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Biomedical subjects

W Rutishauser

Publications and source records attributed to W Rutishauser.

At least 127 records · Page 7Linked to original sources
PubMed1981

Assessment of myocardial sympathetic activity in coronary heart disease.

We measured adrenaline, noradrenaline and dopamine beta-hydroxylase in arterial and in coronary sinus blood in 14 patients with coronary artery disease, at rest and under pacing-induced ischemia. Pacing increased the concentrations of adrenaline and noradrenaline in both arterial and coronary sinus blood. The origin of the adrenaline increase appears to be extramyocardial. The arteriovenous differences indicated that the heart extracts adrenaline and releases noradrenaline. These differences were not significantly changed by pacing, nor by the administration of propranolol. No marked changes in the concentrations of dopamine beta-hydroxylase were observed, except under pacing after propranolol, in which case a release from the heart occurred.

Adult↗
PubMed1981

[Value of transverse radiotomography in the control of the permeability of aortocoronary bypasses, compared with coronary angiography].

The object of this study was to determine whether transverse radiotomography, despite cardiac movement, could be used to visualise aortocoronary bypass grafts to confirm their patency or obstruction. The results were then compared with those of coronary angiography. 20 patients with a total of 38 grafts (18 on the left anterior descending, 8 on the circumflex and 12 on the right coronary artery) underwent tomography. 1 or 2 60 ml boluses of iodide contrast medium were injected into a fore arm vein and 3-5 films were exposed after each injection at 15 sec intervals. Coronary angiography was performed in 16 patients and the results of tomography were identical to those of coronary angiography : 23 patent and 6 occluded grafts. In one case, subtotal proximal stenosis of the left anterior descending artery allowed sufficient flow for the graft to be opacified and considered patent on tomography. The correlation between transverse radiotomography and coronary angiography was excellent. Transverse radiotomography, a non-invasive technique, is very useful in operated patients with atypical chest pain and in those with recurrent angina in whom obstruction of the graft is feared. It does not seem destined to replace control coronary angiography after bypass surgery, but it may be indicated is selected cases.

Adult↗
PubMed1980

[The value and advantage of computer assisted tomography as compared to angiography in evaluating patency of aorto-coronary grafts].

Sixteen patients with 31 aorto-coronary grafts have been studied by CT and by coronary arteriography to compare the results of the two methods in the evaluation of graft patency or occlusion. Correlation of the two technics is excellent (100%). However, graft stenoses are not visualized on CT in its present state of technical performance and are the limiting factor for this noninvasive procedure. In patients with precordial pain and aorto-coronary grafts, CT should be done first to evaluate graft patency and only be checked by coronary arteriography if there is disagreement between the CT result and clinical assessment of the case.

Coronary Angiography↗
PubMed1979

Use of apexcardiography to evaluate left ventricular diastolic compliance in human beings.

The relation between various relative amplitude measurements of the left apexcardiogram and internally derived indexes of diastolic compliance of the left ventricle was studied in 29 patients. Simultaneous high fidelity recordings of the left apex tracing and left ventricular pressure were obtained in 11 patients without left ventricular disease (group I) and 18 patients with congestive cardiomyopathy (group II). In 204 normal subjects the ratio of the A wave amplitude to the total diastolic deflection (A/D ratio) of the left apexcardiogram was 31.4 +/- 11.4 (mean +/- standard deviation) percent, the ratio of the A wave amplitude to the total height (A/H ratio) 8.9 +/- 4.3 percent and the D/H ratio 30.4 +/- 14.7 percent. The A/D and A/H ratios were significantly (P less than 0.001 and P less than 0.005) increased in group II (69.2 +/- 12.2 percent and 16.8 +/- 8.2 percent, respectively); they were within normal limits in group I. In contrast, the D/H ratio was within normal limits in both groups of patients. The A/D ratio correlated significantly better with specific compliance (deltaV/deltaP.V) (r = -0.87) than did the A/H ratio (r = -0.53), whereas similar correlations were obtained with end-diastolic volume compliance (dV/dPV) (r = -0.61 and r = - 0.64, respectively). In contrast, the D/H ratio correlated significantly only with end-diastolic distensibility index (dV/dP) (r = -0.52). It is concluded that A wave amplitude/total diastolic deflection (A/D) ratio and, to a lesser degree, the A wave amplitude/total height (A/H) ratio of the left apexcardiogram correspond best to diastolic compliance and are useful noninvasive measurements of this property of the left ventricle.

Adolescent↗
PubMed1977

[Myocardial function and metabolism during local coronary flow reduction].

In 6 open chest dogs, regional myocardial function und metabolic changes (ATP, creatine phosphate, lactate) were studied during coronary flow reduction in LAD by ultrasonic dimension gauges and transmural biopsies. After reduction of the perfusion pressure from 108 to 50 mm Hg the ischemic segment showed a marked dyskinesis: the enddiastolic segment length increased by 7%, and segment shortening and segment stroke work decreased by 22% and 63% respectively. Left ventricular (LV) enddiastolic pressure rose from 5 to 8 mm Hg (p less than 0.05). Heart rate, LV systolic pressure, LV max dP/dt and Vpm did not change significantly.

Adenosine Triphosphate↗
PubMed1977

[Study of systolic ventricular volume changes by means of current measurement of contrast media].

Systolic changes of left ventricular volume were estimated after left ventricular contrast injections in dogs by roentgen-videodensitometry with adjustable windows. Good correlations were found between densitometric volume changes and the integral of electromagnetic aortic flow, as measured every 20 msec (r greater than or equal to 0.95 in 118 of 124 systoles analyzed). Videodensitometry avoids the time consuming frame-to-frame analysis with the errors inherent in geometric assumptions in ventricular volume measurements.

Animals↗
PubMed1976

[Effect of coronary flow reduction on the coronary flow distribution, the myocardial metabolism and left ventricular hemodynamics].

Myocardial blood flow, left ventricular performance, regional myocardial metabolites (ATP, CrP, lactate) and a-v differences of oxygen, lactate and pyruvate were determined in 6 open chest dogs with cannulated left coronary artery. A mean flow reduction from 92 to 43 ml/min/100 g heart weight resulted in marked heart failure accompanied by extensive flow reduction to the endocard with nearly 10 fold increase of lactate and a decrease of CrP content to 50% of control. In contrast, flow and metabolic parameters of the epicardial part changed only slightly. Furthermore, the DPTI/SPTI-ratio showed a good correlation with the subendocardial CrP content (r = 0.93, p less than 0.01).

Adenosine Triphosphate↗
PubMed1976

[Left ventricular function at rest and during dynamic load before and after aortocoronary bypass. Preliminary report].

17 patients with coronary artery disease were studied before and 10 +/- 3 months (mean +/- 1 SD) after aortocoronary bypass surgery. Left ventricular performance was analyzed at rest and in 12 cases during dynamic exercise (work load 59 +/- 22 watts) with tip manometer pressure measurements. The degree of coronary artery obstruction was estimated pre- and postoperatively by vascularization index (VaI). Patients were separated into 2 groups (group A: 8 patients with postoperatively improved VaI, and group B: 9 patients with unchanged or worsened VaI). Apart from a significant fall in LVEDP (p less than 0.025) in group A, there was no significant change in left ventricular dynamics in either group at rest, while a significant improvement in mean LVEDP (p less than 0.05), max dP/dt (p less than 0.05), Vpm (p less than 0.005) and Vmax (p less than 0.005) during dynamic exercise was observed in group A, but no significant change in these terms in group B, after surgery.

Coronary Artery Bypass↗
PubMed1976

Relationship between duration of systolic upstroke of apexcardiogram and internal indexes of myocardial function in man.

In 11 patients with nonobstructive cardiomyopathy and coronary heart disease and decreased myocardial function of the left ventricle, as well as in nine patients without left heart valvular or myocardial disease, left apexcardiograms were recorded during diagnostic heart catheterization, wherein micromanometers were used; ACG's were registered additionally in 54 healthy volunteers in order to establish the normal range of apexcardiographic parameters. In all cases the apex tracings were recorded by means of a pulse transducer with infinite time constant. The most important finding of this study was the close correlation between the duration of the systolic upstroke (SUT) of the apex tracing and some accepted isovolumic indexes of left heart function (isovolumic contraction time, time interval from the onset to peak of the first derivative of left ventricular pressure, maximal value of the first derivative of left ventricular pressure, and the peak measured velocity of shortening of the contractile elements). Further, the mean value of SUT in patients with impaired left myocardial function was significantly prolonged, compared to the control subjects; an overlap was apparent due to the fact that some of these patients showed a normal left myocardial performance at rest, having an abnormal response only to exercise tests. The apexcardiographic SUT can practically always be measured when the first derivative of apex tracing is simultaneously recorded. It showed itself to be only slightly influenced by the resting heart rate. The mentioned relationship of the systolic upstroke time of the ACG to internal isovolumic indexes of myocardial function makes this noninvasive measurable parameter an additional excellent tool for the evaluation of the left myocardial state, thus supporting a new aspect of the value of quantitative apexcardiography.

Adult↗
PubMed1976

Probe for production and measurement of acute mitral regurgitant flow in dog.

A probe for production and measurement of acute mitral regurgitation in dogs is described. It consists of a tube that is introduced into the mitral valve through the left atrial appendage. Regurgitant flow through the tube is measured by an electromagnetic device. Variation of flow and zero flow are achieved by narrowing or occluding the tube with a rubber cuff. In animals weighing 30-50 kg, the probe does not produce significant mitral stenosis and the mitral leaflets fit closely around the probe during ventricular systole. The instantaneous relationship between mitral regurgitant flow (MRF) and the gradient between left ventricular and left atrial pressure shows a marked delay of MRF at the beginning and end of regurgitation. This delay can be attributed to some extent to electrical phase lag and to the small movement of the probe relative to the mitral valve during the cardiac cycle. Measurement of regurgitant stroke volume is affected by this movement only to a small extent.

Animals↗
PubMed1975

[Proceedings: Clinical findings and coronary morphology before and after aorto-coronary venous bypass].

37 patients (mean age 51+/-8 years) were clinically and angiographically investigated before and 11+/-5 months after implantation of an aortocoronary vein graft. The rate of bypass patency was 78%. Postoperatively 57% of the patients were free of symptoms, 35% were improved and 8% unimproved or worse. The reduced incidence of angina pectoris during exercise testing appears to be correlated with graft patency, an improved vascularization index and probably the absence of preoperative myocardial infarction. The systolic time intervals and the lung-ear time at rest are of no value for differentiation of improved and unimproved patients.

Adult↗
PubMed1975

[Proceedings: Quantification of mitral valve insufficiency by means of videodensitometric measurement of the amount of contrast media in angiocardiography].

A new indicator quantity principle is presented which permits estimation of the regurgitant fraction in mitral incompetence from left heart angiocardiography by videodensitometric measurement of contrast medium content in the left heart chambers. In 90 experiments on dogs, a linear correlation of r = 0.89 was established between simultaneous determinations of mitral regurgitation by videodensitometry and electromagnetic flow measurement. Since only 1 catheter is needed for the injection of contrast medium and concomitant aortic incompetence can be computed from the same videodensitograms, this method is considered to be of special interest in clinical heart catheterization.

Angiocardiography↗