Size and blood flow of central and peripheral arteries in highly trained able-bodied and disabled athletes.

In a cross-sectional study, central and peripheral arteries were investigated noninvasively in high-performance athletes and in untrained subjects. The diastolic inner vessel diameter (D) of the thoracic and abdominal aorta, the subclavian artery (Sub), and common femoral artery (Fem) were determined by duplex sonography in 18 able-bodied professional tennis players, 34 able-bodied elite road cyclist athletes, 26 athletes with paraplegia, 17 below-knee amputated athletes, and 30 able-bodied, untrained subjects. The vessel cross-sectional areas (CSA) were set in relation to body surface area (BSA), and the cross-section index (CS-index = CSA/BSA) was calculated. Volumetric blood flow was determined in Sub and Fem via a pulsed-wave Doppler system and was set in relation to heart rate to calculate the stroke flow. A significantly increased D of Sub was found in the racket arm of able-bodied tennis players compared with the opposite arm (19%). Fem of able-bodied road cyclist athletes and of the intact limb in below-knee amputated athletes showed similar increases. D of Fem was lower in athletes with paraplegia (37%) and in below-knee amputated athletes proximal to the lesion (21%) compared with able-bodied, untrained subjects; CS-indexes were reduced 57 and 31%, respectively. Athletes with paraplegia demonstrated a larger D (19%) and a larger CS-index in Sub (54%) than able-bodied, untrained subjects. No significant differences in D and CS-indexes of the thoracic and abdominal aorta were found between any of the groups. The changes measured in Sub and Fem were associated with corresponding alterations in blood flow and stroke flow in all groups. The study suggests that the size and blood flow volume of the proximal limb arteries are adjusted to the metabolic needs of the corresponding extremity musculature and underscore the impact of exercise training or disuse on the structure and the function of the arterial system.

[Effects of physical training and age-induced structural and functional changes in cardiovascular system and skeletal muscles]. / Trainingseinflüsse auf altersbedingte strukturelle und funktionelle Veränderungen am Herzkreislaufsystem und an der Skelettmuskulatur.

Age-related morphological changes in the cardiovascular system refer to a thickening of the arterial wall as well as a diffuse increase in the wall thickness of the myocardium. In terms of function, this leads to a decrease of the myocardial contractility in systole and to a delay of the diastolic myocardial relaxation. At the arterial wall, an impairment of wall elasticity as well as a decrease of the vasoreagibility can be observed. The systolic blood pressure and the blood pressure amplitude rise; the blood flow-dependent vasodilatation mediated by endothelial cells decreases. The loss of cardiac pacemaker cells by approximately 90% from the 2nd to the 8th decade leads to a reduction of the heart rate variability and to a decrease of the maximum heart rate during exhaustive physical exercise. Hemodynamically these changes resulted in a continuous decline of the maximum cardiac output as well as the maximum oxygen transport capacity. Between the 3rd and 8th decade the peripheral skeletal muscle mass decreases as a result of a reduction of the size and the number of muscle fibers with an overproportional loss of 30-40% regarding the highly glycolytic type IIb fibers. Furthermore, the intramuscular capillarization declines so that, with a concomitant decrease in the number and size of the mitochondria, the supply with oxygen and energy sources and consecutively the aerobic muscular energy metabolism decreases by 8-10% per decade beginning with the 4th to 5th decade. Additionally, the maximum and explosive muscular strength decreases by 30-35% from the 4th decade onwards. In older, healthy men who perform a regular aerobic muscular training in endurance sport disciplines (e.g., walking, jogging or cycling), a decrease of the resting heart rate, a restoration of the primarily lowered heart rate variability, an improvement of the early diastolic left-ventricular filling as well as a significant increase in the VO2max could be proven. Other studies showed that regular endurance training on a cycle-ergometer resulted in a significant increase in capillarization within the exercising muscle groups. In older, trained individuals a reduced stiffness of the arterial vessel walls and an improved maximum exercise-induced muscular blood supply occurs. In other training studies performed with older subjects, a positive influence of regular endurance training on the carbohydrate metabolism along with an improvement of the primarily reduced insulin sensitivity could be demonstrated. In older men and women who regularly underwent muscular strength training, a significant increase in maximum strength with a significant increase in the proportion of type II muscle fibers was found.

Computerized analysing system using the active contour in ultrasound measurement of carotid artery intima-media thickness.

BACKGROUND AND PURPOSE: B-mode measurement of the carotid intima-media (IM) thickness (T) based on manual tracing (MT) procedures are dependent on the subjectivity of the reader and the existing automatic tracing procedures often fail to detect the IM boundaries accurately. The purpose of this study was to compare the tracing results of the IM boundaries of the carotid wall with a new automatic identification (AI) procedure, based on an active contour model, and computer-assisted manual tracing (MT). METHODS: The detection of the IM boundaries was performed with both procedures in 126 ultrasound images [63 each of the common carotid artery (CCA) and carotid bulb] along the far wall of the distal CCA and the carotid bulb. Intra- and inter-reader variability for mean and maximum IMT with AI and MT and accuracy of identification of both IM boundaries were evaluated. RESULTS: Using MT the intra- and inter-reader variability amounted to 0.01-0.03 and 0.03-0.07 mm, respectively. The variability was slightly higher in the carotid bulb than in the CCA. Using AI the variability was almost eliminated. Mean and maximum IMT were measured systematically lower by AI compared with MT in all regions by 0.01 mm. The accuracy of identification was similar for both IM boundaries, but lower in the carotid bulb region than in the CCA. CONCLUSIONS: The new AI procedure identifies both IM boundaries in the region of the far wall of the CCA and carotid bulb with high precision, and eliminates most of the intra- and inter-reader variability of the IMT measurement using MT.

Cardiovascular, metabolic, and hormonal parameters in professional tennis players.

During the past decade, the physical and mental stress in professional tennis has been constantly increasing. The overall intensity in tennis ranges between 60 and 70% of maximum oxygen uptake and the energy requirements are mainly provided by aerobic energy metabolism. Therefore, particularly with respect to the duration of the tournaments and the length of the matches, a good aerobic capacity promotes continuous success in professional tennis. During frequent periods of high intensity, however, muscular energy is derived from anaerobic glycolysis. Therefore, sports-specific conditioning programs in tennis should improve both glycolytic and oxidative muscular metabolism. Years of training and competition induce a number of cardiovascular and metabolic adaptations: an increase in heart size in terms of an athlete's heart, higher oxygen uptake capacity, improved muscular oxidative enzyme activities, reduced baseline catecholamine levels, and a lower resting heart rate. In addition, tennis induces side-specific increments in bone density, bone diameter, and bone length of the upper extremity. Furthermore, structural and functional adaptations of the conducting arteries in the preferred arm could be demonstrated in professional tennis players. In conclusion, tennis is a very complex sport involving strength, power, speed, agility and explosiveness, as well as endurance components. Scientific data on exercise-related cardiovascular and metabolic parameters in professional tennis are important to evaluate the players individual fitness level and will help to improve sports-specific conditioning programs. This in turn will not only enhance performance but also prevent overstrain and burnout syndromes.

Catecholamines response of high performance wheelchair athletes at rest and during exercise with autonomic dysreflexia.

Autonomic dysreflexia presents a special situation in high-lesion spinal cord injury, however, intentionally or self-induced autonomic dysreflexia directly before or during competition to increase performance, so called 'boosting', is also being reported. In order to examine the influence of autonomic dysreflexia on plasma catecholamines, cardiocirculatory and metabolic parameters, 6 spinal cord injured wheelchair athletes with high-level lesions underwent wheelchair ergometry without (ST1) and with (ST2) autonomic dysreflexia. At the point of exhaustion significantly higher values for norepinephrine and epinephrine were observed in ST2 than in ST1. During autonomic dysreflexia a significantly higher peak performance (77.5 vs. 72.5 watt), higher peak heart rate (161 vs. 149 x min(-1)), and peak oxygen consumption (1.96 vs. 1.85 l x min(-1)), with comparable peak lactate (7.11 vs. 7.00 mmol x l(-1)) were reached on average. The blood pressure values in ST2 were partially hypertensive and higher than in ST1. In conclusion, autonomic dysreflexia, as a sympathetic spinal reflex, leads to a higher release of catecholamines during exercise. This results in higher peak performance, peak heart rate, peak oxygen consumption, and higher blood pressure values. The peak lactate, as an indicator of the anaerobic lactate metabolism, was unchanged. However, autonomic dysreflexia presents an unpredictable risk, caused predominantly by hypertensive blood pressure values, for high-lesion spinal cord injured persons at rest and more so during exercise; it is seen as a prohibited manipulation by the doping guidelines of the International Paralympic Committee.

Release of muscle proteins after downhill running in male and female subjects.

The release of muscle proteins after downhill running, which mainly includes eccentric muscle action, was compared in females (F; n=9) and males (M; n=9). They performed 20 min of downhill treadmill running with 16% decline with a target heart rate of 70% of the individual VO2peak, which was determined two weeks before. Blood samples were drawn before, 6 and 24 h after exercise to measure plasma levels of skeletal troponin I (sTnI), myosin heavy chain fragments (MHC), creatine kinase (CK), and myoglobin (Mb). Baseline levels before exercise were significantly higher in males compared to females for the cytoplasmic proteins CK and Mb, but the difference for MHC and sTnI was not significant. Both groups displayed marked and significant early (6 h) increases (P<0.05) for sTnI (median: F: 8.2 microg/L; M: 22.0 microg/L), Mb (median: F: 86.8 microg/L; M: 407 microg/L), and CK (median: F: 162 U/L; M: 339 U/L). A significant (P<0.05) but delayed (24 h) increase was found for MHC (median: F: 482 microU/L; M: 651 microU/L). The absolute values for all four parameters were significantly (P<0.05) higher in males compared to females; however, no difference was found for the relative increases and the time course of all parameters between females and males. We conclude 1) that there were no significant differences in the basal concentrations of predominantly bound proteins, and 2) that there were no differences in the relative muscle protein release between females and males before and after one bout of high-intensive eccentric exercise. The higher plasma concentrations of all measured muscle proteins in males are probably caused by the higher muscle mass compared to females.

Left ventricular wall motion during diastolic filling in endurance-trained athletes.

PURPOSE: The purpose of this study was to assess left ventricular (LV) wall motion in highly endurance-trained athletes to evaluate LV diastolic function in physiologically hypertrophied hearts. BACKGROUND: Diastolic filling dynamics have previously been examined in endurance-trained athletes by measuring pulsed-wave mitral inflow velocities during the early and atrial filling phase, indicating an unimpaired LV function. Assessment of LV wall motion may give additional information about the LV diastolic function in endurance-trained athletes. METHODS: Left ventricular mass (LVM) and volume (LVV) were determined by M-mode echocardiography. Peak LV wall motion in the region of the basal septum close to the mitral anulus were measured during the early rapid and atrial filling phase by tissue Doppler in 30 endurance-trained athletes (T) and 16 sedentary control subjects (C) presumed to be healthy. RESULTS: Myocardial LVM and LVV in T (LVM 159.4 +/- 18.0 g.m(-2), LVV 100.4 +/- 13.0 mL.m(-2)) were significantly higher than in C (LVM 105.7 +/- 12.0.m(-2), LVV 70.1 +/- 11.9 mL.m(-2)), and heart rate (HR) was significantly lower (HR C: 69.6 +/- 11.0 bpm, T 50.9 +/- 8.7 bpm),which is consistent with endurance training (P < 0.01 for both). Peak LV wall motion during the early rapid filling phase did not differ significantly between the groups (T: 10.69 +/- 1.46 cm.(s-)1; C: 10.61 +/- 1.52 cm.(s-)1). Peak atrial wall motion was significantly lower in T (4.53 +/- 0.84 cm.s-1) versus C (5.74 +/- 0.75 cm.s(-1)), and the ratio of peak early diastolic to atrial wall motion was consequently higher in athletes (P < 0.01 for both). CONCLUSION: Regional wall motion at the basal septum near the mitral anulus during the early rapid filling phase is not altered by an increase in LVM or LVV when associated with endurance training.

[Value of training-induced effects on arterial vascular system and skeletal muscles in therapy of NYHA II/III heart failure]. / Stellenwert von trainingsbedingten Rückwirkungen am arteriellen Gefässystem und der Skelettmuskulatur in der Therapie der Herzinsuffizienz NYHA II/III.

Dynamic muscular exercise performed by healthy subjects leads to a rise in the left ventricular blood ejection with an acute increase in the local wall shear stress on the endothelium of the arterial vessels. These hemodynamic changes results in a release of endothelium-dependent relaxing factors, one of them concerns nitric oxide (NO). Therefore an arterial vasodilatation with an acute increase in the blood flow volume to the exercising muscle groups occurs. If more than 1/6 of the skeletal musculature is involved in exercise and if training duration exceeds 3-5 hours a week the chronically increased blood flow volume in the cardiovascular system triggers structural and functional changes of the heart and the arterial vessels. It develops a functional intact excentric hypertrophy of the myocardium; within the arterial vessels an increase in the diameter of the muscular arteries supplying the trained muscle groups occurs. These training-induced adaptations of the cardiovascular system are adjusted to improve the aerobic skeletal muscle metabolism. In congestive heart failure a pathological excentric myocardial hypertrophy is found. In this case the systolic myocardial function is impaired and the left ventricular ejection fraction is reduced already in early stages, so that the cardiac output can not be sufficiently increased during exercise. In addition a dysfunction of the endothelium of the arterial vessels occurs. As a consequence the endothelium-dependent arterial vasodilation is reduced, so that the peripheral arteries could not supply the muscle groups involved in exercise with enough blood flow volume. Therefore, the acute delivery of the working musculature with oxygen and energy substrates is insufficient, so that premature muscular fatigue occurs. The reduced exercise resistance of the patients leads chronically to a generalized skeletal muscle atrophy. Ultrastructural analysis revealed a decrease of oxidative type 1 muscle fibers with a relative increase of more glycolytic type 2 fibers. In addition, the volume density and the surface area of the cristae of mitochondria are reduced. All these changes results in a decrease of aerobic skeletal muscle metabolism independent of the blood flow volume, so that the physical fitness of the patients progressively decline. On the basis of the training-induced physiological adaptations of the cardiovascular system, a special exercise therapy supervised by a physician was developed for patients with congestive heart failure NYHA II/III. It have been shown that various exercise programs, which are adjusted to the degree of cardiac function impairment are suitable to restore the endothelial dysfunction of the arterial vessels as well as to cure the disturbed skeletal muscle metabolism in these patients independent of an improvement of cardiac function. Therefore in patients with congestive heart failure NYHA II/III who underwent regularly such an exercise therapy, the secondary impaired physical fitness could be rebuild without an excessive risk for an acute exercise-induced cardiovascular emergency.

Arterial properties of the carotid and femoral artery in endurance-trained and paraplegic subjects.

In humans, the relationships of blood flow changes to structure, function, and shear rate of conducting arteries have not been thoroughly examined. Therefore, the purpose of this study was to investigate these parameters of the elastic-type, common carotid artery (CCA) and the muscular-type, common femoral artery (CFA) in long-term highly active and extremely inactive individuals, assuming that the impact of activity-induced blood flow changes on conduit arteries, if any, should be seen in these subjects. We examined 21 highly endurance-trained athletes (A), 10 paraplegic subjects (P), and 20 sedentary subjects (S) by means of noninvasive ultrasound. As a result, the CFA diameter and compliance were highest in A (9.7+/-0.81 mm; 1.84 +/-0.54 mm(2)/kPa) and lowest in P (5.9+/-0.7 mm; 0.54+/-0.27 mm(2)/kPa) compared with S (8.3+/-1.0 mm; 0.92+/-0.48 mm(2)/kPa) with P <0.01 among the groups. Both parameters correlated with each other (r = 0.62; P<0.01). Compared with A (378+/-84 s(-1); 37+/-15 s(-1)) and S (356+/-113 s(-1); 36+/-20 s(-1)), the peak and mean shear rates of the CFA were almost or more than doubled in P (588+/-120 s(-1); 89+/-26 s(-1)). In the CCA, only the compliance and peak shear rate showed significant differences among the groups (A: 1.28+/-0.47 mm(2)/kPa, 660+/-138 s(-1); S: 1.04+/-0.27 mm(2)/kPa, 588+/-109 s(-1); P: 0.65+/- 0.22 mm(2)/kPa, 490+/-149 s(-1); P<0.05). In conclusion, the results suggest a structural and functional adaptation in the CFA and a predominantly functional adaptation of the arterial wall properties to differences in the physical activity level and associated exercise-induced blood flow changes in the CCA. The results for humans confirm those from animal experiments. Similar shear rate values of S and P in the CFA support the hypothesis of constant shear stress regulation due to local blood flow changes in humans. On the other hand, the increased shear rate in the CFA in P indicates an at least partially nonphysiological response of the arterial wall in long-term chronic sympathectomy due to a change in local blood flow.

Assessment of atherosclerotic arterial changes in the carotid artery with noninvasive ultrasound.

Atherosclerotic changes of the carotid tree comprise changes of the wall structure, the wall stiffness, and local blood flow properties. They are associated with atherosclerotic changes in other arterial beds such as the coronary and cerebral arteries and with manifest atherosclerotic diseases. It has also been shown that they are at least in part potent predictors for future cardiovascular disease. Transcutaneous ultrasound of the carotid tree offers the possibility of detecting atherosclerotic changes on a noninvasive basis. In the following, the different methods for the assessment of atherosclerotic changes of the carotid wall structure, wall stiffness, and local hemodynamics with noninvasive ultrasound are briefly reviewed. The combined assessment of all these arterial properties may increase the predictive value of non-invasive ultrasound in detecting early atherosclerosis in other arterial beds. However, more prospective studies are necessary to examine the possible value of increased wall stiffness, altered local hemodynamics, and the combined assessment of these parameters together with the assessment of arterial wall structure in this respect. Therefore, the current ultrasound methods for the measurement of structure, function, and hemodynamics has yet to be optimized for usage in routine medical examinations.

Assessment of arterial blood flow characteristics in normal and atherosclerotic vessels with the fast Fourier flow method.

The purpose of this study was to scrutinize the ability of magnetic resonance imaging (MRI)-performed measurements to compare arterial flow patterns in patients with peripheral arterial occlusive disease (PAOD), healthy volunteers (HV) and endurance athletes (EA). MRI blood flow data were partially repeated with Doppler ultrasound (DUS) with a view to a methodical comparison. Additionally, pulse wave velocity was assessed with the MUFF technique. For this purpose, MRI-performed flow measurements were performed in the common femoral artery in 21 patients with PAOD, in 34 HV and in 12 EA. The analysis included maximum flow velocities (MFV), velocity/time profile (VTP), pulse wave velocity (Vpulse), and vessel diameter (VD). In addition, MFV and VD were observed by DUS in most individuals. The results revealed a significant change regarding arterial blood flow characteristics in patients compared with HV and EA, with respect to the span between the peak positive and negative blood flow velocity in the femoral artery. The pulse wave velocity in patients was markedly elevated compared with healthy individuals. Furthermore, a complete, characteristic change in the VTP could be observed in patients. The methodical comparison between DUS and MRI showed a good correlation. Multi-slice Fourier flow data have indicated markedly increased pulse wave velocity in PAOD patients. Changes in the arterial blood flow can be clearly observed with MRI. In the future, this might offer a noninvasive possibility not only for the evaluation of the stage of the disease, but also for the detection of early, pre-clinical stages of atherosclerosis.

Effectiveness of digitoxin versus trichlormethiazide/amiloride in congestive heart failure NYHA class II/III and sinus rhythm.

The effects of digitoxin and/or diuretic agents were investigated in patients with congestive heart failure (CHF) in sinus rhythm with respect to changes in hemodynamic parameters, cardiac dimensions, and bicycle ergometric exercise capacity. In a randomized, double-blind study 16 male patients with CHF NYHA class II and III received a placebo for 1 week (baseline) and then were randomly allocated, double blind, to take either digitoxin (digitalis group, DI: N = 8) or trichlormethiazide/amiloride (diuretic group, DG: N = 8) for 3 weeks (VP I). The patients who were first treated with digitoxin received the diuretic agent for a further 3 weeks and vice versa (VP II). At baseline and after VP I and II, a physical examination, two-dimensional echocardiography, and bicycle ergometry were performed. Heart rate (HR), systolic (BPs), and diastolic (BPd) blood pressure at rest, and BPs and 50 watts, were not significantly changed during the observation period. HR at 50 watts was decreased in DI (11.5 +/- 10.1 beats/min.) after VP I and II, but not in DG. BPd was significantly reduced after VP II in DI (8.2 +/- 4.6 mmHg) and in DG (9.3 +/- 8.9 mmHg). DI presents at baseline significantly higher end-diastolic (LVEDV) and end-systolic (LVESV) left ventricular dimensions, whereas left atrial diameter (LA) and stroke volume (SV) and ejection fraction (LVEF) were not significantly different. After VP I, a significantly decreased LA was found in DI, but not in DG. After VP II, all cardiac dimensions were significantly reduced compared with the baseline in DI, whereas in DG only a decrease in LVESV was found. SV was significantly increased in DI, but not in DG after VP I, SV and LVEF were significantly improved in DI and in DG after VP II. Exercise capacity did not change significantly in DI and DG. Digitoxin in combination with trichlormethiazide/amiloride is effective in reducing primarily enlarged left atrial and left ventricular dimensions, and is sufficient to improve the impaired systolic left ventricular function in CHF of NYHA class II and III in sinus rhythm. However, a significant increase in exercise capacity was not found. Treatment with digitoxin seems to be more relevant as a monotherapy with trichlormethiazide/amiloride.

Relation of leisure-time physical activity to structural and functional arterial properties of the common carotid artery in male subjects.

The structure and function of central arteries are altered with advancing age. These changes comprise arterial dilation, intima-media thickening and increase in stiffness. Arterial wall hypertrophy and increased stiffness are associated with major cardiovascular disease. In contrast to this, physical activity has been found to be inversely related to the incidence of major cardiovascular disease and mortality in humans. However, conflicting data exist on the effect of physical activity on arterial stiffness and very little data about its association with structural arterial properties. We therefore investigated the association of the self-selected leisure-time physical activity (LTPA), assessed by a self-administered questionnaire, with the structure and function of the common carotid artery, examined with high-resolution ultrasound, in 51 male subjects aged between 16 and 78 years. We found that men with a higher level of LTPA (> 38.1 MET*h/week = H-LTPA) (metabolic equivalent value; 1 MET= energy expended by a person at rest, i.e. approximately 3.5 ml oxygen uptake/kg body mass or 1 kcal/kg per h) had a significantly lower arterial stiffness (P = 0.02) than men with lower levels ( < 38.1 MET*h/week = L-LTPA) (4.32+/-1.17 versus 5.75+/-1.21 x 10(6) cm(-2)). In multiple regression analyses, with several atherosclerotic risk factors as correlating variables with arterial stiffness, LTPA persisted as an independent predictor of arterial stiffness (adjusted R2=0.19) in addition to apolipoprotein B level (adjusted R2 = 0.33). The study could not, however, show an association of LTPA with reduced intima-media thickness (L-LTPA = 0.66+/-0.15 versus H-LTPA 0.66+/-0.14) or arterial dilation of diastolic diameter (L-LTPA = 6.34 + 0.64 versus H-LTPA 6.08+/-0.69). However, the positive association of LTPA with several parameters, which correlated inversely with intima-media thickness, may be taken as an indicator for a possible positive (not visible in an ultrasonic examination of the common carotid artery) effect of LTPA on the arterial wall structure.

QT dispersion in exercise-induced myocardial hypertrophy.

BACKGROUND: The measurement of QT dispersion in the surface electrocardiogram is a noninvasive method used for assessing inhomogeneity of myocardial repolarization. Elevated QT dispersion is found in myocardial disease and is associated with an increased incidence of arrhythmic events. QT dispersion is also increased in myocardial hypertrophy secondary to systemic hypertension. However, the relation between left ventricular (LV) enlargement in endurance trained subjects and QT dispersion is unknown. METHODS AND RESULTS: In this study, LV mass (2-dimensional echocardiography) and QT dispersion (12-lead resting electrocardiogram) were assessed in 26 normotensive endurance trained subjects and 26 matched, less trained control subjects. Endurance trained subjects had a significantly greater LV mass (216 +/- 39 g vs 155 +/- 30 g, P <.001) but lower heart rate-corrected QTc dispersion (42 +/- 13 ms vs 51 +/- 15 ms, P =.012) than less trained control subjects. When all individuals were included, LV mass was inversely correlated with QT dispersion (r = -0.38; P =.002) and heart rate-corrected QTc dispersion (r = -0.53, P <.0001). CONCLUSIONS: These data show that myocardial hypertrophy induced by exercise training is not associated with increased QT dispersion as observed in systemic hypertension. The reduced QT dispersion reflects homogeneous myocardial repolarization and may help to explain the reduced mortality rate in regularly exercising subjects. If confirmed in further studies, the measurement of QT dispersion could provide a simple and inexpensive screening method for differentiating between physiologic and pathologic myocardial hypertrophy.

Structural, functional, and hemodynamic changes of the common carotid artery with age in male subjects.

Aging of the common carotid artery (CCA) is associated with different principal structural, functional, and hemodynamic changes, which are often influenced by several atherosclerotic risk factors, so that it is difficult to estimate the exclusive effect of aging on this process. Studies dealing with vascular aging of the CCA usually assess only single, dimensional, or functional parameters, although it is likely that there are interactions and probably differences between them. Moreover, regional vascular blood flow characteristics are often not taken into consideration. Therefore, the aim of the study was to assess the age-related multiparametric changes of the CCA properties with ultrasound in 69 male subjects between the ages of 16 and 75 (42.4+/-16.5 years), who were screened for the absence of major atherosclerotic risk factors or existing vascular disease. As a result, the intima media thickness (0.052 mm/10 y) and diastolic diameter (0.17 mm/10 y) increased nearly linearly with age (r=0.60, P<0.001; and r=0.46, P<0.001, respectively). The absolute diastolic/systolic diameter change diminished by 0.10 mm/10 y (r=-0. 73, P<0.001) and peak expansion velocity dropped by 0.12 cm/s per 10 years (r=-0.62, P<0.001) highly significantly with age. The peak blood flow velocity decreased continuously with age (r=-0.67, P<0. 00) by 9.3 cm/s per 10 years. According to multiple regression analysis, peak blood flow velocity seems to reflect the changes of several structural and functional parameters in one; intima-media thickness was determined by diastolic arterial diameter and age as independent variables. The data indicate that a multiparametric assessment may contribute to a better understanding of vascular aging and might be the basis for further studies to evaluate the association of atherosclerotic risk factors and/or major vascular disease with local changes in the CCA.

Cardiac function and haemodynamics in alcoholic cirrhosis and effects of the transjugular intrahepatic portosystemic stent shunt.

BACKGROUND: A portosystemic stent shunt may impair cardiac function and haemodynamics. AIMS: To investigate the effects of a transjugular intrahepatic portosystemic shunt (TIPS) on cardiac function and pulmonary and systemic circulation in patients with alcoholic cirrhosis. PATIENTS/METHODS: 17 patients with alcoholic cirrhosis and recent variceal bleeding were evaluated by echocardiography and catheterisation of the splanchnic and pulmonary circulation before and after TIPS. The period of catheter measurement was extended to nine hours in nine of the patients. The portal vein was investigated by Doppler ultrasound before and nine hours after TIPS. RESULTS: Baseline echocardiography showed the left atrial diameter to be slightly increased and the left ventricular volume to be in the upper normal range. Nine hours after TIPS, the left atrial diameter and left ventricular end diastolic volume were increased (by 6% (p<0.01) and 7% (p<0.01) respectively); end systolic volume had not changed significantly. Invasive measurements showed a sharp increase in right atrial pressure (by 101%; p<0.01), mean pulmonary artery pressure (by 92%; p<0.01), pulmonary capillary wedge pressure (by 111%; p<0.01), and cardiac output (8.1 (1.6) to 11.9 (2.4) l/min; p<0.01). Systemic vascular resistance decreased (824 (242) to 600 (265) dyn.s.cm-5 p<0.01), and total pulmonary resistance increased (140 (58.5) to 188 (69.5) dyn.s.cm-5; p<0.05). Total pulmonary resistance (12%; NS), cardiac output (1.4 l/min; p<0. 05), and portal vein blood flow (1.4 l/min; p<0.05) remained elevated for nine hours after TIPS in the subgroup. Portoatrial pressure gradient (43%; p<0.05), portohepatic vascular resistance (72%; p<0.05), and systemic vascular resistance (27%; p<0.01) were consistently reduced. CONCLUSIONS: The increase in the left atrial diameter, the pulmonary capillary wedge pressure, and total pulmonary resistance observed after the TIPS procedure reflected diastolic dysfunction of the hyperdynamic left ventricle in patients with alcoholic cirrhosis. The haemodynamic effects of the portosystemic stent shunt itself on the splanchnic circulation seem to be mainly responsible for the further decrease in systemic vascular resistance. TIPS may unmask a coexisting preclinical cardiomyopathy in patients with alcoholic cirrhosis and portal hypertension.

Influence of mild to moderately elevated triglycerides on low density lipoprotein subfraction concentration and composition in healthy men with low high density lipoprotein cholesterol levels.

Epidemiologic studies have shown that a dyslipoproteinemia with low concentrations of high density lipoprotein (HDL) cholesterol and elevated serum triglycerides (TG) is associated with a particularly high incidence of coronary artery disease. This lipid profile is associated with increased concentrations of small, dense low density lipoprotein (LDL) particles. To evaluate the role of mild to moderately elevated TG on the LDL subfraction profile in patients with low HDL cholesterol, concentration and composition of six LDL subfractions was determined by density gradient ultracentrifugation in 41 healthy men (31+/-9 years, body mass index (BMI) 25.1+/-3.9 kg/m2) with equally low HDL cholesterol levels < 0.91 mmol/l but different TG levels: TG < 1.13 mmol/l, n = 16; TG = 1.13-2.26 mmol/l, n = 13: TG = 2.26-3.39 mmol/l, n = 12. Those men with moderately elevated TG levels between 2.26 and 3.39 mmol/l had significantly higher concentrations of very low density lipoprotein (VLDL), intermediate low density lipoprotein (IDL), and small, dense LDL apoB and cholesterol than men with TG < 1.13 mmol/l. With increasing serum TG, the TG content per particle also increased in VLDL, IDL as well as total LDL particles while the cholesterol and phospholipid (PL) content decreased in VLDL and IDL, but not in LDL particles. LDL subfraction analysis revealed that only large, more buoyant LDL particles (d < 1.044 g/ml) but not the smaller, more dense LDL, were enriched in TG. Small, dense LDL particles were depleted of free cholesterol (FC) and PL. This study has shown that in men with low HDL cholesterol levels mild to moderately elevated serum TG strongly suggest the presence of other metabolic cardiovascular risk factors and in particular of a more atherogenic LDL subfraction profile of increased concentration of small, dense LDL particles that are depleted in surface lipids.

Physical performance and cardiovascular and metabolic adaptation of elite female wheelchair basketball players in wheelchair ergometry and in competition.

Spinal cord injury leads to a pronounced reduction of cardiovascular, pulmonary, and metabolic ability. Physical activity, up to and including high-performance sports, has obtained importance in the course of rehabilitation and the postclinical phase. Thirteen elite female wheelchair basketball players from the German National Basketball Team and 10 female sedentary spinal cord-injured persons were examined in the study. Heart volume was measured by an echocardiography. All subjects underwent a graded exercise test on a wheelchair ergometer. Additionally, heart rate, lactate, and player points were measured during a competitive basketball game in wheelchair basketball players. Cardiac dimensions were larger for spinal cord-injured wheelchair basketball players (620.3 ml; 9.6 ml x kg(-1)) in comparison with spinal cord-injured persons (477.4 ml; 8.2 ml x kg(-1)) but did not exceed the heart volume of untrained nonhandicapped persons. In contrast, athletes with amputations or those having had poliomyelitis reached training-induced cardiac hypertrophy in relation to body mass (713.7 ml; 13.2 ml x kg(-1)), as observed in nonhandicapped athletes. During graded wheelchair ergometry, wheelchair basketball players showed a higher maximal work rate (59.9 v 45.5 W), maximal oxygen consumption (33.7 v 18.3 ml x min(-1) x kg(-1)), and maximal lactate (9.1 v 5.47 mmol x l(-1)) without a difference in maximal heart rate and workload at AT4 than did spinal cord-injured persons. The average heart rate during the wheelchair basketball game was 151 x min(-1), and the lactate concentration was 1.92 mmol x l(-1). Female athletes with a less severe handicap and higher maximal oxygen consumption during the graded exercise test reached a higher game level in the evaluation. During the competitive basketball game, high cardiovascular stress was observed, indicating a fast aerobic metabolism; the anaerobic lactic acid capacity played a subordinate role. Wheelchair basketball is an effective and suitable sport to enhance physical performance and to induce positive physiological adaptations.