Thrombus formation on the device is not uncommon in patients with AF who are treated by LAA closure. Such events are strongly associated with a higher risk of ischemic stroke during follow-up. (REgistry on Real-Life EXperience With Left Atrial Appendage Occlusion [RELEXAO]; NCT03279406).

Ventricular Arrhythmia Occurrence and Compliance in Patients Treated With the Wearable Cardioverter Defibrillator Following Percutaneous Coronary Intervention.

BACKGROUND: The wearable cardioverter defibrillator (WCD) is a life-saving therapy in patients with high risk of arrhythmic death. We aimed to evaluate ventricular arrhythmia (VA) occurrence rate and compliance with the WCD during the first 90 days following myocardial revascularisation with percutaneous coronary intervention (PCI) in patients with left ventricular ejection fraction (LVEF) <30%. METHODS: From September 2015 to November 2016, clinical characteristics, WCD recordings and compliance data of the aforementioned subset of patients were prospectively collected. RESULTS: Twenty-four patients (men=20, 80%) were included in this analysis. Mean age was 56±10 years and mean LVEF at enrolment was 26.6±4.3%. During a mean wearing period of 3.0±1.3 months, two episodes of VA occurred in two patients (8.3%): one successfully treated with WCD shock and one with spontaneous termination. The mean and median daily use of the WCD was 21.5hours and 23.5hours a day, respectively. Eighteen patients (75%) wore the WCD more than 22hours a day. CONCLUSIONS: The rate of VA, during the WCD period use after myocardial revascularisation with PCI, was high in our study. Otherwise it underlined that patient compliance is critical during the WCD period use. Remote monitoring and patient education are keys to achieve good compliance.

Comparison of epicardial vs. endocardial reimplantation in pacemaker-dependent patients with device infection.

Aims: Reimplantation of cardiac implantable electronic devices (CIEDs) after extraction due to device infection is a major issue in pacemaker-dependent patients. We compared in-hospital and long-term outcomes with two techniques: epicardial reimplantation (EPI) before CIED extraction and temporary pacing (TP) with a view to delayed endocardial reimplantation. Methods and results: Two cohorts of consecutive pacemaker-dependent patients who underwent transvenous lead extraction at our tertiary centre were included in this retrospective cohort study. According to successive policies, either the EPI or the TP approach was used. In-hospital complications occurred at similar rates in the EPI (n = 59) and TP (n = 52) cohorts (37.3% vs. 32.7%, respectively; P = 0.61). Thirteen (25.0%) patients in the TP cohort eventually were reimplanted epicardially, mainly because of infection of the temporary lead. Finally, 65 patients were discharged with an epicardial device and 37 with an endocardial device. Median follow-up was 41.7 (interquartile range 34.1-51.5) months. No difference was observed in long-term mortality according to the reimplantation strategy, but use of TP was associated with a reduced risk of late endocarditis and device reintervention (hazard ratio (HR) 0.25, 95% confidence interval (CI) 0.09-0.069, P = 0.01), whereas epicardial device reimplantation was associated with an increased risk (HR 3.62, 95% CI 1.07-12.21, P = 0.04). Conclusion: We observed similar in-hospital outcomes in our EPI and TP cohorts. Twenty-five percent of the patients initially paced by a TP strategy finally needed an epicardial device, mainly because of infection of their TP lead. Use of TP resulted in lower rates of late endocarditis and device reintervention.

Right ventricular and tricuspid valve function in patients chronically implanted with leadless pacemakers.

Aims: Leadless cardiac pacing has recently been proposed as alternative to conventional right ventricular (RV) pacing. With this approach, devices are directly screwed or fixed with tines in the RV wall, but the possible consequences on RV and tricuspid valve (TV) structure and function remain unknown. We thus conducted a study to evaluate this potential impact in chronically implanted patients. Methods and results: Repeated echocardiographic studies were performed prior to implantation, at discharge, and 2 months thereafter on all consecutive patients implanted with a leadless pacemaker at our centre between October 2014 and end-December 2015. Whenever possible, patients were evaluated in non-paced rhythm. Anatomical and functional parameters of RV, TV, and left cardiac structures were assessed. Overall, 23 patients (12 females, aged 85.2 ± 6.3 years) were included, with 14 implanted using Nanostim™ (Saint Jude Medical) and 9 with Micra™ (Medtronic). Indications for pacing were paroxysmal atrio-ventricular block in 12 patients, intermittent sinus bradycardia in 5, unexplained syncope in 3, and atrial fibrillation with slow ventricular rate in the remaining 3. The pacing percentage was 34 ± 42% at the last visit. Most devices were implanted in the septo-apical or mid-septal region. There were no significant changes in echocardiographic parameters observed. One patient developed significantly increased TV regurgitation, without abnormal leaflet motion or TV annulus size changes, suggesting it to be due to RV pressure changes. Conclusion: In patients chronically implanted with leadless pacemakers, there were no significant changes in heart structure and function observed, especially concerning the RV and TV.

Theophylline as an adjunct to control malignant ventricular arrhythmia associated with early repolarization.

Early repolarization (ER) has been associated with an increased risk of sudden cardiac arrest. Interestingly, ventricular arrhythmias seem to be triggered by parasympathetic stimulation. In the present case report, we describe complete control of highly frequent malignant ventricular arrhythmias after adding theophylline to ineffective oral hydroquinidine and high-rate pacing in a patient suffering from malignant ER. We hypothesize that the theophylline-mediated enhanced beta-adrenergic stimulation could reduce the transmural myocardial voltage discrepancy by increasing the inward ICa,L current.