A 10 J shock impedance in sinus rhythm correlates with a 65 J defibrillation impedance during subcutaneous defibrillator implantation using an intermuscular technique

Abstract Aims The traditional technique for subcutaneous implantable cardioverter-defibrillator (S-ICD) implantation involves three incisions and a subcutaneous pocket. Recently, a two-incision and intermuscular (IM) technique has been adopted. The PRAETORIAN score is a chest radiograph-based tool that predicts S-ICD conversion testing. We assessed whether the S-ICD implantation technique affects optimal position of the defibrillation system according to the PRAETORIAN score. Methods and results We analysed consecutive patients undergoing S-ICD implantation. The χ2 test and regression analysis were used to determine the association between the PRAETORIAN score and implantation technique. Two hundred and thirteen patients were enrolled. The S-ICD generator was positioned in an IM pocket in 174 patients (81.7%) and the two-incision approach was adopted in 199 (93.4%). According to the PRAETORIAN score, the risk of conversion failure was classified as low in 198 patients (93.0%), intermediate in 13 (6.1%), and high in 2 (0.9%). Patients undergoing the two-incision and IM technique were more likely to have a low (<90) PRAETORIAN score than those undergoing the three-incision and subcutaneous technique (two-incision: 94.0% vs. three-incision: 78.6%; P = 0.004 and IM: 96.0% vs. subcutaneous: 79.5%; P = 0.001). Intermuscular plus two-incision technique was associated with a low-risk PRAETORIAN score (hazard ratio 3.76; 95% confidence interval 1.01–14.02; P = 0.04). Shock impedance was lower in PRAETORIAN low-risk patients than in intermediate-/high-risk categories (66 vs. 96 Ohm; P = 0.001). The PRAETORIAN score did not predict shock failure at 65 J. Conclusion In this cohort of S-ICD recipients, combining the two-incision technique and IM generator implantation yielded the lowest PRAETORIAN score values, indicating optimal defibrillation system position. Clinical trial registration http://clinicaltrials.gov/ Identifier: NCT02275637.

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853Could baseline electrical parameters be a marker of arrhythmia occurrence and poorer prognosis in implantable cardioverter defibrillator patients?

EP Europace ◽

10.1093/europace/euaa162.182 ◽

2020 ◽

Vol 22 (Supplement_1) ◽

Author(s):

M Zecchin ◽

F Solimene ◽

A D"onofrio ◽

G Zanotto ◽

S Iacopino ◽

...

Keyword(s):

High Risk ◽

Sinus Rhythm ◽

Statistical Significance ◽

Univariate Analysis ◽

Multivariable Analysis ◽

Electrical Parameters ◽

Cardioverter Defibrillator ◽

Shock Impedance ◽

All Cause Mortality ◽

Atrial Sensing

Abstract Funding Acknowledgements This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Background/Introduction: Parameters routinely measured during cardiac devices implantation also depend on bioelectrical properties of the myocardial tissue. Purpose To explore the potential association of electrical parameters with clinical outcomes in implantable cardioverter-defibrillator (ICD) and cardiac resynchronization therapy defibrillators (CRT-D) recipients. Methods In the framework of the Home Monitoring Expert Alliance, baseline electrical parameters for all implanted leads were compared by occurrence of all-cause mortality, adjudicated ventricular arrhythmia (VA) and atrial high rate episode lasting ≥7 days (7day-AHRE). Results In a cohort of 2,976 patients (58.1% ICD) with a median follow-up of 25 months, events rates were 3.1/100 patient-years for all-cause mortality, 18.1/100 patient-years for VA and 8.9/100 patient-years for 7day-AHRE. At univariate analysis baseline shock impedance was consistently lower in groups with events than in those without, with a 40 Ohm cut-off better identifying patients at high risk, but at multivariable analysis the adjusted-hazard ratios (HRs) lost statistical significance for any endpoint. Baseline atrial sensing amplitude during sinus rhythm was lower in patients with 7-day AHRE as compared to those without (2.40 [IQ: 1.62-3.71] Vs 3.50 [IQ: 2.35-4.66] mV, p < 0.01). The adjusted-HR for 7-day AHRE in patients with atrial sensing >1.5 mV versus those with values ≤1.5 mV was 0.44 (95% CI:0.27-0.72), p = 0.001. Conclusion Despite in patients with events a lower baseline shock impedance was observed at univariate analysis, the association lost statistical significance at multivariable analysis. Conversely, low sinus rhythm atrial sensing (≤1.5 mV) measured with standard transvenous leads could identify subjects at high risk of long-lasting atrial arrhythmia. Abstract Figure. AHRE occurrence by atrial sensing

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