[Apical-Ballooning-Syndrome (Tako-Tsubo-Syndrome, neurogenic cardiomyopathy)].
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Aged↗
Biomedical subjects
R Pfister
Publications and source records attributed to R Pfister.
Recurrent varicose veins: sonography-based re-examination of 210 patients 14 years after ligation and saphenous vein stripping.
BACKGROUND: The objective of this study was to assess the frequency of varicose recurrence 14 years after flush ligation of the saphenofemoral (SFJ) or saphenopopliteal (SPJ) junction with additional stripping of the incompetent saphenous vein. PATIENTS AND METHODS: Our study group comprised 245 extremities of 210 patients operated upon in 1990 for either great saphenous vein (GSV) or small saphenous vein (SSV) incompetence. Limbs were assessed with Duplex ultrasound by a practitioner other than the original surgeon and relevant patient data was recorded. RESULTS: In 68.5% of re-examined limbs Duplex imaging provided no evidence for recurrent varicose veins at the former SFJ or SPJ. This included 15 legs (= 6.1%) where reflux immediately proximal to the junction but originating from adjacent veins (i.e. pudendal vein, epigastrical vein) was detected. In 31.5%, reflux from the operated SFJ or SPJ (junctional recurrence) was detected but only a minor percentage of legs (6.9%) had actually developed a clinically relevant recurrent varicosity (> 3 mm in diameter) branching out from the former junction and requiring treatment. Patients with a BMI < 30 were less likely to suffer recurrent varicose veins (no recurrence in 72.7%) than patients with a BMI > or = 30 (no recurrence in 54.5%). CONCLUSIONS: 14 years after flush ligation of the SFJ or SPJ with stripping of the incompetent saphenous vein, junctional recurrences were found in less than one-third of re-examined extremities. In the absence of surgical errors, we must assume neovascularisation as cause for these recurrences. Duplex US determined a clinically relevant recurrence (> 3 mm in diameter) in only 7% of limbs. Post-operative varices seem to develop less often after SPJ surgery than after SFJ surgery and according to our data, obesity (BMI > or = 30) constitutes a significant risk factor.
Adult↗
The impact of prolonged strenuous endurance exercise on interleukin 18 and interleukin 18 binding protein in recreational cyclists.
Interleukin 18 (IL-18) is an important pro-inflammatory cytokine in the early phase of human immune response to microbial infections. The influence of strenuous exercise on the intrinsic balance of IL-18 and its endogenous antagonist IL-18 binding protein (IL-18 BP) is unknown, but could be of major relevance for the athlete's immune function empirically and epidemiologically proven to be altered after exhaustive exertion. To study the effect of strenuous marathon cycling on the interaction of IL-18 and IL-18 BP we investigated 37 male, healthy, and well-trained amateur cyclists participating in the Otztaler Radmarathon in Tyrol (distance: 230 km; cumulative altitude difference: 5500 m). IL-18 was measured by a commercially available ELISA-Kit and IL-18 BP by a novel IL-18 BP ELISA method. Free, unbound IL-18 was calculated according to a standard equation. The mean plasma level of IL-18 was 142.27 +/- 21.85 pg/ml pre-race, remained nearly unchanged (124.35 +/- 13.16 pg/ml; p = 1.0) immediately after competition (mean race time 9 h 38 min), but declined significantly 24 h afterward (62.92 +/- 6.80 pg/ml; p = 0.002). The plasma levels of IL-18 BP increased considerably immediately after and kept on rising for the following 24 h (pre-race: 1.51 +/- 0.20 ng/ml; immediately post-race: 3.84 +/- 0.26 ng/ml, p < 0.001; 24 h post-race: 4.33 +/- 0.42 ng/ml, p < 0.001). Therefore, the calculated free IL-18 was 122.06 +/- 16.79 pg/ml pre-race, declined to 82.86 +/- 8.59 (p = 0.05) immediately post-race and to 39.17 +/- 3.76 pg/ml 24 h post-race (p < 0.001). The respective percentages of this post-exercise reduction in free IL-18 plasma levels were 32 % and 68 %. The present study reveals an exercise-induced significant decline in free IL-18 accompanied by an immediate up-regulation of IL-18 BP and decreased IL-18 in marathon cyclists. This down-regulation of free IL-18 may (i) limit the magnitude and duration of a too excessive inflammatory response to the exercise-induced tissue damage and (ii) on the other hand contribute to the elevated susceptibility to infection in athletes undergoing exhaustive exercise.
Adult↗
Direct observation of self-trapped vibrational states in alpha-helices.
Femtosecond infrared pump-probe spectroscopy of the N-H mode of a stable alpha-helix reveals two excited-state absorption bands, which disappear upon unfolding of the helix. A quantitative comparison with polaron theory shows that these two bands reflect two types of two-vibron bound states connected to the trapping of two vibrons at the same site and at nearest neighbor sites, respectively. The latter states originate from an acoustic phonon in the helix, which correlates adjacent sites.
Amino Acids↗
Use of NT-proBNP in routine testing and comparison to BNP.
OBJECTIVES: B-type natriuretic peptide (BNP) is a strong diagnostic predictor of left-ventricular (LV)-dysfunction. Recently, the aminoterminal portion of pro-BNP (NT-proBNP) has been introduced, which could be even more sensitive because of its longer half-life. The aim of this study was to evaluate the new marker NT-proBNP within a large, heterogeneous population of patients with suspected cardiovascular disease at risk of cardiovascular dysfunction and to compare it with the established diagnostic parameter BNP. SUBJECTS AND METHODS: NT-proBNP and BNP were measured in 339 hospitalised patients undergoing diagnostic angiography (median age 66 years, 244 male vs. 95 female). RESULTS: Median values of NT-proBNP increased with worsening LV-dysfunction and higher NYHA class. The area under the receiver operator characteristics curve (AUC) of NT-proBNP for detecting severe systolic dysfunction or for detecting any systolic LV-dysfunction was 0.83 and 0.77, respectively. The latter improved (AUC=0.81) when patients with clinically relevant heart disease like valvular dysfunction were included, independent of the haemodynamic values. Compared to BNP, NT-proBNP tended to be more accurate in identifying lesser degrees of LV-dysfunction. CONCLUSIONS: Even after optimisation of target criteria, there was still a substantial overlap of NT-proBNP values between patients with and without relevant heart disease. Therefore, NT-proBNP is not suitable as a screening test for LV-dysfunction in the community. Nevertheless, because of its good negative predictive value, NT-proBNP could be an easy and effective tool to rule out severe systolic LV-dysfunction in high risk patients. No clinically significant advantage of BNP testing could be found.
Aged↗
Natriuretic peptides BNP and NT-pro-BNP: established laboratory markers in clinical practice or just perspectives?
A growing body of literature describes diagnostic and prognostic value of B-type natriuretic peptides (BNP) in cardiac diseases since it was first described in 1988. As BNP is mainly secreted in the left ventricular (LV) myocardium, BNP was found to reflect LV function much better than any other neurohumoral factor. Thus, BNP is recommended as the first noninvasive blood test for determination of cardiac function by some authors. The introduction of fully automated, rapid bioassays for measurement of BNP and the aminoterminal part of its pro-hormone (NT-pro-BNP) made it possible to use the test even in emergency care settings. Here we review the literature with special focus on assessment of BNP and NT-pro-BNP in the following clinical settings: community screening for LV dysfunction, primary diagnosis of heart failure in general practice and emergency department (ED) and risk stratification in cardiac dysfunction and acute coronary syndromes. In addition, we discuss which applications can be recommended for daily clinical use from the cardiologist's point of view.
Coronary Disease↗
Effect of ultramarathon cycling on the heart rate in elite cyclists.
OBJECTIVES: To analyse the heart rate (HR) response and estimate the ultraendurance threshold-the optimum maintainable exercise intensity of ultraendurance cycling-in ultraendurance elite cyclists competing in the Race across the Alps. METHODS: HR monitoring was performed in 10 male elite cyclists during the first Race across the Alps in 2001 (distance: 525 km; cumulative altitude difference: 12 600 m) to investigate the exercise intensity of a cycle ultramarathon and the cardiopulmonary strains involved. Four different exercise intensities were defined as percentages of maximal HR (HR(max)) as follows: recovery HR (HR(re)), <70% of HR(max); moderate aerobic HR (HR(ma)), 70-80%; intense aerobic HR (HR(ia)), 80-90%; and high intensity HR (HR(hi)), >90%. RESULTS: All athletes investigated finished the competition. The mean racing time was 27 hours and 25 minutes, and the average speed was 18.6 km/h. The mean HR(max) was 186 beats/min, and the average value of measured HRs (HR(average)) was 126 beats/min resulting in a mean HR(average)/HR(max) ratio of 0.68, which probably corresponds to the ultraendurance threshold. The athletes spent 53% (14 hours 32 minutes) of total race time within HR(re), 25% (6 hours 51 minutes) within HR(ma), 19% (5 hours 13 minutes) within HR(ia), and only 3% (49 minutes) within HR(hi), which shows the exercise intensity to be predominantly moderate (HR(re) + HR(ma) = 78% or 21 hours 23 minutes). The HR response was influenced by the course profile as well as the duration. In all subjects, exercise intensity declined significantly during the race, as indicated by a decrease in HR(average)/HR(max) of 23% from 0.86 at the start to 0.66 at the end. CONCLUSIONS: A substantial decrease (10% every 10 hours) in the HR response is a general cardiovascular feature of ultramarathon cycling, suggesting that the ultraendurance threshold lies at about 70% of HR(max) in elite ultramarathon cyclists.
Adult↗
Facial expression recognition and subthalamic nucleus stimulation.
BACKGROUND: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) improves motor signs in Parkinson's disease. However, clinical studies suggest that DBS of the STN may also affect cognitive and emotional functions. OBJECTIVE: To study the impact of STN stimulation in Parkinson's disease on perception of facial expressions. RESULTS: There was a selective reduction in recognition of angry faces, but not other expressions, during STN stimulation. CONCLUSIONS: The findings may have important implications for social adjustment in these patients.
Adult↗
[Management of acute exacerbation of chronic obstructive pulmonary disease (COPD)].
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Acute Disease↗
[Natriuretic peptides BNP and NT-pro-BNP--the "new troponins" for estimation of heart failure?].
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Atrial Natriuretic Factor↗
Differential modulation of subcortical target and cortex during deep brain stimulation.
The combination of electrical deep brain stimulation (DBS) with functional imaging offers a unique model for tracing brain circuitry and for testing the modulatory potential of electrical stimulation on a neuronal network in vivo. We therefore applied parametric positron emission tomography (PET) analyses that allow characterization of rCBF responses as linear and nonlinear functions of the experimentally modulated stimulus (variable stimulator setting). In patients with electrodes in the thalamic ventrointermediate nucleus (VIM) for the treatment of essential tremor (ET) here we show that variations in voltage and frequency of thalamic stimulation have differential effects in a thalamo-cortical circuitry. Increasing stimulation amplitude was associated with a linear raise in rCBF at the thalamic stimulation site, but with a nonlinear rCBF response in the primary sensorimotor cortex (M1/S1). The reverse pattern in rCBF changes was observed with increasing stimulation frequency. These results indicate close connectivity between the stimulated nucleus (VIM) and primary sensorimotor cortex. Likewise, stimulation parameter-specific modulation occurs at this simple interface between an electrical and a cerebral system and suggests that the scope of DBS extends beyond an ablation-like on-off effect: DBS could rather allow a gradual tuning of activity within a neuronal circuit.
Aged↗
The effect of marathon cycling on renal function.
The stress of strenuous long-term exercise may alter renal function. Whether this is also true for marathon cycling is unknown so far. The purpose of this study was to evaluate renal function following competitive marathon cycling. We investigated 38-male, well-trained recreational cyclists credibly not taking any kind of doping who participated in the Otztal Radmarathon. Blood and urine specimens were taken the day before, immediately after and one day after competition. Baseline renal functional parameters--normal before competition--increased significantly afterwards and remained elevated during 24 hours of recovery. The rises in serum creatinine, urea and uric acid were 20, 54 and 42 % (p < 0.001 respectively). The corresponding decline in estimated creatinine clearance was 18 %. In all athletes the serum urea/creatinine ratio rose above 40, fractional sodium excretion and fractional uric acid excretion fell below 0.4 % and 15 %, indicating reduced renal perfusion. The observed effects lasted for at least 24 h despite a stable fluid balance during the race and an expanding plasma volume (PV) in the recovery period. Levels of haematocrit remained unchanged immediately post-race but significantly declined from 0.44 to 0.41 on the following day (p < 0.001). The calculated rise in PV was + 10.8 %. Electrolyte homeostasis was preserved throughout the observation period. Post-exercise proteinuria was small and of the mixed glomerular-tubular type. There was neither evidence for exercise-induced haemolysis, nor for significant skeletal muscle damage. The finding obtained from well-hydrated recreational athletes reveals that the extraordinary strains of marathon cycling influence renal function only on a minimal scale. Though minor, the physiological effects were long-lasting. The results obtained suggest that a reduced renal perfusion is the mechanism responsible for the slight impairment of renal function following exhaustive marathon cycling.
Adult↗
Physical and physiological factors associated with success in professional alpine skiing.
Scientific data on the physiological profile of world class skiers are sparse. During the last decade the Austria Ski Team was the most successful in the world. It was the objective of this study to describe the physical and physiological characteristics of World Cup (WC) skiers. Twenty female and 28 male members of the Austrian WC Ski Team were examined pre- and post-seasonally from 1997 to 2000. Physical parameters such as age, height, body mass, body mass index, percent body fat and thigh circumference were recorded from each athlete. The physiological variables investigated consisted in the aerobic power and in the muscle strength of the lower limbs. Racing performance was defined by the WC ranking position. The athlete's aerobic performance capacity was assessed by maximal exercise testing on a bicycle ergometer, and the isokinetic muscle strength of the knee extensor and flexor muscles by the use of a computer-interfaced dynamometer. From 1997 to 2000 about half (48 %; n = 106) of all alpine WC racing events (n = 221) were won by the athletes investigated. The typical world class skier is in the mid-twenties (25.2 y [female]; 27.6 y [male]). The mean values for height were 1.66 m (female) vs. 1.81 m (male), for body mass 65.1 kg (female) vs. 87 kg (male) and for the percentage of body fat 24.5 % (female) vs. 15.8 % (male). The maximum power output was 4.3 +/- 0.4 (female ) and 4.7 +/- 0.4 W/kg (male), the corresponding values for VO(2)max were 55 +/- 3.5 (female) and 60 +/- 4.7 ml/kg/min (male). The maximal values for peak torque and work for knee extension amounted to 206 +/- 21 (female) and 334 +/- 43 Nm (male), and 2690 +/- 364 (female) and 4414 +/- 629 J (male), respectively. In both sexes there were neither significant laterality nor dysbalance. The hamstring/quadriceps ratios were between 0.57 - 0.60. Among all physical and physiological variables, only the aerobic power in males was found to be strongly correlated (r = 0.947; p = 0.001 for W (max); r = 0.964; p < 0.001 for VO(2)max) to racing performance. The study proves the practical experience that success in professional alpine skiing is not related to single physiological variables. Two main factors, however, are crucial, i. e. high levels of aerobic power and muscle strength.
Adult↗
Heart rate response to ultraendurance cycling.
The heart rate (HR) response to ultraendurance cycling is poorly understood. This case report describes the exercise intensity of ultraendurance cycling by means of HR monitoring in a well trained male amateur cyclist performing the Otztal Radmarathon twice en bloque in a circuit of two identical laps (distance 460 km; cumulative altitude difference 11,000 m). The overall intensity was moderate (HR(mean) = 130 beats/min; HR(mean)/HR(max) = 0.71) corresponding to an average individual workload of 47% of VO(2)MAX. Almost the whole race was performed under aerobic conditions (99.6%); high intensity work was negligible (0.4%). The average speed and the HR response also declined in the course of the two laps, average speed by 17.2% (23.8 to 19.7 km/h), HR(mean) by 10.1% (138 to 124 beats/min), and HR(mean)/HR(max) by 10.7% (0.75 to 0.67). This scale of HR decrease corresponds to comparable data gained in the field of triathlon and represents a specific cardiac feature of ultraendurance exercise in general.
Adult↗
[The value of natriuretic peptides NT-pro-BNP and BNP for the assessment of left-ventricular volume and function. A prospective study of 150 patients].
BACKGROUND AND OBJECTIVE: An early detection of patients with left-ventricular (LV) dysfunction is essential for effective treatment of congestive heart failure. The B-type natriuretic peptide (BNP) was described as a strong diagnostic parameter of LV-dysfunction. Aim of this study was to compare the diagnostic value of BNP and the aminoterminal part of pro-BNP (NT-pro-BNP) within an heterogenous patient population. SUBJECTS AND METHODS: NT-pro-BNP and BNP were measured in 150 hospitalized cardiologic patients (age-median 64 years, 109 male versus 41 female). The values were correlated with clinical and haemodynamic parameters of the invasively determined LV-function. RESULTS: Patients with pathologic haemodynamic values of the LV-function had significantly higher NT-pro-BNP and BNP levels than patients with normal haemodynamic parameters. In our study population a severe systolic LV-dysfunction (ejectionfraction EF<40 %) could be detected with a sensitivity and specifity of 100 % and 64 % by NT-pro-BNP and 100 % and 45 % by BNP. Sensitivity and specifity for the detection of any systolic dysfunction (EF<60 %) and of a systolic or diastolic dysfunction, respectively, were 94 %, 37 % and 88 %, 41 % for NT-pro-BNP (94 %, 40 % and 84 %, 44 % for BNP). The corresponding negative predictive values were 100 %, 96 % and 71 % for NT-pro-BNP and 100 %, 96 % and 68 % for BNP. CONCLUSION: NT-pro-BNP and BNP were highly sensitive diagnostic parameters with a very good negative predictive value for LV-dysfunction. Because of the uncomplicated measurement, they could be used effectively to rule out LV-dysfunction in cardiovascular high risk patients by general practitioners.
Adult↗
Hydration for treatment of preterm labour.
BACKGROUND: Hydration has been proposed as a treatment for women with preterm labour. Theoretically, hydration may reduce uterine contractility by increasing uterine blood flow and by decreasing pituitary secretion of antidiuretic hormone and oxytocin. OBJECTIVES: To evaluate the effectiveness of intravenous or oral hydration to avoid preterm birth and its consequences in women with preterm labour. SEARCH STRATEGY: The Cochrane Pregnancy and Childbirth Group trials register (January 2002), the Cochrane Controlled Trials register (The Cochrane Library, Issue 1, 2002) and bibliographies of relevant papers were searched. SELECTION CRITERIA: Randomised controlled trials, including women with a viable pregnancy less than 37 completed weeks' gestation and presenting with preterm labour, comparing intravenous or oral hydration with no treatment. The intervention might or might not be associated with bed rest. Studies comparing tocolytic drugs with intravenous fluids used in the control group as a placebo were not included in this review. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed the reports, to determine if the study met the inclusion criteria and to evaluate the methodological quality. Data were extracted independently by two of the reviewers. The results were expressed as relative risks (RR) for dichotomous outcomes and weighted mean difference for continuous outcomes. MAIN RESULTS: Two studies, including a total of 228 women with preterm labour and intact membranes, compared intravenous hydration with bed rest alone. Risk of preterm delivery, before 37 weeks (relative risk (RR): 1.09; 95% confidence interval (CI): 0.71-1.68), before 34 weeks (RR: 0.72; 95% CI: 0.20-2.56) or before 32 weeks (RR: 0.76; 95% CI: 0.29-1.97), was similar between groups. Admission to neonatal intensive care unit occurred with similar frequency in both groups (RR: 0.99; 95% CI: 0.46-2.16). Cost of treatment was slightly higher (US$39) in the hydration group. This difference was not statistically significant and only includes hospital costs during a visit of less than 24 hours. No studies evaluated oral hydration. REVIEWER'S CONCLUSIONS: The data are too few to support the use of hydration as a specific treatment for women presenting with preterm labour. The two small studies available do not show any advantage of hydration compared to bed rest alone. Intravenous hydration does not seem to be beneficial, even during the period of evaluation soon after admission, in women with preterm labour. Women with evidence of dehydration may, however, benefit from the intervention.
Female↗
[Difficult to manage asthma: clinical phenotypes and principles of therapy].
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Adult↗
Short-term effects of prolonged strenuous endurance exercise on the level of haematocrit in amateur cyclists.
Knowledge is sparse about the extent of potential dehydration due to prolonged strenuous cycling and its haematological acute effects on the haematocrit (Hct) in study populations credibly not taking any kind of doping. With increasing training load levels of Hct and haemoglobin (Hb) decrease in both amateurs and professionals as a long-term consequence due to expanded plasma volume (PV). On a short-term basis, however, counteracting dehydration potentially brought about by endurance exercise may cause a rise in Hct bringing competitive cyclists into conflict with the current condition regulations and Hct cut-off of 50 % set by the International Cycling Union (UCI) in its fight against erythropoietin (rhEPO) doping. On the other hand adequate and sufficient fluid substitution being substantial for a successful endurance performance should prevent any pronounced Hct rises. To study the haematological acute effects of prolonged strenuous cycling we measured Hct, Hb, red blood cell (RBC) count and plasma protein in a reliably 'clean' population of 38 well-trained male amateur cyclists before, immediately after and one day after an extraordinary ultramarathon. The pre-race levels of Hct, Hb and RBC count were placed in the lower range of normal distribution and well below the Hct cut-off limit of the UCI. Immediately post-exercise the mean levels of Hct, Hb, RBC count and protein remained unchanged. One day after race, however, all four parameters significantly dropped by 3 %, 6.7 %, 6.5 %, 9.9 % respectively (p < 0.001), indicating marked post-exercise PV expansion. The calculated percentage increase in PV was 11.9 %. No evidence for coexisting exercise-induced haemolysis was found. Our study shows that in "clean, rhEPO-free" amateur cyclists who involve in strenuous marathon cycling the haematological short-term effects of extraordinary marathon cycling consist in considerable PV expansion making Hct values fall on the following day. The findings - gained from amateurs though - suggest that despite all its disadvantages the UCI Hct cut-off represents an appropriate means to discourage from excessive rhEPO doping at least as long as the available direct methods for detecting this kind of misuse are not yet applied by the international sports federations.
Adult↗