Selective sinoatrial node optical mapping to investigate the mechanism of sinus rate acceleration

Shien-Fong Lin, Tetsuji Shinohara, Boyoung Joung, Peng-Sheng Chen

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Studies using isolated sinoatrial node (SAN) cells indicate that rhythmic spontaneous sarcoplasmic reticulum Ca release (Ca clock) plays an important role in SAN automaticity. However, it is difficult to translate these findings into intact SAN because the SAN is embedded in the right atrium (RA). Cross contamination of the optical signals between SAN and RA prevented the definitive testing of Ca clock hypothesis in intact SAN. We use a novel approach to selectively map intact SAN to examine the Ca clock function in intact RA. We simultaneously mapped intracellular Ca (Cai) and membrane potential (Vm) in 7 isolated, Langendorff perfused normal canine RA. Electrical conduction from the SAN to RA was inhibited with high potassium (10 mmol/L) Tyrode's solution, allowing selective optical mapping of Vm and Cai of the SAN. Isoproterenol (ISO, 0.03 μmol/L) decreased cycle length of the sinus beats from 586±17 ms at baseline to 366±32 ms, and shifted the leading pacemaker site from the middle or inferior SAN to the superior SAN in all RAs. The Cai upstroke preceded the Vm in the leading pacemaker site by up to 18±2 ms. ISO-induced changes to SAN were inhibited by ryanodine (3 μmol/L), but not ZD7288 (3 μmol/L), a selective If blocker. We conclude that a high extracellular potassium concentration results in intermittent SAN-RA conduction block, allowing selective optical mapping of the intact SAN. Acceleration of Ca cycling in the superior SAN underlies the mechanism of sinus tachycardia during sympathetic stimulation.

Original languageEnglish
Title of host publicationProgress in Biomedical Optics and Imaging - Proceedings of SPIE
Volume7883
DOIs
StatePublished - 2011
EventPhotonic Therapeutics and Diagnostics VII - San Francisco, CA, United States
Duration: Jan 22 2011Jan 24 2011

Other

OtherPhotonic Therapeutics and Diagnostics VII
CountryUnited States
CitySan Francisco, CA
Period1/22/111/24/11

Fingerprint

sinuses
Sinoatrial Node
clocks
Clocks
Pacemakers
Potassium
potassium
sarcoplasmic reticulum
tachycardia
conduction
Ryanodine
cycles
Heart Atria
stimulation
Isoproterenol
optical communication
synchronism
contamination
Contamination
membranes

Keywords

  • calcium
  • nervous system, sympathetic
  • sarcoplasmic reticulum
  • sinoatrial node

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Electronic, Optical and Magnetic Materials
  • Biomaterials
  • Radiology Nuclear Medicine and imaging

Cite this

Lin, S-F., Shinohara, T., Joung, B., & Chen, P-S. (2011). Selective sinoatrial node optical mapping to investigate the mechanism of sinus rate acceleration. In Progress in Biomedical Optics and Imaging - Proceedings of SPIE (Vol. 7883). [78832Z] https://doi.org/10.1117/12.873606

Selective sinoatrial node optical mapping to investigate the mechanism of sinus rate acceleration. / Lin, Shien-Fong; Shinohara, Tetsuji; Joung, Boyoung; Chen, Peng-Sheng.

Progress in Biomedical Optics and Imaging - Proceedings of SPIE. Vol. 7883 2011. 78832Z.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Lin, S-F, Shinohara, T, Joung, B & Chen, P-S 2011, Selective sinoatrial node optical mapping to investigate the mechanism of sinus rate acceleration. in Progress in Biomedical Optics and Imaging - Proceedings of SPIE. vol. 7883, 78832Z, Photonic Therapeutics and Diagnostics VII, San Francisco, CA, United States, 1/22/11. https://doi.org/10.1117/12.873606
Lin S-F, Shinohara T, Joung B, Chen P-S. Selective sinoatrial node optical mapping to investigate the mechanism of sinus rate acceleration. In Progress in Biomedical Optics and Imaging - Proceedings of SPIE. Vol. 7883. 2011. 78832Z https://doi.org/10.1117/12.873606
Lin, Shien-Fong ; Shinohara, Tetsuji ; Joung, Boyoung ; Chen, Peng-Sheng. / Selective sinoatrial node optical mapping to investigate the mechanism of sinus rate acceleration. Progress in Biomedical Optics and Imaging - Proceedings of SPIE. Vol. 7883 2011.
@inproceedings{48cece62bc624ed2baf7da53aa14b080,
title = "Selective sinoatrial node optical mapping to investigate the mechanism of sinus rate acceleration",
abstract = "Studies using isolated sinoatrial node (SAN) cells indicate that rhythmic spontaneous sarcoplasmic reticulum Ca release (Ca clock) plays an important role in SAN automaticity. However, it is difficult to translate these findings into intact SAN because the SAN is embedded in the right atrium (RA). Cross contamination of the optical signals between SAN and RA prevented the definitive testing of Ca clock hypothesis in intact SAN. We use a novel approach to selectively map intact SAN to examine the Ca clock function in intact RA. We simultaneously mapped intracellular Ca (Cai) and membrane potential (Vm) in 7 isolated, Langendorff perfused normal canine RA. Electrical conduction from the SAN to RA was inhibited with high potassium (10 mmol/L) Tyrode's solution, allowing selective optical mapping of Vm and Cai of the SAN. Isoproterenol (ISO, 0.03 μmol/L) decreased cycle length of the sinus beats from 586±17 ms at baseline to 366±32 ms, and shifted the leading pacemaker site from the middle or inferior SAN to the superior SAN in all RAs. The Cai upstroke preceded the Vm in the leading pacemaker site by up to 18±2 ms. ISO-induced changes to SAN were inhibited by ryanodine (3 μmol/L), but not ZD7288 (3 μmol/L), a selective If blocker. We conclude that a high extracellular potassium concentration results in intermittent SAN-RA conduction block, allowing selective optical mapping of the intact SAN. Acceleration of Ca cycling in the superior SAN underlies the mechanism of sinus tachycardia during sympathetic stimulation.",
keywords = "calcium, nervous system, sympathetic, sarcoplasmic reticulum, sinoatrial node",
author = "Shien-Fong Lin and Tetsuji Shinohara and Boyoung Joung and Peng-Sheng Chen",
year = "2011",
doi = "10.1117/12.873606",
language = "English",
isbn = "9780819484208",
volume = "7883",
booktitle = "Progress in Biomedical Optics and Imaging - Proceedings of SPIE",

}

TY - GEN

T1 - Selective sinoatrial node optical mapping to investigate the mechanism of sinus rate acceleration

AU - Lin, Shien-Fong

AU - Shinohara, Tetsuji

AU - Joung, Boyoung

AU - Chen, Peng-Sheng

PY - 2011

Y1 - 2011

N2 - Studies using isolated sinoatrial node (SAN) cells indicate that rhythmic spontaneous sarcoplasmic reticulum Ca release (Ca clock) plays an important role in SAN automaticity. However, it is difficult to translate these findings into intact SAN because the SAN is embedded in the right atrium (RA). Cross contamination of the optical signals between SAN and RA prevented the definitive testing of Ca clock hypothesis in intact SAN. We use a novel approach to selectively map intact SAN to examine the Ca clock function in intact RA. We simultaneously mapped intracellular Ca (Cai) and membrane potential (Vm) in 7 isolated, Langendorff perfused normal canine RA. Electrical conduction from the SAN to RA was inhibited with high potassium (10 mmol/L) Tyrode's solution, allowing selective optical mapping of Vm and Cai of the SAN. Isoproterenol (ISO, 0.03 μmol/L) decreased cycle length of the sinus beats from 586±17 ms at baseline to 366±32 ms, and shifted the leading pacemaker site from the middle or inferior SAN to the superior SAN in all RAs. The Cai upstroke preceded the Vm in the leading pacemaker site by up to 18±2 ms. ISO-induced changes to SAN were inhibited by ryanodine (3 μmol/L), but not ZD7288 (3 μmol/L), a selective If blocker. We conclude that a high extracellular potassium concentration results in intermittent SAN-RA conduction block, allowing selective optical mapping of the intact SAN. Acceleration of Ca cycling in the superior SAN underlies the mechanism of sinus tachycardia during sympathetic stimulation.

AB - Studies using isolated sinoatrial node (SAN) cells indicate that rhythmic spontaneous sarcoplasmic reticulum Ca release (Ca clock) plays an important role in SAN automaticity. However, it is difficult to translate these findings into intact SAN because the SAN is embedded in the right atrium (RA). Cross contamination of the optical signals between SAN and RA prevented the definitive testing of Ca clock hypothesis in intact SAN. We use a novel approach to selectively map intact SAN to examine the Ca clock function in intact RA. We simultaneously mapped intracellular Ca (Cai) and membrane potential (Vm) in 7 isolated, Langendorff perfused normal canine RA. Electrical conduction from the SAN to RA was inhibited with high potassium (10 mmol/L) Tyrode's solution, allowing selective optical mapping of Vm and Cai of the SAN. Isoproterenol (ISO, 0.03 μmol/L) decreased cycle length of the sinus beats from 586±17 ms at baseline to 366±32 ms, and shifted the leading pacemaker site from the middle or inferior SAN to the superior SAN in all RAs. The Cai upstroke preceded the Vm in the leading pacemaker site by up to 18±2 ms. ISO-induced changes to SAN were inhibited by ryanodine (3 μmol/L), but not ZD7288 (3 μmol/L), a selective If blocker. We conclude that a high extracellular potassium concentration results in intermittent SAN-RA conduction block, allowing selective optical mapping of the intact SAN. Acceleration of Ca cycling in the superior SAN underlies the mechanism of sinus tachycardia during sympathetic stimulation.

KW - calcium

KW - nervous system, sympathetic

KW - sarcoplasmic reticulum

KW - sinoatrial node

UR - http://www.scopus.com/inward/record.url?scp=79953738673&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=79953738673&partnerID=8YFLogxK

U2 - 10.1117/12.873606

DO - 10.1117/12.873606

M3 - Conference contribution

SN - 9780819484208

VL - 7883

BT - Progress in Biomedical Optics and Imaging - Proceedings of SPIE

ER -