Dataset Information

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

ABSTRACT:

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.

SUBMITTER: Kyriacou A

PROVIDER: S-EPMC6099378 | biostudies-literature | 2018 Jun

REPOSITORIES: biostudies-literature

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Publications

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

Kyriacou Andreas A Rajkumar Christopher A CA Pabari Punam A PA Sohaib S M Afzal SMA Willson Keith K Peters Nicholas S NS Lim Phang B PB Kanagaratnam Prapa P Hughes Alun D AD Mayet Jamil J Whinnett Zachary I ZI Francis Darrel P DP

Pacing and clinical electrophysiology : PACE 20180601

<h4>Background</h4>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.<h4>Methods</h4>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 ...[more]

PMID: 29856077

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Dataset Information

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

Background

Methods

Results

Conclusions

Publications

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

Similar Datasets

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