Intrinsic regulation of sinoatrial node function and the zebrafish as a model of stretch effects on pacemaking

Macdonald, Eilidh; Stoyek, Matthew R.; Rose, Robert A.; Quinn, T. Alexander

doi:10.1016/j.pbiomolbio.2017.07.012

Cited by 25 publications

(32 citation statements)

References 157 publications

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“…ASD-related characteristic Occluder size 14 [12][13][14][15][16][17][18] 22 [17][18][19][20][21][22][23][24][25][26] Data are presented as median [25th-75th percentile] or frequency (%).…”

Section: Ecg Changes After Asd Closure In Childrenmentioning

confidence: 99%

“…The present study showed a direct decrease in heart rate after ASD closure in both children and adults, with a maintained decrease on the long term. We hypothesize that two mechanisms may have contributed to this heart rate decrease: deactivation of the Bainbridge reflex [20] and a decreased stretching of the pacemaking tissue in the sinus node [21]. Heart rate lowering via deactivation of the Bainbridge reflex after ASD can be expected on the basis of deactivation of the stretch receptors at the junction of the vena cava and the right atrium.…”

Section: Mechanisms Of Ecg Changes After Percutaneous Asd Closurementioning

confidence: 99%

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Electrical remodeling after percutaneous atrial septal defect closure in pediatric and adult patients

Kamphuis

Nassif

Man

et al. 2019

International Journal of Cardiology

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Background: Several studies have reported changes in electrocardiographic variables after atrial septal defect (ASD) closure. However no temporal electro-and vectorcardiographic changes have been described from acute to long-term follow-up at different ages. We aimed to study electrical remodeling after percutaneous ASD closure in pediatric and adult patients. Methods: ECGs of 69 children and 75 adults (median age 6 [IQR 4-11] years and 45 [IQR 33-54] years, respectively) were retrospectively selected before percutaneous ASD closure and at acute (1-7 days), intermediate (4-14 weeks) and late (6-18 months) follow-up. Apart from electrocardiographic variables, spatial QRS-T angle and ventricular gradient (VG) were derived from mathematically-synthesized vectorcardiograms. Results: In both pediatric and adult patients, the heart rate decreased immediately post-closure, which persisted to late follow-up. The P-wave amplitude also decreased acutely post-closure, but remained unchanged at later follow-up. The PQ duration shortened immediately in children and at intermediate follow-up in adults. The QRS duration and QTc interval decreased at intermediate-term follow-up in both children and adults. In both groups the spatial QRS-T angle decreased at late follow-up. The VG magnitude increased at intermediate follow-up in children and at late follow-up in adults, after an initial decrease in children. Conclusion: In both pediatric and adult ASD patients, electrocardiographic changes mainly occurred directly after ASD closure except for shortening of QRS duration and QTc interval, which occurred at later follow-up. Adults also showed late changes in PQ duration. At 6-to-18 month post-closure, the spatial QRS-T angle decreased, reflecting increased electrocardiographic concordance. The initial acute decrease in VG in children, which was followed by a significant increase, may be the effect of action potential duration dynamics directly after percutaneous ASD closure.

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“…ASD-related characteristic Occluder size 14 [12][13][14][15][16][17][18] 22 [17][18][19][20][21][22][23][24][25][26] Data are presented as median [25th-75th percentile] or frequency (%).…”

Section: Ecg Changes After Asd Closure In Childrenmentioning

confidence: 99%

Section: Mechanisms Of Ecg Changes After Percutaneous Asd Closurementioning

confidence: 99%

Electrical remodeling after percutaneous atrial septal defect closure in pediatric and adult patients

Kamphuis

Nassif

Man

et al. 2019

International Journal of Cardiology

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“…The rate of SAN firing, and, thus, cardiac beating rate (BR), is determined by multiple subcellular mechanisms whose interaction and mutual entrainment form a robust system that drives SAN automaticity ( Jalife, 1984 ; Noble et al, 1992 ; Lakatta et al, 2010 ). SAN automaticity is modulated by multiple factors, including the autonomic nervous system and various endocrine, paracrine, and autocrine agents, allowing adaptation of BR to changes in physiological demand ( MacDonald et al, 2017 , 2020 ). The SAN also responds to altered hemodynamic load through the Bainbridge response: an increase in BR upon right atrial distention, which may help in matching cardiac output to venous return ( Bainbridge, 1915 ).…”

Section: Introductionmentioning

confidence: 99%

Sinoatrial Node Structure, Mechanics, Electrophysiology and the Chronotropic Response to Stretch in Rabbit and Mouse

et al. 2020

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“…In each functionally specialized cardiac tissue, the AP has a characteristic shape generated by chamber-specific ion currents and ion channel compositions (43). However, the shape of the chamber-specific AP is far from constant; neuronal inputs, hormones, local tissue factors, temperature changes and stretch modifying AP waveform so that the pump function of the heart is optimally adjusted to the circulatory demands (20,28,32,33,43). The delicate and complex balance between interacting cardiac ion channels is affected, and sometimes severely disturbed, by acute temperature changes and stresses that alter ion concentrations of the external fluid around cardiac myocytes (25,46).…”

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confidence: 99%

Electrical excitability of roach (Rutilus rutilus) ventricular myocytes: effects of extracellular K⁺, temperature, and pacing frequency

Badr

Abu-Amra

El-Sayed

et al. 2018

American Journal of Physiology-Regulatory, Integrative and Comp

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Exercise, capture, and handling stress in fish can elevate extracellular K concentration ([K]) with potential impact on heart function in a temperature- and frequency-dependent manner. To this end, the effects of [K] on the excitability of ventricular myocytes of winter-acclimatized roach ( Rutilus rutilus) (4 ± 0.5°C) were examined at different test temperatures and varying pacing rates. Frequencies corresponding to in vivo heart rates at 4°C (0.37 Hz), 14°C (1.16 Hz), and 24°C (1.96 Hz) had no significant effect on the excitability of ventricular myocytes. Acute increase of temperature from 4 to 14°C did not affect excitability, but a further rise to 24 markedly decreased excitability: stimulus current and critical depolarization needed to elicit an action potential (AP) were ~25 and 14% higher, respectively, at 24°C than at 4°C and 14°C ( P < 0.05). This depression could be due to temperature-related mismatch between inward Na and outward K currents. In contrast, an increase of [K] from 3 to 5.4 or 8 mM at 24°C reduced the stimulus current needed to trigger AP. However, other aspects of excitability were strongly depressed by high [K]: maximum rate of AP upstroke and AP duration were drastically (89 and 50%, respectively) reduced at 8 mM [K] in comparison with 3 mM ( P < 0.05). As an extreme case, some myocytes completely failed to elicit all-or-none AP at 8 mM [K] at 24°C. Also, amplitude and overshoot of AP were reduced by elevation of [K] ( P < 0.05). Although high [K] antagonizes the negative effects of high temperature on excitation threshold, the precipitous depression of the rate of AP upstroke and complete loss of excitability in some myocytes suggest that the combination of high temperature and high [K] will severely impair ventricular excitability in roach.

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Intrinsic regulation of sinoatrial node function and the zebrafish as a model of stretch effects on pacemaking

Cited by 25 publications

References 157 publications

Electrical remodeling after percutaneous atrial septal defect closure in pediatric and adult patients

Electrical remodeling after percutaneous atrial septal defect closure in pediatric and adult patients

Sinoatrial Node Structure, Mechanics, Electrophysiology and the Chronotropic Response to Stretch in Rabbit and Mouse

Electrical excitability of roach (Rutilus rutilus) ventricular myocytes: effects of extracellular K⁺, temperature, and pacing frequency

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Intrinsic regulation of sinoatrial node function and the zebrafish as a model of stretch effects on pacemaking

Cited by 25 publications

References 157 publications

Electrical remodeling after percutaneous atrial septal defect closure in pediatric and adult patients

Electrical remodeling after percutaneous atrial septal defect closure in pediatric and adult patients

Sinoatrial Node Structure, Mechanics, Electrophysiology and the Chronotropic Response to Stretch in Rabbit and Mouse

Electrical excitability of roach (Rutilus rutilus) ventricular myocytes: effects of extracellular K+, temperature, and pacing frequency

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Product

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Electrical excitability of roach (Rutilus rutilus) ventricular myocytes: effects of extracellular K⁺, temperature, and pacing frequency