New calculation of internal Ca2+ recirculation fraction from alternans decay of postextrasystolic potentiation

Gentaro Iribe, J. Araki, S. Mohri, J. Shimizu, T. Imaoka, Y. Kanmura, F. Kajiya, H. Suga

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

In our previous studies, we calculated the internal Ca2+ recirculation fraction (RF) after obtaining the beat decay constant (τe) of the monoexponential component in the postextrasystolic potentiation (PESP) of the alternans decay by curve fitting. However, this method sometimes suffers from the sensitive variation of τe with small noises in the measured contractilities of the 5th and 6th postextrasystolic (PES) beats in the tail of the exponential component. We now succeeded in preventing this problem by a new method to calculate RF without obtaining τe. The equation for the calculation in the new method expresses an alternans decay of PESP as a recurrence formula of PESP. It can calculate RF directly from the contractilities of the 1st through the 4th PES beats without any fitting procedure. To evaluate the reliability of the new method, we calculated RF from the alternans decay of PESP of the left ventricle (LV) of the canine excised cross-circulated heart preparation by both the original fitting and the new method. Although there was no significant difference in the mean value of the obtained RF between these two methods, the variance of RF was smaller with the new method than with the original method. Thus the new method proved useful and more reliable than the original fitting method.

Original languageEnglish
Pages (from-to)143-149
Number of pages7
JournalJapanese Journal of Physiology
Volume51
Issue number2
DOIs
Publication statusPublished - 2001

Fingerprint

Heart Ventricles
Canidae
Recurrence

Keywords

  • Arrhythmia
  • Beat constant
  • Contractility
  • Extrasystole
  • Myocardial Ca

ASJC Scopus subject areas

  • Physiology

Cite this

New calculation of internal Ca2+ recirculation fraction from alternans decay of postextrasystolic potentiation. / Iribe, Gentaro; Araki, J.; Mohri, S.; Shimizu, J.; Imaoka, T.; Kanmura, Y.; Kajiya, F.; Suga, H.

In: Japanese Journal of Physiology, Vol. 51, No. 2, 2001, p. 143-149.

Research output: Contribution to journalArticle

Iribe, Gentaro ; Araki, J. ; Mohri, S. ; Shimizu, J. ; Imaoka, T. ; Kanmura, Y. ; Kajiya, F. ; Suga, H. / New calculation of internal Ca2+ recirculation fraction from alternans decay of postextrasystolic potentiation. In: Japanese Journal of Physiology. 2001 ; Vol. 51, No. 2. pp. 143-149.
@article{1b6d3f676f55478f9ee983472068cf17,
title = "New calculation of internal Ca2+ recirculation fraction from alternans decay of postextrasystolic potentiation",
abstract = "In our previous studies, we calculated the internal Ca2+ recirculation fraction (RF) after obtaining the beat decay constant (τe) of the monoexponential component in the postextrasystolic potentiation (PESP) of the alternans decay by curve fitting. However, this method sometimes suffers from the sensitive variation of τe with small noises in the measured contractilities of the 5th and 6th postextrasystolic (PES) beats in the tail of the exponential component. We now succeeded in preventing this problem by a new method to calculate RF without obtaining τe. The equation for the calculation in the new method expresses an alternans decay of PESP as a recurrence formula of PESP. It can calculate RF directly from the contractilities of the 1st through the 4th PES beats without any fitting procedure. To evaluate the reliability of the new method, we calculated RF from the alternans decay of PESP of the left ventricle (LV) of the canine excised cross-circulated heart preparation by both the original fitting and the new method. Although there was no significant difference in the mean value of the obtained RF between these two methods, the variance of RF was smaller with the new method than with the original method. Thus the new method proved useful and more reliable than the original fitting method.",
keywords = "Arrhythmia, Beat constant, Contractility, Extrasystole, Myocardial Ca",
author = "Gentaro Iribe and J. Araki and S. Mohri and J. Shimizu and T. Imaoka and Y. Kanmura and F. Kajiya and H. Suga",
year = "2001",
doi = "10.2170/jjphysiol.51.143",
language = "English",
volume = "51",
pages = "143--149",
journal = "Journal of Physiological Sciences",
issn = "1880-6546",
publisher = "Springer Japan",
number = "2",

}

TY - JOUR

T1 - New calculation of internal Ca2+ recirculation fraction from alternans decay of postextrasystolic potentiation

AU - Iribe, Gentaro

AU - Araki, J.

AU - Mohri, S.

AU - Shimizu, J.

AU - Imaoka, T.

AU - Kanmura, Y.

AU - Kajiya, F.

AU - Suga, H.

PY - 2001

Y1 - 2001

N2 - In our previous studies, we calculated the internal Ca2+ recirculation fraction (RF) after obtaining the beat decay constant (τe) of the monoexponential component in the postextrasystolic potentiation (PESP) of the alternans decay by curve fitting. However, this method sometimes suffers from the sensitive variation of τe with small noises in the measured contractilities of the 5th and 6th postextrasystolic (PES) beats in the tail of the exponential component. We now succeeded in preventing this problem by a new method to calculate RF without obtaining τe. The equation for the calculation in the new method expresses an alternans decay of PESP as a recurrence formula of PESP. It can calculate RF directly from the contractilities of the 1st through the 4th PES beats without any fitting procedure. To evaluate the reliability of the new method, we calculated RF from the alternans decay of PESP of the left ventricle (LV) of the canine excised cross-circulated heart preparation by both the original fitting and the new method. Although there was no significant difference in the mean value of the obtained RF between these two methods, the variance of RF was smaller with the new method than with the original method. Thus the new method proved useful and more reliable than the original fitting method.

AB - In our previous studies, we calculated the internal Ca2+ recirculation fraction (RF) after obtaining the beat decay constant (τe) of the monoexponential component in the postextrasystolic potentiation (PESP) of the alternans decay by curve fitting. However, this method sometimes suffers from the sensitive variation of τe with small noises in the measured contractilities of the 5th and 6th postextrasystolic (PES) beats in the tail of the exponential component. We now succeeded in preventing this problem by a new method to calculate RF without obtaining τe. The equation for the calculation in the new method expresses an alternans decay of PESP as a recurrence formula of PESP. It can calculate RF directly from the contractilities of the 1st through the 4th PES beats without any fitting procedure. To evaluate the reliability of the new method, we calculated RF from the alternans decay of PESP of the left ventricle (LV) of the canine excised cross-circulated heart preparation by both the original fitting and the new method. Although there was no significant difference in the mean value of the obtained RF between these two methods, the variance of RF was smaller with the new method than with the original method. Thus the new method proved useful and more reliable than the original fitting method.

KW - Arrhythmia

KW - Beat constant

KW - Contractility

KW - Extrasystole

KW - Myocardial Ca

UR - http://www.scopus.com/inward/record.url?scp=0034955595&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0034955595&partnerID=8YFLogxK

U2 - 10.2170/jjphysiol.51.143

DO - 10.2170/jjphysiol.51.143

M3 - Article

VL - 51

SP - 143

EP - 149

JO - Journal of Physiological Sciences

JF - Journal of Physiological Sciences

SN - 1880-6546

IS - 2

ER -