Estimation and Quantification of Myocardial Contractility in the Closed-chest Dog

Veragut, U.P.; Krayenbühl, H. P.

doi:10.1159/000168382

Cited by 121 publications

(28 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…It is generally recognized that LV dDIdtntar is more sensitive to changes in afterload (1), while LV dPldtmar is thought to be more sensitive to changes in preload (2). The concept of preload de-pendency of LV dPldtmax is based on numerous studies in isolated cardiac muscle (3)(4)(5)(6), isolated hearts (6)(7)(8)(9)(10)(11), anesthetized dogs (11)(12)(13)(14)(15)(16) and even intact, conscious dogs (17), and man (18). The conceptual basis for the preload dependency of LV dPldtmar is that an increase in preload activates the Frank-Starling mechanism, which in turn, increases LV dP/dtmar…”

Section: Introductionmentioning

confidence: 99%

“…The specific hypothesis to be tested was to determine if an acute increase in preload would elicit the Frank-Starling mechanism, and secondly if under these conditions, LV 12 baboons (papio anubis), [20][21][22][23][24][25][26] kg, were tranquilized with ketamine hydrochloride, 10 mg/kg i.m., mechanically ventilated, and anesthetized using either halothane 1.5 vol% or pentobarbital, Na, 15 (Fig. 1).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effects of Acute Increases in Left Ventricular Preload on Indices of Myocardial Function in Conscious, Unrestrained and Intact, Tranquilized Baboons

Zimpfer¹,

Vatner²

1981

J. Clin. Invest.

View full text Add to dashboard Cite

A B S T R A C T The effects of acute volume loading were examined on indices of left ventricular (LV) function in conscious, unrestrained and intact, tranquilized baboons. Experiments were conducted 1-3 mo after implantation of ultrasonic transducers to measure LV internal diameter and wall thickness, and miniature LV pressure gauges and aortic and left atrial catheters. In 10 intact, tranquilized baboons, rapid volume loading with saline increased LV end-diastolic pressure by 23.7 ±2.6 mm Hg, LV end-diastolic diameter by 7.8±1.5%, LV stroke work by 37.5±7.8%, while mean arterial pressure and peak LV wall stress did not change significantly. Despite the increase in preload and activation of the Frank-Starling mechanism, LV dPldtmar and the maximum velocity of myocardial fiber shortening (LV dD/ dtmax) did not change. Volume loading afterf/-adrenergic or combined 3-adrenergic and cholinergic blockades or volume loading with blood instead of saline also failed to augment LV dP/dt max and LV dDIdt max despite the increase in preload. In order to volume load the baboons in the conscious state, a radiofrequency (RF) interrogator system was devised, which upon receipt of a radio command, activated a battery operated pump to infuse 1,000 ml of saline i.v. to the baboons. In these experiments, preload rose, i.e., LV end-diastolic diameter increased by 13

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Effects of Acute Increases in Left Ventricular Preload on Indices of Myocardial Function in Conscious, Unrestrained and Intact, Tranquilized Baboons

Zimpfer¹,

Vatner²

1981

J. Clin. Invest.

View full text Add to dashboard Cite

show abstract

“…[10][11][12][13][14][15][16][17][18] However, since in the ejecting ventricle isovolumic dp/dt usually reaches a peak at the opening of the semilunar valves,19 this ratio, as well as peak dp/dt itself, are influenced profoundly by the level of arterial diastolic pressure, and, therefore, the value of these measurements as indices of myocardial contractility are seriously limited. 8 In the present investigation, the possibility was considered that the relation between dp/dt and the simultaneously developed pressure throughout the course of isovolumic contraction, or the dp/dt at a given level of intraventricular pressure during isovolumic systole, might provide an accurate and practical measure of ventricular contractility independent of changes in preload and afterload.…”

mentioning

confidence: 99%

Assessment of Cardiac Contractility

et al. 1971

View full text Add to dashboard Cite

SUMMARYIt was considered that the relationship between dp/dt and simultaneously developed pressure during the course of isovolumic contraction might afford a more accurate measure of contractility than the maximum rate of intraventricular pressure rise (peak dp/dt). In six cat papillary muscles contracting isometrically from any given preload, the ratio of the rate of tension development (dT/dt) to simultaneously occurring isometric tension always varied directly with the contractile state. This ratio rose slightly as preload was increased, but it was not affected by changes in afterload. In 17 experiments in an intact canine heart preparation in which left ventricular end-diastolic pressure was constant, dp/dt at any given pressure during isovolumetric contraction again was observed to be a function of the contractile state when the latter was enhanced by norepinephrine and acetylstrophanthidin. High-fidelity left ventricular pressures and dp/dt were recorded throughout isovolumic contraction in eight patients. Isoproterenol and exercise raised the level of dp/dt at any given pressure prior to ejection. Interventions known to alter ventricular loading but not to influence the contractile state, such as elevation of ventricular end-diastolic pressure by leg raising and increases in aortic pressure induced by methoxamine, did not influence this relation significantly. In conclusion, the determination of dp/dt and intraventricular pressure throughout isovolumic contraction in the presence of variable arterial pressure and small changes of preload provides a useful, simple, and experimentally verified approach to the assessment of alterations of the contractile state of the heart in intact man.

show abstract

“…During 218 Veragut / Bauknecht / Gander / Kr ayenbCiil / Rutisii auser the experiment additional chloralose was given as needed. Placing of the catheters and the recording equipment were the same as previously described [25]. Left ventricular pressure was measured with a Telco micromanometer which was placed into the left ventricle by the Iransseptal route via the right jugular vein.…”

Section: Methods A) Experimental Designmentioning

confidence: 99%

Quantitation of Myocardial Contractility by Means of Harmonic Analysis of Isovolumic Left Ventricular Pressure Pulses

Up¹,

Bauknecht²,

Gander³

et al. 1969

Cardiology

View full text Add to dashboard Cite

Estimation and Quantification of Myocardial Contractility in the Closed-chest Dog

Cited by 121 publications

References 0 publications

Effects of Acute Increases in Left Ventricular Preload on Indices of Myocardial Function in Conscious, Unrestrained and Intact, Tranquilized Baboons

Effects of Acute Increases in Left Ventricular Preload on Indices of Myocardial Function in Conscious, Unrestrained and Intact, Tranquilized Baboons

Assessment of Cardiac Contractility

Quantitation of Myocardial Contractility by Means of Harmonic Analysis of Isovolumic Left Ventricular Pressure Pulses

Contact Info

Product

Resources

About