Influence of ethanol on circulation in surface-induced hypothermia and subsequent rewarming

Lauri, Timo; Timisjärvi, J.; Saukko, Pekka

doi:10.1016/0741-8329(95)02022-5

Cited by 5 publications

(6 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…3A). Other cardiovascular studies have variously reported that E for LV pressure fall increases with cooling and decreases with warming (Fischer et al 2005;Greene et al 1989;Langer and Schmidt 1998;Lauri et al 1996;Tveita et al 1998). For example, E increases from 44.8 to 61.6 ms with cooling from 38 to 34 8C at HR pacing of 150 beats/min in the RV bypassed pig (Greene et al 1989).…”

Section: Time Constant and Temperaturementioning

confidence: 91%

“…It has been reported that E increases linearly with cooling and recovers linearly with warming in the anaesthetized canine heart (Lauri et al 1996). The r value between E and temperature was 0.91 (Fischer et al 2005).…”

Section: Time Constant and Temperaturementioning

confidence: 96%

“…It is known that cooling induces a significant increase of E (Fischer et al 2005;Greene et al 1989;Langer and Schmidt. 1998;Lauri et al 1996;Tveita et al 1998) and warming induces a significant decrease of E (Saeki et al 2000). The monoexponential fit, however, does not perfectly characterize the isovolumic relaxation LV pressure curve (Frederiksen et al 1978;Yellin et al 1986).…”

Section: Introductionmentioning

confidence: 94%

See 2 more Smart Citations

Half-logistic time constant: a more reliable lusitropic index than monoexponential time constant regardless of temperature in canine left ventricle

Mizuno

Matsubara

Mohri

et al. 2008

Can. J. Physiol. Pharmacol.

View full text Add to dashboard Cite

Temperature changes influence cardiac diastolic function. The monoexponential time constant (tauE), which is a conventional lusitropic index of the rate of left ventricular (LV) pressure fall, increases with cooling and decreases with warming. We have proposed that a half-logistic time constant (tauL) is a better lusitropic index than tauE at normothermia. In the present study, we investigated whether tauL can remain a superior measure as temperature varies. The isovolumic relaxation LV pressure curves from the minimum of the first time derivative of LV pressure (dP/dtmin) to the LV end-diastolic pressure were analyzed at 30, 33, 36, 38, and 40 degrees C in excised, cross-circulated canine hearts. tauL and tauE were evaluated by curve-fitting using the least squares method and applying the half-logistic equation, P(t) = PA/[1 + exp(t/tauL)] + PB, and the monoexponential equation, P(t) = P0exp(-t/tauE) + Pinfinity. Both tauL and tauE increased significantly with decreasing temperature and decreased with increasing temperature. The half-logistic correlation coefficient (r) values were significantly higher than the monoexponential r values at the 5 above-mentioned temperatures. This implies that the superiority of the goodness of the half-logistic fit is not temperature dependent. The half-logistic model characterizes the amplitude and time course of LV pressure fall more reliably than the monoexponential model. Hence, we concluded that tauL is a more useful lusitropic index regardless of temperature.

show abstract

Section: Time Constant and Temperaturementioning

confidence: 91%

Section: Time Constant and Temperaturementioning

confidence: 96%

Section: Introductionmentioning

confidence: 94%

See 1 more Smart Citation

Half-logistic time constant: a more reliable lusitropic index than monoexponential time constant regardless of temperature in canine left ventricle

Mizuno

Matsubara

Mohri

et al. 2008

Can. J. Physiol. Pharmacol.

View full text Add to dashboard Cite

show abstract

“…In our previous study, both Pτ 4L and Pτ 4E shortened with increasing temperature from 36°C to 38°C, 40°C (Mizuno et al 2008a). Thus, Pτ 4E prolonged linearly with cooling and recovered linearly with rewarming in the anesthetized canine (Lauri et al 1996). A study showed that the r value between Pτ 4E and temperature was 0.91 (Fischer et al 2005).…”

Section: Temperature-dependent H-l Time Constantsmentioning

confidence: 99%

“…In previous studies, hypothermia-induced prolongation in the lusitropic index m-E time constant obtained by fitting using the m-E function for Phase IV in the isovolumic LV PTC and hyperthermia-induced shortness (Fischer et al 2005;Greene et al 1980;Lauri et al 1996;Saeki et al 2000;Tveita et al 1998). However, we found that the h-L function provided better fits for Phase IV in the isovolumic LV PTC than the m-E function at any temperature (Mizuno et al 2008a The bilateral common carotid arteries and unilateral external jugular vein of the support dog were cannulated and connected to the arterial and venous cross-circulation tubes, respectively.…”

Section: Introductionmentioning

confidence: 99%

Temperature-dependent inotropic and lusitropic indices based on half-logistic time constants for four segmental phases in isovolumic left ventricular pressure–time curve in excised, cross-circulated canine heart

Mizuno

Mohri

Yokoyama

et al. 2017

Can. J. Physiol. Pharmacol.

View full text Add to dashboard Cite

by fitting using h-L functions for four segmental phases (Phases I-IV) in the isovolumic LV PTC are more useful indices for estimating LV inotropism and lusitropism during contraction and relaxation periods than the mono-exponential (m-E) time constants at normal temperature. In this study, we investigated whether the superiority of the goodness of h-L fits remained even at hypothermia and hyperthermia. Phases I-IV in the isovolumic LV PTCs in eight excised, cross-circulated canine hearts at 33°C, 36°C, and 38°C were analyzed using h-L and m-E functions and the least-squares method.The h-L and m-E time constants for Phases I-IV significantly shortened with increasing temperature. Curve fitting using h-L functions was significantly better than that using m-E functions for Phases I-IV at all temperatures. Therefore, the superiority of the goodness of h-L fit vs. m-E fit remained at all temperatures. As LV inotropic and lusitropic indices, temperature-dependent h-L time constants could be more useful than m-E time constants for Phases I-IV.

show abstract

Effects of ethanol on systemic hemodynamics in a porcine model of accidental hypothermia

Loppnow

Wilson

2015

The American Journal of Emergency Medicine

View full text Add to dashboard Cite

Influence of ethanol on circulation in surface-induced hypothermia and subsequent rewarming

Cited by 5 publications

References 53 publications

Half-logistic time constant: a more reliable lusitropic index than monoexponential time constant regardless of temperature in canine left ventricle

Half-logistic time constant: a more reliable lusitropic index than monoexponential time constant regardless of temperature in canine left ventricle

Temperature-dependent inotropic and lusitropic indices based on half-logistic time constants for four segmental phases in isovolumic left ventricular pressure–time curve in excised, cross-circulated canine heart

Effects of ethanol on systemic hemodynamics in a porcine model of accidental hypothermia

Contact Info

Product

Resources

About