Multinational evaluation of the interpretability of the iterative method of optimisation of AV delay for CRT

Raphael, Claire E.; Kyriacou, Andreas; Jones, Siana; Pabari, Punam A.; Cole, Graham D.; Baruah, Resham; Hughes, Alun D.; Francis, Dárrel P.

doi:10.1016/j.ijcard.2012.09.097

Cited by 17 publications

(12 citation statements)

References 13 publications

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“…As consequence of the different mechanism of optimization of CRT, different protocols are being used for optimization of CRT, using either filling (E-A-wave separation, diastolic filling times) or systolic parameters with respect to the latter either externally measured indices, like aortic velocity-time integral and systolic blood pressure are being used, as well as device-based algorithm using signals from lead electrograms or accelerometer sensors. [3][4][5] Clearly, better insight into the mechanisms of…”

Section: Clinical Perspective On P 931mentioning

confidence: 99%

Interplay of Electrical Wavefronts as Determinant of the Response to Cardiac Resynchronization Therapy in Dyssynchronous Canine Hearts

Strik

Middendorp

Houthuizen

et al. 2013

Circ: Arrhythmia and Electrophysiology

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Background-The relative contribution of electromechanical synchronization and ventricular filling to the optimal hemodynamic effect in cardiac resynchronization therapy (CRT) during adjustment of stimulation-timings is incompletely understood. We investigated whether optimal hemodynamic effect in CRT requires collision of pacing-induced and intrinsic activation waves and optimal filling of the left ventricle (LV). Methods and Results-CRT was performed in dogs with chronic left bundle-branch block (n=8) or atrioventricular (AV) block (n=6) through atrial (A), right ventricular (RV) apex, and LV-basolateral pacing. A 100 randomized combinations of A-LV/A-RV intervals were tested. Total activation time (TAT) was calculated from >100 contact mapping electrodes. Mechanical interventricular dyssynchrony was determined as the time delay between upslopes of LV and RV pressure curves. Settings providing an increase in LVdP/dt max (maximal rate of rise of left ventricular pressure) of ≥90% of the maximum LVdP/dt max value were defined as optimal (CRT opt ). Filling was assessed by changes in LV end-diastolic volume (EDV; conductance catheter technique). In all hearts, CRT opt was observed during multiple settings, providing an average LVdP/dt max increase of ≈15%. In AV-block hearts, CRT opt exclusively depended on interventricular-interval and not on AVinterval. In left bundle-branch block hearts, CRT opt occurred at A-LV intervals that allowed fusion of LV-pacing-derived activation with right bundle-derived activation. In all animals, CRT opt occurred at settings resulting in the largest decrease in TAT and mechanical interventricular dyssynchrony, whereas LV EDV hardly changed. Conclusions-In left bundle-branch block and AV-block hearts, optimal hemodynamic effect of CRT depends on optimal interplay between pacing-induced and intrinsic activation waves and the corresponding mechanical resynchronization rather than filling.

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Section: Clinical Perspective On P 931mentioning

confidence: 99%

Interplay of Electrical Wavefronts as Determinant of the Response to Cardiac Resynchronization Therapy in Dyssynchronous Canine Hearts

Strik

Middendorp

Houthuizen

et al. 2013

Circ: Arrhythmia and Electrophysiology

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“…Different observers may do this differently (4,5), which we may falsely attribute to lack of skill on the part of the junior observer. In reality, even experienced observers may not realize they are doing it differently when secretly given identical data twice (95). …”

Section: Noise Optimism and Denial – Perspectives For Reliable Discomentioning

confidence: 99%

Translating Stem Cell Research to Cardiac Disease Therapies

Rosen

Myerburg

Francis

et al. 2014

Journal of the American College of Cardiology

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Over the past 2 decades, there have been numerous stem cell studies focused on cardiac diseases, ranging from proof-of-concept to phase 2 trials. This series of articles focuses on the legacy of these studies and the outlook for future treatment of cardiac diseases with stem cell therapies. The first section by Rosen and Myerburg is an independent review that analyzes the basic science and translational strategies supporting the rapid advance of stem cell technology to the clinic, the philosophies behind them, trial designs, and means for going forward that may impact favorably on progress. The second and third sections were collected in response to the initial section of this review. The commentary by Francis and Cole discusses the Rosen and Myerburg review and details how trial outcomes can be affected by noise, poor trial design (particularly the absence of blinding), and normal human tendencies toward optimism and denial. The final, independent article by Marbán takes a different perspective concerning the potential for positive impact of stem cell research applied to heart disease and future prospects for its clinical application.

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“…71 The AV delay found to provide maxi-mum separation of the E and A waves can be programmed, but this method has, however, been criticized for high inter-and intraobserver variability. 72 VV optimization can be performed by a number of estimations of stroke volume. 71,[73][74][75] Non-randomized studies have shown benefit of VV optimization, and improved exercise capacity, 74,76 while randomized studies 77,78 have failed to show an effect, when compared to a nominal setting.…”

Section: Device Interrogation and Programmingmentioning

confidence: 99%

Individualized cardiac resynchronization therapy: current status

Ruwald¹,

Bruun²

2014

RRCC

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Cardiac resynchronization therapy (CRT) has shown a substantial reduction in heart failure patient morbidity and mortality, with improvement in quality of life as well as symptoms. The therapy is, however, limited to approximately 10%-15% of heart failure patients and, typically, 30% do not derive benefit from the device. For optimal outcomes with CRT, the correct selection of patients is of paramount importance. The first parameter is depressed left ventricular systolic function, and the second is a wide QRS complex. Different nuances among clinical trials have rendered guidelines pragmatic and compromising, but also conflicting and confusing. A large proportion of real-life CRTs are implanted in patients where the evidence for benefit is scarce or not present. Further, for optimal benefit, patients require evidence-directed medical therapy at maximal doses, effective placement of ventricular leads, and high biventricular pacing percentages, along with optimized atrioventricular (AV) and interventricular interval device programming. These items, as well as specific clinical characteristics, such as AV block and atrial fibrillation, in the context of CRT indications, are discussed. This review focuses on these issues to guide the clinician through guidelines, with an evidence-based update on the current status of CRT.

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Multinational evaluation of the interpretability of the iterative method of optimisation of AV delay for CRT

Cited by 17 publications

References 13 publications

Interplay of Electrical Wavefronts as Determinant of the Response to Cardiac Resynchronization Therapy in Dyssynchronous Canine Hearts

Interplay of Electrical Wavefronts as Determinant of the Response to Cardiac Resynchronization Therapy in Dyssynchronous Canine Hearts

Translating Stem Cell Research to Cardiac Disease Therapies

Individualized cardiac resynchronization therapy: current status

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