Simultaneous comparison and calibration of the Doppler and electromagnetic flowmeters

Vatner, Stephen F.; Franklin, Dean; VanCitters, R. L.

doi:10.1152/jappl.1970.29.6.907

Cited by 120 publications

(58 citation statements)

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“…______ FIGURE 6 Phasic waveforms for segment length and velocity for two segments in the moderately ischemic zone (IZm) are shown, along with LV pressure, dP/dt, and an electrogram (ECG) from the first segment. Occlusion (center panel) impaired function substantially, which was then improved by isoproterenol.…”

Section: Resultsmentioning

confidence: 99%

Effects of isoproterenol on regional myocardial function, electrogram, and blood flow in conscious dogs with myocardial ischemia.

et al. 1976

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A B S T R A C T The effects of coronary occlusion and of subsequent isoproterenol infusion were examined in conscious dogs. Left ventricular (LV) function was assessed by measurements of LV diameter, pressure, velocity and dP/dt/P, and regional myocardial function was assessed by measurements of segment length (SL) and velocity of SL shortening in normal, border, and ischemic zones. Regional myocardial function was measured from the same sites, along with intramyocardial electrograms and regional myocardial blood flow as determined by radioactive microspheres. Coronary occlusion resulted in graded loss of function from the normal to severely ischemic zones with graded flow reductions and graded increases in ST segment elevation. Isoproterenol improved overall LV function, and function in the normal zone. Isoproterenol also improved function in 19 of 21 border-zone segments and in all moderately ischemic segments, while elevating further the ST segments. These changes were accompanied by increases in myocardial blood flow. In contrast, in severely ischemic segments, isoproterenol resulted in a deterioration of function, in that paradoxical motion occurred in segments previously akinetic during systole, while paradoxical motion was intensified in those segments iii which it was already present. These changes were accompanied by further ST segment elevation but not by concurrent increases in blood flow. In addition, in 2 of 21 border zone segments, myocardial blood flow fell and Dr.

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Section: Resultsmentioning

confidence: 99%

Effects of isoproterenol on regional myocardial function, electrogram, and blood flow in conscious dogs with myocardial ischemia.

et al. 1976

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“…Thus, even in the absence of a change in \oluine flow, the fiownieter would register a change in blood velocity. During the week foilowintj implantation, however, the space between the transducer and vessel becomes packed with granulation tissue which prevents significant changes in luminal diameter when distending pressure changes (Vatner et aL, 1970). Relationship between mean aortic root blood velocity (calculated from the Doppler flowmeter signal) and simultaneously determined cardiac output (volume flow, measured using thermodilutian) in an uiianaesthetized rabbit.…”

Section: Mea-turcjitejit Of Blood Fiowmentioning

confidence: 99%

Autonomic Cardiovascular Effects of Nasal Inhalation of Cigarette Smoke in the Rabbit

White

McRitchie

Franklin

1974

Aust J Exp Biol Med

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Summary. Nasopharyngeal stimulation hy cigarette smoke in iinanaesthetised rabbits evokes apnoea in expiration, liradycardia (to 30% of control), a rise in mean arterial (to 110?) and right atrial pressure (by 6 mm Hg) and a fall in cardiac output (to 415^ of control) and systemic conductance (to 36%). Blood flow (measured by Doppler fiownieter) and conductance in the me.senteric. renal, hind limb and ear beds falls tmiformly between beds and to the extent that, on occasions, flow in all these beds ceases. Sagittal sinus flow and conductance, in contrast, do not change or rise. The cardiovascular response is mediated predominantly through cardiac vagal and peripheral ,';ympathetic vasoconstrictor nervous pathways. PvO^ in animals with intact autonomic reflex mechanisms falls by 10 ± 0-4 mm Ilg 25 sec after the onset of apnoea, but in animals with either combined or selective blockade of vaga! and sympathoadrenal pathways peripheral flow is not reduced as in animals with intact autonnmic pathways, and PvOg falls by a significantly greater but equal amount in each (av. 15 ± 0-6 mm Hg, p,,j,f < 0-001). The circulatory changes thus appear to conserve body oxygen stores during the induced apnoea, an effect dependent on the integration of evoked vagal an

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“…Hemodynamic measurements were obtained instantaneously and continuously before, during, and after the intravenous infusion of this drug in order to study the temporal sequence of the hemodynamic changes. This approach was employed since the reduction in arterial and cardiac pressures induced by the direct relaxant action on vascular smooth muscle might be expected to induce reflex cardiovascular adjustments and the resultant pattern of hemodynamic responses might be complex and vary both in time and intensity as occurs with nitroglycerin.3" Methods Twenty-one mongrel dogs, weighing [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35] …”

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Hemodynamic effects of intravenous sodium nitroprusside in the conscious dog.

Pagani¹,

Vatner²,

Braunwald³

1978

Circulation

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cessation of infusion. In contrast, when the drug was administered intra-arterially to the iliac bed, arterial pressure did not fall and only iliac vasodilation was observed. Peak cardiac effects were characterized by increases in heart rate and LV dP/dt, along with marked reductions in LV end-systolic diameter (-13 ± 2%), and in end-diastolic diameter (-17 ± 2%) and pressure. LV end-diastolic diameter fell even when heart rate was maintained at a constant rate by pacing.Thus, in the conscious dog, NP reduced LV dimensions substantially, while inducing changes in peripheral beds. The differences in these effects depend on interactions between the direct effects of NP and the opposing effects of reflex adjustments which appear sufficiently powerful to result in net constriction of the iliac bed late during the infusion.limitations dictated by the use of human subjects, or in anesthetized animal preparations where the complicating effects of anesthesia and recent surgery are present. ', 1' The goal of the present study was to characterize more completely the hemodynamic effects of intravenously administered NP in the normal conscious dog. Hemodynamic measurements were obtained instantaneously and continuously before, during, and after the intravenous infusion of this drug in order to study the temporal sequence of the hemodynamic changes. This approach was employed since the reduction in arterial and cardiac pressures induced by the direct relaxant action on vascular smooth muscle might be expected to induce reflex cardiovascular adjustments and the resultant pattern of hemodynamic responses might be complex and vary both in time and intensity as occurs with nitroglycerin.3" Methods Twenty-one mongrel dogs, weighing [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35]

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Simultaneous comparison and calibration of the Doppler and electromagnetic flowmeters

Cited by 120 publications

References 0 publications

Effects of isoproterenol on regional myocardial function, electrogram, and blood flow in conscious dogs with myocardial ischemia.

Effects of isoproterenol on regional myocardial function, electrogram, and blood flow in conscious dogs with myocardial ischemia.

Autonomic Cardiovascular Effects of Nasal Inhalation of Cigarette Smoke in the Rabbit

Hemodynamic effects of intravenous sodium nitroprusside in the conscious dog.

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