1251
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1252
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Ross J, Sonnenblick EH, Covell JW, Kaiser G, Spiro D. The architecture of the heart in systole and diastole. Technique of rapid fixation and analysis of left ventricular geometry. Circ Res 1967; 21:409-21. [PMID: 6057699 DOI: 10.1161/01.res.21.4.409] [Citation(s) in RCA: 103] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Techniques for rapid fixation of the canine left ventricle in systole or diastole that have permitted analysis of ventricular geometry under known hemodynamic conditions are described. Six ventricles were arrested at and diastole, 7 at end ejection, and 7 in diastole following acute ventricular overdistension. The architecture of the ventricles was analyzed from measurements of the fixed ventricles and silicone-rubber casts of the ventricular cavities. In ventricles of matched weights, the average reduction, from end diastole to end ejection, of the apex to mitral valve distance was 4.6%, while that from apex to aortic valve was less than 1%. The minor internal equator was reduced by 26%, the midwall radius by 16%, and the outer radius by 8.5%. The ratio of the average end-diastolic volume minus end-systolic volume to the end-diastolic volume (analogous to stroke volume/end-diastolic volume) averaged 59%. The average wall thickness was 28% greater in systolic than in diastolic ventricles. The papillary muscle volume averaged 5.0%e of ventricular volume at end diastole and 14.7% at end systole. The area of the mitral valve orifice averaged 28% less at end systole than at end diastole; this area was 39% more in the hearts subjected to over-transfusion than in those with normal filling pressures. These data provide a framework for construction of a geometric model suitable for use in analyses of the mechanics of left ventricular contraction. Moreover, the methods described offer the possibility of correlating ventricular geometry and ultrastructure with cardiac function in normal and in abnormal hearts.
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1253
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Taylor RR, Covell JW, Sonnenblick EH, Ross J. Dependence of ventricular distensibility on filling of the opposite ventricle. THE AMERICAN JOURNAL OF PHYSIOLOGY 1967; 213:711-8. [PMID: 6036789 DOI: 10.1152/ajplegacy.1967.213.3.711] [Citation(s) in RCA: 278] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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1254
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Graham TP, Ross J, Covell JW, Sonnenblick EH, Clancy RL. Myocardial oxygen consumption in acute experimental cardiac depression. Circ Res 1967; 21:123-38. [PMID: 4157323 DOI: 10.1161/01.res.21.2.123] [Citation(s) in RCA: 59] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Myocardial oxygen consumption (MV
·
o
2
) during drug-induced cardiac depression was measured in 8 anesthetized, open chest dogs in which myocardial wall tension was controlled. The right side of the heart was bypassed and myocardial contractility was reduced with procaine HCl, propranolol, or pronethalol. MV
·
o
2
consistently fell during cardiac depression (avg = 1.52 ml/min per 100 g left ventricle or - 11.6%). These reductions occurred despite small increases in developed tension. Changes in the tension-time index, contractile element work, and contractile element power did not correlate invariably with ΔMV
·
o
2
, while reductions in velocity of the contractile elements at isotension, maximum left ventricular dp/dt, and the extent of shortening of the contractile elements and circumferential fibers were associated in every experiment with the reductions in MV
·
o
2
. The finding that negative inotropic influences are associated with a reduction in myocardial energy utilization, when considered with earlier observations showing that positive inotropic influences induce an augmentation of MV
·
o
2
, provides evidence that the inotropic state and its mechanical correlates are coupled with myocardial energy utilization by a mechanism that is independent of tension development.
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1255
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Taylor RR, Ross J, Covell JW, Sonnenblick EH. A quantitative analysis of left ventricular myocardial function in the intact, sedated dog. Circ Res 1967; 21:99-115. [PMID: 6028859 DOI: 10.1161/01.res.21.1.99] [Citation(s) in RCA: 75] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Instantaneous contractile element velocity was calculated from left ventricular pressure and its first derivative during isovolumic left ventricular contractions produced by sudden balloon occlusion of the ascending aorta during diastole in closed-chest, sedated dogs. Wall tension was derived from ventricular pressure and volume, the latter being obtained from the pressure-volume relation of the arrested ventricle. During isovolumic contractions, there was an inverse curvilinear relation between tension and velocity, except at the onset of contraction and near peak tension. Increasing diastolic ventricular volume shifted the tension-velocity relations to the right, with increase in mean total isovolumic tension from 188 to 471 g/cm
2
, but without an obvious change in extrapolation to maximum velocity, which averaged 3.0 circumferences/sec. End-diastolic pressure-tension and circumference-tension relations indicated that active tension development continued to increase up to the maximum measured enddiastolic pressures of approximately 20 mm Hg. The normalized data, pooled from 15 animals, showed little scatter in the data for tension and velocity. It is concluded that the contractile properties of left ventricular muscle in the intact, sedated dog may be meaningfully described by tension-velocity relations obtained from single isovolumic contractions. The responses of the intact ventricle to increased diastolic volume and digitalis glycosides are analogous to those of isolated cardiac muscle. The small variability in the normalized tension-velocity relations in the normal dog suggests that it will also be possible to characterize abnormal left ventricular function with this approach.
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1256
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1257
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Mason DT, Cohn LH, Ross J, Braunwald E. Idiopathic hypertrophic subaortic stenosis. Effects of changes in heart rate on the severity of obstruction to left ventricular outflow. Am J Cardiol 1967; 19:797-805. [PMID: 5338118 DOI: 10.1016/0002-9149(67)90502-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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1258
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Ross J, Mangete E, Vorlaender KO. [On the determination of precipitating antibodies against leukocyte extracts. Experimental and clinical studies]. KLINISCHE WOCHENSCHRIFT 1967; 45:522-7. [PMID: 5241266 DOI: 10.1007/bf01716369] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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1259
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Sun HY, Ross J. Evaluation of Scattering Cross Sections in the Optical Model by the Method of Stationary Phase. J Chem Phys 1967. [DOI: 10.1063/1.1841215] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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1260
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Airey JR, Greene EF, Reck GP, Ross J. Scattering of Potassium by a Series of Reactive and Nonreactive Compounds in Crossed Molecular Beams. J Chem Phys 1967. [DOI: 10.1063/1.1841214] [Citation(s) in RCA: 49] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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1261
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Airey JR, Greene EF, Kodera K, Reck GP, Ross J. Nonreactive Scattering of K by HBr and DBr in Crossed Molecular Beams. J Chem Phys 1967. [DOI: 10.1063/1.1841213] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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1262
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Braunwald NS, Ross J, Morrow AG. Conservative management of tricuspid regurgitation in patients undergoing mitral valve replacement. Circulation 1967; 35:I63-9. [PMID: 6024041 DOI: 10.1161/01.cir.35.4s1.i-63] [Citation(s) in RCA: 153] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Among 100 consecutive patients undergoing mitral valve replacement, 28 had clinically and hemodynamically significant tricuspid regurgitation without tricuspid stenosis. In 21 patients the mitral valve was regurgitant, and in eight it was stenotic. The characteristic murmur of tricuspid regurgitation was present in 27 patients; 25 had abnormal venous distention, 14 peripheral edema, and seven ascites; and in 27 the liver was enlarged more than 4 cm below the costal margin. The mean right atrial pressure was abnormally high in every patient (average 11 mm Hg), and 25 had severe pulmonary hypertension (average systolic pressure 75 mm Hg). At the time of mitral replacement, 25 patients had no operative procedure on the tricuspid valve, and three had a tricuspid annuloplasty. Four patients died, a mortality rate (14%) not different from that in the patients without tricuspid regurgitation.
Twenty-four patients were reassessed at postoperative intervals of one to four years (average 30 months). All evidenced symptomatic improvement; 16 observed no dietary restriction of sodium, six ate regular diets without added salt, and only two limited sodium intake more stringently. Postoperatively, mean right atrial pressures averaged 5 mm Hg and systolic pulmonary arterial pressures 39 mm Hg.
In many patients with advanced mitral valve disease, associated tricuspid regurgitation is of a functional nature and secondary to right ventricular hypertension and dilatation of the tricuspid annulus. The present results indicate that in such patients tricuspid regurgitation will improve or disappear after mitral replacement and that tricuspid valve replacement is seldom necessary.
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1263
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1264
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Mason DT, Ross J, Gault JH, Braunwald E, Morrow AG. Combined prosthetic replacement of the mitral and aortic valves. Preoperative and postoperative hemodynamic studies at rest and the left ventricular response to muscular exercise. Circulation 1967; 35:I15-23. [PMID: 6024024 DOI: 10.1161/01.cir.35.4s1.i-15] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Detailed preoperative and postoperative hemodynamic studies were carried out in 12 patients with severe aortic and mitral valve disease in whom replacement of both valves with ball-valve prostheses was carried out. Replacement of both valves resulted in restoration to normal, or nearly normal, the resting values of cardiac output, left ventricular end-diastolic pressure (LVEDP), pulmonary arterial pressure, and pulmonary vascular resistance. However, studies of left ventricular function during muscular exercise revealed abnormalities in the relationships between cardiac output and oxygen consumption in six of seven patients, and in no patient was the left ventricular response to exercise normal when assessed by the relation between LVEDP and stroke volume. It appears likely, therefore, that underlying myocardial disease or coronary arterial disease contributed to the preoperative disability in these patients, and may limit complete symptomatic recovery following operation. The residual impairment of myocardial performance observed in these patients appears to be more pronounced than that previously demonstrated in patients in whom isolated replacement of either the mitral or aortic valve had been performed.
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1265
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Ross J, Covell JW, Sonnenblick EH. The mechanics of left ventricular contraction in acute experimental cardiac failure. J Clin Invest 1967; 46:299-312. [PMID: 4381563 PMCID: PMC297051 DOI: 10.1172/jci105532] [Citation(s) in RCA: 49] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The effects of acute cardiac failure induced by pentobarbital or pronethalol on the basic mechanical properties of the intact left ventricle were examined in the dog, and the influence on auxotonic and isovolumic contractions of the increase in end-diastolic volume that usually accompanies cardiac failure was assessed. The right heart bypass preparation was employed, and isovolumic beats were induced by sudden balloon occlusion of the aortic root. The ventricular pressure-volume curve was determined directly, and the mechanical responses of the myocardial fibers and contractile elements were calculated.When end-diastolic pressure was held constant, failure reduced the extent of circumferential fiber shortening, and the tension-velocity relation calculated during isovolumic beats was always shifted, with reductions in both maximal velocity (average decrease 30%) and maximal developed tension (average 23%); in addition, during failure achievement of maximal contractile element velocity and maximal tension was delayed, whereas the total duration of contraction was always prolonged. Acetylstrophanthidin tended to reverse all of these changes. When end-diastolic volume was augmented during failure at a constant stroke volume, the extent of circumferential fiber shortening was reduced (3.82 cm to 2.02 cm), and during ejection the fiber and contractile element velocities were diminished at wall tensions comparable to control; maximal velocity and velocity at peak tension were also decreased. The tension-velocity relation during isovolumic beats was shifted by failure with consistent reductions in maximal shortening velocity, but changes in maximal tension were small. Maximal instantaneous power was always reduced by failure, and a striking alteration occurred in the relation between work expended in stretching the series elastic component and the external work; the former, "internal work," increased by an average of 90%, the latter diminished by 11%, and the total contractile element work remained essentially unchanged. These findings are discussed within the framework of a three dimensional model that included fiber length, wall tension, and contractile element velocity. The experimental techniques employed appear to permit a more complete definition of the abnormalities of the ventricular myocardium in experimental failure. They are potentially applicable in the closed-chest animal and allow quantitative determinations of the contractile properties of the left ventricle.
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1266
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Cohn LH, Mason DT, Ross J, Morrow AG, Braunwald E. Preoperative assessment of aortic regurgitation in patients with mitral valve disease. Am J Cardiol 1967; 19:177-82. [PMID: 6016416 DOI: 10.1016/0002-9149(67)90530-9] [Citation(s) in RCA: 84] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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1267
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Covell JW, Ross J, Taylor R, Sonnenblick EH, Braunwald E. Effects of increasing frequency of contraction on the force velocity relation of left ventricle. Cardiovasc Res 1967; 1:2-8. [PMID: 6060158 DOI: 10.1093/cvr/1.1.2] [Citation(s) in RCA: 111] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
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1268
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Eu BC, Ross J. Comments on Two Derivations of a Transition‐State Theory of Chemical Reactions. J Chem Phys 1967. [DOI: 10.1063/1.1840425] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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1269
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Sonnenblick EH, Ross J, Covell JW, Braunwald E. Alterations in resting length-tension relations of cardiac muscle induced by changes in contractile force. Circ Res 1966; 19:980-8. [PMID: 5954130 DOI: 10.1161/01.res.19.5.980] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Effects of sustained postextrasystolic potentiation (P.S.), norepinephrine (NE), and calcium on resting length-tension relations of heart muscle were studied in the cat papillary muscle and isovolumic dog ventricle. In papillary muscles, P.S., calcium or NE produced no change in diastolic compliance when the muscles were freely isotonic, or afterloaded, and force remained constant. However, under isometric conditions, P.S. induced a small fall in diastolic tension while systolic force rose. Similar decrements in diastolic tension were observed when force of contraction was augmented by simply increasing afterload from a constant initial muscle length.
In the isovolumic ventricle, P.S., NE, and calcium each induced substantial increments in developed pressure, accompanied by small decreases in end-diastolic pressure. The latter was reduced or abolished by augmenting the initial contractile state with calcium or NE, so that the super-imposition of P.S. induced only trivial increments in developed pressure.
It is concluded that P.S., calcium, or NE do not induce changes in the resting length-tension relations of heart muscle per se. However, resting length at any given resting tension does increase slightly upon the augmentation of systolic force alone. It is postulated that these findings may be explained by the existence of a series viscous component.
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1270
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Gault JH, Ross J, Mason DT. Patterns of brachial arterial blood flow in conscious human subjects with and without cardiac dysfunction. Circulation 1966; 34:833-48. [PMID: 5923846 DOI: 10.1161/01.cir.34.5.833] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The patterns of phasic and instantaneous mean brachial arterial blood flow at rest, and during various interventions, were studied in 35 conscious human subjects. Flow was measured with an electromagnetic flowmeter applied to the brachial artery (BA) prior to retrograde arterial catheterization of the left ventricle.
The patterns of phasic BA flow in six patients without left-heart disease were compared with those of patients having a variety of cardiac lesions. In three patients with aortic stenosis, a prolonged upslope and a delayed systolic flow peak were noted, while in five patients with severe aortic regurgitation, a progressive decline in flow occurred throughout diastole; retrograde diastolic flow occurred infrequently at end diastole, but was elicited in three patients by inflation of a wrist cuff. Among seven patients with idiopathic hypertrophic subaortic stenosis, those with large pressure gradients across the left ventricular outflow tract exhibited a bifid systolic brachial arterial flow pulse and an abnormal response in brachial arterial flow during the beat following a premature ventricular contraction. In patients with mitral stenosis, the flow pulse was normal, while in three patients with mitral regurgitation, the period during which systolic flow occurred was abbreviated.
Mean brachial arterial blood flow averaged 72.7 ml/min, and neither peak nor mean flow levels bore a relation to the cardiac lesion, the stroke volume, or the cardiac index. All patients exhibited spontaneous variations in resting brachial arterial flow. Usually the fluctuations were in phase with periodic fluctuations in mean arterial pressure, although in some patients periodic fluctuations in arterial pressure and brachial arterial flow occurred in opposite directions, and in other patients random flow changes were observed.
Contractions of the forearm muscles were found to cause striking mechanical limitation of instantaneous brachial arterial flow. During maximal contraction of the forearm muscles, actual cessation of flow occurred.
Prior to investigating the influence of reflex interventions on brachial arterial flow, studies were performed to determine whether or not local anesthesia and surgical exposure of the brachial artery altered resting flow in forearm bed or the reflex connections to the forearm. Plethysmographic determinations of the resting forearm blood flow, and of the response to a cold pressor test, before and after exposure of the brachial artery, indicated that resting flow was unchanged and that reflex activity was essentially intact. Carotid arterial compression in five patients resulted in a prompt increase in forearm vascular resistance (average 53.4%). The response to manual stimulation of the carotid sinus in four patients suggested that reflex forearm vasodilatation was rapidly induced. In six patients studied during the course of a 20-second Valsalva maneuver, marked reflex vasoconstriction occurred approximately 10 seconds after the onset of the maneuver.
The present technique has permitted the first description of the normal pattern of phasic brachial arterial flow in unanesthetized human subjects, as well as the alterations in phasic flow contour accompanying various cardiac lesions. In addition, it has allowed investigation of rapid, transient alterations in peripheral arterial blood flow not previously accessible to measurement.
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1271
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Covell JW, Braunwald E, Ross J, Sonnenblick EH. Studies on digitalis. XVI. Effects on myocardial oxygen consumption. J Clin Invest 1966; 45:1535-42. [PMID: 5925512 PMCID: PMC292835 DOI: 10.1172/jci105460] [Citation(s) in RCA: 143] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
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1272
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Ross J, Gault JH, Mason DT. On the question of obstruction in idiopathic hypertrophic subaortic stenosis. Ann Intern Med 1966; 65:859-61. [PMID: 4224499 DOI: 10.7326/0003-4819-65-4-859] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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1273
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Ross J, Braunwald E, Gault JH, Mason DT, Morrow AG. The mechanism of the intraventricular pressure gradient in idiopathic hypertrophic subaortic stenosis. Circulation 1966; 34:558-78. [PMID: 5950829 DOI: 10.1161/01.cir.34.4.558] [Citation(s) in RCA: 139] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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1274
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Ross J, Gault JH, Mason DT, Linhart JW, Braunwald E. Left ventricular performance during muscular exercise in patients with and without cardiac dysfunction. Circulation 1966; 34:597-608. [PMID: 5950833 DOI: 10.1161/01.cir.34.4.597] [Citation(s) in RCA: 130] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The LVEDP, cardiac output, and V
o
o2
were measured before and during supine muscular exercise in 38 patients. The normal pattern, established in seven patients without left ventricular dysfunction, consisted of an exercise factor [see Equation in PDF File], an LVEDP during exercise of less than 12 mm Hg, and little change or a decrease in LVEDP, which was accompanied in most instances by an increase in the stroke volume. In the majority of 31 patients with various cardiac lesions, but without valvular regurgitation, measurement of the LVEDP before and during exercise permitted the definition of normal or abnormal left ventricular function when the status of the left ventricle could not have been ascertained from other measurements. Thus, in most of the patients with mitral stenosis and abnormal resting hemodynamics, the pattern of left ventricular function during exercise was considered to be normal. Among the patients with aortic stenosis or left ventricular myocardial disease and elevated resting LVEDP, two types of abnormal performance of the left ventricle were identified. In some patients, an increase in LVEDP was accompanied by an increase in stroke volume, and this response was termed "abnormal left ventricular dynamics"; in the remaining patients, an increase in LVEDP and no change or a fall in stroke volume occurred and this response was termed "depressed left ventricular function." It is concluded that determination of the LVEDP before and during exercise adds importantly to measurements of the changes in cardiac output and O
2
consumption in characterizing left ventricular performance. The method employs standard catheterization techniques and appears to provide a practical and useful means for evaluating the functional status of the left ventricle in patients with and without myocardial dysfunction.
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1275
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Abstract
Improvements in the equipment and technique for transseptal left heart catheterization appear to have largely overcome the major problems and complications that have been encountered in recent years with this procedure. Improvements in equipment have included the addition of a stylet for the needle, modifications in the design of the catheter, and the use of a catheter tip occluder both for manipulation of the catheter within the left heart and to close the end hole during selective angiography. The steps employed for insertion of the catheter and needle were described in detail, and the use of landmarks such as the left main-stem bronchus, the spine, the left atrial shadow, and the aortic bulge was discussed. The indications for, and relative contraindications to, transseptal catheterization currently applied in this laboratory were also described. The relative contraindications consist of (1) a giant right atrium, (2) severe rotational anomalies of the heart or great vessels, and kyphoscoliosis; (3) marked dilation of the ascending aorta; (4) anticoagulant therapy, and (5) a history of recent systemic arterial embolization. Since the introduction of these technical changes and precautions, with the exception of one nonfatal aortic puncture, the problems previously encountered during transseptal catheterizations have been avoided in more than 350 consecutive transseptal left heart studies in this laboratory.
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1276
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Covell JW, Ross J, Sonnenblick EH, Braunwald E. Comparison of the force-velocity relation and the ventricular function curve as measures of the contractile state of the intact heart. Circ Res 1966; 19:364-72. [PMID: 5914848 DOI: 10.1161/01.res.19.2.364] [Citation(s) in RCA: 96] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The contractile state of the intact canine left ventricle was investigated by determining the instantaneous relations between tension and contractile element velocity (V
CE
) during the course of single, isovolumic beats produced by balloon occlusion of the aorta. The relative sensitivity of this relation was compared with that of the ventricular function curve (VFC) by exerting small inotropic influences. In seven experiments, low doses of norepinephrine always shifted the isovolumic force-velocity (FV) relation, increases occurring in maximum V
CE
(32.7%) and maximum tension (P
0
) (16.9%). The VFC was unchanged in four of the seven dogs. Moderate hypothermia (average 30.8°C) in four dogs increased P
0
(average 28%), with no change, or a fall, in maximum VCE; the VFC during hypothermia was shifted upward and to the left in two experiments and unchanged in two. Moderate increases in heart rate always produced increases in maximum V
CE
(average 13.5%) but no change in the VFC was observed. Thus, the isovolumic FV relation proved more sensitive than the VFC in detecting changes in myocardial contractile state and allowed more complete definition of these alterations by providing separation of changes in shortening velocity from alterations in the strength of myocardial contraction.
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1277
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Rockoff SD, Ross J, Oldham NN, Mason DT, Morrow AG, Braunwald E. Ventriculo-atrial regurgitation following prosthetic replacement of the mitral valve. Angiocardiographic and hemodynamic findings. Am J Cardiol 1966; 17:817-24. [PMID: 5916467 DOI: 10.1016/0002-9149(66)90377-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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1278
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Gault JH, Ross J, Braunwald E. Persistent atrioventricular dissociation with block and nodal rhythm after cardiac catheterization. Am Heart J 1966; 71:690-4. [PMID: 5935861 DOI: 10.1016/0002-8703(66)90321-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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1279
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Ross J, Morrow AG, Mason DT, Braunwald E. Left ventricular function following replacement of the aortic valve. Hemodynamic responses to muscular exercise. Circulation 1966; 33:507-16. [PMID: 5937549 DOI: 10.1161/01.cir.33.4.507] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Evaluations of left ventricular myocardial function were carried out in 14 patients 4 to 16 months after stenotic or regurgitant malformations of the aortic valve had been corrected by valve replacement. The circulatory responses to exercise, judged by the increases in cardiac output in relation to the increases in oxygen consumption, were normal or only mildly reduced in 12 patients. In five patients, the relationships between the change in the left ventricular end-diastolic pressure and the alteration in the stroke volume were also normal, a fall or an increase in left ventricular end-diastolic pressure of less than 3 mm. Hg being accompanied by an increase in stroke volume. In eight patients, however, abnormal increases in the left ventricular end-diastolic pressure occurred during exercise, and in four the left ventricular end-diastolic pressure was increased to levels above 12 mm. Hg. Variable alterations in the stroke volume accompanied these increases in end-diastolic pressure. It is suggested that in the three patients who exhibited simultaneous increases in left ventricular end-diastolic pressure and stroke volume, the changes were either a manifestation of the Frank-Starling mechanism, or primarily the result of a positive inotropic influence. In the five patients who exhibited increases in left ventricular end-diastolic pressure, but no change or a fall in stroke volume, it is proposed that a distinct depression of left ventricular performance was present. Thus, while the cardiac output response was adequate to meet the stress of exercise in the majority of the patients studied following aortic valve replacement, determination of the relationship between the left ventricular end-diastolic pressure and the stroke volume permitted the detection of abnormalities in the function of the left ventricle.
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1280
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Abstract
The present study was undertaken to define the O
2
requirements of electrical activation of the heart. Thirteen isolated canine hearts were perfused with whole blood from which calcium had been removed with an exchange resin and to which the disodium salt of ethylenediaminetetraacetic acid had been added. Spontaneous depolarizations were suppressed by raising the plasma potassium to an average concentration of 7.5 mEq/liter, and the right ventricle was stimulated electrically at controlled frequencies. Although the stimuli produced propagated depolarizations, neither high-sensitivity strain gauge arches sutured to both ventricles, nor careful visual observation, showed any evidence of associated contractile activity. Ten of the hearts were studied with repetitive single stimuli applied in the conventional fashion, while the remaining three hearts were subjected to paired electrical stimulation. Changes of myocardial O
2
consumption (MV
·
O
2
) were measured at a constant coronary blood flow and arterial O
2
content by determining changes of venous O
2
content from a continuous recording of venous PO
2
. Increases of the frequency of depolarization were uniformly accompanied by small increases of MV
·
O
2
, averaging 0.40 ± 0.04 (SEM) µliter/activation/100 g. The increases were of the same order of magnitude in the hearts subjected to paired electrical stimulation as in the hearts studied with single stimulation, suggesting that the altered frequency and rhythm of depolarization in paired electrical stimulation cannot account for the marked increase of MV
·
O
2
which this intervention produces in the intact heart. It is concluded that the amount of O
2
required for electrical activation of the heart is less than 1% of the total O
2
consumption of the normally working heart.
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1281
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Braunwald E, Chidsey CA, Pool PE, Sonnenblick EH, Ross J, Mason DT, Spann JF, Covell JW. Congestive heart failure. Biochemical and physiological considerations. Combined clinical staff conference at the National Institutes of Health. Ann Intern Med 1966; 64:904-41. [PMID: 23841211 DOI: 10.7326/0003-4819-64-4-904] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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1282
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Abstract
There has been considerable dispute concerning the role of atrial contraction in the closure of the atrioventricular valves. Selective angiocardiograms with left ventricular [see figure in the PDF file] opacification in 43 patients having a variety of arrhythmias that resulted in the absence of atrial systole, or in an abnormal temporal relationship between atrial and ventricular contractions, revealed no evidence of mitral regurgitation. From this observation it is concluded that a properly timed atrial contraction is not always essential for effective closure of the mitral valve in man.
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1283
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Mason DT, Braunwald E, Ross J. Effects of changes in body position on the severity of obstruction to left ventricular outflow in idiopathic hypertrophic subaortic stenosis. Circulation 1966; 33:374-82. [PMID: 5904414 DOI: 10.1161/01.cir.33.3.374] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The circulatory responses to alterations in posture were determined in 10 patients with idiopathic hypertrophic subaortic stenosis. Tilting to a 45° head-up position augmented the subaortic gradient by an average of 35 mm Hg and intensified the obstruction to left ventricular outflow. In addition, the post-extrasystolic decrease of the arterial pulse pressure became more prominent. Tilting to a 20° head-down position reduced the gradient by an average of 11 mm Hg and tended to reduce the severity of the obstruction. Elevation of the lower extremities also resulted in a reduction of the intraventricular systolic pressure gradient, the reduction averaging 28 mm Hg, and apparently increased the dimensions of the obstructing orifice.
It is postulated that these effects on the obstruction to outflow induced by changes in posture result primarily from alterations in left ventricular volume secondary to changes in venous return. As a consequence, in the upright position, the size of the left ventricular outflow tract is reduced and the intraventricular pressure gradient is augmented while the cardiac output is reduced, resulting in an intensification of the obstruction. The opposite changes occur during the head-down tilt or during elevation of the legs.
These hemodynamic findings provide an explanation for the intensification of symptoms commonly experienced by patients with idiopathic hypertrophic subaortic stenosis in the erect position, and for the discrepancies between the symptoms and the severity of obstruction determined by cardiac catheterization carried out in the supine position. Assumption of the head-down, legs-up position is suggested as an emergency therapeutic maneuver for patients with hypertrophic subaortic stenosis.
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1284
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Fairchild HM, Ross J, Guyton AC. Failure of recovery from reactive hyperemia in the absence of oxygen. THE AMERICAN JOURNAL OF PHYSIOLOGY 1966; 210:490-2. [PMID: 5933198 DOI: 10.1152/ajplegacy.1966.210.3.490] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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1285
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Rosenfeld JLJ, Ross J. Calculation of Chemical Reaction Probabilities from Elastic Scattering Data. J Chem Phys 1966. [DOI: 10.1063/1.1726444] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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1286
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1287
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Ross J, Schumacher K, Mangete E. [The demonstration and identification of a factor of the nature of immune globulin M and the antibody properties in the serum of patients with multiple sclerosis]. KLINISCHE WOCHENSCHRIFT 1965; 43:1324-31. [PMID: 4163288 DOI: 10.1007/bf01745801] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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1288
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1289
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Rockoff SD, Braunwald E, Ross J, Frommer PL, Mason DT, Gault JH. Simultaneous recording of oscillographic and radiologic events on cine film. Applications of the cinetrace during cardiac catheterization. Am J Cardiol 1965; 16:708-16. [PMID: 5839408 DOI: 10.1016/0002-9149(65)90055-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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1290
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Klocke FJ, Kaiser GA, Ross J, Braunwald E. Mechanism of increase of myocardial oxygen uptake produced by catecholamines. THE AMERICAN JOURNAL OF PHYSIOLOGY 1965; 209:913-8. [PMID: 5850655 DOI: 10.1152/ajplegacy.1965.209.5.913] [Citation(s) in RCA: 68] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The relative roles of augmented hemodynamic performance and direct stimulation of oxidative metabolism in mediating the increase of myocardial oxygen uptake (MVo2) produced by catecholamines have been examined in an isolated canine heart preparation. The responses of MVo2 to graded doses of isoproterenol, norepinephrine, or epinephrine were determined before and after the induction of cardiac arrest with potassium. Although increases of MVo2 occurred in the arrested state with the larger doses of the amines, they constituted only a small fraction, generally between 5 and 20%, of the increases produced by the same doses of amines when the hearts were beating. It is concluded that while large doses of catecholamines can increase oxidative metabolism of the nonbeating heart by a small amount, the increases of MVo2 produced by catecholamines in the beating heart are due in large part to the hemodynamic alterations which the amines induce.
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1291
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Braunwald E, Sonnenblick EH, Ross J, Frommer PL. Paired electrical stimulation of the heart: a physiologic riddle and a clinical challenge. Circulation 1965; 32:677-81. [PMID: 5846390 DOI: 10.1161/01.cir.32.5.677] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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1292
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Sonnenblick EH, Ross J, Covell JW, Kaiser GA, Braunwald E. Velocity of contraction as a determinant of myocardial oxygen consumption. THE AMERICAN JOURNAL OF PHYSIOLOGY 1965; 209:919-27. [PMID: 5849492 DOI: 10.1152/ajplegacy.1965.209.5.919] [Citation(s) in RCA: 261] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
In 12 dogs on right-heart bypass with heart rate, stroke volume, and aortic pressure constant, the velocity of contraction was augmented comparably by three fundamentally distinct interventions in the same heart: 1) sustained postextrasystolic potentiation produced by paired, electrical stimulation; 2) norepinephrine infusion; and 3) calcium infusion. In each instance the correlation between velocity of contraction and MVo2 was striking. During paired stimulation, maximum rate of left ventricular ejection increased by an average of 50.3% ± 3.8% (se of mean) above control, MVo2 increased by 1.96 ± 0.10 ml/100 g per min (39.8% ± 1.6% above control), while the tension-time index (TTI) fell 12.4% ± 1.1%. With norepinephrine, and with calcium, left ventricular ejection rates were increased 52.9 ± 3.2% and 55.1 ± 3.2%, respectively, and MVo2 was augmented 2.03 ± 0.08 ml/100 g per min and 1.87 ± 0.04 ml/100 g per min, while the TTI decreased 15.9 ± 0.6% and 12.4 ± 2.4%. Since MVo2 always increased substantially while TTI fell, tension cannot be considered to be the sole determinant of MVo2. Since comparable increases in velocity of contraction produced by different interventions were associated with similar large augmentations of MVo2, it appears that the velocity of contraction is an important determinant of MVo2. Furthermore, it is likely that the so-called O2 wasting effect exerted by norepinephrine on myocardial metabolism may be explained largely by an increased velocity of contraction.
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1293
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Ross J, Linhart JW, Brauwald E. Effects of changing heart rate in man by electrical stimulation of the right atrium. studies at rest, during exercise, and with isoproterenol. Circulation 1965; 32:549-58. [PMID: 5825546 DOI: 10.1161/01.cir.32.4.549] [Citation(s) in RCA: 183] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
A technic is described for controlling the heart rate in patients with normal atrioventricular conduction by means of an electrical pacemaker catheter that stimulated the right atrium. When the heart rates of 17 patients in the resting state were elevated from an average of 80 to 121 beats/min., the cardiac indices remained virtually unchanged and averaged 3.67 and 3.72 L./min./M.
2
, respectively. Further increases in the heart rates resulted in small reductions in the cardiac indices to an average value of 3.21 L./min./M.
2
at 148 beats/min. The stroke volumes, ejection periods, and mean rates of ejection decreased as heart rate was increased.
The role of heart rate in the circulatory response to exercise was examined in seven patients. When the heart rates were controlled by electrical stimulation at rates comparable to those previously achieved spontaneously during exercise, it was observed that cardiac output rose normally with exercise and that this rise was accomplished entirely through an increase in the stroke volume. In five patients the effects of isoproterenol infusion were also studied before and during control of the heart rate at the level reached spontaneously during isoproterenol administration. Again, when the heart rate was not permitted to rise, the increases in cardiac output with isoproterenol were mediated through increases in the stroke volume. These studies indicate that in the absence of augmented metabolic requirements, homeostatic mechanisms maintain cardiac output relatively constant despite large induced changes in the heart rate. However, when metabolic demands are increased by muscular exercise, or the circulation is stimulated by catecholamines, cardiac output can rise through an increase in stroke volume, even when alterations in the heart rate are prevented.
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1294
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1295
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Abstract
A logical space developed by Oppenheim to differentiate and locate publications was used to construct a self-report questionnaire. Factor analysis of responses to the questionnaire gave reason to suppose that Oppenheim's dimensional scheme may provide a basis for cognitive styles each corresponding to a different dimension.
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1296
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Ackerman M, Greene EF, Moursund AL, Ross J. Elastic and Reactive Scattering of K by HCl and HI in Crossed Molecular Beams. J Chem Phys 1964. [DOI: 10.1063/1.1726049] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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1297
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Barua AK, Afzal M, Flynn GP, Ross J. Viscosity of Hydrogen, Deuterium, Methane, and Carbon Monoxide from —50° to 150°C below 200 Atmospheres. J Chem Phys 1964. [DOI: 10.1063/1.1725877] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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1298
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Rieder H, Ross J, Ritzel G, Wüthrich R. Über den Nachweis von Autoantikörpern bei Multipler Sklerose. Pharmacology 1964. [DOI: 10.1159/000135468] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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1299
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Flynn GP, Hanks RV, Lemaire NA, Ross J. Viscosity of Nitrogen, Helium, Neon, and Argon from —78.5° to 100°C below 200 Atmospheres. J Chem Phys 1963. [DOI: 10.1063/1.1733455] [Citation(s) in RCA: 82] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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1300
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Beck D, Greene EF, Ross J. Study of the Reaction of K with HBr in Crossed Molecular Beams. J Chem Phys 1962. [DOI: 10.1063/1.1733115] [Citation(s) in RCA: 66] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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