Hyperbaric oxygen therapy attenuates central sensitization induced by a thermal injury in humans.

BACKGROUND: Hyperbaric oxygen (HBO2 ) treatment has in animal experiments demonstrated antinociceptive effects. It was hypothesized that these effects would attenuate secondary hyperalgesia areas (SHAs), an expression of central sensitization, after a first-degree thermal injury in humans. METHODS: Seventeen healthy volunteers were examined during two sessions using a randomized crossover design. Volunteers were studied during control conditions (ambient pressure, FI O2 = 0.21) and during HBO2 (2.4 standard atmosphere, FI O2 = 1.0, 90 min) conditions in a pressure chamber. Quantitative sensory testing, including assessment of SHAs was performed. RESULTS: A statistically significant overall attenuation of SHAs was seen during the HBO2 sessions compared with the control-sessions (P = 0.011). In the eight volunteers starting with the HBO2 session, no difference in SHAs compared with control was demonstrated. However, in the nine volunteers starting with the control session, a statistical significant attenuation of SHAs was demonstrated in the HBO2 session (P = 0.004). CONCLUSIONS: The results indicate that HBO2 therapy in humans attenuates central sensitization induced by a thermal skin injury, compared with control. These new and original findings in humans corroborate animal experimental data. The thermal injury model may give impetus to future human neurophysiological studies exploring the central effects of hyperbaric oxygen treatment.

Heart valve disease associated with treatment with ergot-derived dopamine agonists: a clinical and echocardiographic study of patients with Parkinson's disease.

OBJECTIVE: To elucidate the association between treatment with ergot-derived dopamine agonists (EDDA) and valvular abnormalities amongst patients with idiopathic Parkinson's disease (IPD) and secondly, to analyse the yield of clinical screening for valvular heart disease. DESIGN: A cross-sectional controlled study. SETTING: The cohort of IPD patients treated in the outpatient clinic, Department of Neurology, Aarhus University Hospital, Denmark. SUBJECTS: A total of 138 IPD patients [median age 64 (39-87) years, 62% men] treated with either EDDA (n = 85) or non-EDDA (n = 53) for at least 6 months. Interventions. Patients were screened for valvular heart disease by clinical means and by examiner-blinded echocardiography. Main outcome measure was valvular regurgitation revealed by echocardiography. RESULTS: Severe aortic regurgitation (n = 4) or moderate aortic (n = 12), mitral (n = 3) or tricuspidal valve regurgitation (n = 5) was found in 22 EDDA patients (25.9%). Two patients had coexistent moderate mitral and tricuspid valvular regurgitation. Two non-EDDA patients had moderate valve insufficiency (3.8%, P < 0.05). The adjusted relative risk for at least moderate valve insufficiency in the EDDA patients was 7.2% (P < 0.05). The sensitivity of detecting at least moderate valvular disease by cardiac murmur, dyspnoea, or the heart failure marker NT-proBNP (natriuretic peptide) was 62% for the neurologists and 93% for the cardiologist but with equally low specificity (30-35%). CONCLUSION: EDDA was associated with a clinically important and statistically significant risk of at least moderate valve regurgitation. Clinical screening for valve disease was inadequate and it seems advisable to offer EDDA patients control with echocardiography.

C-reactive protein, heart rate variability and prognosis in community subjects with no apparent heart disease.

OBJECTIVES: Increased C-reactive protein (CRP) and reduced heart rate variability (HRV) both indicate poor prognosis. An inverse association between HRV and CRP has been reported, suggesting an interaction between inflammatory and autonomic systems. However, the prognostic impact of this interaction has not been studied. We thus investigated the prognostic impact of CRP, HRV and their combinations. DESIGN: Population-based study. SUBJECTS: A total of 638 middle-aged and elderly subjects with no apparent heart disease from community. METHODS: All were studied by clinical and laboratory examinations, and 24-h Holter monitoring. Four time domain measures of HRV were studied. All were prospectively followed for up to 5 years. RESULTS: Mean age was 64 years (55-75). During the follow-up, 46 total deaths and 11 cases of definite acute myocardial infarction were observed. Both CRP and three of four HRV measures were significantly associated with increased rate of death or myocardial infarction. In a Cox model with CRP >or=2.5 microg mL(-1), standard deviation for the mean value of the time between normal complexes

Effect of organic loading rate on a wastewater treatment process combining moving bed biofilm and membrane reactors.

The effect of moving bed biofilm reactor (MBBR) loading rate on membrane fouling rate was studied in two parallel units combining MBBR and membrane reactor. Hollow fiber membranes with molecular weight cut-off of 30 kD were used. The HRTs of the MBBRs varied from 45 min to 4 h and the COD loading rates ranged from 4.1 to 26.6 g COD m(-2) d(-1). The trans-membrane pressure (TMP) was very sensitive to fluxes for the used membranes and the experiments were carried out at relatively low fluxes (3.3-5.6 l m(-2) h(-1)). Beside the test with the highest flux, there were no consistent differences in fouling rate between the low- and high-rate reactors. Also, the removal efficiencies were quite similar in both systems. The average COD removal efficiencies in the total process were 87% at 3-4 h HRT and 83% at 0.75-1 h HRT. At high loading rates, there was a shift in particle size distribution towards smaller particles in the MBBR effluents. However, 79-81% of the COD was in particles that were separated by membranes, explaining the relatively small differences in the removal efficiencies at different loading rates. The COD fractionation also indicated that the choice of membrane pore size within the range of 30 kD to 0.1 microm has very small effect on the COD removal in the MBBR/membrane process, especially with low-rate MBBRs.

High-rate wastewater treatment combining a moving bed biofilm reactor and enhanced particle separation.

Many cities around the world are looking for compact wastewater treatment alternatives since space for treatment plants is becoming scarce. In this paper development of a new compact, high-rate treatment concept with results from experiments in lab-scale and pilot-scale are presented. The idea behind the treatment concept is that coagulation/floc separation may be used to separate suspended and colloidal matter (resulting in > 70% organic matter removal in normal wastewater) while a high-rate biofilm process (based on Moving Bed biofilm reactors) may be used for removing low molecular weight, easily biodegradable, soluble organic matter. By using flotation for floc/biomass separation, the total residence time for a plant according to this concept will normally be < 1 hour. A cationic polymer combined with iron is used as coagulant at low dosages (i.e. 1-2 mg polymer/l, 5-10 mg Fe/l) resulting in low sludge production (compared to conventional chemical treatment) and sufficient P-removal.

Neuroendocrine testing in community patients with heart disease: plasma N-terminal proatrial natriuretic peptide predicts morbidity and mortality stronger than catecholamines and heart rate variability.

BACKGROUND: Patients with heart disease are at risk of developing congestive heart failure (CHF). Neurohormonal activation may make an important contribution. AIM: In stable heart patients from primary care, to examine neuroendocrine markers of cardiac performance for the association to cardiac dysfunction, morbidity and mortality. METHODS: Plasma N-terminal atrial natriuretic peptide (N-ANP), catecholamines, 24-h ECG and blood pressure, serum urea and creatinine, echocardiography, chest X-ray and physical examination were performed. Death was recorded during 5 to 7 years of follow-up. RESULTS: The study included 56 patients. Mean age was 71 years, 54% were men, 43% had clinical signs of CHF, 39 + 52 + 9% were in NYHA I + II + III, 34% had echocardiographic cardiac dysfunction, and 18 died during follow-up. N-ANP was related to all subtypes of cardiac dysfunction (p < 0.05). Catecholamines and premature ventricular captures (PVC) were related to valvular and systolic dysfunction, but heart rate variability and dipping blood pressure were not (p > 0.05). On multivariate analyses only, N-ANP and PVC were associated with clinical signs of CHF, echocardiographic cardiac dysfunction, and mortality (p < 0.05). CONCLUSIONS: Plasma N-ANP was stronger than catecholamines and variables of 24-h monitoring (blood pressure and electrocardiogram) in predicting morbidity and mortality, thereby supporting the use of cardiac natriuretic peptides (i.e. N-ANP, BNP, or N-BNP) as the most valuable biomarker in community patients at risk of CHF.

Relationship between nocturnal hypoxaemia, tachycardia and myocardial ischaemia after major abdominal surgery.

BACKGROUND: Episodic hypoxaemia, cardiac arrhythmias, and myocardial ischaemia may be related after major abdominal surgery. METHODS: We studied 52 patients on the second and third nights after major abdominal operations, using continuous pulse oximetry and Holter ECG. We recorded the amount of time spent with oxygen saturation values less than 90, 85, and 80% during the night, and noted episodes of hypoxaemia, tachycardia, bradycardia, and ST-segment changes. RESULTS: In 87 study nights there were 2403 (individual range 1-229) episodes of hypoxaemia, 3509 (individual range 1-234) episodes of tachycardia, and 265 (individual range 1-73) episodes of ST segment deviation. Of the 52 patients, 50 had episodes of hypoxaemia and tachycardia, and 19 patients had one or more episodes of ST segment deviation. For 38% of the episodes of ST deviation, there was an episode of hypoxaemia at the same time and in 16% there was an episode of tachycardia. ST deviation was only noted in 4% of the episodes of hypoxaemia and in 1% of the episodes of tachycardia. CONCLUSION: Episodes of hypoxaemia and tachycardia frequently occur together after surgery but are rarely associated with ST deviation. Hypoxaemia or tachycardia is often present at the same time as ST deviation occurs.

Health Behaviour in School-aged Children (HBSC) study: international report from the 2001 / 2002 survey

This report covers the physical, emotional and psychological aspects of health, and the influences of the family, schools and peers on young people aged 11, 13 and 15 years in 35 countries and regions in the WHO European Region and North America, and gives comprehensive cross-national data on health and well-being, smoking, alcohol consumption, physical activity and sedentary behaviour, eating habits and body image, oral health, bullying and fighting, injuries, cannabis use, and sexual health. Document in pdf format; Acrobat Reader required.

Prolonged signal-averaged P wave duration after elective cardioversion increases the risk of recurrent atrial fibrillation.

OBJECTIVE: To assess the risk of atrial fibrillation (AF) recurrence after elective cardioversion of AF in relation to the signal-averaged P wave duration (SAPWD), clinical characteristics of the patient, and the duration of the AF disease. DESIGN: We studied 131 consecutive patients (88 men, 43 women), median age 67 years (range 29-87 years), after elective cardioversion of AF into sinus rhythm. The SAPWD was measured on inclusion, and the follow-up period was 1 month. Recurrent AF within the first month after cardioversion was regarded as endpoint. RESULTS: AF recurred in 73 patients (56%). Multiple logistic regression analysis showed that prolonged SAPWD above 160 ms was the only significant risk factor for recurrent AF, OR=2.22 (95% CI 1.07-4.60), p=0.03. There was no significant effect of age, diagnosed hypertension, diagnosed congestive heart failure, dilated left atrium, or long duration of AF on the risk of AF relapse. CONCLUSION: Prolonged SAPWD above 160 ms is a risk factor for recurrent AF after elective cardioversion of persistent AF.

Left ventricular dysfunction in normotensive Type 1 diabetic patients: the impact of autonomic neuropathy.

AIMS: The pathophysiological mechanisms responsible for increased cardiovascular mortality in diabetic autonomic neuropathy (AN) are largely unknown. The aim was to determine the relative role of AN in the pathogenesis of cardiac diastolic dysfunction and left ventricular hypertrophy in Type 1 diabetes. METHODS: Ten Type 1 diabetic patients with AN, defined by cardiovascular tests (AN+) and 10 age- and sex-matched patients without neuropathy (AN-) as well as 10 healthy subjects (C) participated in the study. Left ventricular diastolic function was assessed by Doppler echocardiography, whilst systolic function was evaluated by cine magnetic resonance (MR) imaging. RESULTS: Doppler echocardiography showed a significant decrease in E/A ratio, i.e. the ratio between peak Early transmitral filling velocity during early diastole (E-wave) and peak transmitral Atrial filling velocity during late diastole (A-wave), in AN+ compared with C (P < 0.01) [0.95 +/- 0.08 (mean +/- sem) (AN+); 1.19 +/- 0.09 (AN-); 1.33 +/- 0.10 (C)]. The E-wave deceleration time was significantly shorter in AN+ compared with AN- and C (P < 0.02) [178 +/- 7 ms (AN+); 203 +/- 9 ms (AN-); 205 +/- 9 ms (C)]. Cine MR imaging showed a significantly greater left ventricular mass index in AN+ compared with C [103 +/- 4 g/m(2) (AN+) vs. 98 +/- 7 (AN-) and 92 +/- 4 g/m(2) (C), P < 0.05]. CONCLUSION: Autonomic neuropathy is associated with left ventricular hypertrophy and diastolic dysfunction in Type 1 diabetic patients.

A high-rate secondary treatment based on a moving bed bioreactor and multimedia filters for small wastewater treatment plants.

For small wastewater treatment plants (WWPTs), high-rate secondary treatment systems with good treatment efficiency and easy, stable, and robust operation are called for. In this paper an experimental study on a high rate secondary treatment based on moving bed biofilm reactor (MBBR) and multimedia filters is presented. A high rate MBBR converts easily biodegradable SCOD in short HRT (0.5 h) directly after screening, then a Kaldnes-Filtralite-Sand (KFS) filter removes the particulate COD and detached biofilms at filtration rates of 10-20 m/h. The whole system gave effluent SS and COD less than 30 mg/L and 100 mg/L when total detention time is less than 1 h and small dosage of chemicals (iron and/or cationic polymer) is used. A new scenario of high rate secondary system with a primary Kaldnes coarse media filter in front of high rate MBBR and the KFS filter is proposed and discussed. This scenario with total HRT less than 2h is more suitable for high influent SS concentrations and may also be extended for nitrogen and phosphorous removal. Compared to conventional secondary treatment, the high rate secondary treatment will be using only 1/5-1/10 of the space, resulting in considerable savings for construction, energy and operation.

Endoscopic retrograde cholangiopancreatography causes reduced myocardial blood flow.

BACKGROUND AND STUDY AIMS: Previous studies have shown that up to 50% of healthy patients may develop ST-segment changes during upper gastrointestinal endoscopy. The aim of the study was to evaluate myocardial blood flow in patients during endoscopic retrograde cholangiopancreatography (ERCP). PATIENTS AND METHODS: 11 patients scheduled for ERCP were monitored with a Holter tape recorder and underwent myocardial perfusion scintigraphies, to evaluate myocardial perfusion at rest and during ERCP. RESULTS: Ten patients completed the study. Eight patients had no sign of myocardial ischemia with either of the two methods, while two patients developed signs of ischemia during ERCP with both the Holter tape recording and on myocardial scintigraphy (P = 0.02). CONCLUSIONS: Patients undergoing ERCP may develop true myocardial ischemia with reduced myocardial blood flow. Although this is a small-scale study, these findings strongly support the use of alternative methods for diagnostic evaluation of the pancreatic duct and biliary tree.

Recovery of autonomic nervous activity after myocardial infarction demonstrated by short-term measurements of SDNN.

OBJECTIVE: Heart rate variability (HRV) has been demonstrated to be a risk factor after acute myocardial infarction (AMI). In the present study serial measurement of SDNN (standard deviation of the mean of qualified NN-interval) in short intervals was used to assess HRV changes after AMI, and determine the role of these as independent risk factors compared to clinical, arrhythmic, ischemic and anamnestic variables. Measurements from a normal healthy middle-aged male population were used as reference (n = 63). METHODS: SDNN from a five-minute period during day and night-time, respectively, was examined in 103 patients 1 week (n = 54), 1 month (n = 72) and 12-16 months (n = 54) after infarction. RESULTS: Day SDNN did not change during one-and-a-half years after AMI, and was significantly reduced compared with healthy males. Night SDNN, low after 1 week, with recovery 1 month after AMI, was significantly reduced compared with healthy males early, but not late after AMI. Thus, the study indicated during day-time a continuous abnormal sympathetic preponderance in the course of 16 months after AMI, and during night-time a gradual recovery of parasympathetic preponderance beginning early after AMI. CONCLUSION: One week after AMI day-time SDNN of <30 ms, and night-time SDNN of < 18 ms, age > or =60 years, and myocardial ischemia (Holter monitoring) were independent predictors of 9 years' mortality. One and 12-16 months after AMI reduced day and night-time SDNN had no prognostic implication.

Temporal changes in clinic and ambulatory blood pressure during cyclic post-menopausal hormone replacement therapy.

OBJECTIVE: Post-menopausal hormone replacement (HRT) might protect against cardiovascular disease, possibly by arterial vasodilation and reduced blood pressure. Progestogens are needed to avoid endometrial disease but vascular effects are controversial. The objective was to assess temporal changes in blood pressure (BP) by two measurement techniques during a cyclic hormone replacement regimen. DESIGN AND METHODS: Sixteen healthy and normotensive post-menopausal women (age 55 +/- 3 years) were studied in a placebo-controlled, randomized crossover study, and were randomized to 17beta-oestradiol plus cyclic norethisterone acetate (NETA) or placebo in two 12-week periods separated by a 3-month washout Clinic blood pressure was measured sitting by the same observer with a mercury manometer at four visits in each period. Twenty-four hour ambulatory blood pressure was measured at baseline and in the ninth weeks of treatment in both periods. RESULTS: Clinic systolic and diastolic BP were reduced after 10 days of oestradiol (-5.1 and -3.2 mmHg respectively, P < or = 0.05). After 9 weeks of cyclic HRT, prior to progestogen addition, clinic BP returned to baseline. During addition of NETA, diastolic blood pressure was again reduced (-3.6 mmHg, P= 0.037). Mean 24 h ambulatory systolic and diastolic blood pressures were significantly lower than clinic measurements (-15.7 and -5.9 mmHg, P < 0.001) but were unaffected by HRT. CONCLUSIONS: Clinic blood pressure is reduced during a cyclic HRT regimen but the reduction varies with the HRT regimen, which might explain the diversity in previous BP findings during HRT. Norethisterone acetate might possess additive blood pressure-lowering effects in postmenopausal women.

Blood pressure level and relation to other cardiovascular risk factors in male hypertensive patients without clinical evidence of ischemic heart disease.

Arterial hypertension is accompanied by increased morbidity and mortality and constitutes a substantial part of medical care. Antihypertensive intervention reduces the cardiovascular morbidity and mortality. The aims of the study were to evaluate the relationship between cardiovascular risk factors and the blood pressure (BP), and to evaluate the percentage of patients who had achieved a BP level as recommended by the sixth report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC VI). BP was evaluated in relation to age, body mass index, duration of hypertension, cholesterol and triglyceride level, smoking status, information of regular exercise, a family history of ischemic heart disease (IHD) and drug treatment, in 220 men treated for arterial hypertension. In the univariate analyses we found a higher systolic blood pressure (SBP) with older age, higher SBP in smoking patients and lower SBP in patients with regular exercise. In a multivariate model age (p = 0.0004), smoking status (p = 0.01) and regular exercise (p= 0.06) were independently associated with SBP. There was a lower diastolic blood pressure (DBP) with older age, and age was independently associated with DBP. Office SBP was above 140 mmHg in 83% and above 160 mmHg in 44% of patients. During ambulatory blood pressure monitoring (AMBP), SBP was above 135 mmHg in 40% and above 155 mmHg in 15% of patients. In addition to male sex and hypertension there was a high percentage of other cardiovascular risk factors--43% was smoking, 21% had a family history of IHD, 77% had a se-cholesterol above 5.5 mmol/l and 48% had a se-triglyceride above 1.6 mmol/l. In a consecutive group of asymptomatic male treated hypertensive patients SBP is independently associated with age and smoking status, and DBP with age. A high percentage of the patients do not have a well controlled BP, and a high percentage have additional risk factors such as smoking, hypercholesterolaemia, hypertriglyceridaemia and a family history of IHD. This means that there is room for much improvement in the control of hypertension.

Vagal withdrawal during endoscopic retrograde cholangiopancreatography.

BACKGROUND: Patients undergoing endoscopic retrograde cholangiopancreatography (ERCP) are at risk of developing cardiorespiratory complications, but the mechanism is still unknown. Treatment with metoprolol 2 h before the endoscopy has been shown to decrease the incidence of myocardial ischaemia during ERCP. The present study evaluated whether the endoscopic stress would decrease vagal tone and whether metoprolol given before the procedure could prevent this defence-like reaction. METHODS: Thirty-eight patients were randomized to receive either placebo or 100 mg metoprolol 2 h before ERCP. During ERCP the patients were monitored with a Holter tape recorder. Holter tapes from 31 patients (16 receiving metoprolol) were available to analyse the ratio of the standard deviations of the RR intervals (SDRR) to the mean RR intervals (measure of vagal tone) during ERCP. RESULTS: A decreased vagal tone during the ERCP was found, but we observed no difference between the metoprolol and the placebo group. For both groups the lowest vagal tone occurred at maximum heart rate during endoscopy. The SDRR/meanRR ratio returned towards base line for the subsequent 60 min after endoscopy. CONCLUSIONS: The existence of a defence-like reaction ('vagal withdrawal') during ERCP has been shown. Metoprolol given 2 h before the procedure did not affect the occurrence of this phenomenon. The interaction of other periendoscopic factors is still unclear and should be studied further.

Cardiovascular and respiratory changes and convalescence in laparoscopic colonic surgery: comparison between carbon dioxide pneumoperitoneum and gasless laparoscopy.

HYPOTHESIS: Gasless laparoscopy produces smaller cardiopulmonary and systemic changes than carbon dioxide (CO2) laparoscopy during colonic surgery. DESIGN: Prospective randomized trial. SETTING: Department of Surgery in a university hospital. PATIENTS: Twenty-two patients scheduled for laparoscopic colonic resection; 5 patients were excluded because of conversion to open surgery (N = 17). INTERVENTIONS: Patients were randomized to either gasless (n = 9) or conventional CO2 (n = 8) surgery. MAIN OUTCOME MEASURES: Intraoperative assessment of hemodynamic factors and pulmonary function, and postoperative assessment of pain, pulmonary function, convalescence, and various injury factors were done several times until 30 days after surgery. Surgical complications were noted. RESULTS: Descending aorta blood flow after 30 minutes (P=.03) and heart rate after 150 minutes were higher in the CO2 group (P=.009). Central venous pressure, PaCO2 inspiration pressure, and end tidal CO2 level were significantly higher in the CO2 group (P = .05, .03, .04, and .01, respectively). Patients in the CO2 group had less pain during mobilization and coughing (P = .008 and .006, respectively), and were significantly more fatigued (P = .04). No other important differences were observed in intraoperative hemodynamic factors, postoperative convalescence, immunocompetence, or pulmonary function. CONCLUSION: No clinically important differences in cardiovascular and systemic response were observed between patients undergoing CO2 or gasless laparoscopy for colonic disease.

Stress response to endoscopy.

BACKGROUND: Upper gastrointestinal endoscopy is often accompanied by tachycardia, which may lead to myocardial ischaemia. The pathogenesis for tachycardia is unknown, but the classic endocrine stress response may be of importance. METHODS: Seventeen patients (median age, 60 years) undergoing diagnostic gastroscopy without sedation or supplemental oxygen therapy were monitored by means of electrocardiogram, blood pressure, and pulse oximetry from 20 min before to 2 h after the procedure. Blood concentrations of glucose, cortisol, epinephrine, and norepinephrine were measured before, during, and after the endoscopy. Anxiety level was rated before the examination. RESULTS: Endoscopy was followed by a significant increase in norepinephrine and cortisol levels concomitant with a significant peak in heart rate (76 to 90 min(-1)) and mean arterial blood pressure (97 to 111 mmHg). Epinephrine was significantly reduced after the endoscopic procedure. We found no changes in glucose level or in arterial oxygen saturation. None of the patients developed signs of myocardial ischaemia during the procedure. There was no correlation between preendoscopy anxiety and the different stress variables (P > 0.3). CONCLUSIONS: The endoscopic procedure induces a classic endocrine metabolic stress response, probably causing the observed tachycardia.

Cardiovascular effects of oesophageal dilation under general anaesthesia.

Myocardial ischaemia and cardiac arrhythmias may occur during oesophageal dilation under conscious sedation, but no prospective data exist regarding dilation under general anaesthesia. We have studied the haemodynamic and electrocardiographic changes during routine oesophageal balloon dilation under general anaesthesia. Ten consecutive patients with benign oesophageal strictures were evaluated. Arterial oxygen saturation was measured by continuous pulse oximetry, ECG was recorded continuously with a Holter tape recorder, and blood pressure was measured non-invasively every five minutes during the procedure. Four patients developed significant hypotension at the time of balloon inflation with two patients requiring medical intervention to re-establish sufficient cardiovascular function. Tachycardia and ST-deviation occurred in four and three patients, respectively, during the general anaesthesia, but was not associated with the actual time of oesophageal distension. Thus, all cases of myocardial ischaemia were related to the time of extubation. No lasting complications were seen, and all patients could be discharged a maximum of 24 hours after the procedure. Pneumatic dilation of the oesophagus under general anaesthesia may be associated with significant hypotension, but the pathogenetic mechanisms involved are not clear. In this pilot study, the observed hypotension was not related to concurrent myocardial ischaemia.

ST-segment deviation during 24-hour ambulatory electrocardiographic monitoring and exercise stress test in healthy male subjects 51 to 75 years of age: the Copenhagen City Heart Study.

BACKGROUND: Although ST-segment deviation has been evaluated and used during many years both on continuous electrocardiographic Holter monitoring and during exercise stress testing, considerable controversy still remains concerning the prevalence and diagnostic significance of fortuitously discovered ST-segment deviation in asymptomatic healthy persons. METHODS AND RESULTS: The occurrence of ST-segment deviation was studied in a population of 63 clinically healthy male subjects 51 to 75 years of age, with the use of 24-hour Holter monitoring and exercise stress testing. The subjects were recruited from the Copenhagen City Heart Study and were without cardiovascular risk factors, chronic diseases, or medication and without cardiovascular events during 5 to 12 years before and 3 to 5 years after admission. The specificity, that is, the probability of displaying a negative test result in healthy subjects without disease, was 1.0 when using as criterion for significant ST-segment deviation a horizontal or descending ST-segment depression of >0.20 mV or ST-segment elevation >/=0.15 mV during Holter monitoring, and acceptable, for example, 0.95, when using as criterion a horizontal or descending ST-segment depression of >/=0.15 mV during Holter monitoring or at the exercise test, respectively. Furthermore, the specificity was 0.95 when a horizontal or downsloping ST-segment depression of 0.1 mV was displayed in both the Holter and exercise electrocardiographic recording system. CONCLUSIONS: Thus in asymptomatic persons, the usual criterion for significant ST-segment depression of 0.1 mV can be applied when occurring in both electrocardiographic recording systems. However, if one test alone is used, the criterion of significant ST-segment depression should be 0.15 mV. Absence of ST-segment deviation during Holter monitoring and exercise stress testing, indicated with a specificity of 1.0 or 0.95 according to choice of criterion, implies that the person is in a healthy state.