Paradoxical change in atrial fibrillation dominant frequencies with baroreflex-mediated parasympathetic stimulation with phenylephrine infusion

Jason Ng, Rod S. Passman, Rishi Arora, Alan H. Kadish, Jeffrey Goldberger

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

Baroreflex Response and AF Dominant Frequency. Introduction: Parasympathetic stimulation is known to promote atrial fibrillation (AF) through shortening of atrial refractory periods. We hypothesized that baroreflex-mediated parasympathetic stimulation via phenylephrine (PE) infusion would increase AF rate as measured by dominant frequency (DF). Methods and Results: The protocol was performed in 27 patients (24 M, 59 ± 1 years old) prior to AF ablation. For 10 patients in AF, PE was infused until systolic blood pressure increased ≥30 mmHg. Electrograms were recorded in the left atrium before and after PE. DFs of each recording were calculated offline. Atrial effective refractory periods (ERPs) were measured before and after PE in 11 patients who were in sinus rhythm during the procedure. DFs were also measured in 6 patients in AF before and after complete parasympathetic blockade with atropine (0.04 mg/kg). PE resulted in increased RR intervals during sinus rhythm (1,170 ± 77 to 1,282 ± 85 ms, P = 0.03) and AF (743 ± 32 to 826 ± 30 ms, P = 0.03), consistent with parasympathetic effect on the sinus and AV nodes, respectively. DFs were decreased by PE in the left atrium (6.2 ± 0.2 to 6.0 ± 0.2 Hz, P = 0.004). Correspondingly, atrial ERPs significantly increased from 218 ± 13 to 232 ± 11 ms (P = 0.04). Atropine resulted in a decreasing trend in DF in the left atrium (5.9 ± 0.1 to 5.8 ± 0.1 Hz, P = 0.07). Conclusions: Despite baroreflex-mediated parasympathetic effect, PE produced a slowing of AF along with lengthening of ERP, while parasympathetic blockade also slowed DF. It is therefore likely that the direct and indirect adrenergic effects of PE on atrial electrophysiology are more prominent than its parasympathetic effects.

Original languageEnglish (US)
Pages (from-to)1045-1050
Number of pages6
JournalJournal of Cardiovascular Electrophysiology
Volume23
Issue number10
DOIs
StatePublished - Oct 1 2012
Externally publishedYes

Fingerprint

Baroreflex
Phenylephrine
Atrial Fibrillation
Heart Atria
Atropine
Blood Pressure
Atrioventricular Node
Sinoatrial Node
Electrophysiology
Adrenergic Agents

Keywords

  • alpha-adrenergic receptors
  • atrial fibrillation
  • autonomic nervous system
  • baroreflex
  • dominant frequency
  • electrograms

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)

Cite this

Paradoxical change in atrial fibrillation dominant frequencies with baroreflex-mediated parasympathetic stimulation with phenylephrine infusion. / Ng, Jason; Passman, Rod S.; Arora, Rishi; Kadish, Alan H.; Goldberger, Jeffrey.

In: Journal of Cardiovascular Electrophysiology, Vol. 23, No. 10, 01.10.2012, p. 1045-1050.

Research output: Contribution to journalArticle

@article{8bb3ae879dd24169bb03bcca47e5a5b0,
title = "Paradoxical change in atrial fibrillation dominant frequencies with baroreflex-mediated parasympathetic stimulation with phenylephrine infusion",
abstract = "Baroreflex Response and AF Dominant Frequency. Introduction: Parasympathetic stimulation is known to promote atrial fibrillation (AF) through shortening of atrial refractory periods. We hypothesized that baroreflex-mediated parasympathetic stimulation via phenylephrine (PE) infusion would increase AF rate as measured by dominant frequency (DF). Methods and Results: The protocol was performed in 27 patients (24 M, 59 ± 1 years old) prior to AF ablation. For 10 patients in AF, PE was infused until systolic blood pressure increased ≥30 mmHg. Electrograms were recorded in the left atrium before and after PE. DFs of each recording were calculated offline. Atrial effective refractory periods (ERPs) were measured before and after PE in 11 patients who were in sinus rhythm during the procedure. DFs were also measured in 6 patients in AF before and after complete parasympathetic blockade with atropine (0.04 mg/kg). PE resulted in increased RR intervals during sinus rhythm (1,170 ± 77 to 1,282 ± 85 ms, P = 0.03) and AF (743 ± 32 to 826 ± 30 ms, P = 0.03), consistent with parasympathetic effect on the sinus and AV nodes, respectively. DFs were decreased by PE in the left atrium (6.2 ± 0.2 to 6.0 ± 0.2 Hz, P = 0.004). Correspondingly, atrial ERPs significantly increased from 218 ± 13 to 232 ± 11 ms (P = 0.04). Atropine resulted in a decreasing trend in DF in the left atrium (5.9 ± 0.1 to 5.8 ± 0.1 Hz, P = 0.07). Conclusions: Despite baroreflex-mediated parasympathetic effect, PE produced a slowing of AF along with lengthening of ERP, while parasympathetic blockade also slowed DF. It is therefore likely that the direct and indirect adrenergic effects of PE on atrial electrophysiology are more prominent than its parasympathetic effects.",
keywords = "alpha-adrenergic receptors, atrial fibrillation, autonomic nervous system, baroreflex, dominant frequency, electrograms",
author = "Jason Ng and Passman, {Rod S.} and Rishi Arora and Kadish, {Alan H.} and Jeffrey Goldberger",
year = "2012",
month = "10",
day = "1",
doi = "10.1111/j.1540-8167.2012.02362.x",
language = "English (US)",
volume = "23",
pages = "1045--1050",
journal = "Journal of Cardiovascular Electrophysiology",
issn = "1045-3873",
publisher = "Wiley-Blackwell",
number = "10",

}

TY - JOUR

T1 - Paradoxical change in atrial fibrillation dominant frequencies with baroreflex-mediated parasympathetic stimulation with phenylephrine infusion

AU - Ng, Jason

AU - Passman, Rod S.

AU - Arora, Rishi

AU - Kadish, Alan H.

AU - Goldberger, Jeffrey

PY - 2012/10/1

Y1 - 2012/10/1

N2 - Baroreflex Response and AF Dominant Frequency. Introduction: Parasympathetic stimulation is known to promote atrial fibrillation (AF) through shortening of atrial refractory periods. We hypothesized that baroreflex-mediated parasympathetic stimulation via phenylephrine (PE) infusion would increase AF rate as measured by dominant frequency (DF). Methods and Results: The protocol was performed in 27 patients (24 M, 59 ± 1 years old) prior to AF ablation. For 10 patients in AF, PE was infused until systolic blood pressure increased ≥30 mmHg. Electrograms were recorded in the left atrium before and after PE. DFs of each recording were calculated offline. Atrial effective refractory periods (ERPs) were measured before and after PE in 11 patients who were in sinus rhythm during the procedure. DFs were also measured in 6 patients in AF before and after complete parasympathetic blockade with atropine (0.04 mg/kg). PE resulted in increased RR intervals during sinus rhythm (1,170 ± 77 to 1,282 ± 85 ms, P = 0.03) and AF (743 ± 32 to 826 ± 30 ms, P = 0.03), consistent with parasympathetic effect on the sinus and AV nodes, respectively. DFs were decreased by PE in the left atrium (6.2 ± 0.2 to 6.0 ± 0.2 Hz, P = 0.004). Correspondingly, atrial ERPs significantly increased from 218 ± 13 to 232 ± 11 ms (P = 0.04). Atropine resulted in a decreasing trend in DF in the left atrium (5.9 ± 0.1 to 5.8 ± 0.1 Hz, P = 0.07). Conclusions: Despite baroreflex-mediated parasympathetic effect, PE produced a slowing of AF along with lengthening of ERP, while parasympathetic blockade also slowed DF. It is therefore likely that the direct and indirect adrenergic effects of PE on atrial electrophysiology are more prominent than its parasympathetic effects.

AB - Baroreflex Response and AF Dominant Frequency. Introduction: Parasympathetic stimulation is known to promote atrial fibrillation (AF) through shortening of atrial refractory periods. We hypothesized that baroreflex-mediated parasympathetic stimulation via phenylephrine (PE) infusion would increase AF rate as measured by dominant frequency (DF). Methods and Results: The protocol was performed in 27 patients (24 M, 59 ± 1 years old) prior to AF ablation. For 10 patients in AF, PE was infused until systolic blood pressure increased ≥30 mmHg. Electrograms were recorded in the left atrium before and after PE. DFs of each recording were calculated offline. Atrial effective refractory periods (ERPs) were measured before and after PE in 11 patients who were in sinus rhythm during the procedure. DFs were also measured in 6 patients in AF before and after complete parasympathetic blockade with atropine (0.04 mg/kg). PE resulted in increased RR intervals during sinus rhythm (1,170 ± 77 to 1,282 ± 85 ms, P = 0.03) and AF (743 ± 32 to 826 ± 30 ms, P = 0.03), consistent with parasympathetic effect on the sinus and AV nodes, respectively. DFs were decreased by PE in the left atrium (6.2 ± 0.2 to 6.0 ± 0.2 Hz, P = 0.004). Correspondingly, atrial ERPs significantly increased from 218 ± 13 to 232 ± 11 ms (P = 0.04). Atropine resulted in a decreasing trend in DF in the left atrium (5.9 ± 0.1 to 5.8 ± 0.1 Hz, P = 0.07). Conclusions: Despite baroreflex-mediated parasympathetic effect, PE produced a slowing of AF along with lengthening of ERP, while parasympathetic blockade also slowed DF. It is therefore likely that the direct and indirect adrenergic effects of PE on atrial electrophysiology are more prominent than its parasympathetic effects.

KW - alpha-adrenergic receptors

KW - atrial fibrillation

KW - autonomic nervous system

KW - baroreflex

KW - dominant frequency

KW - electrograms

UR - http://www.scopus.com/inward/record.url?scp=84867744730&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84867744730&partnerID=8YFLogxK

U2 - 10.1111/j.1540-8167.2012.02362.x

DO - 10.1111/j.1540-8167.2012.02362.x

M3 - Article

C2 - 22612719

AN - SCOPUS:84867744730

VL - 23

SP - 1045

EP - 1050

JO - Journal of Cardiovascular Electrophysiology

JF - Journal of Cardiovascular Electrophysiology

SN - 1045-3873

IS - 10

ER -