scholarly journals High-rate pacing guided by short-term variability of repolarization prevents imminent ventricular arrhythmias automatically by an implantable cardioverter-defibrillator in the chronic atrioventricular block dog model

Heart Rhythm ◽  
2020 ◽  
Vol 17 (12) ◽  
pp. 2078-2085
Author(s):  
Agnieszka Smoczyńska ◽  
Vera Loen ◽  
Alfonso Aranda ◽  
Henriëtte D.M. Beekman ◽  
Mathias Meine ◽  
...  
Keyword(s):  
Implantable Cardioverter Defibrillator ◽  
Atrioventricular Block ◽  
Ventricular Arrhythmias ◽  
High Rate ◽  
Short Term ◽  
Cardioverter Defibrillator ◽  
Dog Model ◽  
Short Term Variability

Short-term variability of repolarization is equally modulated by atrial and (bi)ventricular high rate pacing in patients with an indication for an implantable cardioverter defibrillator

EP Europace ◽  
2021 ◽  
Vol 23 (Supplement_3) ◽  
Author(s):  
A Smoczynska ◽  
DJ Sprenkeler ◽  
H Jalink ◽  
HJ Ritsema Van Eck ◽  
M Meine ◽  
...  
Keyword(s):  
Sinus Rhythm ◽  
Implantable Cardioverter Defibrillator ◽  
Qt Interval ◽  
Biventricular Pacing ◽  
High Rate ◽  
Dual Chamber ◽  
Short Term ◽  
Cardioverter Defibrillator ◽  
Dispersion Of Repolarization ◽  
Short Term Variability

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Dutch Heart Foundation Background  An increase in temporal dispersion of repolarization, quantified as short-term variability of the QT-interval (STV-QT), precedes ventricular arrhythmias and has therefore been proposed as a marker for monitoring of imminent arrhythmic risk. A reversal of an increased STV by high rate pacing at 100 bpm was anti-arrhythmic in the chronic atrioventricular block dog model susceptible to Torsade de Pointes arrhythmias upon challenge with an IKr-blocker. The objective of the current study was to investigate the physiological modulation of STV by pacing in patients with an indication for an implantable cardioverter defibrillator (ICD), and to compare atrial and ventricular pacing. Methods  ECG recordings were obtained with a sampling frequency of 1200 Hz in 10 dual chamber ICD patients and 10 patients with cardiac resynchronization therapy with defibrillation function (CRT-D) during the implantation or replacement. One-minute recordings were made during sinus rhythm (SR), and during pacing at 80 and 100 beats per minute (bpm) from the atrium (AAI), atrium and right ventricle (DDD RVp), and during atrio-biventricular pacing (DDD BiVp). The QT-interval was determined offline with fiducial segment averaging at one minute of each pacing rate, and 31 consecutive beats were used to calculate STV-QT with the following formula: ∑|D(n + 1)-Dn |/(N×√2), where D represents the determinant of repolarization (in this case the QT interval), and N represents the number of beats taken into account minus 1. Results  In the patients overall, STV-QT decreased from 1.27 ± 0.38 ms in SR (±58 bpm) to 0.86 ± 0.26 ms* during AAI80, and to 0.68 ± 0.22 ms*† during AAI100 (*p < 0.05 compared to SR, †p < 0.05 compared to 80 bpm). The same decrease was seen during DDD80 RVp (0.81 ± 0.28 ms*) and during DDD100 RVp (0.66 ± 0.22 ms*†) (fig. 1). Additionally, DDD BiVp decreased STV-QT to 0.78 ± 0.20 ms* at 80 bpm and to 0.62 ± 0.19 ms* at 100 bpm in CRT-D patients (fig. 2). Conclusion  Pacing at 80 and 100 bpm decreases STV-QT compared to sinus rhythm both in dual chamber ICD patients and CRT-D patients. The modulation of STV-QT is similar during atrial, and atrio- right ventricular and atrio-biventricular pacing. Abstract Figure. Modulation of STV-QT by AAI and DDD RVp

scholarly journals The Increment of Short-term Variability of Repolarisation Determines the Severity of the Imminent Arrhythmic Outcome

2019 ◽  
Vol 8 (3) ◽  
pp. 166-172 ◽  
Author(s):  
Agnieszka Smoczynska ◽  
Henriëtte DM Beekman ◽  
Marc A Vos
Keyword(s):  
Experimental Data ◽  
Atrioventricular Block ◽  
Ventricular Arrhythmias ◽  
Torsades De Pointes ◽  
Canine Model ◽  
Ventricular Remodelling ◽  
Short Term ◽  
Determining Factors ◽  
Underlying Mechanisms ◽  
Short Term Variability

Ventricular remodelling can make the heart more susceptible to ventricular arrhythmias like torsades de pointes. Understanding the underlying mechanisms of initiation of ventricular arrhythmias and the determining factors for its severity has the potential to uncover new interventions. Beat-to-beat variation of repolarisation, quantified as short-term variability of repolarisation (STV), has been identified as an important factor contributing to arrhythmogenesis. This article provides an overview of experimental data about STV in relation to the initiation of torsades de pointes in a canine model of complete chronic atrioventricular block susceptible to torsades de pointes arrhythmias. Furthermore, it explores STV in relation to the severity of the arrhythmic outcome.

scholarly journals High rate pacing guided by short-term variability of repolarization prevents imminent ventricular arrhythmias autonomically by an ICD

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
A Smoczynska ◽  
V Loen ◽  
A.A Hernandez ◽  
H.D.M Beekman ◽  
M Meine ◽  
...  
Keyword(s):  
Ventricular Arrhythmias ◽  
Torsade De Pointes ◽  
Left Ventricular ◽  
High Rate ◽  
Monophasic Action Potential ◽  
Funding Source ◽  
Short Term ◽  
Dispersion Of Repolarization ◽  
Temporal Dispersion ◽  
Short Term Variability

Abstract Background The anesthetized, chronic complete atrioventricular block (CAVB) dog model allows reproducible inducibility of Torsade de Pointes (TdP) arrhythmias due to ventricular remodeling and after a challenge with an IKr-blocker. High rate pacing (HRP) prevents ventricular arrhythmias, but has long-term detrimental effects on cardiac function when applied continuously. Temporal dispersion of repolarization, quantified as short-term variability (STV), increases prior to ventricular arrhythmias and has been proposed as a marker to guide HRP. Purpose A proof-of-principle study to show STV determined automatically and in real-time by an ICD can guide HRP to prevent imminent ventricular arrhythmias. Methods Eight CAVB dogs were implanted with an ICD (Medtronic, lead in the right ventricular (RV) apex), with software to automatically determine STV online (STV-ICD). STV was determined from the activation recovery interval (ARI) of 31 consecutive beats with the formula: STV = Σ|ARI(n+1) − ARI(n)|/(N*√2). The CAVB dogs were challenged twice with dofetilide (0.025 mg/kg i.v. in 5 minutes or until the first TdP). In the first experiment, the individual STV-ICD threshold was determined prior to the first arrhythmic event and programmed into the ICD. In a serial experiment, HRP was initiated automatically once the STV-ICD threshold was reached, by gradually increasing the heart rate to 100 bpm. Occurrence of TdPs was monitored for 10 minutes from the start of dofetilide infusion in both experiments. During HRP, STV was measured offline from RV electrograms (EGM) and left ventricular (LV) monophasic action potential durations (MAPD) (STV-offline). Results During the inducibility experiment, 8/8 dogs had repetitive TdPs and STV-ICD increased from 0.96±0.42 to 2.10±1.26 ms* (*p<0.05). During the prevention experiment, all dogs reached the STV threshold. HRP decreased STV-offline from 2.02±1.12 to 0.78±0.28 ms*, which was accompanied by prevention of TdPs in 7/8 dogs* (Figure 1). Conclusion Temporal dispersion of repolarization, quantified as STV, can guide HRP automatically by an ICD to prevent ventricular arrhythmias. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): Dutch Heart Foundation Public Private Partnership

scholarly journals LEFT VENTRICULAR LEAD IMPLANTATION FOR DETECTION OF VENTRICULAR ARRHYTHMIAS IN PATIENT WITH IMPLANTABLE CARDIOVERTER DEFIBRILLATOR AND LOW R WAVE IN RIGHT VENTRICLE

2021 ◽  
pp. 17
Author(s):  
Keyword(s):  
Sudden Cardiac Death ◽  
Right Ventricle ◽  
Implantable Cardioverter Defibrillator ◽  
Cardiac Death ◽  
Ventricular Arrhythmias ◽  
Systolic Function ◽  
Left Ventricular ◽  
Icd Implantation ◽  
Cardioverter Defibrillator ◽  
Ventricular Lead

Dilated cardiomyopathy (DCM) is a disease characterised as left ventricular (LV) or biventricular dilatation with impaired systolic function. Regardless of underlying cause patients with DCM have a propensity to ventricular arrhythmias and sudden cardiac death. Implantable Cardioverter Defibrillator (ICD) implantation for these patients results in significant reduction of sudden cardiac death [1-3]. ICD devices may be limited by right ventricle (RV) sensing dysfunction with low RV sensing amplitude. We present a clinical case of patient with DCM, implanted ICD and low R wave sensing on RV lead.

scholarly journals Incidence of Ventricular Arrhythmias and 1‐Year Predictors of Mortality in Patients Treated With Implantable Cardioverter‐Defibrillator Undergoing Generator Replacement

2021 ◽  
Vol 10 (4) ◽  
Author(s):  
Andrea Demarchi ◽  
Stefano Cornara ◽  
Antonio Sanzo ◽  
Simone Savastano ◽  
Barbara Petracci ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Heart Disease ◽  
Implantable Cardioverter Defibrillator ◽  
Ventricular Arrhythmias ◽  
Multivariable Analysis ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Ventricular Ejection Fraction ◽  
Cardioverter Defibrillator ◽  
Generator Replacement

Background When implantable cardioverter defibrillator (ICD) battery is depleted most patients undergo generator replacement (GR) even in the absence of persistent ICD indication. The aim of this study was to assess the incidence of ventricular arrhythmias and the overall prognosis of patients with and without persistent ICD indication undergoing GR. Predictors of 1‐year mortality were also analyzed. Methods and Results Patients with structural heart disease implanted with primary prevention ICD undergoing GR were included. Patients were stratified based on the presence/absence of persistent ICD indication (left ventricular ejection fraction ≤35% at the time of GR and/or history of appropriate ICD therapies during the first generator's life). The study included 371 patients (82% male, 40% with ischemic heart disease). One third of patients (n=121) no longer met ICD indication at the time of GR. During a median follow‐up of 34 months after GR patients without persistent ICD indication showed a significantly lower incidence of appropriate ICD shocks (1.9% versus 16.2%, P <0.001) and ICD therapies. 1‐year mortality was also significantly lower in patients without persistent ICD indication (1% versus 8.3%, P =0.009). At multivariable analysis permanent atrial fibrillation, chronic advanced renal impairment, age >80, and persistent ICD indication were found to be significant predictors of 1‐year mortality. Conclusions Patients without persistent ICD indication at the time of GR show a low incidence of appropriate ICD therapies after GR. Persistent ICD indication, atrial fibrillation, advanced chronic renal disease, and age >80 are significant predictors of 1‐year mortality. Our findings enlighten the need of performing a comprehensive clinical reevaluation of ICD patients at the time of GR.

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