Biomedical subjects

K Lindvall

Publications and source records attributed to K Lindvall.

At least 37 records · Page 2Linked to original sources

PubMed1995

Structural cardiac changes in relation to 24-h ambulatory blood pressure levels in borderline hypertension.

OBJECTIVES: To investigate left ventricular hypertrophy (LVH) in relation to 24-h ambulatory blood pressure (24-ABPM) and insulin levels in borderline hypertension. DESIGN: A case-control study. SUBJECTS: Borderline hypertensive men (diastolic blood pressure (DBP) 85-94 mmHg, n = 69) and age-matched normotensive controls (DBP < or = 80 mmHg, n = 69) from a population screening programme. MAIN OUTCOME MEASURES: Echocardiography (M-mode), insulin (RIA) and 24-APBM (Del Mar P-IV) levels. RESULTS: The borderline group showed a significant increase in septal thickness (10.4 +/- 1.5 vs. 9.7 +/- 1.5 mm, P < 0.01), peak systolic wall stress (218 +/- 38 vs. 202 +/- 38 10(3) dynes cm-2, P < 0.05) and a decrease in LV ejection time (28.4 +/- 2.5 vs. 29.5 +/- 2.1s, P < 0.01). The septum vs. posterior wall thickness ratio was significantly higher in the borderline group (1.13 +/- 0.14 vs. 1.06 +/- 0.14, P < 0.01). Casual BP levels did not correlate with LVH indices, while 24-ABPM systolic levels correlated strongly with LVH indices in the borderline group (r = 0.22-0.52, P < 0.05) but not in the normotensive group. Insulin levels correlates strongly with LVH indices in the normotensive group (r = 0.34-0.47, P < 0.01) but not the borderline, group. CONCLUSIONS: Signs of asymmetric LVH and altered ventricular function are already detectable in borderline hypertension. The data also suggest that early structural cardiac changes are related to ambulatory blood pressure profile, but not to casual blood pressure or trophic factors such as insulin.

Adult↗

PubMed1995

Long-term prognostic significance of M mode echocardiography in young men after myocardial infarction.

OBJECTIVE: To evaluate the power of measurements of left ventricular size and function for predicting long term (82 month) mortality by performing echocardiography in 97 men who had survived an acute myocardial infarction. SETTING: University hospital specialising in cardiology. PARTICIPANTS: 97 consecutive male patients who had survived a myocardial infarction. MAIN OUTCOME MEASURES: The additive prognostic value of functional measurements to that provided by primary risk factors (smoking habits and lipoprotein levels), radiological heart size, exercise capacity, and number of major coronary arteries with haemodynamically significant stenoses was evaluated. An echo index was calculated from three echocardiographic variables (yielding one score point each if: left ventricular diameter at the end of diastole (LVDD) > or = 5.7 cm, left ventricular fractional shortening < or = 24%, and E point-separation (EPSS) > or = 10 mm). MAIN OUTCOME: 17 cardiac deaths occurred during follow up. RESULTS: Univariate analysis showed that treatment with loop diuretics for heart failure (P < 0.01), LVDD (P < 0.01), left ventricular diameter at the end of systole (LVDS) (P < 0.001), left atrial diameter (P < 0.001), fractional shortening (P < 0.05), and echo index (P < 0.001) were all associated with cardiac death. Angiographically determined regional wall motion disturbances (P < 0.005) and angiographic ejection fraction (P < 0.001) were also associated with cardiac death, as was the number of major coronary arteries with significant stenosis (P < 0.05). When all significant echocardiographic variables from univariate analysis were entered into Cox proportional hazards survival analysis, LVDS and left atrial diameter contributed independently to the prediction of cardiac death. If angiographic data were also entered into the model, the echo index made an independent contribution to the prediction of cardiac death. CONCLUSIONS: Among young male patients with a previous myocardial infarction, a simple M mode echocardiographic examination can identify high and low risk patients and improve the prediction of cardiac death made from clinical information, exercise test, chest x ray and angiographically determined ejection fraction.

Adult↗

PubMed1995

Long-term prognostic importance of exercise echocardiography after an episode of unstable angina.

The aim of this study was to determine whether exercise echocardiography gives long-term prognostic information in patients with unstable angina. Treadmill exercise echocardiography was performed before discharge in 33 consecutive patients (23 men, 10 women) with unstable angina. A wall motion score index (WMSI) was calculated from visual interpretation of 9 left-ventricular segments, registered with two-dimensional echocardiography. Within an 8-year follow-up period, there were 10 medical events (2 cardiac deaths and 8 myocardial infarctions). New or worsening wall motion abnormalities and a low WMSI immediately after the exercise test were associated with subsequent myocardial infarction or cardiac death during follow-up (p < 0.05). Only 1 of the patients with a WMSI above the median suffered a myocardial infarction, which was not fatal. In contrast, 9 (56%) of the 16 patients with a WMSI below the median suffered myocardial infarction or cardiac death during follow-up. These findings in patients with unstable angina suggest that exercise echocardiography is a sensitive method for detecting those with increased risk of myocardial infarction or cardiac death. These high-risk patients might benefit from a more aggressive therapeutic approach.

Adolescent↗

PubMed1995

Prognostic value of exercise stress testing versus ambulatory electrocardiography after acute myocardial infarction: a 3 year follow-up study.

BACKGROUND: The aim of this study was to evaluate the prognostic significance of myocardial ischemia detected by ambulatory ECG monitoring (AEM) and exercise stress testing (ExT) following acute myocardial infarction. METHODS: The prognostic value of AEM versus ExT was studied prospectively in 74 patients with a recent acute myocardial infarction. Myocardial ischemia was diagnosed by the presence of ST-segment depression occurring during AEM or ExT 4 +/- 2 and 7 +/- 4 days after hospital admission respectively. ST-segment depression during AEM was defined as a horizontal/downsloping depression of > or = 0.1 mV from the reference baseline, measured 80 ms after the J point, elapsing > or = 1 min. ST-segment depression at ExT was determined as > or = 1mm horizontal or downsloping ST-segment depression in at least two consecutive ECG leads. RESULTS: Twenty-two patients (30%) showed ST-segment depression during AEM and 34 (49%) on ExT. During a mean follow-up period of 3 years (36 +/- 15 months), 10 patients (45%) with ST-segment depression on AEM died compared with eight (15%) without; 12 patients (35%) with ST-segment depression on ExT died versus three (8%) without. Death or reinfarction occurred in 13 patients (59%) with ST-segment depression on AEM versus nine (17%) without, and in 13 patients (38%) with ST-segment depression on ExT compared with six (17%) without. Revascularization procedures were similar in patients with or without ST-segment depression during AEM and ExT. Cardiac events defined as death, nonfatal reinfarction or revascularization, occurred in 18 patients (82%) with ST-segment depression on AEM versus 20 (38%) without, and in 23 patients (68%) with ST-segment depression on ExT versus 11 (31%) without. Survival analysis using Kaplan-Meier curves showed that patients showing no ST-segment depression with either technique had longer survival times than did patients showing ST-segment depression on either AEM or ExT, or showing ST-segment depression with both techniques. This was also true when analyzing the cumulative survival rate until the occurrence of any endpoint. With multivariate regression analysis, ST-segment depression on AEM was the variable most strongly predictive of mortality, followed by ST-segment depression on ExT, hypertension, and diabetes. CONCLUSIONS: These findings illustrate the ability AEM and Ext independently to predict long-term cardiac mortality and morbidity rates in patients recovering from acute myocardial infarction. The combined use of these techniques is useful for detecting patients at high risk after acute myocardial infarction.

Electrocardiography, Ambulatory↗

PubMed1994

Response of plasma neuropeptide Y and noradrenaline to dynamic exercise and ramipril treatment in patients with congestive heart failure.

Forty-two patients with congestive heart failure were studied in order to clarify whether the plasma level of neuropeptide Y-like immunoreactivity (NPY-LI) rises in parallel with plasma noradrenaline (NA) during physical exercise in congestive heart failure (CHF). All patients were studied in a randomized placebo-controlled trial with the ACE-inhibitor ramipril during 12 weeks to determine whether ACE-inhibition alters the response of plasma NPY-LI to exercise. The patients were treated with diuretics and had stable congestive heart failure (NYHA classes II-III). Plasma NPY-LI was 50 +/- 5 pmol l-1 (mean +/- standard error of the mean) at rest and 60 +/- 6 pmol l-1 at the end of exercise at baseline (P < 0.01). The corresponding values for plasma NA were 2.8 +/- 0.2 nmol l-1 and 15.3 +/- 1.2 nmol l-1 (P < 0.001). Before ACE-inhibition, there was a correlation between high NPY-LI and NA values after exercise. After treatment with ramipril or placebo for 12 weeks, there was no difference in plasma NPY-LI and NA at rest or after exercise between the two treatment groups. The maximal exercise time was unchanged. It is concluded that plasma NPY-LI and NA were elevated at rest in CHF. The additional rise of plasma NPY-LI and NA after exercise was attenuated in CHF compared to healthy individuals. ACE-inhibition with ramipril did not alter plasma NPY-LI or NA at rest or after exercise compared to placebo.

Aged↗

PubMed1993

Assessment of left ventricular wall motion in angina pectoris by two-dimensional echocardiography and myocardial perfusion by technetium-99m sestamibi tomography during adenosine-induced coronary vasodilation and comparison with coronary angiography.

Myocardial perfusion and regional wall motion during adenosine-induced coronary vasodilation were assessed in 40 patients with angina pectoris by technetium-99m sestamibi single-photon emission computed tomography (SPECT) and simultaneous 2-dimensional echocardiography. Adenosine was infused intravenously at a dose of 140 micrograms/kg body weight per minute for 6 minutes, and technetium-99m sestamibi was injected at 3 minutes. Adenosine caused a significant decrease in systolic and diastolic blood pressure and a significant increase in heart rate and the heart rate-blood pressure product. Adverse effects were mild and transient and no patient required aminophylline. Completely or partially reversible defects on SPECT were present in 28 patients, a fixed defect was seen in 4 patients, and no defect was seen in 8 patients. Two-dimensional echocardiography revealed a new or worsening wall motion abnormality in 21 patients, a fixed abnormality in 4 patients and no abnormality in 15. Transient perfusion defects were associated with transient wall motion abnormalities in 71% of cases. The overall sensitivity, specificity and predictive accuracy of adenosine echocardiography in detecting significant coronary artery disease (> 50% diameter stenosis) were 74, 100 and 78%, respectively, whereas those of adenosine SPECT were 94, 100 and 95%, respectively (p < 0.05, NS, and < 0.05, respectively). Thus adenosine technetium-99m sestamibi SPECT has a higher sensitivity and predictive accuracy than adenosine echocardiography, suggesting that adenosine-induced perfusion defects are not always associated with wall motion abnormality.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine↗

PubMed1993

Prevalence and significance of transient--predominantly asymptomatic--myocardial ischemia on Holter monitoring in unstable angina pectoris, and correlation with exercise test and thallium-201 myocardial perfusion imaging.

The prevalence and clinical significance of transient myocardial ischemia was evaluated prospectively in 43 patients with a clinical diagnosis of unstable angina. Continuous 2-channel Holter electrocardiographic monitoring was begun < 24 hours after admission. In 3,558 hours of recordings (mean 83 +/- 20 hours/patient), there were 1,671 episodes of transient ischemia; > 90% were asymptomatic. All patients but 1 had at least 1 episode of transient ischemia. Twenty-two patients (group 1) had a total ischemic duration of > or = 30 minutes/day, whereas 21 patients (group 2) had a total ischemic duration of < 30 minutes/day. A predischarge symptom-limited exercise test was performed in 40 of these patients after medical stabilization and 39 patients underwent exercise thallium-201 imaging, an average of 3 days after the exercise test. During a follow-up period of 39.9 +/- 9 months (range 28 to 49), 4 patients developed myocardial infarction and 22 required revascularization because of medically refractory angina. There were significantly more patients with total cardiac events (myocardial infarction or a need for revascularization) in group 1 than in group 2 (p < 0.05). Among patients undergoing an exercise test and exercise thallium-201 imaging, a positive exercise electrocardiogram and the presence of a reversible thallium-201 perfusion defect were also significant predictors of subsequent cardiac events (p < 0.05 and p < 0.001, respectively). The results of the Holter recordings did not add significantly more prognostic information.(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗

PubMed1993

Prognostic significance of exercise thallium-201 myocardial perfusion imaging compared to stress echocardiography and clinical variables in patients with unstable angina who respond to medical treatment.

The prognostic value of thallium-201 imaging in patients with unstable angina is not well established. Forty consecutive patients with unstable angina who had responded to medical therapy underwent predischarge symptom-limited exercise testing and 39 of them underwent exercise thallium-201 imaging, on average 3 days after the exercise test. Exercise echocardiography was performed in 36 of these patients in conjunction with the predischarge exercise test. Patients with previous myocardial infarction, coronary revascularization, left bundle branch block and dilated cardiomyopathy were not included in the study. An echocardiographic wall-motion score index was derived by analyzing left ventricular regional wall motion. During a follow-up period of 30 +/- 6.4 months, 3 patients had a non-fatal myocardial infarction and 20 required revascularization because of a recurrence of severe medically refractory angina. Univariate predictors of cardiac events (non-fatal myocardial infarction or a need for revascularization) during follow-up included ST-depression during exercise, positive exercise echocardiography, a low exercise wall-motion score index, the presence of thallium-201 redistribution and the number of myocardial segments with thallium-201 redistribution. However, stepwise logistic regression analysis revealed that the presence of thallium-201 redistribution was the only significant non-invasive predictor (P < 0.005) of a cardiac event among patients who underwent predischarge exercise testing and exercise thallium-201 imaging. Among patients undergoing exercise echocardiography and exercise thallium-201 imaging, the number of segments with thallium-201 redistribution was the only significant predictor (P < 0.0005) of future cardiac events.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1993

Noninvasive ambulatory 24 h blood pressures and basal blood pressures predict development of sustained hypertension from a borderline state.

A sample of 143 male borderline hypertensives aged 35 to 45, screened from a population cohort, were subjected to psychological stress, static work, and ambulatory 24 h blood pressure (BP) monitoring to assess the predictive power of BP reactivity in the development of established hypertension. After 1 year, a follow-up showed that 21 subjects (14.7%) had developed established hypertension (causal diastolic (D) BP > or = 95 mm Hg), 25 subjects (15.7%) had become normotensive (causal DBP < 85 mm Hg), and 97 (67.8%) remained within the borderline range (causal DBP 85 to 94 mm Hg). Those who developed established hypertension had considerably higher initial basal resting blood pressures than those who remained borderline: systolic (S) BP 134.2 +/- 12.5 v 127.6 +/- 10.7 mm Hg, P < .05 and DBP 86.8 +/- 7.9 v 80.4 +/- 7.0 mm Hg, P < .01. They had also somewhat higher BP values during mental arithmetic exercises and hand-grip work (peak DBP 101.1 +/- 8.8 v 96.8 +/- 8.7 mm Hg, P < .05, and 131.4 +/- 14.8 v 123.5 +/- 12.9 mm Hg, P < .05, respectively). Those subjects who developed established hypertension had significantly higher 24 h mean blood pressures than those who remained borderline (24 h SBP 133.3 +/- 11.4 v 126.0 +/- 10.1 mm Hg, P < .01, and DBP 84.7 +/- 5.7 v 81.6 +/- 6.8 mm Hg, P < .05). This difference was attributed mainly to the differences found during daytime (07:00 to 19:00) hours but was also found to be nominally dependent upon those found during nighttime (01:00 to 07:00) hours.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1993

Pharmacokinetic dosing in prophylactic treatment of hemophilia A.

The aim of this study was to investigate individual pharmacokinetics as a tool for dosing of factor VIII (FVIII) in severe hemophilia A. It is assumed that effective prophylaxis against bleedings is maintained if the plasma FVIII:C activity is kept above 1 U/dl, and the present study is based on this assumption. A current standard dosage regimen for FVIII is 25-40 U/kg up to three times weekly. However, there is considerable individual variation in the pharmacokinetics of FVIII:C. Individual pharmacokinetic data were used to computer-simulate plasma activity curves after repeated doses in 8 patients. Going from prophylaxis regimens of normally 2-3 infusions per week to dosing every 2 days would theoretically reduce their average FVIII consumption by 43% with maintained or increased trough levels of FVIII:C. Daily dosing would reduce their mean FVIII usage by 82%. Modified dosage regimens, infusions every 2 days, were implemented in the patients, and plasma samples were drawn to verify the pharmacokinetic models. The feasibility of the method to generally raise trough levels with a decreased consumption of FVIII was confirmed. Dosing of coagulation factors according to kinetic principles can result in more cost-effective utilization of these very expensive preparations.

Adult↗

PubMed1992

Predischarge exercise echocardiography in patients with unstable angina who respond to medical treatment.

The diagnostic and prognostic value of predischarge exercise echocardiography (echo) was assessed prospectively in 36 patients with unstable angina soon after stabilization on medical treatment. Two-dimensional echo was performed at rest and immediately after a symptom-limited exercise test. Patients with previous myocardial infarction, coronary revascularization, left bundle-branch block and dilated cardiomyopathy were excluded. Left ventricular regional wall motion was analyzed visually and a wall motion score index (WMSI) was derived. Patients were followed prospectively for an average period of 26 months (range 16-34 months). The study end points were a new cardiac event defined as acute myocardial infarction or a need for coronary revascularization because of a recurrence of severe medically refractory angina. Sixteen patients (44%) had positive exercise electrocardiography (ECG), while exercise echo was positive in 22 patients (61%). Of 28 patients undergoing coronary angiography, 23 had significant coronary artery disease (CAD). The sensitivity of exercise ECG in detecting CAD was 61% while the corresponding result was 83% for exercise echo. Cardiac events occurred in 21 patients (58%). Exercise ECG was positive in 12 of these patients (57%), while a positive exercise echo was found in 17 patients (81%). There were significantly more patients with positive exercise echo among patients experiencing cardiac events than among those without cardiac events (p less than 0.01). In patients with CAD, WMSI decreased significantly after exercise (p less than 0.05). Exercise WMSI was also significantly lower in patients with CAD than in those without CAD (p less than 0.02). Exercise WMSI also discriminated patients with cardiac events from those without such events (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗

PubMed1992

Exercise echocardiography after stabilization of unstable angina: correlation with exercise thallium-201 single photon emission computed tomography.

The diagnostic usefulness of predischarge exercise echocardiography in 35 patients with unstable angina who responded to medical therapy was correlated with exercise thallium-201 single photon emission computed tomography (TI-SPECT) performed, on the average, three days after the exercise echocardiography. None of the patients had myocardial infarction prior to hospitalization or before TI-SPECT and none had left bundle-branch block on their rest electrocardiogram (ECG). Exercise echocardiography was positive in 21 patients and TI-SPECT in 24. The results of the two techniques were concordant in 28 of 35 patients (agreement = 80%, k = 0.57 +/- 0.14, p less than 0.001). Wall-by-wall comparison of the distribution of exercise-induced wall motion abnormalities with reversible thallium defects showed complete or partial correlation in all of 19 patients in whom both the tests were positive. A positive exercise ECG and positive exercise echocardiography identified 11 of 11 patients with angiographically verified significant coronary artery disease (CAD) and 11 of 12 patients (92%) with positive TI-SPECT. Thus, exercise echocardiography is a valuable addition to routine predischarge exercise test in the noninvasive diagnosis of myocardial ischemia and shows a good correlation with TI-SPECT in detecting and localizing ischemia in patients with unstable angina stabilized on medical therapy.

Angina, Unstable↗

PubMed1992

Early exercise thallium-201 single photon emission computed tomography in unstable angina: a prospective study.

To evaluate the safety and diagnostic value of early symptom-limited exercise electrocardiography (ECG) and exercise thallium-201 single photon emission computed tomography (SPECT) in unstable angina (UA), 39 patients were studied prospectively soon after stabilization on medical treatment. No patient had a history of myocardial infarction (MI) or revascularization and patients with left bundle branch block were excluded. Exercise ECG and exercise thallium-201 SPECT were performed 8 +/- 4 days and 11 +/- 6 days respectively after admission to hospital. Seventeen out of 39 patients (44%) had positive exercise ECGs and 22 (56%) negative or inconclusive ones. Exercise thallium-201 SPECT was positive in 26 patients (67%) and negative in 13 patients (33%). Thirty-one patients underwent coronary arteriography and 24 of them proved to have significant coronary artery disease (CAD). The sensitivity, specificity and positive predictive value of exercise ECG in detecting CAD are 62%, 86%, and 94% respectively while the corresponding results are 96%, 100%, and 100% for exercise thallium-201 SPECT. Therefore, it is concluded that the early symptom-limited exercise test is safe in medically stabilized patients with UA. Early exercise thallium-201 SPECT is highly sensitive and predictive of the presence of significant CAD among patients in the early recovery phase of UA and can be used in selecting this group of patients for coronary angiography and other therapeutic strategies.

Adult↗

PubMed1992

Echocardiographic findings and the increased risk of stroke in nonvalvular atrial fibrillation.

We studied whether cardiac abnormalities contribute to the increased risk of stroke in patients with nonvalvular atrial fibrillation (NVAF). M-mode and 2D echocardiography were performed in four age- and gender-matched groups: 20 stroke patients with NVAF, 20 patients with NVAF who had not suffered a previous stroke, 20 stroke patients with sinus rhythm, and 40 healthy controls. Their mean age was 77 years. The two groups with atrial fibrillation differed from healthy controls in that they had more 2D-echocardiographic findings of severe left-ventricular-wall-motion abnormalities (p < 0.05) and tended more often to have enlarged left ventricles, and hypertrophic and congestive cardiomyopathy. Left atrial diameter was 47 mm compared to 41 and 39 mm in the two groups with sinus rhythm (p < 0.001). Intracardiac thrombi were only found in the two atrial-fibrillation groups (with stroke: 15% without stroke: 5%). Aortic sclerosis was common in all groups (30-60%), as was mitral annulus calcification (10-20%). The only significant difference between the two atrial-fibrillation groups was a higher frequency of earlier ischemic heart disease in the stroke group. Both atrial-fibrillation groups had cardiac abnormalities predisposing for embolic as well as thrombotic stroke.

Aged↗

PubMed1992

Effects of sympatho-adrenal activation on the finger microcirculation in mild hypertension.

Finger skin circulatory responses to three forms of sympatho-adrenal activation were investigated in 14 patients with mild hypertension and 14 matched normotensive controls. Finger nailfold skin capillary blood cell velocity was measured by video-photometric capillaroscopy and finger pulse volume by strain-gauge plethysmography (digital arterial pulse amplitude; DAPA). DAPA decreased more markedly in the normotensive as compared with the hypertensive group during mental arithmetic stress (38 vs. 19%; P less than 0.05) and a cold pressor test (55 vs. 32%; P less than 0.05). Intravenous infusions of adrenaline (0.1-0.8 nmol/kg/min) decreased DAPA in normotensives but not in hypertensives (P less than 0.05). Capillary blood cell velocity was similar in the two groups at rest and decreased promptly and to a similar extent in both groups following mental arithmetic, adrenaline infusion and the cold pressor test (by approximately 60, 60 and 35%, respectively). It is concluded that mental stress and the cold pressor test induce instantaneous and marked effects on the skin circulation via neurogenic activation. The less marked effect on DAPA in the hypertensive group may reflect an elevation of basal vascular tone and/or early structural vascular changes in mild hypertension. The discrepancy between total finger and capillary circulatory responses to adrenaline may be attributable to different adrenoceptor populations and/or sensitivity in arteriovenous shunts, as compared with precapillary vessels.

Adrenal Glands↗

PubMed1991

Stress-induced changes in blood pressure and left ventricular function in mild hypertension.

Left ventricular function was studied by M-mode echocardiography at rest and during a mental arithmetic stress test and a cold-pressor test in 14 patients with mild hypertension and in 14 matched normotensive subjects. The elevation of blood pressure at rest in the hypertensive group (154 +/- 4/87 +/- 3 vs. 120 +/- 3/66 +/- 3 mmHg in the control group) was due mainly to a higher cardiac output (6.0 +/- 0.3 vs. 5.0 +/- 0.3 L/min), which was related to elevations of stroke volume and heart rate (73 +/- 2 vs. 66 +/- 2 beats/min). Venous plasma catecholamines were similar in the two groups. Mental stress induced cardiac output-dependent increases in blood pressure in both groups; systemic vascular resistance tended to decrease. The relative increases in diastolic and mean arterial blood pressure were smaller in the hypertensive group (15 vs. 26% and 15 vs. 21%, respectively), which exhibited signs of a reduced cardiac compliance, possibly related to a left ventricular hypertrophy. Mental stress elevated venous plasma adrenaline similarly in the two groups; effects on noradrenaline were small. The cold-pressor test increased blood pressure similarly in the two groups, largely due to increased systemic vascular resistance; plasma noradrenaline responses were also similar. Mental stress appears to elicit a differentiated sympathetic nerve activation pattern resembling the hypothalamic defense reaction. Mild hypertension seems to be associated with increased arousal and cardiac activation at rest. However, an attenuated blood pressure reactivity to mental stress may reflect reduced stroke volume responsiveness, which is related to structural changes, as heart rate reactivity tended to be enhanced in mild hypertension.

Adult↗

PubMed1991

Comparison between isoprenaline infusions and bolus injections to assess beta-adrenoceptor function in man, with special reference to cardiac contractility and the influence of autonomic reflexes.

The present study was performed to characterize cardiovascular responses to isoprenaline and the influence of autonomic reflexes on these responses. Nine healthy volunteers received infusions and bolus injections of isoprenaline before and after 'autonomic blockade' produced by intravenous atropine 0.04 mg kg-1 and clonidine 300 micrograms. Heart rate, blood pressures, systolic time intervals and various echocardiographic measures of cardiac contractility were registered. No significant differences in responsiveness to isoprenaline were seen when infusions were repeated on the same day without 'autonomic blockade'. After 'blockade', delta responses at 1 nmol l-1 isoprenaline (infusions) were increased for diastolic blood pressure and decreased for systolic blood pressure and stroke volume. Bolus injections of 2 micrograms isoprenaline caused enhanced delta responses after 'autonomic blockade' of diastolic blood pressure, left ventricular diameter in systole, ventricular circumferential fibre shortening, mean posterior wall velocity (Vmean PW), stroke volume, systemic vascular resistance, electromechanical systole (QS2) and pre-ejection period. Systolic blood pressure decreased, in contrast to a small increase without 'blockade'. These findings are explained by differences in haemodynamic effects of isoprenaline and by the dependence of responses on reflexes when isoprenaline is administered in different ways. When heart rate was increased by bolus doses of atropine, in the presence of beta-blockade (propranolol), pre-ejection period and left ventricular diameter in systole were unaffected, and Vmean PW and ventricular circumferential fibre shortening showed only small increases (compared with alterations induced by isoprenaline). However, left ventricular ejection time, QS2 and ejection time (by echocardiography), were markedly dependent on heart rate alterations. Thus, pre-ejection period, left ventricular diameter in systole Vmean PW and ventricular circumferential fibre shortening are parameters which can be useful in order to evaluate cardiac beta-adrenoceptor sensitivity in vivo in man.

Adult↗

PubMed1991

Oral health in adolescents with immigrant background in Stockholm.

Dental caries and periodontal health was studied in 225 18- and 19-year-old adolescents with different ethnic background. The results showed that immigrant adolescents exhibit an increased prevalence of periodontal disease compared to the Swedish control group whereas no differences were found concerning the prevalence of dental caries. Alveolar bone loss was diagnosed on one or more surfaces in 4.3% of the Swedish adolescents compared to 16.2% in the immigrant group. Subgingival calculus was found among 5.3% of the Swedish adolescents compared to 35.1% in the immigrant group. This study shows that immigrant adolescents must be considered at high risk to develop periodontal disease during adolescents while dental caries can be managed.

Adolescent↗