Distinct impacts of heart rate and right atrial-pacing on left atrial mechanical activation and optimal AV delay in CRT.

Autor: Kyriacou A; The Northern General Hospital, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, UK., Rajkumar CA; International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London, London, W12 0HS, UK., Pabari PA; International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London, London, W12 0HS, UK., Sohaib SMA; International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London, London, W12 0HS, UK., Willson K; International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London, London, W12 0HS, UK., Peters NS; International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London, London, W12 0HS, UK., Lim PB; International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London, London, W12 0HS, UK., Kanagaratnam P; International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London, London, W12 0HS, UK., Hughes AD; International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London, London, W12 0HS, UK., Mayet J; International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London, London, W12 0HS, UK., Whinnett ZI; International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London, London, W12 0HS, UK., Francis DP; International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London, London, W12 0HS, UK.
Jazyk: angličtina
Zdroj: Pacing and clinical electrophysiology : PACE [Pacing Clin Electrophysiol] 2018 Jun 01. Date of Electronic Publication: 2018 Jun 01.
DOI: 10.1111/pace.13401
Abstrakt: Background: Controversy exists regarding how atrial activation mode and heart rate affect optimal atrioventricular (AV) delay in cardiac resynchronization therapy. We studied these questions using high-reproducibility hemodynamic and echocardiographic measurements.
Methods: Twenty patients were hemodynamically optimized using noninvasive beat-to-beat blood pressure at rest (62 ± 11 beats/min), during exercise (80 ± 6 beats/min), and at three atrially paced rates: 5, 25, and 45 beats/min above rest, denoted as A paced,r+5 , A paced,r+25 , and A paced,r+45 , respectively. Left atrial myocardial motion and transmitral flow were timed echocardiographically.
Results: During atrial sensing, raising heart rate shortened optimal AV delay by 25 ± 6 ms (P < 0.001). During atrial pacing, raising heart rate from A paced,r+5 to A paced,r+25 shortened it by 16 ± 6 ms; A paced,r+45 shortened it 17 ± 6 ms further (P < 0.001). In comparison to atrial-sensed activation, atrial pacing lengthened optimal AV delay by 76 ± 6 ms (P < 0.0001) at rest, and at ∼20 beats/min faster, by 85 ± 7 ms (P < 0.0001), 9 ± 4 ms more (P  =  0.017). Mechanically, atrial pacing delayed left atrial contraction by 63 ± 5 ms at rest and by 73 ± 5 ms (i.e., by 10 ± 5 ms more, P < 0.05) at ∼20 beats/min faster. Raising atrial rate by exercise advanced left atrial contraction by 7 ± 2 ms (P  =  0.001). Raising it by atrial pacing did not (P  =  0.2).
Conclusions: Hemodynamic optimal AV delay shortens with elevation of heart rate. It lengthens on switching from atrial-sensed to atrial-paced at the same rate, and echocardiography shows this sensed-paced difference in optima results from a sensed-paced difference in atrial electromechanical delay. The reason for the widening of the sensed-paced difference in AV optimum may be physiological stimuli (e.g., adrenergic drive) advancing left atrial contraction during exercise but not with fast atrial pacing.
(© 2018 The Authors. Pacing and Clinical Electrophysiology published by Wiley Periodicals, Inc.)
Databáze: MEDLINE
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