A comparison of two exponential models of the time constant during left ventricular isovolumic pressure decay in coronary artery disease
| Autor: | Tohru Yamasaki, K Fujitani, Keiji Kurogane, Motoshi Takeuchi, Hong Tai Bai, Hisashi Fukuzaki, Shinji Takano, Chuichi Toda |
|---|---|
| Rok vydání: | 1985 |
| Předmět: |
Adult
Male medicine.medical_specialty Physiology Heart Ventricles Rest Ischemia Hemodynamics Coronary Disease Coronary artery disease Internal medicine Linear regression Pressure Humans Medicine Aged business.industry Cardiac Pacing Artificial Time constant Stroke Volume Stroke volume Middle Aged medicine.disease Myocardial Contraction Preload Cardiology Regression Analysis Relaxation (physics) Female Cardiology and Cardiovascular Medicine business |
| Zdroj: | Japanese Circulation Journal. 49:1225-1234 |
| ISSN: | 1347-4839 0047-1828 |
| Popis: | To make a comparison of two exponential models of the time constant (Tw: Weiss's method, Tc: exponential analysis with a variable asymptote) during left ventricular (LV) isovolumic relaxation, we assessed LV pressure decay in 104 patients with coronary artery disease (CADpts) and 21 normal subjects at rest and after pacing, and investigated the hemodynamic determinants of these two models using forward-backward stepwise multiple regression analysis. At rest, Tw was prolonged as the left ventricular minimal pressure (LVPmin), the left ventricular end-diastolic pressure (LVEDP) and the end-systolic volume (ESV) increased (multiple regression coefficient: R = 0.87), whereas Tc was prolonged as ESV and regional wall motion abnormality (RWMA) increased (R = 0.72). Pacing-induced changes in Tw were augmented as LVPmin and RWMA increased (R = 0.75), whereas changes in Tc were augmented as RWMA increased (R = 0.63). Thus, the changes in Tw may be due to an increase in LVPmin rather than to any direct effect of ischemia on the relaxation rate. The relaxation rate can be evaluated more reliably by Tc than by Tw, irrespective of associated pressure changes during ischemia in CADpts. |
| Databáze: | OpenAIRE |
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