Endocarditis: clinical outcome and benefit of trans-oesophageal echocardiography.

The improved prognosis for infective endocarditis (IE) seen in the last decade is due partly to more active surgical treatment and partly to improved diagnosis by echocardiography. To evaluate the clinical value of repeated trans-oesophageal echocardiography (TEE) 34 patients with 35 episodes of suspected IE were included in a prospective part of the study (group A). TEE was carried out for diagnosis, at discharge and about 5 months after hospitalization. Endocarditis was classified using Duke's criteria. In a retrospective part of the study 32 other patients with 34 episodes of IE were included (group B). Both groups were analysed regarding mortality, frequency of surgery and classification according to Duke. The diagnosis was regarded as definite in 49 and possible in 20 episodes. Vegetation-size decreased significantly (p < 0.001) during treatment. In contrast, no significant changes in valvular insufficiency were found. In episodes diagnosed as definite, the mortality was 2/49 (4.1%). The low mortality might be explained by the high frequency of surgery (22%), the inclusion of patients with right-sided IE, and 'early diagnosis'. The first TEE was important for correct diagnosis in patients with small vegetations and for those needing surgery. The clinical value of the additional investigations was low in native valve endocarditis.

Influence of food intake on electrocardiograms of healthy male volunteers.

OBJECTIVE: To study the influence of food intake on electrocardiogram (ECG) variables (heart rate, QT-, QTc-, PR-intervals, QRS-time) and morphological alterations of the T-waves in 12 healthy male volunteers. METHODS: The study was of open, three-period crossover design. On each occasion, all subjects fasted from midnight. During two of the study periods, the subjects were given a standardised meal at 1.5 h and 5.5 h after the baseline assessments, respectively, whereas, during the third period, they remained fasting for the entire study period of about 9 h. ECG and blood pressure were recorded at baseline and thereafter every hour for 8 h. RESULTS: No ECG changes were observed following the fasting condition, whereas a clear change in ECG and an increased heart rate were recorded in response to the meal intake during the other two periods. The most prominent ECG effect was the change in the size and shape of the T-waves, which were described as flattened to biphasic and, occasionally, negative. These alterations were most pronounced in the precordial leads V4 to V6 in the ECG recording immediately following the meal intake, with a gradual return to baseline conditions over 4-5 h. Moreover, a transient increase of supine systolic blood pressure was also recorded in response to the meal intake. CONCLUSIONS: The intake of a meal can cause clear and consistent ECG changes in healthy male subjects, comprising increases in heart rate as well as alterations in the size and shape of the T-waves (flattened to biphasic and, occasionally, negative). Also, a post-meal increase in the supine systolic blood pressure was recorded.

A critical evaluation of ultrasound measurement of inferior vena cava diameter in assessing dry weight in normotensive and hypertensive hemodialysis patients.

The utility of measurement of the inferior vena cava diameter (IVCD) with ultrasound for the assessment of fluid status and posthemodialysis dry weight was studied in 35 hemodialysis (HD) patients, 17 with and 18 without hypertension. In 17 patients (group A), IVCD was measured before and 35 to 40 minutes after HD, pre-HD blood volume (BV) was measured with radiolabeled albumin and post-HD BV was calculated from the change in hematocrit. In 18 patients (group B), IVCD was measured repeatedly during HD and 2 hours after HD. Changes in BV were recorded by monitoring of the hematocrit "on line." Body weight, blood pressure (BP), BV, and IVCD decreased in the entire population. In group A, BV was significantly larger in the hypertensive patients than in the normotensive patients, and it was correlated with the mean BP before and after HD. In the whole population, IVCD was larger in the hypertensive than in the normotensive patients before and after HD. These results confirm that extracellular fluid overload plays an important role in the pathogenesis of dialysis-associated hypertension. In group B, BV and IVCD decreased in parallel during HD and increased during 2 hours after HD due to refilling of the intravascular space, indicating that changes in IVCD reflect changes in BV. In 8 patients studied twice, IVCD increased much more after a 3-hour HD session than after a 6-hour session. At the end of HD, several patients had IVCD below the reference range but IVCD increased during the following 1 to 2 hours, in some patients to values above the reference range. IVCD measured at the end or shortly after HD may therefore be misleading in assessing dry weight.

Classification of infective endocarditis by Duke's criteria and transesophageal echocardiography: a 1-year retrospective analysis.

A sensitive, specific, and rapid diagnosis of infective endocarditis (IE) is important for prognosis, and to exclude IE and thus avoid prolonged treatment with antibiotics. The diagnostic system for IE according to Duke's university includes echocardiographic results and classifies patients in 3 categories--'definite', 'possible', and 'rejected'--by combining pathologic, echocardiographic, clinical, and blood culture findings. Transesophageal echocardiography (TEE) has better diagnostic sensitivity compared to transthoracic echocardiography. Duke's criteria were used on 83 patients examined by TEE in a retrospective study. Of 83 patients with suspected IE, 49 episodes in 48 patients were classified as 'rejected' and were not treated. The remaining 37 patients (15 of whom were intravenous drug users) were treated and classified as follows: 'definite', 26 episodes in 24 patients, 'possible', 11 episodes in 11 patients; and 'rejected', 2 episodes in 2 patients. In this retrospective analysis Duke's criteria were easy to apply. A negative TEE made IE unlikely and a positive TEE made IE probable when other signs of infection were present.

Signal variance electrocardiogram: a test for early detection of myocardial involvement in cystic fibrosis?

1. Variance electrocardiography is a new resting procedure for the detection of ischaemia-induced variability in the electrical expression of the depolarization phase. The analysis is performed on 220 cardiac cycles using high-fidelity ECG signals from 24 leads, and the electrical variability is expressed as an electrical variability index ranging from 1 to 150. In this study, variance electrocardiography was employed to detect cardiac involvement in 23 patients with cystic fibrosis. 2. Patients with cystic fibrosis presented a significantly higher mean electrical variability index than control subjects, and their index values correlated inversely with the arterial oxygen partial pressure and forced expiratory volume in 1.0 s. Patients with a high electrical variability index (> 75) displayed a lower clinical score (Shwachman score) and a longer duration of chronic colonization with Pseudomonas aeruginosa. Patients with conduction disturbances and patients with echocardiographic right ventricular pathology presented higher indices than those without. 3. Electrical variability index is increased in cystic fibrosis and correlates with other signs of cardiac and pulmonary derangement. Variance electrocardiography may therefore have the potential to be a sensitive and simple method for monitoring cardiac involvement in this disease.

Blood pressure response to physical exercise in healthy adolescents and adolescents with insulin-dependent diabetes mellitus.

1. Reference values for systolic blood pressure during exercise are provided for 88 healthy adolescents (12-22 years of age) of both sexes. Data were related to oxygen uptake, heart rate, blood lactate concentration, rate of perceived exertion, age, sex, body size and physical fitness. 2. The same variables were measured in 55 adolescents of both sexes with insulin-dependent diabetes mellitus of about 12 years duration and were analysed with respect to the healthy control group, to degree of metabolic control and to late diabetic complications. 3. In healthy adolescents the pressure response was not related to sex or age. When compared with control subjects diabetic patients had a higher diastolic blood pressure at rest and a more marked blood pressure increase, 23 versus 19 mmHg W-1 kg-1 body weight, during exercise with no sex difference. The blood pressure rise was not related to metabolic control, glomerular hyperfiltration or physical fitness. 4. Prolonged exercise tests were no more informative regarding the blood pressure response to exercise than the stepwise increased load test. Analysing the blood pressure increase versus relative work load (W/kg body weight) during exercise reveals blood pressure differences otherwise not noted. A diabetic patient with blood pressure above the 97.5% confidence limit during exercise seems to have a higher risk of developing incipient nephropathy 5 years later.

Treatment of anaemia in haemodialysis patients with erythropoietin: long-term effects on exercise capacity.

1. The effects of correcting anaemia on exercise capacity were evaluated in 21 haemodialysis patients (aged 39 +/- 12 years) before starting treatment with recombinant human erythropoietin (Hb concentration, 73 +/- 10 g/l; total Hb, 59 +/- 12% of expected), after correction of the anaemia to a Hb concentration of 108 +/- 7 g/l and a total Hb 82 +/- 10% of expected, and in 13 of the patients after 12 months on maintenance recombinant human erythropoietin treatment (Hb concentration 104 +/- 14 g/l, total Hb 79 +/- 17% of expected). Fifteen healthy subjects (aged 41 +/- 9 years), who took no regular exercise, constituted the control group. Maximal exercise capacity was determined on a bicycle ergometer. Oxygen uptake, respiratory quotient, blood lactate concentration, heart rate and blood pressure were measured at rest and at maximal workload. 2. After 6 +/- 3 months on recombinant human erythropoietin, maximal exercise capacity increased from 108 +/- 27 W to 130 +/- 36W (P < 0.001) and the maximal oxygen uptake increased from 1.24 +/- 0.39 litres/min to 1.50 +/- 0.45 litres/min (P < 0.001). No significant changes in respiratory quotient (1.16 +/- 0.13 versus 1.18 +/- 0.13) and blood lactate concentration (4.0 +/- 1.8 versus 3.6 +/- 1.1 mmol/l) at maximal workload were observed, but the blood lactate concentration in the patients was significantly lower than that in the control subjects (6.7 +/- 2.3 mmol/l, P < 0.01). After the correction of anaemia, the aerobic power was still 38% lower in the patients than in the control subjects and 17% lower than the reference values.(ABSTRACT TRUNCATED AT 250 WORDS)

Physiological effects of mental stress and orthostasis in young insulin-dependent diabetic patients.

The effects of procedures which stimulate sympathetic activity, viz. mental stress induced by a colour-word conflict test (CWT) for 20 min, and orthostasis (ORT) for 8 min were studied in 8 young (16-20 yr) insulin-dependent diabetes mellitus (IDDM) patients and 9 age and sex-matched healthy controls. The IDDM patients showed no signs of neuropathy or retinopathy and their mean HbA1c value was 8.4 +/- 0.6% (normal value less than 5.0%). Blood pressure and heart rate increased significantly during CWT and ORT in both groups. The changes in systolic blood pressure and heart rate were comparable in both groups during CWT; the IDDM group showed a higher (p less than 0.05) heart rate after 8 min of orthostasis, however. CWT and ORT elicited equivalent increases in noradrenaline in venous plasma in both groups (p less than 0.05), but the IDDM patients had 50% lower values (p less than 0.01) at rest, during CWT and at rest after CWT than controls. CWT and ORT evoked equivalent plasma adrenaline increases in both groups. The lipolysis marker, plasma glycerol, was about 40% lower (p less than 0.05) in the IDDM group before and after CWT. Yet, mental stress evoked equivalent increases in glycerol levels (p less than 0.01) in both groups. These findings indicate that sympathetic activity in the young diabetic patients without signs of neuropathy may be blunted.

Factors related to renal haemodynamics in young type-1 diabetes mellitus patients.

The influence of metabolic control (HbA1c), noradrenaline (NA) and insulin-like growth factors (IGF-I and IGF-II) on renal function and size was investigated in 11 insulin-dependent diabetes mellitus patients aged 11-17 years. Renal function was evaluated in terms of glomerular filtration rate (GFR) and effective renal plasma flow (ERPF). Renal size was determined as renal parenchymal volume (RPV) by ultrasonography. The patients' HbA1c values ranged from 8.2% to 12.9% (normal range 5.5-8.5%) and their GFR and ERPF were higher than normal. Their IGF-II values were higher, and NA and IGF-I levels were lower than those of healthy controls. Inverse correlations between NA and GFR (r = -0.66) and NA and ERPF (r = -0.63) were found. No correlation was found between serum IGF-I and renal functional parameters. The IGF-II values correlated with GFR and HbA1c (r = 0.63, r = 0.70 respectively). There were linear correlations between RPV and GFR, RPV and ERPF, HbA1c and GFR, and ERPF and RPV. Decreased NA concentrations and increased IGF-II values appear to be factors contributing to renal hyperfunction in these patients.

Enalapril reduces microalbuminuria in young normotensive type 1 (insulin-dependent) diabetic patients irrespective of its hypotensive effect.

The effect of enalapril on albumin excretion rate was studied in two groups of age- and sex-matched Type 1 (insulin-dependent) diabetic patients, aged 15-20 years, with persistent microalbuminuria greater than 20 micrograms/min. Group 1 contained six patients with systolic blood pressure greater than or equal to 75th percentile for age and sex, group 2 six normotensive patients. Enalapril (10-20 mg/day) was given for six months. Albumin excretion rate, glomerular filtration rate, renal plasma flow, blood pressure at rest and during exercise, and angiotensin converting enzyme activity were measured before, after three weeks' and six months' treatment and six months after treatment withdrawal. Albumin excretion rate decreased in all patients after three weeks' (mean decreases 55% in group 1, 65% in group 2) and six months' treatment (35% in group 1, 61% in group 2). Systolic blood pressure remained unchanged in both groups. Diastolic pressure was reduced after three weeks in group 1 (p = 0.001). No reduction in increment in systolic pressure during exercise test occurred in any group during treatment. Angiotensin converting enzyme activity decreased in all patients after three weeks (p = 0.001) and six months (p = 0.003). This correlated to the decrease in albumin excretion rate after three weeks (r = 0.79, p = 0.05) and six months (r = 0.59, p = 0.04). HbA1c, mean blood glucose and glomerular filtration rate remained unchanged during the study in both groups. Renal plasma flow tended to increase after three weeks' and six months' treatment in group 2 (p = 0.06, respectively) but not in group 1.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiovascular and sympathoadrenal responses to mental stress: a study of sensory intake and rejection reactions.

Cardiovascular, sympathoadrenal and subjective responses to mental stress induced by two mental challenges eliciting sensory intake (word identification test = WIT) and sensory rejection (colour word conflict test = CWT) reactions were studied in 10 healthy males. Pressor responses to these stressors have been proposed to differ haemodynamically. Sympathoadrenal activity was assessed by arterial and femoral venous plasma catecholamine determinations and direct recordings of muscle sympathetic activity in the right peroneal nerve (MSA). Basal measurements differed little from those made during an active relaxation procedure, with the exception of MSA, which decreased. Both stress tasks elicited increases in heart rate, cardiac output, calf blood flow and brachial and pulmonary arterial blood pressures. WIT and CWT elicited qualitatively similar responses, but the amplitudes of the circulatory responses were lower with WIT, which also was rated as a weaker stressor. MSA increased during CWT, while marginal increases were seen during WIT. Arterial adrenaline showed a transient increase by 0.14 nmol l-1 during WIT. During CWT arterial adrenaline increased significantly by 50%. Increases in arterial adrenaline and subjective stress ratings were related to increases in cardiac output and reductions of systemic vascular resistance. Arterial and femoral venous noradrenaline increased during CWT, while changes during WIT were small. MSA and noradrenaline responses did not correlate to local vascular responses in the calf. Differences in the responses to mental challenges evoking sensory intake or rejection seem to be of a quantitative rather than a qualitative character.

Muscle sympathetic activity and norepinephrine release during mental challenge in humans.

Muscle sympathetic nerve activity (MSA; peroneal nerve) and arterial and femoral venous plasma norepinephrine (NE) were studied in 10 volunteers at rest, during a relaxation procedure (RELAX), and during two mental challenges, a word identification test (WIT) and a color word test (CWT). [3H]NE infusions were used to assess NE spillover to and clearance from plasma. Net NE overflow from the leg was calculated. RELAX reduced MSA and femoral venous NE concentrations. CWT increased blood pressure, cardiac output (thermodilution), and calf flow and reduced systemic vascular resistance. Responses to WIT were less marked. CWT increased MSA by 25%, femoral venous NE concentrations by 25%, and NE overflow from the leg by 26% at 3 min. Fractional epinephrine and [3H]NE extractions were flow related and decreased during CWT. The arterial contribution to femoral venous NE (about half) increased by 10% during CWT. Arterial NE levels and spillover increased, but NE clearance was unchanged. Femoral venous NE concentrations and NE spillover (not based on flow measurements) and regional NE overflow correlated with MSA. Thus NE concentrations in plasma reflect spillover rather than clearance at rest and during mental challenge. Biochemical and neurophysiological indexes of sympathetic activity correlate when assessed in the same region. Mental stress increases sympathetic activity in leg muscle.

Adipose tissue and skeletal muscle blood flow during mental stress.

Mental stress [a modified Stroop color word conflict test (CWT)] increased adipose tissue blood flow (ATBF; 133Xe clearance) by 70% and reduced adipose tissue vascular resistance (ATR) by 25% in healthy male volunteers. The vasculatures of adipose tissue (abdomen as well as thigh), skeletal muscle of the calf (133Xe clearance), and the entire calf (venous occlusion plethysmography) responded similarly. Arterial epinephrine (Epi) and glycerol levels were approximately doubled by stress. beta-Blockade by metoprolol (beta 1-selective) or propranolol (nonselective) attenuated CWT-induced tachycardia similarly. Metoprolol attenuated stress-induced vasodilation in the calf and tended to do so in adipose tissue. Propranolol abolished vasodilation in the calf and resulted in vasoconstriction during CWT in adipose tissue. Decreases in ATR, but not in skeletal muscle or calf vascular resistances, were correlated to increases in arterial plasma glycerol (r = -0.42, P less than 0.05), whereas decreases in skeletal muscle and calf vascular resistances, but not in ATR, were correlated to increases in arterial Epi levels (r = -0.69, P less than 0.01; and r = -0.43, P less than 0.05, respectively). The results suggest that mental stress increases nutritive blood flow in adipose tissue and skeletal muscle considerably, both through the elevation of perfusion pressure and via vasodilatation. Withdrawal of vasoconstrictor nerve activity, vascular beta 2-adrenoceptor stimulation by circulating Epi, and metabolic mechanisms (in adipose tissue) may contribute to the vasodilatation.

Cardiovascular and sympathoadrenal responses to mental stress: influence of beta-blockade.

Cardiovascular, sympathoadrenal, and subjective responses to mental stress induced by a color-word conflict test (CWT) were studied in 30 healthy males before and after intravenous administration of either placebo, beta 1-blockade by metoprolol (0.15 mg/kg), or nonselective beta-blockade by propranolol (0.15 mg/kg). CWT responses were reproducible. Mean arterial pressure increased by 20%. A mainly heart rate-dependent 65% increase in cardiac output (thermodilution) was associated with 25% decreases of both systemic (SVR) and calf vascular (CVR) resistances. Arterial plasma epinephrine (Epi) was doubled, and norepinephrine (NE) increased by 50%. Self-evaluated stress score correlated positively with changes in cardiac output and inversely with changes in SVR during CWT. Both metoprolol and propranolol halved heart rate responses; whereas increases in mean arterial pressure, Epi, and NE were uninfluenced. Metoprolol reduced the increase in stroke volume, and propranolol abolished it. SVR and CVR responses were attenuated by metoprolol and abolished by propranolol. The results suggest that mental stress accelerates the heart through neurogenic mechanisms and that peripheral vasodilatation is achieved through the concerted actions of reduced vasoconstrictor activity and elevated circulating Epi.

Risk factors for occasional and recurrent wheezing after RSV infection in infancy.

Sixty-seven children who were hospitalized with a verified RSV infection were reexamined after 4 years at the age of 4 to 7 years. Twenty-four children had had no subsequent respiratory symptoms, 22 had wheezed 1-3 times and 21 had recurrent wheezing. A family history of atopy and a personal history of neonatal respiratory problems were more common in the group with recurrent wheezing, whereas paternal smoking was more frequent in the group with occasional wheezing. RSV infection in early infancy was more related to occasional wheezing than recurrent episodes. The spirometric data obtained from the force expirograms were normal, compared to the predicted normal values. In the children with recurrent wheezing, however, the values for PEF and the MEF25 were significantly lower in comparison with all the other children showing a mild obstruction.

Renal function and albumin excretion during exercise in children during remission of the minimal change nephrotic syndrome.

Six patients with the minimal change nephrotic syndrome in remission and seven healthy controls were investigated with regard to renal haemodynamics and albumin excretion before, during and after exercise. The glomerular filtration rate and effective renal plasma flow were determined by a standard clearance method, employing continuous infusion of inulin and para-aminohippuric acid. Microalbuminuria was measured by an immunoturbidimetric method. The work load was standardized at 70% of the maximal working capacity and was applied for 20 min. During exercise there was a significant fall in the glomerular filtration rate and effective renal plasma flow and a significant rise in the filtration fraction. The pattern of renal haemodynamic changes did not differ between the groups. Nor was there any statistically significant difference in urinary albumin excretion, although the exercise-induced increase in albumin excretion of the controls did not reach statistical significance. It is concluded that the renal haemodynamics and urinary albumin excretion of children having long remissions of the minimal change nephrotic syndrome are normal at rest as well as during and after a submaximal exercise test.

Influence of long-term metoprolol treatment on early and late exercise test performance after acute myocardial infarction.

The effect of therapy on exercise performance during a 3-year follow-up after acute myocardial infarction (AMI) was evaluated in a double-blind randomized comparison between 154 patients given metoprolol (100 mg twice daily) and 147 patients given placebo. Exercise tests were performed 1.5, 6, 12, 24 and 36 months after AMI. Maximal accomplished workloads were similar in the 2 groups throughout follow-up. Maximal heart rate was significantly higher in the placebo-treated group throughout the study (p less than 0.001). At the 6-week test more patients in the placebo group terminated exercise due to angina pectoris (40 vs 25%, p less than 0.05) and showed exercise-induced ST-depressions (38 vs 27%, p = 0.05) compared with the metoprolol group. Exercise-induced ventricular arrhythmias were significantly more common in the placebo group during the initial 6 months. Death, another AMI or both were significantly reduced by metoprolol treatment in patients with exercise-induced ST depression greater than or equal to 1 mm at the 6-week test. In a multiple logistic regression analysis maximal accomplished workload at 6 weeks (p less than 0.026), male sex (relative risk [rr] = 3.57, p = 0.016), previous AMI (rr = 3.07, p = 0.001), therapy with placebo (rr = 2.14, p = 0.007) and left ventricular failure (rr = 2.04, p = 0.023) were shown to carry independent prognostic information as well as exercise-induced ST-depression (greater than or equal to 1 mm) in placebo-treated patients (rr = 2.70, p = 0.01).

Cardiovascular function and arterial blood gases during sham dialysis in healthy man.

Cardiovascular function and alveolar gas exchange were studied in healthy subjects undergoing sham dialysis (SHD)--i.e. the circulation of blood through a cuprophane dialyzer with the dialysate compartment closed to avoid diffusion and convective transport of fluid and solutes. The blood-membrane contact induced complement activation (rise in C3d) and transient leukopenia, as described during clinical hemodialysis. PaO2, PaCO2 and calculated oxygen uptake remained unchanged. Heart rate, cardiac index (thermodilution), systemic vascular resistance index and brachial and pulmonary arterial blood pressures did not change significantly during 150 min of SHD (n = 8). In 12 subjects, in whom more frequent measurements were made during the first 30 min of SHD, pulmonary arterial systolic and diastolic blood pressures decreased significantly while the dialyzer and the tubing set filled with blood, and pulmonary arterial mean blood pressure did not change significantly. Pulmonary capillary wedge pressure fell during the filling phase, but did not change significantly during SHD; pulmonary vascular resistance index remained unchanged. We conclude that in nonuremic subjects sham dialysis with a cuprophane dialyzer does not result in hypoxemia, pulmonary vascular constriction and pulmonary hypertension, in spite of complement activation and marked leukopenia.