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Biomedical subjects

E Nylander

Publications and source records attributed to E Nylander.

At least 37 records · Page 2Linked to original sources
PubMed1998

Quantitative digital evaluation of myocardial exercise thallium-201 single-photon emission tomography in post-menopausal women.

Quantitative computerized analysis of data from myocardial thallium-201 (201Tl) single-photon emission tomography (SPET) may improve the diagnostic accuracy of coronary heart disease. The reference ranges for post-menopausal women are, however, limited and obtained mainly from patients. To compare reference values from healthy post-menopausal women and to improve the quantitative analysis, 20 women (10 patients with coronary heart disease and previous infarction and 10 age-matched healthy volunteers) were examined immediately post exercise and after a delay. A nine-segment 'bull's-eye' model was used for analysis. At visual evaluation, reproducibility was high (93%), no false-positive results were obtained and in 70% of the patients the SPET was interpreted as abnormal. Using reported reference values for quantitative analysis, all the healthy women had an abnormal result. New reference values based on three different methods of 'normalization' were calculated: the relative activity of segment 3 set to 100%, the segment with the highest activity set to 100% and a least-squares method. They all differed significantly from those that had previously been reported. The frequencies of agreement between visual and quantitative analysis were 84-92% and were highest when segment 3 was used as a reference, but in this case only 40% of the patients with coronary heart disease had an abnormal SPET. Using the least-squares method for handling digital information, the SD of the normal values decreased and 90% of the patients with coronary heart disease were accurately diagnosed. These results provide quantitative digital reference values for healthy post-menopausal women. They verify that quantitative analysis is in diagnostic agreement with visual evaluation, stress the need for local verification of reference ranges and suggest a least-square normalization method for the analysis.

Aged↗
PubMed1997

More favourable haemodynamic effects from metoprolol than from captopril in patients with dilated cardiomyopathy.

AIM: The object of this study was to investigate and compare the haemodynamic effects of treatment with a beta receptor blocker (metoprolol) or an angiotensin-converting-enzyme inhibitor (captopril) in 54 patients with idiopathic dilated cardiomyopathy. METHOD: All patients had cardiac catheterization performed at rest and during exercise, before and after 3 months of treatment. RESULTS: The mean dose of metoprolol was 135 mg.day-1 and of captopril 98 mg.day-1. After treatment there was a significant reduction in left ventricular filling pressure both at rest (from 16 to 12 mmHg) and during exercise (from 27 to 20 mmHg) in the metoprolol group. In the captopril group a significant reduction was seen only during exercise (25 to 20 mmHg), compared to baseline. The stroke volume increased significantly after 3 months of therapy in the metoprolol group, both at rest (53 to 70 ml) and during exercise (56 to 79 ml). In the captopril group the increase reached significance only during exercise (72 to 79 ml). Cardiac output was maintained in both groups. CONCLUSION: There were positive effects on left ventricular function in the metoprolol group as well as in the captopril group. Metoprolol reduced left ventricular filling pressure at rest and increased stroke volume both at rest and during exercise significantly more than captopril.

Adrenergic beta-Antagonists↗
PubMed1996

Aortic valve replacement for aortic stenosis in patients with small aortic root.

BACKGROUND AND AIMS OF THE STUDY: Patients with aortic stenosis and small aortic ostia are getting more and more common in our practice. They now constitute a third of our aortic valve replacement (AVR) material. The patients are usually elderly women with small heart and body dimensions, sometimes making it difficult to implant sufficiently large valve prostheses. MATERIALS AND METHODS: We describe a non-selected series of 254 patients from a geographically defined area who underwent AVR during a six year period (1989-1995) and who were considered to have small aortic annulus, defined as patients receiving 19 and 21 mm prostheses. Mean age was 71 years, 42% were over the age of 75, 88% were women and 32% underwent concomitant coronary artery bypass grafting (CABG). Fifty-nine (23%) required pericardial patch enlargement of the aortic root to accommodate sufficiently large prostheses. Prostheses used included Björk-Shiley Monostrut (n = 54), CarboMedics (n = 58), St. Jude (n = 74), Sorin Bicarbon (n = 2), Mitroflow pericardial (n = 26) and Carpentier-Edwards pericardial valve (n = 40). Pericardial valves were usually employed in patients 75 years and older. RESULTS: Operative mortality was 3.1%. There was no mortality in patients undergoing isolated AVR. Late mortality, after a mean observation period of two years, was 4.9%. At Doppler echocardiography one week postoperatively, 95% had a gradient across the prosthesis that was considered to be within acceptable limits (resting mean gradient < 30 mmHg). In the remaining patients higher gradients indicated some degree of prosthesis-patient mismatch. CONCLUSIONS: To avoid this mismatch the surgical considerations include choosing a prosthesis with a large effective orifice area, using an optimal valve implantation technique (partly or completely supra-annular placement of the prosthesis) and, if this is not enough, enlarging the annulus with an outflow patch.

Aged↗
PubMed1995

Natural history of digital replantation: a 12-year prospective study.

UNLABELLED: The purpose of the study was to evaluate the fate of the digital arterial anastomoses, resting total digit blood flow, and cold-induced discomfort following digital replantation with two repaired arteries. The evaluation was done with a Doppler ultrasound of the anastomoses, temperature recording from the finger pulp at room temperature, and a questionnaire regarding the patient's impression of cold-induced discomfort. At the 2-year follow-up all anastomoses were patent, but in two of the six patients one anastomosis was occluded at the 12-year follow-up. The replanted digits generally showed lower skin temperatures compared with controls at the 2-year follow-up but these had normalized 10 years later, even in digits with one of the two repaired arteries occluded. The number of patients with severe cold-induced discomfort was unchanged during the observation period. CONCLUSION: The digital flow continues to increase after the first 2 years after replantation and may reach normal levels at room temperature; however, cold-induced discomfort is not normalized. Total blood flow improvement is not affected by late arterial occlusion.

Adolescent↗
PubMed1995

Additional value of thallium-201 SPECT to a conventional exercise test for the identification of severe coronary lesions after an episode of unstable coronary artery disease.

The additional value of thallium-201 SPECT to a conventional exercise test for the identification of patients with severe coronary lesions was evaluated in 170 men, one month after an episode of unstable coronary artery disease. Severe coronary lesions at coronary angiography--defined as three vessel disease, left main stenosis or proximal left anterior descending artery stenosis as part of two vessel disease--were observed in 45.9%. In the SPECT image, the left ventricular myocardium was divided into nine segments and each segment was classified as either normal (= 0), reduced uptake (= 1) or uptake defect (= 2). The sum of gradings in all segments post-exercise was denoted "SPECT score". The patients were divided into nine different groups regarding ST-depression during exercise (no ST-depression, ST-depression in 1-2 leads or > or = 3 leads) and "SPECT score" (no SPECT score, 1-3 scores or > or = 4 scores). Severe coronary lesions were, in 68% identified by SPECT score > or = 4 and in 65% by ST-depression in > or = 1 lead at exercise test. The specificity for identification of severe coronary lesions was, for both tests, 65%. SPECT score > or = 4 and/or ST-depression in > or = 3 leads identified 82% of the patients with severe coronary lesions with a specificity of 63%. Furthermore, SPECT score > or = 3 identified more patients with isolated proximal left anterior descending artery stenosis than ST-depression alone at exercise test.

Adult↗
PubMed1995

Cold-induced vasospasm after digital replantation does not improve with time. A 12-year prospective study.

The incidence of cold-induced vasospasm after hand injuries has been reported to be as high as 100%, following replanted digital amputations. The exact cause of this problem is obscure, no specific treatment is available and little is known about the long-term prognosis. Further knowledge is therefore needed in order to advise patients concerning future job potential at an early stage. In a previous paper we evaluated the incidence and severity of cold intolerance 2 years after digital replantation. The incidence of cold-induced vasospasm then was high as well as the discomfort experienced by the patients. We carried out a follow-up of patients previously examined 10 years ago. Our results show that cold induced vasospasm in replanted digits does not improve with time. Patients with moderate symptoms may perceive improvement, probably due to a change of habits. Patients with severe problems did not experience improvement and should be given early advice to seek work in warm surroundings to reduce the discomfort.

Amputation, Traumatic↗
PubMed1995

Biplane transoesophageal echocardiography, transthoracic Doppler, and magnetic resonance imaging in the assessment of coarctation of the aorta.

This study compared flow-sensitive magnetic resonance imaging with biplane transoesophageal echocardiography in combination with continuous wave Doppler from the suprasternal notch in patients with native coarctation or after surgical repair. Twenty patients (mean age 33 years, range 17-60) were investigated, of whom 15 had undergone surgery at mean age 13 years, range 5-43. Peak and mean flow in the ascending and descending aorta as well as coarctation peak velocity were determined with the magnetic resonance imaging phase contrast technique. Coarctation peak velocity was also measured by Doppler from the jugulum. Magnetic resonance imaging axial sections as well as biplane transoesophageal echocardiography were used to measure the smallest diameter of the constricted segment. Sixteen healthy volunteers, mean age 36 years, range 22-63, provided reference values for magnetic resonance imaging determined volume of flow in the aorta. Peak flow in the descending aorta was 9.2 +/- 3.7 l. min-1 (reference 13.0 +/- 2.5, P < 0.01) and mean flow 3.1 +/- 0.9 l. min-1 (reference 3.4 +/- 0.8, P > 0.05). The ratio of descending-to-ascending peak flow was 0.54 +/- 0.17 (reference 0.69 +/- 0.10, P < 0.01) and mean flow 0.68 +/- 0.15 (reference 0.69 +/- 0.08, P > 0.05). The coarctation velocity was slightly higher with Doppler than with magnetic resonance imaging (+0.24 +/- 0.44 m. s-1, 95% confidence interval +0.45 to +0.02 m. s-1, P = 0.05). The coarctation diameter was slightly larger with magnetic resonance imaging than with transoesophageal echocardiography (1.4 +/- 3.5 mm, 95% confidence interval +3.1 to -0.3 mm, P = 0.11). Both methods are suitable for the assessment and follow-up of coarctation of the aorta. Flow assessment with magnetic resonance imaging provides a hitherto unavailable measure with which to assess the severity of obstruction.

Adolescent↗
PubMed1995

Arm-ankle systolic blood pressure difference at rest and after exercise in the assessment of aortic coarctation.

OBJECTIVE: To evaluate the difference in systolic blood pressure at the arm and ankle at rest and after various exercise tests for the assessment of aortic coarctation. METHODS: 22 patients (mean age 33 years, range 17-66) were investigated on the suspicion of having haemodynamically significant aortic coarctation. Eight had undergone previous coarctation surgery, of whom five had received vascular grafts and three end to end anastomoses. The patients exercised submaximally while supine, seated on a bicycle, and walking on a treadmill, as well as exercising maximally on a treadmill. Arm and ankle blood pressure were measured with a cuff at rest and 1-10 minutes after exercise. Invasive pressures and cardiac output by thermodilution were recorded during catheterisation while patients were at rest and during and after supine bicycle exercise. The degree of constriction was assessed by angiography. Twelve healthy volunteers (mean age 32 years, range 17-56) provided reference values for cuff pressures after exercise. RESULTS: All patients with a difference in cuff pressure at rest of 35 mm Hg or more had a difference in invasive pressure of 35 mm Hg or more. Increasing severity of constriction on angiography correlated with larger pressure gradients at rest and during exercise (P < 0.0001). When cuff measurements after exercise were considered singly or combined to form a predictor they did not improve the prediction of the invasive pressure gradients at rest or after maximal exercise. A pressure gradient between arm and ankle also developed in normal subjects after maximal but not after submaximal exercise. CONCLUSION: In most patients with suspected haemodynamically significant coarctation the difference in cuff pressure between arm and ankle at rest is sufficient to select patients in need of further evaluation. If exercise is performed submaximal exercise is preferable.

Adolescent↗
PubMed1995

Atrial and ventricular function after cardioversion of atrial fibrillation.

OBJECTIVE: Previous studies on atrial recovery after cardioversion of atrial fibrillation have not taken into account new knowledge about the pathophysiology of transmitral and transtricuspid flow velocity patterns. It is possible to shed further light on this problem if atrioventricular inflow velocity, venous filling pattern, and atrioventricular annulus motion are recorded and interpreted together. DESIGN: Prospective examinations of mitral and tricuspid transvalvar flow velocities, superior caval and pulmonary venous filling, and mitral and tricuspid annulus motion were recorded using Doppler echocardiography. Examinations were performed before and 24 hours, 1 month, and 20 months after cardioversion. SETTING: Tertiary referral centre for cardiac disease with facilities for invasive and non-invasive investigation. PATIENTS: 16 patients undergoing cardioversion of atrial fibrillation in whom sinus rhythm had persisted for 24 hours or more. RESULTS: Before conversion there was no identifiable A wave in transvalvar flow recordings. The total motion of the tricuspid and mitral annulus was subnormal and there was no identifiable atrial component. Venous flow patterns in general showed a low systolic velocity. After conversion, A waves and atrial components were seen in all patients and increased significantly (P < 0.01) with time. There was a similar time course for the amplitude of annulus atrial components, an increased systolic component of venous inflow, an increased A wave velocity, and a decreased E/A ratio of the transvalvar velocity curves. The ventricular component of annulus motion was unchanged. Changes in general occurred earlier on the right side than the left. CONCLUSIONS: This study indicates that, in addition to the previously known electromechanical dissociation of atrial recovery that exists after cardioversion of atrial fibrillation, there may also be a transient deterioration of ventricular function modulating the transvalvar inflow velocity recordings. Function on the right side generally becomes normal earlier than on the left. Integration of information from transvalvar inflow curves, annulus motion, and venous filling patterns gives additional insight into cardiac function.

Aged↗
PubMed1994

Importance of collateral vessels in aortic coarctation: computer simulation at rest and exercise using transmission line elements.

Coarctation of the aorta causes arterial hypertension in the upper body and a low blood pressure downstream. Collateral blood vessels compensate by reducing the downstream pressure drop. To study the effect of various coarctation and collateral properties, we designed a computer model of the arterial circulation. The model contains a flow source and a library of subroutines for the lines and connectors. Distributed friction and wall viscoelasticity effects are included. Computer simulation was performed, using published values for vessel dimensions, in an arterial model with a coarctation and one lumped collateral. Rest and two levels of exercise (by increased heart rate) were studied. Without a collateral, we found the downstream pressure of the model was extremely dependent on the size of the coarctation. A collateral vessel reduced the pressure difference between the up- and downstream circulations. For a severe coarctation, the length and the diameter of the collateral were the main factors determining the downstream pressure and flow, whereas wall stiffness of the collateral had little influence. The relationship between mean pressure drop and cardiac output in coarctation was also dependent on the peripheral resistance in different flow beds, especially during exercise.

Aortic Coarctation↗
PubMed1994

Nutritional assessment and muscle energy metabolism in severe chronic congestive heart failure--effects of long-term dietary supplementation.

In order to investigate nutritional status in relation to the metabolic state of skeletal muscle in patients with severe congestive heart failure, and to explore the influence of long-term dietary supplementation, 22 patients were randomized in a double-blind study to receive either a placebo (n = 13) or high caloric fluid (n = 9). Before treatment, the muscle content of adenosine triphosphate (ATP), creatine and glycogen was lower than in healthy individuals, and muscle biopsies revealed an excess of water. Two patients were found to be malnourished according to nutritional assessment criteria. Following study treatment, no significant changes occurred, either within or between the two subgroups. Thus, patients with severe congestive heart failure displayed metabolic derangement in skeletal muscle which did not seem to be explained by malnutrition.

Aged↗
PubMed1994

Vascular injury following cardiac catheterization, coronary angiography, and coronary angioplasty.

All vascular injuries occurring at this hospital department over a 5-year period (1987-91) as a result of cardiac catheterization, coronary angiography, or coronary angioplasty (PTCA) and requiring transfusion, surgical consultation, or repair, are reviewed. Such complications may occur late and, to detect cases not apparent from the protocol accompanying every examination, a questionnaire was sent to all surgical clinics in the region asking for details of vascular surgical intervention after angiography. The present review of 4879 examinations disclosed 18 patients with 19 vascular injuries (0.39%); four of them were detected by the questionnaire. The types of injury were: pseudoaneurysm (12), thrombembolic episode (4), and excessive bleeding (3). Of the patients with a vascular complication 11 (61%) were receiving anticoagulation treatment, compared to 10% in the whole series; two others suffered from a coagulopathic state. Catheterization was difficult or severe atherosclerosis was present in three, inadvertent mobilization occurred in one, and unintentional puncture distal to the common femoral artery occurred in two patients. With the increasing use of invasive diagnostic and interventional procedures in cardiovascular diseases, knowledge of the type and frequency of possible complications is important, especially of those that may occur late. In the present study anticoagulation, coagulation disorders, and cardiac catheterization combined with brachial puncture and angiography all predisposed to a vascular complication.

Adult↗
PubMed1994

Exercise echocardiography and thallium 201 single-photon emission computed tomography in male patients after an episode of unstable coronary artery disease.

To compare modern, digital exercise echocardiography and thallium 201 single-photon emission computed tomography (SPECT) in patients with unstable coronary artery disease, 65 men unselected with regard to echocardiography were prospectively investigated 1 month after an episode of unstable angina or non-Q-wave myocardial infarction. Exercise echocardiography and 201Tl SPECT were performed on consecutive days in connection with a standard symptom-limited upright bicycle test and analyzed in a 9-segment model. Coronary angiography was performed in all but 1 patient and 60 patients had significant coronary lesions. Wall motion abnormalities were seen in 53 patients (81%) at rest and perfusion defects in 57 patients (88%) at the redistribution images. New or worsening of wall motion abnormalities were seen in 55 patients, either seated at peak exercise or recumbent after exercise, and 43 patients had reversible or partially reversible 201Tl scintigraphic defects (P = .02). The segmental agreement between wall motion abnormalities and scintigraphic defects was low (58%). The additional value of exercise echocardiography and 201Tl SPECT to exercise test was greatest in patients with one-vessel disease. Thus, 1 month after an episode of unstable coronary artery disease in men, there is a high incidence of significant coronary stenoses as well as signs of ischemia shown both by wall motion abnormalities during exercise echocardiography and by postexercise studies with 201Tl SPECT. Exercise echocardiography gives a higher diagnostic yield regarding occurrence of reversible ischemia.

Adult↗
PubMed1993

ST-changes in ECG at rest or during exercise indicate a high risk of severe coronary lesions after an episode of unstable coronary artery disease.

After an episode of unstable coronary artery disease, 190 patients performed a predischarge exercise test. A postdischarge exercise test and coronary angiography was performed by 172 patients after 1 month. A subgroup of 104 men performed both exercise tests with a computer-aided system. More sophisticated methods of evaluating the ECG reaction during exercise were not diagnostically superior to the simple identification of ST-depression of > or = 0.1 mV. ST-depression in ECG at rest indicated a 70% risk of severe coronary lesions and in such patients, the ECG reaction at exercise carried no additional diagnostic information. Stepwise multiple regression analysis showed that ST-depression and low maximal work load were the most important exercise variables for identification of severe coronary lesions. Using a combination of these parameters, the sensitivity and specificity for identification of severe coronary lesions were, respectively, 77% and 61% predischarge and 77% and 70% after 1 month.

Adult↗
PubMed1992

The heart in Duchenne muscular dystrophy: a non-invasive longitudinal study.

Sixteen boys with Duchenne muscular dystrophy (DMD) underwent serial investigations of echocardiographic left ventricular dimensions, systolic time intervals (STI), ECG and vectorcardiography (VCG). Spirometry with measurement of vital capacity and forced expiratory volume was also performed, as well as tests of muscle function. ECG was abnormal with high right precordial R-amplitudes even in the youngest patients. In contrast, VCG QRS area progressively diminished with age. STI and echocardiographic contractility indices decreased with increasing age. There was no clinically useful relationship between the various non-invasive variables on the one hand and results from skeletal muscle tests or lung function tests on the other, or between the different cardiac investigation methods. It is concluded that several non-invasive tests are needed during follow-up studies of Duchenne patients to evaluate the effects of treatment or assess prognosis.

Adolescent↗
PubMed1991

Should the exercise test (ET) be performed at discharge or one month later after an episode of unstable angina or non-Q-wave myocardial infarction?

The diagnostic and prognostic value of symptom limited exercise tests (ET) performed before discharge and after one month were compared in men admitted to hospital after an episode of unstable angina or a non-Q-wave myocardial infarction (MI). A 'Positive ET' was defined as either a maximal work load below 100 W or ST-depression greater than or equal to 0.1 mV in 1-2 leads below 130 W or ST-depression greater than or equal to 0.1 mV in more than 2 leads at any load at the ET. During follow-up, severe angina was the only indication for coronary angiography and revascularization. There were no significant differences in diagnostic findings between the tests--Positive ET in 47% and Negative ET in 25% at both ETs. The occurrence of MI or death and the need of revascularization were related to signs of ischemia at both ETs. There were no differences in prognostic value between the early and late tests regarding MI or death or future severe angina during the 11 months' follow-up after the one month ET. However, half (10%) of the overall event rate (20%) during the one year follow-up occurred during the first months. The risk of these events could be identified by the predischarge but, for obvious reasons, not by the one month ET. Therefore, the present study suggests that a symptom limited ET should be performed before discharge in men stabilized after an episode of unstable angina or non-Q-wave MI.

Angina, Unstable↗