Electrical restitution in diseased human ventricular myocardium

Péter P. Nánási, András Varró, Csaba Pankucsi, Péter Homolay, Timothy K. Knilans, László Kovács, Gyula J. Papp, David A. Lathrop

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

Action potential configuration and electrical restitution were studied in diseased human ventricular muscle by comparing the characteristics of hypertrophic (HYP) and dilated (DIL) human ventricular preparations. Conventional microelectrode techniques were used to evaluate action potentials evoked at increasingly longer diastolic intervals. The steady-state action potential duration (APD90) was significantly longer in DIL than in HYP preparations (393 ± 5 ms, n = 4 and 296 ± 11 ms, n = 4, respectively; P <0.001, mean ± SEM). In the dilated preparations studied at long diastolic intervals, the initial period of rapid repolarization (phase 1) was absent, and the rate of final repolarization (phase 3) was reduced. Electrical restitution relations in these preparations were fitted as the sum of two exponentials. The time constant of the fast component was significantly longer in DIL than in HYP preparations (242 ± 9 ms and 121 ± 4 ms, respectively; P <0.001). No difference was observed in the time constants for the slow component of restitution in the two groups. Electrical restitution was also studied in single human ventricular myocytes by using patch clamp techniques. The initial 600 ms period of restitution was fitted in these cells to a monoexponential function. The time constant for this period of the restitution relation was significantly longer, while the estimated amplitude of this early rising phase was significantly lower in human cells obtained from DIL hearts than the respective parameters obtained in the healthy canine and guinea pig cells also examined. The observed changes in the restitution kinetics of the dilated human heart are, likely, the consequence of alterations in the ionic currents that underlie the cardiac action potential.

Original languageEnglish
Pages (from-to)339-351
Number of pages13
JournalClinical Physiology
Volume16
Issue number4
Publication statusPublished - Jul 1996

Fingerprint

Myocardium
Action Potentials
Microelectrodes
Patch-Clamp Techniques
Muscle Cells
Canidae
Guinea Pigs
Muscles

Keywords

  • Action potential duration
  • Cardiac arrhythmias
  • Congestive heart failure
  • Dilated cardiomyopathies
  • Electrical restitution
  • Human ventricular muscle
  • Ion channels

ASJC Scopus subject areas

  • Physiology

Cite this

Nánási, P. P., Varró, A., Pankucsi, C., Homolay, P., Knilans, T. K., Kovács, L., ... Lathrop, D. A. (1996). Electrical restitution in diseased human ventricular myocardium. Clinical Physiology, 16(4), 339-351.

Electrical restitution in diseased human ventricular myocardium. / Nánási, Péter P.; Varró, András; Pankucsi, Csaba; Homolay, Péter; Knilans, Timothy K.; Kovács, László; Papp, Gyula J.; Lathrop, David A.

In: Clinical Physiology, Vol. 16, No. 4, 07.1996, p. 339-351.

Research output: Contribution to journalArticle

Nánási, PP, Varró, A, Pankucsi, C, Homolay, P, Knilans, TK, Kovács, L, Papp, GJ & Lathrop, DA 1996, 'Electrical restitution in diseased human ventricular myocardium', Clinical Physiology, vol. 16, no. 4, pp. 339-351.
Nánási PP, Varró A, Pankucsi C, Homolay P, Knilans TK, Kovács L et al. Electrical restitution in diseased human ventricular myocardium. Clinical Physiology. 1996 Jul;16(4):339-351.
Nánási, Péter P. ; Varró, András ; Pankucsi, Csaba ; Homolay, Péter ; Knilans, Timothy K. ; Kovács, László ; Papp, Gyula J. ; Lathrop, David A. / Electrical restitution in diseased human ventricular myocardium. In: Clinical Physiology. 1996 ; Vol. 16, No. 4. pp. 339-351.
@article{e587f103c43a47419fcad8a6f752e0bc,
title = "Electrical restitution in diseased human ventricular myocardium",
abstract = "Action potential configuration and electrical restitution were studied in diseased human ventricular muscle by comparing the characteristics of hypertrophic (HYP) and dilated (DIL) human ventricular preparations. Conventional microelectrode techniques were used to evaluate action potentials evoked at increasingly longer diastolic intervals. The steady-state action potential duration (APD90) was significantly longer in DIL than in HYP preparations (393 ± 5 ms, n = 4 and 296 ± 11 ms, n = 4, respectively; P <0.001, mean ± SEM). In the dilated preparations studied at long diastolic intervals, the initial period of rapid repolarization (phase 1) was absent, and the rate of final repolarization (phase 3) was reduced. Electrical restitution relations in these preparations were fitted as the sum of two exponentials. The time constant of the fast component was significantly longer in DIL than in HYP preparations (242 ± 9 ms and 121 ± 4 ms, respectively; P <0.001). No difference was observed in the time constants for the slow component of restitution in the two groups. Electrical restitution was also studied in single human ventricular myocytes by using patch clamp techniques. The initial 600 ms period of restitution was fitted in these cells to a monoexponential function. The time constant for this period of the restitution relation was significantly longer, while the estimated amplitude of this early rising phase was significantly lower in human cells obtained from DIL hearts than the respective parameters obtained in the healthy canine and guinea pig cells also examined. The observed changes in the restitution kinetics of the dilated human heart are, likely, the consequence of alterations in the ionic currents that underlie the cardiac action potential.",
keywords = "Action potential duration, Cardiac arrhythmias, Congestive heart failure, Dilated cardiomyopathies, Electrical restitution, Human ventricular muscle, Ion channels",
author = "N{\'a}n{\'a}si, {P{\'e}ter P.} and Andr{\'a}s Varr{\'o} and Csaba Pankucsi and P{\'e}ter Homolay and Knilans, {Timothy K.} and L{\'a}szl{\'o} Kov{\'a}cs and Papp, {Gyula J.} and Lathrop, {David A.}",
year = "1996",
month = "7",
language = "English",
volume = "16",
pages = "339--351",
journal = "Clinical Physiology and Functional Imaging",
issn = "1475-0961",
publisher = "Wiley-Blackwell",
number = "4",

}

TY - JOUR

T1 - Electrical restitution in diseased human ventricular myocardium

AU - Nánási, Péter P.

AU - Varró, András

AU - Pankucsi, Csaba

AU - Homolay, Péter

AU - Knilans, Timothy K.

AU - Kovács, László

AU - Papp, Gyula J.

AU - Lathrop, David A.

PY - 1996/7

Y1 - 1996/7

N2 - Action potential configuration and electrical restitution were studied in diseased human ventricular muscle by comparing the characteristics of hypertrophic (HYP) and dilated (DIL) human ventricular preparations. Conventional microelectrode techniques were used to evaluate action potentials evoked at increasingly longer diastolic intervals. The steady-state action potential duration (APD90) was significantly longer in DIL than in HYP preparations (393 ± 5 ms, n = 4 and 296 ± 11 ms, n = 4, respectively; P <0.001, mean ± SEM). In the dilated preparations studied at long diastolic intervals, the initial period of rapid repolarization (phase 1) was absent, and the rate of final repolarization (phase 3) was reduced. Electrical restitution relations in these preparations were fitted as the sum of two exponentials. The time constant of the fast component was significantly longer in DIL than in HYP preparations (242 ± 9 ms and 121 ± 4 ms, respectively; P <0.001). No difference was observed in the time constants for the slow component of restitution in the two groups. Electrical restitution was also studied in single human ventricular myocytes by using patch clamp techniques. The initial 600 ms period of restitution was fitted in these cells to a monoexponential function. The time constant for this period of the restitution relation was significantly longer, while the estimated amplitude of this early rising phase was significantly lower in human cells obtained from DIL hearts than the respective parameters obtained in the healthy canine and guinea pig cells also examined. The observed changes in the restitution kinetics of the dilated human heart are, likely, the consequence of alterations in the ionic currents that underlie the cardiac action potential.

AB - Action potential configuration and electrical restitution were studied in diseased human ventricular muscle by comparing the characteristics of hypertrophic (HYP) and dilated (DIL) human ventricular preparations. Conventional microelectrode techniques were used to evaluate action potentials evoked at increasingly longer diastolic intervals. The steady-state action potential duration (APD90) was significantly longer in DIL than in HYP preparations (393 ± 5 ms, n = 4 and 296 ± 11 ms, n = 4, respectively; P <0.001, mean ± SEM). In the dilated preparations studied at long diastolic intervals, the initial period of rapid repolarization (phase 1) was absent, and the rate of final repolarization (phase 3) was reduced. Electrical restitution relations in these preparations were fitted as the sum of two exponentials. The time constant of the fast component was significantly longer in DIL than in HYP preparations (242 ± 9 ms and 121 ± 4 ms, respectively; P <0.001). No difference was observed in the time constants for the slow component of restitution in the two groups. Electrical restitution was also studied in single human ventricular myocytes by using patch clamp techniques. The initial 600 ms period of restitution was fitted in these cells to a monoexponential function. The time constant for this period of the restitution relation was significantly longer, while the estimated amplitude of this early rising phase was significantly lower in human cells obtained from DIL hearts than the respective parameters obtained in the healthy canine and guinea pig cells also examined. The observed changes in the restitution kinetics of the dilated human heart are, likely, the consequence of alterations in the ionic currents that underlie the cardiac action potential.

KW - Action potential duration

KW - Cardiac arrhythmias

KW - Congestive heart failure

KW - Dilated cardiomyopathies

KW - Electrical restitution

KW - Human ventricular muscle

KW - Ion channels

UR - http://www.scopus.com/inward/record.url?scp=0029798762&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0029798762&partnerID=8YFLogxK

M3 - Article

C2 - 8842570

AN - SCOPUS:0029798762

VL - 16

SP - 339

EP - 351

JO - Clinical Physiology and Functional Imaging

JF - Clinical Physiology and Functional Imaging

SN - 1475-0961

IS - 4

ER -