Compartment pressure in association with closed tibial fractures. The relationship between tissue pressure, compartment, and the distance from the site of the fracture

We studied twenty-five consecutive patients who had a closed tibial fracture to determine whether there was a relationship between compartment pressure and the distance at which the pressure was measured from the site of the fracture. Tissue pressure was measured in all four compartments of the leg at the level of the fracture and at five-centimeter increments proximal and distal to the fracture. The peak pressure was usually found at the level of the fracture and was always located within five centimeters of the fracture. The highest pressures were recorded in the anterior and the deep posterior compartments in twenty patients, including all five of those who had had a fasciotomy. The measured pressure decreased steadily when sampled at increasing distances proximal and distal to the site of the highest recorded pressure. Decreases of twenty millimeters of mercury (2.67 kilopascals) five centimeters adjacent to the site of the peak pressure were common. Compartment syndrome was diagnosed in five patients on the basis of clinical findings, and the diagnosis was confirmed when peak compartment pressures of more than the critical threshold (within twenty millimeters of mercury [2.67 kilopascals] of the diastolic blood pressure) were recorded. Three of these five patients had measured pressures that were less than the critical threshold within five centimeters of the site of the peak pressure. Failure to measure tissue pressure within a few centimeters of the zone of peak pressure may result in a serious underestimation of the maximum compartment pressure. Our results suggest that measurements should be performed in both the anterior and the deep posterior compartments at the level of the fracture as well as at locations proximal and distal to the zone of the fracture to determine reliably the location of the highest tissue pressure in a lower extremity when a compartment syndrome is suspected clinically. The highest pressure should be used in the decision-making process.     

Structuring a clinical learning environment for a hybrid-PBL dental curriculum

The standard noninvasive test to assess the severity of peripheral arterial occlusive disease (PAOD) is the ankle/brachial systolic blood pressure index (ABI). While ankle systolic blood pressure is obtained by the Doppler ultrasound technique, brachial systolic blood pressure can be obtained by the Doppler, auscultatory, or oscillometric (Dinamap 1846 SX) methods. The purpose was to determine whether the three methods yielded similar brachial systolic blood pressure values, and consequently similar ABI values, in PAOD patients with intermittent claudication. Fifty patients who had a history of intermittent claudication of 2.3 +/- 2.0 blocks for a duration of 5.7 +/- 5.8 years were recruited. Following 10 minutes of supine rest, brachial systolic blood pressure was measured in the right arm by the three techniques in a randomized order, and ankle systolic blood pressure (87.3 +/- 28.9 mmHg) was measured in the more symptomatic leg with the Doppler technique. Brachial systolic blood pressure was not significantly different (p=0.954) among the Doppler (128.5 +/- 18.4 mmHg), auscultatory (128.4 +/- 17.4 mmHg), and oscillometric (128.2 +/- 17.1 mmHg) methods. Corresponding ABI values also were similar (p=0.922) among the three respective methods (0.68 +/- 0.22, 0.68 +/- 0.22, and 0.68 +/- 0.21), indicating that ABI did not vary according to the technique used to obtain brachial systolic blood pressure. It is concluded that the accuracy of determining ABI in PAOD patients with intermittent claudication was minimally affected by the method chosen to obtain brachial systolic blood pressure.     

Comparison of blood pressure and angiotensin responses to the renin inhibitor Ro 42-5892 and the angiotensin converting enzyme inhibitor enalapril in essential hypertension

OBJECTIVE: To compare the responses of angiotensin II (Ang II) and blood pressure to the renin inhibitor Ro 42-5892 and the angiotensin converting enzyme (ACE) inhibitor enalapril. SUBJECTS: Eight non-sodium-restricted patients with mild-to-moderate essential hypertension. DESIGN: A single-blind crossover study. Ro 42-5892 (600 mg orally, once a day) and enalapril (20 mg orally, once a day) were given for 8 days before detailed investigations were carried out. METHODS: Ambulatory blood pressure was measured directly for 24 h by the Oxford technique on three occasions. Off-treatment and on day 8 of treatment with Ro 42-5892 and with enalapril. Ang II was measured by radioimmunoassay after separation by high-performance liquid chromatography. RESULTS: Plasma renin activity and Ang II were lowered by 83% [95% confidence interval (CI) 61-105] and 68% (95% CI 49-87), respectively, 0.5-1 h after Ro 42-5892, but after only 3 h values had returned to baseline. Unlike this rapid and short-term suppression of Ang II, the maximal antihypertensive response to Ro 42-5892 (fall in blood pressure 12.9/9.0 mmHg) occurred only after 6 h. Blood pressure returned to baseline after 8 h. In response to enalapril, Ang II was maximally suppressed by 63% (95% CI 32-94) after 2 h and by 83% (95% CI 76-90) after 8 h. Despite early maximal Ang II suppression, the maximal antihypertensive response to enalapril occurred only after 12 h (fall in blood pressure 25.3/16.3 mmHg). With this compound a significant antihypertensive effect was still present 24 h after dosing. CONCLUSIONS: Compared with enalapril at 20 mg once a day, repeated oral administration of a single dose of Ro 42-5892 at 600 mg caused only short-term suppression of Ang II and blood pressure. Suppression of Ang II and reduction in blood pressure were temporally dissociated, both with the ACE inhibitor and the renin inhibitor. This implies that the blood pressure lowering effect of these inhibitors is caused partly by Ang II suppression outside the circulation.     

Immune response to changes in training intensity and volume in runners

We examined the acute and chronic effects of changes in training volume and intensity on the blood lymphocyte percentages and immunoglobulin levels in runners. Twelve runners participated in four 10-d phases of low volume/low intensity (LV/LI), high volume/low intensity (HV/LI), or high volume/high intensity (HV/HI) running. Subjects were assigned to one of two different training group orders: 1) LV/LI, HV/LI, LV/LI, HV/HI; or 2) LV/LI, HV/HI, LV/LI, HV/LI. Venous blood was drawn at rest on days 1, 4, and 7; and 5 min post-exercise on days 1 and 7 of each 10-d phase. Lymphocyte subsets were determined by flow cytometry for CD3+, CD4+, CD8+, and HLA-DR+. IgG, and IgM levels were obtained by ELISA analysis. Immunoglobulin, CD8+ and HLA-DR+ levels, and pre-exercise plasma cortisol concentrations were not significantly affected by alterations in volume or intensity. A transient decrease (P < 0.05) was observed in CD4+ and the CD4/CD8 ratio 5 min post-exercise during the HV/LI and HV/HI phases. Results indicate that the exercise-induced lymphocyte subset reduction is transient and suggest that it is more dependent upon training intensity than volume, and the training order of exposure to the high-intensity stimulus may determine the magnitude of subsequent responses.     

Expression of E1AF, an ets-family transcription factor, is correlated with the invasive phenotype of oral squamous cell carcinoma

PURPOSE: To assess the accuracy of intraarterial measurement of transstenotic pressure gradients for the detection of hemodynamically suboptimal iliac angioplasty. METHODS: In 14 patients, referred for diagnostic angiography, mean pressure gradients in the aorta and iliac artery were obtained twice, using a double-sensor pressure catheter. Additional iliac measurements were performed during pharmacologically induced flow augmentation. Repeatability was assessed by calculation of the mean difference plus standard deviation (MD +/- SD) and repeatability coefficient (2 x SD). These results were extrapolated to 137 iliac angioplasty procedures with secondary stenting where there was a residual pressure gradient > 10 mmHg. RESULTS: MD +/- SD for repeated measurements at rest and during flow augmentation were 0 +/- 2 mmHg and 1 +/- 3 mmHg, respectively. Repeatability coefficients were 3 and 6 mmHg. Mean pressure gradients after hemodynamically insufficient angioplasty were 8 +/- 7 mmHg at rest and 17 +/- 5 mmHg following vasodilatation. Inaccurate pressure recordings may have led to inappropriate stent placement in less than 2.5%, and inappropriate denial of stent placement in less than 5% of the lesions. CONCLUSION: Variability of intraarterial pressure measurements has little consequence in the detection of hemodynamically significant stenosis after angioplasty.     

Hemodynamic effects of warm bathing in a Hubbard tank and exercise loading in patients after myocardial infarction

Hemodynamic parameters were measured during bathing and exercise testing in 43 patients with myocardial infarction (mean age: 60.2 years) to investigate the predictive parameters to determine when patients could safely resume bathing. Patients took a fresh water bath at 42 degrees C in the supine position for 5 min in a Hubbard tank. Group A showed an elevation of pulmonary capillary wedge pressure (PCWP) during bathing of 10 mmHg or more (23 patients, mean age: 61.7 years) and group B showed an elevation of less than 10 mmHg (20 patients, mean age: 60.5 years). Continuous multistep exercise tests were performed with a bicycle ergometer in the supine position, and hemodynamic parameters were measured at up to 50 W for 3 min on the day before the warm bathing test. There were no significant differences in the changes of arterial pressure and heart rate between the two groups. The PCWP at 3 min with a load of 50 W was significantly higher in group A (26.9 +/- 9.0 mmHg) than in group B (16.7 +/- 9.1 mmHg, p < 0.01). The stroke index (SI) during exercise testing was significantly lower in group A than in group B. The difference in the stroke index from baseline values (delta SI) at 3 min with a load of 50 W was significantly lower in group A (3.5 +/- 5.5 ml/m2/beat) than in group B (10.6 +/- 7.0 ml/m2/beat, p < 0.01). Similarly, delta CI and delta oxygen pulse during testing were significantly lower in group A than in group B. The physical work capacity and ejection fraction of the left ventricle of group A were significantly lower than those of group B, whereas the left ventricular end-diastolic pressure was higher in group A than in group B. CI, delta CI, SI, delta SI, METs, oxygen pulse, and delta oxygen pulse were examined by regression analysis and multivariate analysis to predict a significant elevation of delta PCWP during bathing. delta SI (p = 0.0032), delta CI (p = 0.0094), delta SI + METs (p = 0.0051), delta CI + METs (p = 0.0061), delta CI + delta SI (p = 0.0084), and delta CI + delta SI + METs (p = 0.0093) showed the highest correlations with delta PCWP. These findings suggest that changes in delta CI, delta SI, and METs are good predictive parameters for determining when patients may safely resume bathing. We suggest that patients with myocardial infarction, reduced cardiac function and a physical work capacity of approximately 4.0 METs, delta SI: 5 ml/m2/beat and delta CI: 2.4 l/min/m2 resume bathing only after careful consideration.     

Vitamin D metabolism is altered in Asian Indians in the southern United States: a clinical research center study

In order to define precisely the relation between descending monoaminergic systems and the motor system, we measured in the ventral horn of spinal cord of adult rats the variations of extracellular concentrations of 5-HT, 5-HIAA, DA and MHPG. Measurements were performed during rest, endurance running on a treadmill, and a post-exercise period, with microdialysis probes implanted permanently for 45 days. We found a slight decrease in both 5-HT and 5-HIAA during locomotion with a more marked decrease during the post-exercise period compared to the mean of rest values. In contrast, the concentration of DA and MHPG increased slightly during the exercise and decreased thereafter. These results, when compared with those of a previous study, which measured monoamines in the spinal cord white matter [C. Gerin, D. Bécquet, A. Privat, Direct evidence for the link between monoaminergic descending pathways and motor activity: I. A study with microdialysis probes implanted in the ventral funiculus of the spinal cord, Brain Res. 704 (1995) 191-201], highlight the complex regulation of the release of monoamines that occurs in the ventral horn.     

Relationship between 800-m running performance and accumulated oxygen deficit in middle-distance runners

PURPOSE: To determine whether there is a significant relationship between accumulated oxygen deficit (AOD) and 800-m running performance in a group of runners of homogeneous ability. METHODS: Nine well-trained male middle and long distance runners (age = 24.7 +/- 4.5 yr, body mass = 69.4 +/- 8.5 kg, VO2max = 64.8 +/- 4.5 mL.kg-1.min-1) underwent treadmill testing to determine maximum oxygen uptake (VO2max), running economy (RE) at 1% and 10.5% treadmill gradient, and AOD at 1% and 10.5% treadmill gradient; 800-m running performance was determined by time trials on an outdoor 440-yd track, for which the average time was 132 +/- 4 s. For the AOD test, subjects were required to run on the treadmill at supramaximal speeds until volitional exhaustion. The AOD value was calculated using linear (LIN) and curvilinear (CUR) extrapolation procedures. RESULTS: Mean AOD values using LIN and CUR were 45.0 +/- 6.9 and 59.3 +/- 10.1 mL.kg-1 at a 1% treadmill gradient and 63.2 +/- 10.6 and 93.6 +/- 19.7 mL.kg-1 at a 10.5% gradient, respectively. No significant relationship was found between 800-m run time and AOD at 1% gradient or 10.5% gradient or when AOD was estimated from a linear or curvilinear fit of the VO2 data. Other variables measured in this study (e.g., VO2max and running economy) were not found to be predictive of 800-m run time. CONCLUSION: Among a homogeneous group of well-trained male middle- and long-distance runners, AOD measured at a 1% and 10.5% treadmill gradient is not significantly related to 800-m running performance.     

Predicting competition performance in long-distance running by means of a treadmill test

PURPOSE: The purpose of this study was to examine the power of 16 parameters beside the individual anaerobic threshold (IAT) in predicting performance in various competition distances. METHODS: This study examined 427 competitive runners to test the prediction probability of the IAT and other parameters for various running distances. All runners (339 men, 88 women; ages, 32.5 +/- 10.14 yr; training, 7.1 +/- 5.53 yr; training distance, 77.9 +/- 35.63 km.wk-1) performed an increment test on the treadmill (starting speed, 6 or 8 km.h-1; increments, 2 km.h-1; increment duration, 3 min to exhaustion). The heart rate (HR) and the lactate concentrations in hemolyzed whole blood were measured at rest and at the end of each exercise level. The IAT was defined as the running speed at a net increase in lactate concentration 1.5 mmol.L-1 above the lactate concentration at LT. RESULTS: Significant correlations (r = 0.88-0.93) with the mean competition speed were found for the competition distances and could be increased using stepwise multiple regression (r = 0.953-0.968) with a set of additional parameters from the training history, anthropometric data, or the performance diagnostics. CONCLUSIONS: The running speed at a defined net lactate increase thus produces an increasing prediction accuracy with increasing distance. A parallel curve of the identity straight lines with the straight lines of regression indicates the independence of at least a second independent performance determining factor.     

The simultaneous comparison of acetylene or carbon dioxide flux as a measure of effective pulmonary blood flow in children

Both acetylene (Ac) and carbon dioxide can be used to measure effective pulmonary blood flow (Q'eff) noninvasively. They are safe and reasonably accurate in adults during rest and exercise, but there have been no simultaneous comparisons in children. One hundred and six healthy children (55 males and 51 females, aged 8-17 yrs) were studied using an Innovision quadrupole mass spectrometer. They all underwent five rebreathing manoeuvres at rest, and then single measurements were again taken after 9 min of bicycle exercise. Mixed venous CO2 levels were calculated either by a linear (L) or curvilinear (C) extrapolation method. At rest, the coefficients of variation for Q'eff were Ac 8%, L 20%, and C 16% (p<0.001). The median resting values were: Ac 3.2 (95% confidence interval (95% CI) 3.1-3.4) L 5.1 (95 % CI 4.6-5.4) and C 4.7 (95 % CI 4.3-5.1) L x min(-1) x m(-2), (p<0.001). Compared to Ac, only 14 and 17% of L and C values, respectively, were +/-0.5 L x min(-1) x m(-2), whilst 41 and 29%, respectively were more than +/-2 L x min(-1) x m(-2). During exercise, median values were: Ac 6.7 (95% CI 6.3-7.0); L 8.0 (95% CI 7.3-8.4); and C 7.2 (95% CI 6.5-7.9) L x min(-1) x m(-2). L was significantly greater than C (p<0.001), but C was similar to Ac (p=0.06). More than 50% of L and C values could not be calculated for various reasons, whereas all 106 Ac values could be calculated. Neither carbon dioxide method is sufficiently reliable to be used in children in a clinical setting. Acetylene was safe, reliable, accurate and preferred.     

Hidden chromosome abnormalities in a primary central nervous system lymphoma detected by multicolor spectral karyotyping

The purpose of this study is to critically investigate the anatomy of the deep posterior compartment of the leg. Specifically, the relationship of the deep posterior compartment to the superficial posterior compartment and their insertion onto the posteromedial border of the tibia are assessed. Cross-sectioning of 10 fresh-frozen cadaver legs was performed at 2-cm increments. The inferior surface of each section was photographed. The photographs were visually analyzed, and the fascial separation between the posterior compartments along with their relationship to the posteromedial border of the tibia were recorded for each specimen. Magnetic resonance images in the axial plane of 10 healthy, normal volunteers' lower extremities at 2-cm increments were obtained and analyzed. All specimens and images demonstrated that the medial fascial attachment of the deep posterior compartment was along the posteromedial aspect of the tibia in the proximal third of the leg and was not superficially accessible. In the proximal third of the leg, the superficial posterior compartment fascial attachment overlapped the deep posterior compartment by inserting medial and anterior to the deep posterior compartment fascial attachment. In the middle and distal thirds of the leg, the medial fascial attachment of the deep posterior compartment shifted medially and anteriorly, making the deep posterior compartment superficially accessible. The surgeon must appreciate the change in the anatomic relationships along the medial side of the leg while performing double-incision four-compartment fasciotomy release to obtain a complete release of the muscular portion of the deep posterior compartment.     

Relationship between iodine-123-beta-methyl-p-iodophenyl-pentadecanoic acid washout ratio and oxygen consumption in normal and ischemic myocardium

The relationship between oxygen consumption and iodine-123-beta-methyl-p-iodophenyl-pentadecanoic acid (123I-BMIPP) washout at rest and after exercise was investigated in normal and ischemic myocardium. Sixteen healthy volunteers and 14 patients with ischemic heart disease were examined. After injection of 111MBq of 123I-BMIPP, serial single photon emission computed tomography imaging was performed to evaluate washout ratio after 30 min and 1 hour of rest and after exercise. In the volunteers, the mean washout ratio was 3.3 +/- 3.5% after 1 hour of rest and increased during exercise. The exercise washout ratio showed a better correlation with net pressure rate product (net PRP: cumulative values of PRP during exercise) than with the peak PRP. The exercise washout ratio showed a strong correlation with the net PRP in the range from 180 to 300 x 10(3) mmHg. beat/min and a plateau of 10-15%. In the nine ischemic patients with net PRP > or = 300 x 10(3) mmHg.beat/min, the exercise washout ratio values were significantly elevated in normal segments relative to ischemic segments (10.1 +/- 1.9% vs 4.7 +/- 2.9%, p < 0.001). In the five ischemic patients with net PRP < 300 x 10(3) mmHg.beat/min, washout ratio at rest and after exercise did not differ significantly between normal and ischemic segments. 123I-BMIPP washout ratio increased with increased oxygen consumption during exercise in normal myocardium but not in ischemic myocardium. The patient must exercise before fatty acid metabolism can be compared between normal and ischemic myocardium.     

Histochemical and laser scanning microscopy characterization of the hydroxyapatite-bone interface: an experimental study in rabbits

OBJECTIVES: To assess the relationship between haematocrit and risk of stroke. DESIGN: Prospective study of a cohort of men followed up for 9.5 years. SETTING: General practices in 24 towns in England, Scotland and Wales (British Regional Heart Study). SUBJECTS: A total of 7735 men aged 40-59 years at screening, selected at random from one general practice in each of 24 towns. MAIN OUTCOME MEASURES: Fatal and non-fatal strokes. RESULTS: During a follow-up period of 9.5 years for all men there were 123 stroke events (33 fatal) in the 7346 men in whom the haematocrit level had been determined. In the cohort as a whole, risk of stroke was significantly raised at haematocrit levels > or = 51% (relative risk [RR] = 2.5; 95% confidence intervals [CI] 1.2-5.0) after adjustment for age, social class, smoking, body mass index, physical activity, presence of diabetes and pre-existing ischaemic heart disease. Further adjustment for systolic blood pressure did not attenuate this association (RR = 2.4; 95% CI 1.2-4.9). A raised haematocrit was associated with an increase of stroke only in men with hypertension (systolic blood pressure > or = 160 mmHg or diastolic blood pressure > or = 90 mmHg or on regular antihypertensive treatment). No increased risk of stroke was seen at the higher haematocrit level (> or = 51%) in normotensive men. At haematocrit levels below 51%, hypertension was associated with a three-fold increase in risk of stroke compared with normotension (RR = 3.4, 95% CI 2.3, 5.1). At haematocrit levels > or = 51%, hypertension was associated with a nine-fold increase in risk of stroke compared with normotension (RR = 9.3; 95% CI 4.2, 21.0). Exclusion of men receiving regular antihypertensive therapy did not alter the strong associations seen. CONCLUSION: The data suggest that an elevated haematocrit is an independent risk factor for stroke and that it interacts synergistically with elevated blood pressure.     

Biomechanics of walking, running, and sprinting

A biomechanical study of 13 runners which consisted of 2 male sprinters, 5 experienced joggers, and 6 elite long-distance runners were studied. We obtained hip, knee, and ankle joints motions in the sagittal plane and electromyographic data from specific muscle groups. As the speed of gait increased, the length of stance phase progressively decreased from 62% for walking to 31% for running and to 22% for sprinting. The sagittal plane motion increased as the speed of gait increased. Generally speaking, the body lowers its center of gravity with the increased speed by increasing flexion of the hips and knees and magnifying dorsiflexion at the ankle joint. Electromyographic activity about the knee demonstrated increased activity in the quadricep muscle group and hamstring group with increased speed. Muscle function about the ankle joint demonstrated that the posterior calf musculature which normally functions during the midstance phase in walking became a late swing phase muscle and was active through the first 80% of stance phase, as compared to 15% in walking. Beside the changes in the electromyographic activity of the muscles, the anterior compartment muscles of the calf undergo a concentric contracture at the time of initial floor contact during running and sprinting but undergo an eccentric contraction during walking.     

Filling and arterial pressures as determinants of RV stroke volume in the sheep fetus

Right ventricular (RV) function was investigated in nine fetal lambs (125-130 days gestation) that were instrumented with pulmonary artery electromagnetic flow sensors and vascular catheters. Control arterial CO2 and O2 tension, pH, and hematocrit values were 46.1 +/- 1.6 (SD) Torr, 20.6 +/- 1.8 Torr, 7.39 +/- 0.02, and 31 +/- 5.3%, respectively. Control values for right ventricular output (247 +/- 75 ml X min-1 X kg-1), stroke volume (SV, 1.5 +/- 0.4 ml X kg-1), right atrial pressure (3.7 +/- 1.2 mmHg), heart rate (166 +/- 18 beats X min-1), and arterial pressure (AP, 43 +/- 4 mmHg) were unchanged by administration of atropine and propranolol. Withdrawal and infusion of fetal blood with or without concomitant infusion of nitroprusside or phenylephrine produced RV function curves at low, normal, and high arterial pressures. All function curves had a steep ascending limb and a plateau. The breakpoint joining the limbs of the control curve was right atrial pressure 3.4 +/- 1.2 mmHg and SV 1.5 +/- 0.4 ml X kg-1. Increased AP shifted the breakpoint downward. Linear regression of SV on AP from 15 to 95 mmHg at right atrial pressure greater than breakpoint was SV = -0.016 ml X kg-1 mmHg-1 X AP + 2.25 ml X kg-1.     

Media sclerosis: a case of pseudohypertension

A 51-year-old diabetic showed symptoms of a hypertensive crisis with a systolic blood pressure above 300 mmHg. The antihypertensive therapy failed and the Doppler-pressure values were also too high for all limb arteries. Duplex-sonography and soft-x-ray examination showed a mediasclerosis of arms and legs. The true pressure, measured at the still compressable arteries of the fingers was relatively low. There was symptomatic improvement after completion of the antihypertensive therapy.     

Pacing in hypertrophic obstructive cardiomyopathy. A randomized crossover study. PIC Study Group

BACKGROUND: Uncontrolled studies have shown that short atrioventricular delay dual chamber pacing reduces outflow tract obstruction in hypertrophic obstructive cardiomyopathy. Although the exact mechanism of this beneficial effect is unclear, this seems a promising potential new treatment for hypertrophic obstructive cardiomyopathy. METHOD: In order to evaluate the impact of pacing therapy, were performed a randomized multicentre double-blind cross-over (pacemaker activated vs non activated) study to investigate modification of echocardiography, exercise tolerance, angina, dyspnoea and quality of life in 83 patients with a mean age of 53 (range 22-87) years with symptoms refractory or intolerant to classical drug treatment. RESULTS: After 12 weeks of activated or inactivated pacing, independent of which phase was first, the pressure gradient fell from 59 +/- 36 mmHg to 30 +/- 25 mmHg (P < 0.001) with active pacing. Exercise tolerance improved by 21% in those patients who at baseline tolerated less than 10 min of Bruce protocol; symptoms of dyspnoea and angina also improved significantly from NYHA class 2.4 to 1.4 and 1.0 to 0.4, respectively (P < 0.007). Quality of life assessment with a validated questionnaire objectivated the subjective improvement. CONCLUSION: Pacemaker therapy is of clinical and haemodynamic benefit for patients with hypertrophic obstructive cardiomyopathy, left ventricular outflow gradient at rest over 30 mmHg who are symptomatic despite drug treatment.     

Running intensity as determined by heart rate is the same in fast and slow runners in both the 10- and 21-km races

The aims of this study were to determine (1) whether running speed is directly proportional to heart rate (HR) during field testing and during 10- and 21-km races, and (2) whether running intensity, as estimated from HR measurements, differs in 10- and 21-km races and between slow and fast runners at those running distances. Male runners were divided into a fast (65-80 min for 21 km; n = 8) or slow (85-110 min for 21 km; n = 8) group. They then competed in 10- and 21-km races while wearing HR monitors. All subjects also ran in a field test in which HR was measured while they ran at predetermined speeds. The 10-km time was significantly less in the fast compared with the slow group (33:15 +/- 1:42 vs 40:07 +/- 3:01 min:s; mean +/- S.D.), as was 21-km time (74:19 +/- 4:30 vs 94:13 +/- 9:54 min:s) (P < 0.01). Despite the differences in running speed, the average running intensity (%HRmax) for the fast and slow groups in the 10-km race was 90 +/- 1 vs 89 +/- 3% and in the 21-km race 91 +/- 1 vs 89 +/- 2%, respectively. In addition, %HRmax was consistently lower in the field test at the comparative average running speeds sustained in the 10-km (P < 0.01) and 21-km (P < 0.001) races. Hence, factors in addition to work rate or running speed influence the HR response during competitive racing. This finding must be considered when running intensity for competitive events is prescribed on the basis of field testing performed under non-competitive conditions in fast and slow runners.     

Agreement on titles and qualifications ... first reports!]

The significance of exercise-induced hypertensive blood pressure values is poorly known. The present study has looked for a correlation between hypertensive systolic blood pressure values on exercise in a normotensive population and later development of hypertension at rest. After elimination of patients with hypertension at rest and of patients lost to the follow-up, this study includes 74 normotensive subjects who had developed exertional hypertension (blood pressure superior to 220/95 mmHg) during exercise testing. At the end of an average follow-up of six years, 40.5% of these patients are showing hypertension at rest. Thus hypertensive blood pressure values on exercise in a normotensive subject is an important finding. It should lead to an adaptation of diet and life style and to regular blood pressure controls.     

Radiation exposure of the population by roentgen diagnosis. II. The collective effective dosage of the population in former East Germany caused by 1987/1988 roentgen diagnosis

OBJECTIVES: To examine the relations between the development of neurologic events and the following variables: degree of stenosis of the contralateral carotid artery, prior neurologic symptoms and stump pressure of the ipsilateral internal carotid artery in patients undergoing carotid endarterectomy under regional anesthesia. PATIENTS AND METHODS: We undertook a prospective study of 92 patients undergoing carotid endarterectomy with a blockade of the superficial and deep cervical plexus. Neurological integrity was assessed and internal carotid artery stump pressure was monitored. Contralateral carotid artery stenosis and neurologic disease present before surgery were studied. RESULTS: Neurologic events developed when the carotid artery was clamped in 9.7% of patients. Mean stump pressure was significantly lower in symptomatic patients (43 +/- 11 mmHg) than in asymptomatic patients (74.6 +/- 24 mmHg) (p < 0.001). Neurologic symptoms developed during clamping of the carotid in 27.2% of the patients with stump pressure less than or equal to 50 mmHg, but in only 4.2% of those with stump pressure surpassing 50 mmHg. Stump pressure was significantly lower in patients with contralateral carotid stenosis. The incidence of neurologic events during clamping was unrelated to contralateral carotid condition, however. Likewise, neurologic symptoms before surgery was also unrelated. In six of the nine patients with neurologic events, internal carotid stump pressure was less than or equal to 50 mmHg, indicating that the sensitivity of this parameter to the development of neurologic events in our series was 66%. CONCLUSIONS: Although internal carotid artery stump pressure identifies a subset of patients likely to have a higher incidence of neurologic events during carotid artery clamping, it can not be considered the only criterion for placement of an intraluminal shunt to prevent such events. The state of the contralateral carotid artery and preexisting neurologic symptoms are not objective screening criteria for identifying patients at high risk of neurologic events during carotid clamping.