Effects of cardiac depression and of anesthesia on the myocardial action of a cardiac glycoside

Vatner, Stephen F.; Higgins, Charles B.; Patrick, Thomas; Franklin, Dean; Braunwald, Eugene

doi:10.1172/jci106759

Cited by 71 publications

(53 citation statements)

References 52 publications

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“…scribed in detail previously (12,18). When, at any given instantaneous myocardial diameter or length (isolength point), the velocity of shortening (Vlsolength, i.e., V,.0) increases, while intraventricular pressure (Pisolength, i.e., P1s0) rises or remains constant, a shift in myocardial force-velocity relations reflecting a positive inotropic effect is considered to have occurred.…”

Section: Methodsmentioning

confidence: 99%

“…The same level of pressure which occurred during isometric contraction, before and after each intervention, was used for this calculation and dP/dt and P were determined at that level of pressure. This technique for evaluating the myocardial contractile state has been described in detail previously (12,19,20).…”

Section: Methodsmentioning

confidence: 99%

“…such inotropic agents as cardiac glycosides (12). Thus, it is possible that surgical trauma, the open chest, and the administration of anesthestic agents, which alter the central nervous system's regulation of circulatory responses and depress the myocardial contractile state, may also modify the extent of carotid sinus regulation of cardiac contractility.…”

Section: The Journal Of Clinical Investigation Volume 51 1972mentioning

confidence: 99%

“…8, 9). (12,19,20,23). The classical studies of A. V. Hill demonstrated that the inverse relationship between the force generated and the velocity of shortening is an important property of skeletal muscle (24).…”

Section: Bilateral Carotid Artery Occlusionmentioning

confidence: 99%

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Extent of Carotid Sinus Regulation of the Myocardial Contractile State in Conscious Dogs

Vatner¹,

Higgins²,

Franklin³

et al. 1972

J. Clin. Invest.

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A B S T R A C T The effects of bilateral carotid artery occlusion (BCO) and carotid sinus nerve stimulation (CSNS) on left ventricular (LV) pressure (P), diameter (D), velocity of contraction (V), rate of change of pressure (dP/dt), and cardiac output were studied in conscious dogs instrumented with ultrasonic diameter gauges, miniature pressure gauges, and aortic electromagnetic flow transducers. The effects of BCO and CSNS were also studied after autonomic blockade and were compared to similar alterations in pressure produced by norepinephrine, methoxamine, and nitroglycerin. When heart rate was maintained constant with atrial stimulation, BCO had little effect on ventricular contractility, increasing isolength systolic pressure (LV Pis.) by 36% while isolength velocity of myocardial shortening (Vt..) decreased by 12% and (dP/dt)/P fell by 8%. These effects could be explained largely by vasoconstriction, since elevating systolic pressure with methoxamine produced similar results, while norepinephrine increased Vt.. by 36% and (dP/dt)/P by 56%S. CSNS produced directionally opposite results from BCO; it decreased Pi.8 by 15%, Vt.0 increased by 11%, while (dP/dt)/P remained almost constant. These effects may be explained largely by vasodilatation since reducing systolic pressure to the same level with nitroglycerin produced similar results. When peripheral vasoconstriction was minimized by phenoxybenzamine pretreatment, BCO produced a slight positive inotropic effect (Ptso increased by 8%o, Vt.. by 4%, and (dp/ This study was presented in part at the 44th Annual Scientific Sessions of the American Heart Association, Anaheim, Calif., November 1971. An

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: The Journal Of Clinical Investigation Volume 51 1972mentioning

confidence: 99%

Section: Bilateral Carotid Artery Occlusionmentioning

confidence: 99%

See 2 more Smart Citations

Extent of Carotid Sinus Regulation of the Myocardial Contractile State in Conscious Dogs

Vatner¹,

Higgins²,

Franklin³

et al. 1972

J. Clin. Invest.

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“…Hydraulic occluders were implanted just distal to the flow transducers and heparin-filled Tygon catheters were implanted in the left atrium and aorta. Up to six pairs of miniature ultrasonic transducers* were implanted intramyocardially, parallel to the muscle fibers, 1-2 cm apart and varying in depth from 4 frequency response is flat to 60 Hz. Any drift in the measuring system, i.e., in the instrument electronics, the data tape recorder and the oscillograph that displayed data, was eliminated during the experiment by periodic calibrations.…”

mentioning

confidence: 99%

Effects of a cardiac glycoside in combination with propranolol on the ischemic heart of conscious dogs.

Vatner¹,

Baig²,

Manders³

et al. 1978

Circulation

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SUMMARY The effects of coronary occlusion and of subsequent propranolol and ouabain administration were examined in 12 conscious dogs. Overall left ventricular (LV) function was assessed by measurement of LV pressure and dP/dt, and regional myocardial function was assessed by measurements of segment length (SL), velocity of SL shortening and regional myocardial "work," i.e., pressure-length loops in normal and moderately and severely ischemic zones. Regional intramyocardial electrograms were measured at the same sites as function along with regional myocardial blood flow as determined by the radioactive microsphere technique. Coronary occlusion resulted in graded loss of function from the normal to severely ischemic zones, along with graded flow reductions and PROPRANOLOL HAS BEEN ADVOCATED for therapy in acute ischemic heart disease, since the drug normally reduces cardiac rate and contractility and on this basis should lower myocardial oxygen demands and thereby protect ischemic myocardium.1 However, the myocardial depressant action of propranolol, which is even evident in ischemic myocardium,2 could be deleterious when cardiac function is already compromised. In this situation it would be important to enhance contractility. Therefore, the clinical question remains regarding the effects of a non-beta adrenergic positive inotropic agent, e.g., digitalis, in the presence of myocardial depression induced by ischemia and propranolol.The goal of this investigation was to examine the effects of ouabain in combination with propranolol on simultaneous measurements of regional myocardial function, blood flow, and electrograms in normal, moderately and severely ischemic zones of the heart of the conscious dog with acute myocardial ischemia. The specific goals of this study were to ascertain 1) whether ouabain could reverse the negative inotropic effects of propranolol on the ischemic heart, 2) whether the changes in function were associated with changes in blood flow, and 3) whether digitalis would enhance or Methods Twenty-one dogs, weighing between 25 and 35 kg, were anesthetized with i.v. sodium pentobarbital, 30 mg/kg. Through a thoracotomy in the fifth left intercostal space, Konigsberg P22 miniature pressure gauges were implanted within the left ventricle through a stab wound in the apex, and Doppler ultrasonic flow transducers were placed around either the left anterior descending (13 dogs) or circumflex coronary (8 dogs) arteries, 2-3 cm from the bifurcation of these vessels. Hydraulic occluders were implanted just distal to the flow transducers and heparin-filled Tygon catheters were implanted in the left atrium and aorta. Up to six pairs of miniature ultrasonic transducers* were implanted intramyocardially, parallel to the muscle fibers, 1-2 cm apart and varying in depth from 4 to 15 mm, in potentially normal, and moderately and severely ischemic zones. These zones were confirmed by regional flow determination after sacrifice of the animal.The miniature pressure gauges were calibrated in vitro and in vivo a...

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Interaktion zwischen Herzglykosiden, β-Rezeptorenblockern und anderen Arzneimitteln

Lydtin¹

1975

Digitalistherapie

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Effects of cardiac depression and of anesthesia on the myocardial action of a cardiac glycoside

Cited by 71 publications

References 52 publications

Extent of Carotid Sinus Regulation of the Myocardial Contractile State in Conscious Dogs

Extent of Carotid Sinus Regulation of the Myocardial Contractile State in Conscious Dogs

Effects of a cardiac glycoside in combination with propranolol on the ischemic heart of conscious dogs.

Interaktion zwischen Herzglykosiden, β-Rezeptorenblockern und anderen Arzneimitteln

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