PubMed Health⌕ Search

Biomedical subjects

S Simonsen

Publications and source records attributed to S Simonsen.

At least 163 records · Page 9Linked to original sources
PubMed1977

Aspects of cardiac venous flow measured by the continuous infusion thermodilution technique.

The continuous infusion thermodilution method for the measurement of cardiac venous blood flow was investigated in 26 patients with angina pectoris. In 10 patients, the correlation coefficients for duplicate flow measurements within 1 min were 0.98 for the coronary sinus (CS) and 0.99 for the great cardiac vein (GCV), with a variation in relation to mean flow of 3.3 and 3.5%, respectively. The average CS drainage in 16 patients amounted to 126 ml/min with the GCV contributing 57% of the total and all other veins (OV) draining into the sinus 43%. Submaximal atrial pacing led to a significant increase in flow in all veins. The mean increase in flow per heart beat was 1.41 ml in the CS, 0.93 ml in the GCV, and 0.58 ml in the OV. The increase in flow per unit (1 X 10(-3) mm Hg - beats) heart rate times blood pressure product was 9.18, 6.97 and 4.71 ml, respectively. The method is suitable for the measurement of rapid changes in total and regional left ventricular blood flow under different conditions. For longer studies spontaneous changes in parameters governing myocardial oxygen demand must be taken into consideration.

Angina Pectoris↗
PubMed1976

Vectorcardiographic-hemodynamic correlations in adult aortic stenosis.

Thirty-nine vectorcardiographic (VCG) data from 45 patients with pure adult aortic stenosis have been tested as to their ability to reflect quantitatively the peak systolic left ventricular pressure (LVPSP), the left ventricular end diastolic pressure (LVEDP), and the X-ray estimated heart volume. VCG was recorded with the axial lead system and simple and multiple linear regression analyses were applied. Eight VCG data correlated significantly (p less than 0.001) with LVPSP, the best indicator being the maximum posterior dislocation in the Z lead (r = 0.65). Through multiple regression analysis a formula was derived which gave a correlation coefficient between observed and calculated pressures of 0.82. The best indicator of LVEDP was the maximum positive P amplitude in the X lead (r = 0.41). The relationship was, however, too poor to have practical significance. A good correlation was found between ST segment dislocation and heart volume (r = 0.65), in good accordance with previous observations as to the effect of right ventricular dilatation on the ECG. The study illustrates how ventricular volume and pressure exert different effects on the ECG, and how all the important hemodynamic aspects in aortic stenosis to some degree are reflected. Only the pressure correlations have, however, practical importance.

Aortic Valve Stenosis↗
PubMed1976

Determination of pressure gradient in mitral stenosis with a non-invasive ultrasound Doppler technique.

A 2 MHz continuous waveform non-invasive ultrasound doppler system has been used in the present investigation. With the aid of the audio signals of the frequency shifts, the ultrasound probe was positioned on the external chest so that the axis of the incident ultrasonic beam coincided with the direction of the maximum velocity vectors of the mitral jet. The frequency shifts due to the mitral jet were frequency analyzed and the time course of the maximum frequency shift was determined. The time course of the maximum mitral jet velocity was then determined from the doppler equation and the time course of the mitral pressure gradient from an orifice equation. The usefulness of the technique was evaluated by studying 25 patients with mitral stenosis and 10 without heart disease. The patients with mitral stenosis were studied during cardiac catheterization and the ultrasound data, the pulmonary artery wedge pressure, and the left ventricular pressure were recorded simultaneously. A table is presented where the gradient determined with the ultrasound technique, deltaPU, is compared with the gradient determined from the pressure tracing, deltaPM. Averaged over the 25 patients studied, deltaPU was 1.7 mmHg smaller than deltaPM at 0.08 sec diastolic time and 1.8 mmHg smaller at 0.25 sec diastolic time. The findings in the patients without heart disease differed distinctly from those in the patients with mitral stenosis. The investigation demonstrated that the non-invasive ultrasound technique can be used with confidence to gain an impression of the magnitude of the mitral pressure gradient. The findings also suggest that deltaPU represents the actual pressure gradient more accurately than deltaPM. Another investigation is proposed to assess the accuracy of the technique more completely.

Adult↗
PubMed1974

Correlations between p wave terminal force and hemodynamic parameters in aortic stenosis. Prediction of left ventricular end-diastolic pressure.

In 38 patients with "pure" aortic stenosis, P terminal force in V(1)(V(1)Ptf) correlated well with left ventricular end-diastolic pressure (LVEDP) (n = 38, r =-0.59, p smaller than 0.001), Poorer, but nevertheless significant correlations were observed with aortic systolic pressure gradient (r = -0;32, p smaller than 0,05) and cardiac volume measured by X-ray (r = -0.34, p smaller than 0.05). No significant correlation was found between V(1)Ptf and peak systolic left ventricular pressure. If V(1)Pft more negative than -0.03 mm sec is used to detect elevated LVEDP (above 12 mm Hg), the sensitivity is 81 percent, and the specificity 86 percent. Increased left atrial volume is probably the most important mechanism of this relationship. V(1)Ptf is a useful tool for the assessment of the functional and hemodynamic state of the left ventircle in aortic stenosis.

Adolescent↗
PubMedDate not supplied

Safety of the nonionic contrast medium omnipaque in coronary angiography.

The low osmolar nonionic contrast medium Omnipaque was used in 5,339 consecutive coronary angiographies and serious complications were registered. Myocardial infarction occurred in 4 patients, of whom 2 died, and ventricular fibrillation in 1. Cerebral embolism occurred in 11 patients, all of whom survived. The results are compared with those of previous series of coronary angiography with high osmolar ionic media. It is concluded that use of the nonionic medium Omnipaque resulted in a significant reduction of the frequency of serious complications.

Adult↗
PubMedDate not supplied

Electrophysiological and hemodynamic disturbances in a patients overdosed with disopyramide.

Disopyramide exerts a quinidinelike effect on the heart and is a valuable drug for treating atrial and, especially, ventricular tachyarrhythmias. The therapeutic plasma concentration of disopyramide is thought to be 2.0-4.0 (5.0) microgram/ml. We here report the cardiac effects of a high dose of disopryamide in a patient with extensive coronary artery disease complicated by ventricular extrasystoles. At plasma levels above approximately 7.0 micrograms/ml, heart rate was decreased, while PQ interval, width, and QT interval were increased. At concentrations above approximately 6.0 micrograms/ml, disopyramide exerted negative intropic effects as judged by increases in mean right atrial, pulmonary arteriolar, and pulmonary capillary venous pressures and a decrease in cardiac output.

Adult↗
PubMedDate not supplied

Attenuated microvascular perfusion and reactivity in cardiac transplant recipients treated with cyclosporine.

Orthotopic heart transplant recipients (TX pts) treated with cyclosporine develop postoperative hypertension and their functional capacity remains less than normal. Altered responsiveness to adrenegic stimuli and impaired release of endothelial-derived relaxing factor are proposed mechanisms of cyclosporine-induced raised peripheral vascular resistance. We compared responses to vasoconstrictor tests that stimulate sympathetic neural outflow (Valasalva maneuver and cold pressor test) and a vasodilator test that is dependent on the presence of a functionally intact endothelium (postocclusive hyperemia) in 16 TX pts with age-matched healthy controls, applying laser Doppler perfusion measurements (LDPM). Mean time since transplantation was 4.5 years (1-10 years). All TX pts received the triple regimen of prednisone, azathioprine and cyclosporine. Fourteen were considered hypertensive. Basal LDPM at rest expressed in arbitrary flux units (AU), was significantly lower in the TX pts (15.9 AU) than the controls (21.5 AU; p < 0.01). The maximal flux changes in the vasoconstrictor and vasodilator responses were comparable. However, the TX pts recovered faster from these responses and flux values at mid-to-late phase were lower following peak hyperemia and higher at any point following a cold pressor test than in the controls. Furthermore, a correlation was found between flux levels 30 s after either stimulus (r = 0.56; p < 0.0009) and time to reach prestimulus baseline after either test (r = 0.55; p < 0.002). With indirect evidence of comparable microvascular architecture, our findings suggest endothelial dysfunction in TX pts with intact functional capacity of the sympathetic nervous system.

Adult↗
PubMedDate not supplied

Doppler flowmetry in the lower thoracic aorta. An indirect estimation of cardiac output.

Duplex scanning of the lower thoracic aorta was performed on 67 patients subjected to routine left and right heart catheterization with estimation of cardiac output ad modum Fick. Adequate Doppler signals from the lower thoracic aorta were obtained in 59 patients (88%), 26 of whom had aortic valve abnormality. A high correlation was found between the Doppler and Fick findings (r=0.89), with a regression line intercepting close to zero (cardiac output = 1.76 X Doppler flow +0.05). The presence of aortic valve abnormality did not seem to influence the accuracy of the Doppler flow results. It is concluded that Doppler flowmetry in the lower thoracic aorta is a useful method in estimation of resting cardiac output, especially in patients with aortic valve lesions making Doppler flowmetry in the ascending aorta impossible.

Adult↗
PubMedDate not supplied

Metrizamide compared with metrizoate in cardioangiography in high-risk patients with coronary artery disease.

In a double-blind, randomized, two-group study of 99 'high-risk' patients mainly with coronary artery disease, the non-ionic contrast medium, Amipaque (metrizamide), was compared with the ionic medium, Isopaque Coronar (meglumine-Na-Ca-metrizoate) in cinecardioangiography. In evaluating the influence of the contrast media on the left ventricular end diastolic pressure (LVEDP), the material was divided into 2 groups, 55 patients with a basal LVEDP of 15 mmHg or less and 44 with an LVEDP above this level. In the former group LVEDP increased significantly after injection of the contrast medium into the left ventricle, but significantly less (p = 0.006) after Amipaque than after Isopaque Coronar. In the patients with a basal LVEDP above 15 mmHg, no significant change occurred in LVEDP after left ventriculography with any of the 2 contrast media. No serious complications occurred.

Adult↗
PubMedDate not supplied

Ultrasonic assessment of abdominal venous return. I. Effect of cardiac action and respiration on mean velocity pattern, cross-sectional area and flow in the inferior vena cava and portal vein.

Duplex scanning, i.e. combined real time ultrasonography and pulsed Doppler velocity measurement, of the inferior vena cava and portal vein was performed in 85 patients subjected to routine left and right heart catheterization. Mean blood velocity and volume blood flow in the inferior vena cava were found to be pulsatile, reflecting both cardiac action and respiration. Different flow patterns could be related to various heart conditions. The cross-sectional area of the inferior vena cava was also pulsatile, the normal variation with respiration being partial collapse during inspiration and maximum distension at end expiration. In the majority of patients, portal vein flow showed variation with respiration only, maximum flow occurring during expiration. The flow patterns found in the two veins were well in accordance with previous invasive findings in animals. It is concluded that duplex scanning is a useful tool in the assessment of abdominal venous return.

Adult↗
PubMedDate not supplied

Ultrasonic assessment of abdominal venous return. II. Volume blood flow in the inferior vena cava and portal vein.

Eighty-five patients subjected to routine heart catheterization, were examined with duplex scanning of the inferior vena cava and portal vein. Volume blood flow in the two veins was estimated and compared with Fick measured cardiac output and duplex measured flow in the lower thoracic aorta. Inferior vena caval and portal vein flow were found to comprise approximately 30 to 40 per cent and 20 per cent, respectively, of cardiac output, but with a large dispersion of individual percentages. A high correlation (r = 0.88) was found between the sum of inferior vena caval and portal vein flow and duplex measured flow in the lower thoracic aorta, the sum of flow in the two veins comprising approximately 90 per cent of lower thoracic aortic flow. It is concluded that duplex scanning seems to be a useful method in estimating volume blood flow in both the inferior vena cava and portal vein.

Abdomen↗
PubMedDate not supplied

Percutaneous transluminal coronary angioplasty. Six years experience.

In a six-year period (1982-1987), 248 patients were treated with 297 procedures (percutaneous transluminal coronary angioplasty, PTCA) on 282 vessels. Two hundred and fifty-nine (87.2%) of the procedures in 210 (76.7%) of the patients appeared successful angiographically. Thirty-eight procedures were unsuccessful due to failure to pass the stenosis in 18 patients, dissection or occlusion of the treated vessel in 11, and significant residual stenosis in 9 patients. Emergency operations were performed after 11 (3.7%) of the procedures. Two patients died postoperatively. Myocardial infarction was seen in 13 patients, of whom 4 developed pathologic Q-waves in their ECG. Restenosis occurred in 60 (28.6%) of the patients. In the last year of the study, the patients selected for PTCA were in a poorer state angiographically, but the results of PTCA were better, without any increase of the complication rate. Our results, which are in accordance with others, support the concept that PTCA is a relatively safe procedure with a primary success rate of almost 90 percent. However, approximately one third of the patients developed restenosis, which in most cases occurred within 3 months.

Adult↗
PubMedDate not supplied

Left ventricular aneurysm and severe cardiac dysfunction: heart transplantation or aneurysm surgery?

We analyzed data from 26 patients with left ventricular aneurysm and severe congestive heart failure to evaluate our selection criteria for aneurysm surgery and heart transplantation. The operative results for patients who underwent aneurysm resection (group A, n = 14) were compared with those of patients who were accepted for heart transplantation (group B, n = 12). All patients were monitored and reinvestigated after surgery. Functional status and left ventricular angiographic and hemodynamic findings were significantly worse in group B than in group A, but with great overlap between the groups. The presence of mitral insufficiency or right ventricular dysfunction (or both), however, was important in our selection for transplantation. Two patients died after aneurysm surgery, whereas one died before heart transplantation. Functional status (p less than 0.004) and left ventricular ejection fraction (p less than 0.05) improved after aneurysm resection, whereas hemodynamic values remained unchanged. Symptoms were relieved (p less than 0.001), and, except for cardiac index, hemodynamic values were normalized in group B. We conclude that the combination of a left ventricular ejection fraction of less than 25%, mitral insufficiency, and right ventricular dysfunction favors heart transplantation in patients with left ventricular aneurysm and end-stage heart disease. The lack of donor organs and acceptable results of aneurysmectomy, however, justify conventional surgery even in high-risk patients.

Adult↗