Ventricular relaxation and myocardial ischemia: A comparison of different models of tau during coronary angioplasty

R. D. Simari, M. R. Bell, R. S. Schwartz, R. A. Nishimura, David Holmes

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

This study compares the sensitivity and variability of four models of tau, the time constant of ventricular relaxation, to detect the presence of myocardial ischemia. High fidelity left ventricular pressure recordings were obtained in ten patients undergoing coronary angioplasty at baseline, during balloon inflation, and at recovery. Four models of tau were considered: 1) a semilogarithmic, zero asymptote model (T(L)), 2) a semilogarithmic model using data from the first 40 ms of isovolumic relaxation (T 40), 3) an exponential non-zero asymptote model (T(E)), and 4) a derivative non-zero asymptote model (T(D)). T(L), T 40, and T(E) increased significantly during inflation and returned to near baseline values at recovery. T(D) showed no change during inflation. Comparisons of T(L), T 40, and T(E) using the derived relaxation half-time (T( 1/2 )), failed to reveal significant differences between the models at baseline, during inflation, or at recovery. The non-zero asymptote models were associated with a greater beat-to-beat variability than the semilogarithmic models. Thus, T( 1/2 ) using the semilogarithmic zero asymptote models (T(L) and T 40) may be more useful and consistent when measuring the rate of isovolumic relaxation during myocardial ischemia.

Original languageEnglish (US)
Pages (from-to)278-284
Number of pages7
JournalCatheterization and Cardiovascular Diagnosis
Volume25
Issue number4
StatePublished - 1992

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Economic Inflation
Angioplasty
Myocardial Ischemia
Ventricular Pressure

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine

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Ventricular relaxation and myocardial ischemia : A comparison of different models of tau during coronary angioplasty. / Simari, R. D.; Bell, M. R.; Schwartz, R. S.; Nishimura, R. A.; Holmes, David.

In: Catheterization and Cardiovascular Diagnosis, Vol. 25, No. 4, 1992, p. 278-284.

Research output: Contribution to journalArticle

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