Can aerobic exercise training be hazardous to human vessels?
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Bicycling↗
Biomedical subjects
B Desvaux
Publications and source records attributed to B Desvaux.
Transcutaneous carbon dioxide threshold during exercise.
BACKGROUND: To study the possible use of transcutaneous carbon dioxide pressure measurements to estimate ventilatory threshold during exercise. METHODS EXPERIMENTAL DESIGN: comparative study. SETTINGS: Institutional practice, ambulatory care. Patients and measures: seventy-nine subjects. INTERVENTION: incremental exercise tests with simultaneous recordings of breath by breath gas exchange and transcutaneous carbon dioxide pressure. MEASURES: Six reviewers determined the ventilatory threshold using both the graphs for the carbon dioxide excretion to oxygen consumption relationship: V slope technique (VTa), and the ventilatory equivalent for oxygen uptake changes over time: (VTb), the respiratory compensation point (RCP) on ventilatory equivalent for carbon dioxide, and the transcutaneous threshold (Ttc) on the transcutaneous carbon dioxide pressure changes over time respectively. RESULTS: A Ttc could be defined by all observers in 85% of the subjects. Correlation between Ttc and VT expressed as oxygen consumption absolute values ranged from 0.971 to 0.975 on the mean values of six observers. Using the Bland-Altmann approach, differences (mean +/- SD) were 13 +/- 215, -40 +/- 204, 231 +/- 221 ml.min-1 between Ttc and VTa, RCP respectively. A difference of 38 +/- 173 ml.min-1 was found between VTa and VTb. This suggests that Ttc shows little difference with VT but not with RCP. CONCLUSIONS: We suggest that a carbon dioxide transcutaneous threshold can be found close to the ventilatory threshold. Potential clinical use of transcutaneous device are vast.
Adolescent↗
Ankle-brachial index after maximum exercise in treadmill and cycle ergometers in athletes.
Previous works have focused on the normal ankle and arm pressure response to maximum bicycle exercise or moderate walking tests. The aim of the present work was to compare the normal ankle and arm pressure and ankle-brachial index response to incremental maximum bicycle and treadmill exercise in 13 athletes (11 men, two women, 24 +/- 11 years) No difference was found at rest on both ankle pressure 139 +/- 21 vs. 163 +/- 22 mmHg and ankle-brachial index 1.18 +/- 0.09 vs. 1.17 +/- 0.10 between bicycle and treadmill tests respectively (mean +/- SD). One minute after maximum exercise, no difference in arm pressure was found between bicycle (182 +/- 16 mmHg) and treadmill tests (190 +/- 17 mmHg), whereas ankle pressure was 139 +/- 21 vs. 163 +/- 22 mmHg respectively (P < 0.05). As a result, a significant difference was found in the ankle-brachial index 0.76 +/- 0.10 vs. 0.86 +/- 0.10 (P < 0.05) between bicycle and treadmill ergometers during the first minute of the recovery period. Although performed at comparable workloads, a significant difference was noted between running and cycling tests. Thereby, the limit cut-off point for the diagnosis of lower extremity arterial disease in athletes defined for maximum bicycle tests may not apply to maximum incremental treadmill tests.
Adolescent↗
An evaluation of hyper-oxygenated fatty acid esters in pressure sore management.
The aim of this study was to use transcutaneous oxygen pressure (tcpO2) measurements to evaluate the efficacy of a solution containing hyper-oxygenated fatty acid esters in the prevention of pressure sores in 28 patients at high risk of developing sores. Statistical analysis indicates a significant difference between tcpO2 values during pressure exertion before and after application of the product (p = 0.014). Oxygen pressure values decreased significantly when the patient applied pressure to the sacral area before the test product was applied whereas no difference in oxygen pressure values was noted after application of the test product.
Blood Gas Monitoring, Transcutaneous↗
Ankle to arm index following maximal exercise in normal subjects and athletes.
Recent reports have suggested that minor arterial lesions can be responsible for claudication in athletes occurring only during maximal exercise. Ankle to arm index measurements (AAI) prove the arterial origin of this claudication, but little is known about the normal response of AAI to maximal exercise. Therefore, we studied the response of AAI to maximal exercise in trained and untrained normal subjects. AAI and heart rate (HR) were recorded at rest and following maximal exercise on a cycle ergometer in 15 untrained (VO2 = 41.5 +/- 4.0 ml.kg-1.min-1) and 15 trained (VO2 = 58.4 +/- 2.8 ml.kg-1.min-1) volunteers. All subjects were without known peripheral arterial disease. At rest, AAI was 1.08 +/- 0.08 in untrained subjects and 1.15 +/- 0.05 in trained subjects (P < 0.05). HR was 73.9 +/- 11.0 in untrained subjects and 57.1 +/- 8.3 in trained subjects (P < 0.05). Following exercise, AAI decreased during the first minutes of recovery in all subjects, with a significant difference between untrained and trained subjects. Although untrained subjects sustained a lower workload than trained subjects, at 1 min following exercise AAI was 0.70 +/- 0.06 in untrained versus 0.8 +/- 0.08 in trained subjects (P < 0.05). No difference in AAI to HR relationships was noted between untrained and trained subjects. In conclusion, we suggest that AAI should be interpreted with regard to HR at the end of maximal exercise and we project normal results for the AAI to HR relationships following maximal exercise.
Adolescent↗
Ankle to arm index response to exercise and heat stress in healthy subjects.
Ankle to arm index (AAI) defined as the ratio of ankle systolic blood pressure (ASBP), to brachial systolic blood pressure is largely used in the study of lower extremity arterial disease (LEAD). To study the hypothesis of the shunt of blood away from the skin as the explanation of AAI decrease in exercise, we studied the AAI and ASBP responses to an increase in cardiac output originating from an increase either in muscle blood flow (exercise) or in cutaneous blood flow (thermal stress). Brachial systolic pressure, ankle systolic pressure and heart rate (HR) were measured in 9 healthy subjects at rest, during heart thermal stress and following maximal exercise on a cycle ergometer. Compared to resting values, AAI decreased in all subjects from 1.05 +/- 0.07 to 0.75 +/- 0.07 (P < 0.05) 1 min following exercise and from 1.08 +/- 0.07 to 0.94 +/- 0.05 (P < 0.05) during heat stress. On the other hand, HR increased from 72.8 +/- 12.2 to 112.4 +/- 19.6 (P < 0.05) min following exercise and from 75.5 +/- 13.6 to 96.8 +/- 15.3 (P < 0.05) during heat stress. Since a comparable relation exists between AAI and HR in thermal stress and exercise, we suggest that the decrease in AAI in normal subjects following exercise is due to turbulences at high flow levels, rather than the shunting of blood to active muscles in exercise.
Adult↗
Heart rate-corrected ankle-to-arm index in the diagnosis of moderate lower extremity arterial disease.
UNLABELLED: Although the ratio of ankle-to-arm systolic pressures (AAI) at rest is widely used in the clinical diagnosis of peripheral arterial disease, the heart rate (HR) at which the measurements are performed is rarely reported. The relation of ankle-to-arm index (AAI) to HR was studied in a normal population (n = 65) and in a population of patients (n = 101) suspected of moderate lower extremity arterial disease (LEAD). In the normal population, a significant inverse correlation was found between AAI and HR at rest: AAI = -0.277 x HR/100 + 1.303; r = -0.52, P < 0.001. In the second population suspected of LEAD, the authors recorded AAI and HR at rest on both legs; 80 normal legs, 110 diseased legs. Thereafter, with normal limits as superior to 0.8, 0.9, and 0.95, sensitivity was respectively 16, 39, and 46%, and specificity was 100, 100, and 98%. In defining normal limit as superior to -2 standard deviations of the AAI-HR relation found in the normal population, sensitivity and specificity were 57 and 100%, respectively. IN CONCLUSION: In screening for LEAD in the general population with the use of AAI at rest, the authors suggest that the heart rate at which arterial pressure measurements are performed should be reported.
Adult↗
A comparison of pressure-relieving surfaces using two measures of pressure.
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Adolescent↗
Ankle systolic blood pressure following sub-maximal and maximal exercises in healthy young men.
Although recent studies have compared the effect of progressive exercise tests to constant moderate work load tests on ankle systolic blood pressure (ASBP) and ankle to arm index (AAI) in claudicants, little is known about the relation of ASBP and AAI to work load in healthy young men. Fifteen normal volunteers were asked to cycle 40, 60, 80, 100% of VO2max. Ankle and humeral pressures were recorded simultaneously, at rest and 1 minute after the end of each test. Thereafter, AAI was calculated as the ratio of ankle to humeral systolic pressure. Compared to resting values: 134.8 +/- 13.9 mmHg, ASBP increased significantly following sub maximal tests up to 157.8 +/- 28.1 mmHg (p < 0.005), but was not increased following maximal exercise: 141.5 +/- 28.2 mmHg (NS). On the other hand, AAI showed a progressive decrease from 1.14 +/- 0.06 at rest to 1.06 +/- 0.08 (p < 0.005), but 0.98 +/- 0.07 (p < 0.005), to 0.84 +/- 0.06 (p < 0.005) and to 0.75 +/- 0.09 (p < 0.005) following 40, 60, 80 and 100% of VO2max respectively. In summary, AAI following exercise is inversely related to workload whereas ASBP is not. We suggest that when studying ankle systolic blood pressure response to heavy load exercises, results should always be compared to humeral pressure, and expressed as ankle to arms indexes.
Adult↗
Diameter and blood velocity changes in the saphenous vein during thermal stress.
Although volume, pressure or flow in superficial veins have been studied extensively, little is known about venous blood velocity during thermal stress. Most authors have suggested that the velocity is decreased in the dilated superficial veins during heat stress to facilitate heat loss, and is increased during cooling as the vein is constricted. Duplex ultrasound has been used to study saphenous cross sectional area (CSA) and mean maximal venous blood velocity (BV) in ten healthy volunteers (age 22-31 years). Compared with unstressed mean values, 4.8 (SD 2.6) mm2, CSA increased to 9.3 (SD 2.1) mm2 (P < 0.005) during heat stress and decreased to 2.1 (SD 1.9) mm2 (P < 0.005) during cold stress. These results are consistent with previous studies, but the absolute CSA of the saphenous vein has never been estimated during thermal stress. The BV increased from 0.07 (SD 0.02) m.s-1 to 0.29 (SD 0.11) m.s-1 (P < 0.005) during warming. During cooling, BV tended to decrease: 0.05 (SD 0.03) m.s-1 (N.S). We would suggest that heat loss during thermal stress can be facilitated by the rapid turnover of warm blood, and not (as usually suggested) by the prolonged cooling of each blood sample in the dilated superficial veins.
Adult↗
Diameter and velocity changes in the femoral vein during thermal stress in humans.
Unlike most studies on deep veins performed with simultaneous suppression of cutaneous blood flow, a sonographic study of femoral diameter and blood flow velocity changes in response to thermal stress was performed while cutaneous flow was preserved. In 11 normal subjects, mean peak blood flow velocity and diameter of the femoral vein were measured at rest and during indirect whole body heating and cooling. Mean peak venous blood flow velocity was 0.12 +/- 0.06 m s-1 at rest, 0.35 +/- 0.23 m s-1 (P < 0.001) during heat stress, and 0.13 +/- 0.07 m s-1 during cold stress (NS). Femoral venous diameter was 5.3 +/- 0.9 mm at rest, 5.1 +/- 1.0 mm (P < 0.05) during warming, and 5.4 +/- 81.0 mm (NS) during cooling. This study showed a decrease in diameter during thermal stress. However, as mean femoral venous blood-flow velocity was doubled during heat stress, femoral venous blood flow was increased. Thus, it is suggested that during heat stress part of the increase in cutaneous flow is returned through deep veins.
Adult↗
Venous return in lower limb during heat stress.
We used ultrasound to study venous return during heat stress. We measured venous cross-sectional area (CSA) and blood flow velocity (BFV) of nine femoral veins and nine saphenous veins. During heat stress, saphenous CSA increased from 4.7 +/- 2.6 mm2 (mean +/- SD) to 9.1 +/- 2.3 mm2 (P < 0.01), whereas femoral CSA was 22.7 +/- 9.5 mm2 at rest and 22.0 +/- 9.6 mm2 during heat stress (NS). Meanwhile, BFV increased from 0.06 +/- 0.02 to 0.30 +/- 0.10 m/s (P < 0.01) in the saphenous vein and from 0.14 +/- 0.08 to 0.38 +/- 0.23 m/s (P < 0.005) in the femoral vein. Maximal venous outflow (MVO) was the product of CSA and BFV. During heat stress, MVO showed an eightfold increase in the saphenous veins (from 22.7 +/- 18.2 to 180.7 +/- 86.7 ml/min) and a 2.5-fold increase in the femoral veins (from 143.4 +/- 52.9 to 354.0 +/- 126.9 ml/min). The results showed that one-half of the cutaneous blood flow increase during heat stress returned through the deep collecting veins in the lower limb. Thereafter, although there was no venodilation of deep veins compared with superficial veins, the deep veins remain the main pathway for the venous return during heat stress.
Adult↗
Transvenous interruption of the inferior vena cava. New model of vena cava filter. Preliminary results in 35 cases.
Partial interruption of inferior vena cava (I.C.V.) forms an integral part of treatment of thromboembolic disease. The most frequently used filter worldwide is currently that of Greenfield, but although its effectiveness and permeability are remarkable it can be the subject of transfixions, sliding movements and migrations. A new model of the authors' own conception is presented which eliminates these faults. The "2612" filter is based on the same concepts, but has added to it 6 lateral flanges soldered to the base of the arms, these applying pressure to the I.V.C. and ensuring its perfect positioning, and 12 hooks (6 turned downwards and 6 upwards) ensuring perfect stability. Results of a multicentre trial in 35 patients, after insertion of the "2612" filter and follow-up assessment after 3 months (28 cases) by cavography and in some patients by a scan, showed permeability of 93% and total efficacy. No side effects were reported. This filter appears to represent true progress in the means of interrupting I.V.C., and further studies are contemplated.
Adult↗