Sporadic high pacing and shock impedance on remote monitoring in hybrid implantable cardioverter-defibrillator systems: Clinical impact and management

Abstract Background Sacubitril/valsartan, the first combined angiotensin receptor-neprilysin inhibitor, has demonstrated a significant benefit compared to angiotensin inhibitor in decreasing ventricular arrhythmias and appropriate implantable cardioverter defibrillator (ICD) shocks in patients with heart failure with reduced ejection fraction (HFrEF). At present, there is no study which evaluates the effect of sacubitril/valsartan on the supraventricular arrhythmic burden in HFrEF patients with an ICD or cardiac resynchronisation therapy-defibrillator (CRT-D) and remote monitoring. Purpose To evaluate the effect of sacubitril/valsartan on the supraventricular arrhythmic burden in HFrEF patients with an ICD or CRTD and remote monitoring. Methods The SAVETHERHYTHM ((SAacubitril Valsartan rEal-world registry evaluating THE arRHYTHMia burden in HFrEF patients with implantable cardioverter defibrillator) is a multicentre, observational, prospective registry enrolling all patients with HFrEF, ICD or CRT-D actively followed through remote monitoring and starting treatment with sacubitril/valsartan. All patients are followed-up for at least one year after sacubitril/valsartan start. The primary endpoint is the mean number of sustained atrial tachycardia or atrial fibrillation (AT/AF) episodes per month. Secondary endpoints include the total burden of AT/AF (defined as the percentage of time in AT/AF per day), the mean number of premature ventricular contractions (PVC) per hour and the percentage of biventricular pacing per day (in patients with CRT-D). All primary and secondary endpoints are collected through remote monitoring. Results At the time of the first ad interim analysis, 60 patients (85.2% male, age 69±10 years) were consecutively enrolled. After treatment with sacubitril/valsartan, patients with at least one episode of AT/AF per month decreased from 32.8% to 21.3% (p=0.015). A significant decrease in number of AT/AF episodes (from 4.3 to 1.2 per year), in AT/AF burden (from 12% to 9%) and in number of PVC (from 83 to 74 per hour) were seen in patients with a previous diagnosis of paroxysmal or persistent AF (n=15; all p<0.05). Patients with permanent AF (n=7) experienced no benefits from sacubitril/valsartan therapy in terms of arrhythmic burden reduction. Patients with no previous history of AF (n=38) showed a decrease in number of AT/AF episodes (from 2.0 to 0.8 per year) and in number of PVC (from 77 to 49 per hour, all p<0.05). No new diagnosis of clinical AF was made after starting treatment with sacubitrl/valsartan, and patients with subclinical AT/AF episodes decreased from 8% to 3%. Conclusions Preliminary data suggest that therapy with sacubitril/valsartan could decrease arrhythmic burden in patients with non-permanent AF and reduce subclinical AT/AF episodes in patients with no history of AF. No positive effect has been noted in patients with permanent AF. Funding Acknowledgement Type of funding source: None

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Defibrillation success after subcutaneous implantable cardioverter-defibrillator generator replacement is not affected by impedance increase

EP Europace ◽

10.1093/europace/euab116.416 ◽

2021 ◽

Vol 23 (Supplement_3) ◽

Author(s):

W Van Der Stuijt ◽

S Pepplinkhuizen ◽

ABE Quast ◽

L Smeding ◽

LRA Olde Nordkamp ◽

...

Keyword(s):

Ventricular Arrhythmia ◽

Success Rate ◽

Implantable Cardioverter Defibrillator ◽

Retrospective Analysis ◽

Analysis Data ◽

Cardioverter Defibrillator ◽

Replacement Procedure ◽

Shock Impedance ◽

Tertiary Center ◽

Generator Replacement

Abstract Funding Acknowledgements Type of funding sources: None. Background Routine defibrillation testing during implant and replacement of the subcutaneous implantable cardioverter-defibrillator (S-ICD) is recommended per current guidelines. Recently, concerns have been raised about an increase in shock impedance and consequent shock failure during defibrillation testing in S-ICD patients undergoing a generator replacement. Purpose We aim to describe the defibrillation success rate in relation to the shock impedance in patients undergoing S-ICD generator replacement in our large tertiary center. Methods In this retrospective analysis, data from replacement procedures were collected from all patients who underwent an S-ICD generator replacement in our center from June 2014 to December 2020. Defibrillation testing was performed with at least one shock of ≤65J, and a successful shock was defined as terminating the ventricular arrhythmia within 5 seconds after the shock. Results A total of 133 patients underwent an S-ICD generator replacement, 5.8 ± 0.9 years after initial implant. Reasons for replacement were: reaching of elective replacement indicator (n = 119), early battery depletion (n = 9), complaints of generator pocket (n = 3) and device malfunction (n = 2). Defibrillation testing was performed in 111 patients (86.5%) undergoing a replacement procedure. Shock impedance data from both the implant and replacement procedure were available in 101 patients. The median shock impedance of these patients during their replacement procedure was significantly higher than during their implant, 79Ω (IQR 66-94) and 66Ω (IQR 57.5-81) respectively (Z = -5.552, p < 0.001). Despite the higher shock impedance, first shock during defibrillation testing was successful in 105/111 patients (94.6%), with a success rate of 97.3% after two attempts. In the remaining three patients, the ventricular arrhythmia could only be terminated with a 80J shock. This was the case during both their initial implant and their replacement procedure. Shock impedance increase between implant and replacement was not significantly higher in patients with a successful first shock compared to patients with an unsuccessful first shock (Δ+11.1 ± 20.0Ω versus Δ+12.7 ± 27.6Ω, p = 0.86). Conclusion In this large retrospective analysis, we have shown a first shock success rate during S-ICD generator replacement of 94.6%, which is similar to the success rate of defibrillation testing after initial implant. After multiple attempts, defibrillation testing success rate was 100%. Even though the median shock impedance during replacement was significantly higher than during the initial implant, there was no difference in impedance increase in patients with a successful shock compared to patients with an unsuccessful shock. Abstract Figure. Defibrillation success

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65Time until diagnosis of ventricular tachyarrhythmia with remote monitoring systems differ considerably according to Implantable Cardioverter-Defibrillator therapies

EP Europace ◽

10.1093/europace/euy015.027 ◽

2018 ◽

Vol 20 (suppl_1) ◽

pp. i12-i12

Author(s):

M Soth-Hansen ◽

C T Witt ◽

M Rasmussen ◽

J Kristensen ◽

C Gerdes ◽

...

Keyword(s):

Implantable Cardioverter Defibrillator ◽

Remote Monitoring ◽

Ventricular Tachyarrhythmia ◽

Monitoring Systems ◽

Cardioverter Defibrillator ◽

Remote Monitoring Systems

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Thoracoscopic Implantation of An Array Electrode in the Pericardium Transverse Sinus to Reduce Defibrillation Threshold

Innovations Technology and Techniques in Cardiothoracic and Vascular Surgery ◽

10.1097/imi.0000000000000384 ◽

2017 ◽

Vol 12 (4) ◽

pp. e6-e9 ◽

Cited By ~ 2

Author(s):

Antonio Curnis ◽

Claudio Muneretto ◽

Gianluigi Bisleri ◽

Manuel Cerini ◽

Lorenza Inama ◽

...

Keyword(s):

Implantable Cardioverter Defibrillator ◽

Transverse Sinus ◽

Cardiac Resynchronization ◽

Defibrillation Threshold ◽

Invasive Approach ◽

Cardioverter Defibrillator ◽

Array Electrode ◽

Shock Impedance ◽

Shock Output ◽

Consequent Increase

Among the implantable cardioverter defibrillator recipients, there is still a subgroup of patients in whom the defibrillation threshold is too high and the maximal shock output of the implantable cardioverter defibrillator can fail to terminate a ventricular arrhythmia. We report a new thoracoscopic minimally invasive approach to place a standard array electrode in the transverse pericardial sinus of a patient implanted with a cardiac resynchronization and defibrillation therapy device with persistent high defibrillation threshold. This approach was developed to achieve very low shock impedance with a consequent increase in the current flow and reduction of defibrillation threshold.

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