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Biomedical subjects

H Vik-Mo

Publications and source records attributed to H Vik-Mo.

At least 55 records · Page 3Linked to original sources
PubMed1988

Hemodynamic and electrocardiographic consequences of high- and low-osmolality contrast agents for left ventricular angiography.

The cardiovascular effects of two nonionic contrast agents with low osmolality (iohexol and metrizamide) were compared with one standard ionic, high-osmolality contrast agent (metrizoate) used for left ventricular (LV) angiography in patients with coronary heart disease. Metrizoate induced a marked elevation of LV end-diastolic pressure and LV systolic pressure and an increase in cardiac output after a delay of a few minutes. All these changes were significantly less severe with iohexol and metrizamide. Hypotension occurring 30 sec after LV angiography was observed only with use of metrizoate. All agents increased heart rate, but the increase after metrizoate was significantly more pronounced and prolonged. The PQ and QT interval was prolonged only by metrizoate. The subjective symptoms were significantly more marked with metrizoate than with the two other agents. Thus the new nonionic contrast agent iohexol and metrizamide produced markedly less hemodynamic and electrocardiographic disturbance than the ionic agent metrizoate.

Aged↗
PubMed1988

Detection of left ventricular ischemia during atrial pacing: simultaneous assessment by echocardiography and invasive hemodynamic measurements.

The ability of cross-sectional echocardiography to detect myocardial ischemia induced by atrial pacing was assessed during cardiac catheterization in 11 patients with coronary arterial disease. Angina pectoris was precipitated in all patients with increase in left ventricular end-diastolic pressure after pacing by 5 +/- 6 (mean +/- standard deviation) mm Hg (P less than 0.01). Regional left ventricular dysfunction occurred during pacing in all patients as determined by quantitative echocardiographic assessment of wall motion. Simultaneously, systolic reduction in parasternal short-axis area decreased (from 42 +/- 13 to 28 +/- 9%, P less than 0.01) with concomitant decrease in ejection fraction as determined in the apical four-chamber view (from 49 +/- 5 to 40 +/- 8%, P less than 0.01). In conclusion, echocardiography may detect pacing-induced myocardial ischemia through detection of regional and global left ventricular dysfunction. Inadequate regional perfusion may be indicated by echocardiography even in patients without apparent evidence of ischemia as determined by invasive hemodynamic measurements.

Adult↗
PubMed1988

Left ventricular diastolic function in young long-term type 1 (insulin-dependent) diabetic men during exercise assessed by digitized echocardiography.

Digitized M-mode echocardiograms were obtained during semisupine bicycle exercise in 10 relatively young (less than 40 years) long-term (greater than or equal to 12 years) type 1 (insulin-dependent) diabetic men, without overt heart disease, and 10 controls. Recordings were done at rest and during workloads of 50 and 100 W. At rest, heart rate was similar in the groups, while at peak exercise it was higher in the diabetics whose left ventricular (LV) end-diastolic dimension was smaller at all study phases. From baseline to peak exercise the diastolic period decreased in both groups, while the LV diastolic peak rate of dimension increase, normalized for end-diastolic dimension, the rapid filling period and the LV dimension change during this period increased. The normalized peak rates of dimension increase and heart rates correlated positively in the groups. However, diabetics had a lower normalized peak rate of dimension increase after adjusting for heart rate by covariance analysis, both at rest (18%) and during peak exercise (20%). Thus, compared to controls, this well defined group of type 1 diabetic men had a consistent subclinical decrease in their peak rate of dimension increase, both at rest and during exercise. Furthermore, the peak rate of dimension increase remained lower in the diabetic subjects after normalization for their smaller end-diastolic dimension and after adjustment for their higher heart rate.

Adult↗
PubMed1988

Left ventricular performance during exercise in long-term type 1 diabetic men: an echocardiographic study.

M-mode echocardiograms were recorded and digitized during semisupine bicycle exercise in 10 young (less than 40 years) long-term (greater than or equal to 12 years) type 1 diabetic men, without heart symptoms, and 10 controls. Recordings were done at rest, during workloads of 50 and 100 W and 1, 3 and 5 min post-exercise. The groups were comparable at rest. Exercise intervention caused a higher heart rate and systolic blood pressure response in the diabetics. Overall, diabetics had a smaller left ventricular (LV) end-diastolic dimension, but it did not change during exercise within either group; LV end-systolic dimensions (ESD), however, decreased in both. The fractional shortening, normalized peak shortening rate and systolic blood pressure/ESD ratio increased in both groups. However, fractional shortening was lower in the diabetics during peak exercise, while the two latter variables of LV systolic function were similar to the controls. Furthermore, fractional shortening during peak exercise remained lower in the diabetics even when adjusted for systolic blood pressure by covariance analysis. Therefore, the decreased LV performance during exercise in the diabetic subjects is most likely secondary to reduced LV diastolic filling, as indicated by their smaller end-diastolic dimension, rather than due to decreased contractility or a higher afterload.

Adult↗
PubMed1988

Limitations in assessing the severity of aortic stenosis by Doppler gradients.

Continuous wave Doppler echocardiography was performed before cardiac catheterisation in 69 consecutive patients with suspected aortic stenosis. Agreement between the maximum and the mean Doppler gradients and catheterisation gradients was good. Doppler echocardiography, however, systematically underestimated the maximum and mean gradients, particularly in the high range. Stepwise regression analysis of the small pressure difference between the two methods showed that it could not be explained by age, sex, stroke volume, differences in heart rate, ejection fraction, the presence of coronary artery disease, or severity of aortic regurgitation. There was a negative curvilinear correlation between the maximum and mean Doppler gradients and the aortic valve areas that were measured at catheterisation in patients with pure aortic stenosis. The degree of correlation decreased when patients with concomitant aortic regurgitation were included. The scatter of gradients above and below the correlation line was large and this was caused by low and high transvalvar flow. These results show that the usefulness of Doppler gradients for judging the severity of aortic stenosis, both in relation to immediate diagnosis and follow up, is severely limited if transvalvar flow is not taken into account.

Adult↗
PubMed1988

Cardiopulmonary effects of enprofylline. A xanthine with weak adenosine receptor antagonism in patients with severe chronic lung disease.

The acute cardiovascular effects of a new xanthine, enprofylline, were studied in patients with chronic lung disease. The studies were done during cardiac catheterization (n = 12) and by radionuclide ventriculography (n = 6). Enprofylline was given intravenously, 2 mg/kg, and measurements were done after ten and 30 min. Enprofylline reduced the mean pulmonary artery pressure from 30 +/- 10 to 26 +/- 7 mm Hg (p less than 0.05) and the mean systemic arterial pressure from 92 +/- 17 to 83 +/- 15 mm Hg (p less than 0.01), increased the heart rate from 89 +/- 15 to 100 +/- 18 beats/min (p less than 0.01) and reduced the stroke volume from 55 +/- 12 to 48 +/- 12 ml (p less than 0.05) after 30 min. Radionuclide ventriculography revealed unchanged ejection fraction of left and right ventricles after enprofylline. None of the patients experienced serious side effects of the drug. Thus, enprofylline induced modest acute cardiovascular effects with a chronotropic response together with a small vasodilation in pulmonary and systemic circulation.

Adult↗
PubMed1988

Echocardiographic decision-making for replacement surgery in mitral valve prolapse.

The clinical usefulness of M-mode echocardiography for predicting severe mitral regurgitation (MR) requiring valve replacement was assessed in 16 men and 10 women with mitral valve prolapse (MVP) as sole primary cardiac disorder. From left ventricular (LV) angiography, MR was classified as none to moderate (8 cases, group A) or severe (18 cases, group B). At echocardiography, increased LV end-diastolic and end-systolic and left atrial (LA) dimensions, corrected for body-surface area, distinguished group B from group A, with the best validities for LA and LV end-diastolic values. The mean echocardiographic LV fractional shortening and ejection fraction (EF) and the angiographic EF were similar in both groups. Echocardiographic and angiocardiographic LV EF correlated poorly, the former usually overestimating the latter. LV end-diastolic and mean pulmonary capillary wedge pressures were highest in group B, and the latter correlated with echocardiographic LA size. Mitral valve replacement was subsequently performed on 15 of the 18 group B patients. M-mode echocardiography is a valuable adjuvant to clinical assessment of MVP for predicting MR severity and for time-planning of cardiac catheterization or mitral valve surgery.

Adult↗
PubMed1988

Assessment of the left ventricular diastolic function in constrictive pericarditis by digitised M-mode echocardiography.

Digitised M-mode echocardiography was used to study the diastolic left ventricular function in ten patients with constrictive pericarditis. Each patient was matched for heart rate and stroke volume with a control patient who had normal left ventricular end-diastolic pressure and coronary arteries. All 20 patients underwent right and left cardiac catheterisation. In patients with constrictive pericarditis compared with controls, the median (range) left ventricular peak diameter lengthening rate, normalised for end-diastolic dimension, was 4.5 (2.5-8.0) s-1 and 2.9 (1.6-4.1) (p less than 0.01), and the rapid filling period fraction of diastole was 0.28 (0.18-0.37) and 0.37 (0.21-0.58) (p less than 0.05), while the mitral valve E-F slope was 20.1 (10.5-39.2) cm/s and 11.8 (7.6-14.5) (p less than 0.05), respectively. Thus, the early rate of left ventricular diameter lengthening is increased in constrictive pericarditis independent of heart rate and stroke volume, while the actual duration of the rapid filling period is decreased. These results, obtained noninvasively, extend the findings of previous invasive studies. The method may help in the difficult clinical diagnosis of constrictive pericarditis, although there is some overlap with the normal control range.

Adult↗
PubMed1988

Factors affecting suitability for coronary bypass surgery.

Factors responsible for unsuitability for bypass surgery were assessed prospectively in 324 consecutive patients with serious angina pectoris undergoing cardiac catheterization. One hundred patients were found to be unsuitable for surgery (31%). These patients usually had peripheral coronary atherosclerosis (44%), stenotic/occluded artery distributing to an infarcted (35%) or small area (25%), or reduced global left ventricular (LV) function (15%). Age over 65 years (p less than 0.05), female sex (p less than 0.05), previous myocardial infarction (p less than 0.05), 1-vessel disease (p less than 0.01) and a low LV ejection fraction (p less than 0.01) occurred more often in patients not accepted for surgery. Of the patients with 3-vessel disease 75% were referred for surgery while only 25% of patients with 1-vessel disease (p less than 0.001) Stepwise logistic regression analysis identified LV ejection fraction as an inverse predictor (p less than 0.001) and number of stenotic coronary arteries as a predictor (p less than 0.001) of suitability for surgery. Thus, peripheral coronary atherosclerosis and global LV function are the main factors determining unsuitability for coronary bypass surgery.

Adult↗
PubMed1987

Subclinical left ventricular abnormalities in young subjects with long-term type 1 diabetes mellitus detected by digitized M-mode echocardiography.

Noninvasive studies in patients with type 1 diabetes mellitus suggest subclinical left ventricular (LV) impairment, but the studies differ with regard to methods, patient selection and results. Thus, digitized M-mode echocardiograms were recorded in 24 persons younger than 50 years with long-term (more than 12 years) type 1 diabetes but without overt heart disease and in 28 control subjects. To improve accuracy, measurements were adjusted for body surface area, LV size and the influence of heart rate, as appropriate. Diabetics had a higher heart rate and systolic and diastolic blood pressure than control subjects. LV end-diastolic and stroke dimensions were smaller, duration of systole longer and preejection period/LV ejection time ratio higher than in control subjects, whereas fractional shortening and peak shortening rate were similar. In diabetics, diastole was shorter, peak filling rate was lower and the rapid filling period was prolonged, while percent filling during the rapid filling period and atrial contribution to filling were higher. Thus, in a well defined study population of relatively young persons with long-term type 1 diabetes, subclinical LV systolic and diastolic dysfunction were found. The diastolic abnormalities suggest reduced LV compliance, while those in systole may be secondary to an increased afterload or decreased myocardial contractility.

Adult↗
PubMed1987

Improved cardiac performance by salbutamol, a selective beta 2-agonist, in chronic cor pulmonale.

The effects of salbutamol, a relative specific beta 2-agonist, on hemodynamics and arterial blood oxygenation, were studied in 12 patients with chronic cor pulmonale. The studies were done during heart catheterization at rest (n = 12) and during arm bicycle exercise (n = 7) before and during salbutamol infusion of 0.2 microgram/kg/min. At rest, salbutamol significantly increased cardiac index on average by 31%, stroke volume index by 11%, and heart rate by 12 beats/min. Mean pulmonary artery pressure was not changed by salbutamol, whereas a small reduction in mean arterial pressure was observed. The vascular resistance was reduced by 15% in pulmonary and 24% in systemic circulation. Similar hemodynamic changes by salbutamol were observed during exercise. Arterial oxygen tension and saturation were not changed by salbutamol, but a significant rise in mixed venous oxygen saturation and oxygen delivery were observed both at rest and during exercise. Thus, salbutamol infusion improves the cardiac performance in patients with chronic cor pulmonale through a chronotropic effect combined with vasodilation in both the systemic and pulmonary circulation and thereby increased stroke volume. No deleterious effects on arterial blood oxygenation by salbutamol infusion were observed.

Aged↗
PubMed1987

High occurrence of mitral valve prolapse in cardiac catheterization patients with pure isolated mitral regurgitation.

The aetiological spectrum of angiographically verified pure isolated mitral regurgitation (MR) was studied in 48 consecutive adult patients (35 males). Severe MR was found in 35 patients (73%) and moderate MR in 13 patients (27%). Mitral valve prolapse (MVP) syndrome was found in 21 patients (44%). These were younger than the rest of the study population (55 +/- 13 vs. 62 +/- 6 years, p less than 0.05) and 15 (71%) of them were men. Endocarditis and chordal rupture occurred in 19% and 43% of the MVP patients. Sixteen patients (33%) had MR secondary to myocardial infarction while only three patients (6%) had MR of rheumatic aetiology. Bacterial endocarditis, hypertensive heart disease, hypertrophic obstructive cardiomyopathy and mitral annulus calcification were less frequently found. Mitral valve replacement was done in 20 (57%) of the patients with severe MR and MVP was the underlying disease in 15 (75%) of these patients. In conclusion, MVP is a frequent cause of pure isolated MR and of mitral valve replacement. In contrast to the preponderance of young females amongst MVP patients in population surveys, most of the MVP patients with MR in this study are middle-aged and elderly men.

Adult↗
PubMed1987

Digitized echocardiographic measurements of left ventricular function: reproducibility and physiological factors influencing the method.

The variability of digitized M-mode echocardiographic measurements and the potential influence of physiological factors on these was studied in 28 relatively young (less than 50 years) healthy subjects. All had heart rates within the normal range. Echocardiographic recordings were standardized in the end-expiratory phase. The coefficients of variation for direct echocardiographic measurements were less than or equal to 6% and for most digitized time derived variables less than or equal to 15%. They were generally greater for inter- than for intracycle comparisons. In systole, the peak shortening rate and the time period from the start of systole to the point of peak shortening rate showed the best reproducibility, while in diastole the peak filling rate, the rapid filling period and the percentage filling during the same period. In multivariate analysis, age and heart rate were found to influence the digitized derived systolic but not the diastolic variables. Their influence, however, on digitized echocardiographic measurements may vary with study subjects selection and should be considered when interpreting results.

Adult↗
PubMed1986

Transient visual disturbance during cardiac catheterization with angiography.

The occurrence of visual disturbances following cardiac catheterization with angiographies was studied in a prospective study of 2,006 consecutive adult patients. The overall incidence of visual disturbances was 1.0% and of complete blindness 0.2%. Women had higher incidence than men (2.0 versus 0.6%, p less than 0.01) and patients with a history of angina pectoris with normal coronary arteries had higher incidence than those with coronary artery stenosis (3.7 versus 0.8%, p less than 0.02). Thirteen of twenty patients also had signs of mental confusion. An abnormal electroencephalogram was found in 8 of 13 patients studied. Other neurological findings were observed in one patient only. All patients had complete recovery within 24 hours. Thus, the incidence of visual disturbances is found to be higher than earlier reported, but the visual loss is transient with a benign course.

Adolescent↗