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PubMed2005

Arterial stiffness index as a screening test for cardiovascular risk: a comparative study between coronary artery calcification determined by electron beam tomography and arterial stiffness index determined by a VitalVision device in asymptomatic subjects.

BACKGROUND: Arterial stiffness has recently been proposed as a powerful independent predictor of cardiovascular disease. However, the influence of arterial stiffening on the interaction between the heart and large vessels and atherosclerosis is not well defined. The arterial stiffness index (ASI) has recently been determined with a new device (VitalVision) that calculates ASI in the upper arm using computerized oscillometry. Coronary artery calcification (CAC) is a useful surrogate marker of coronary artery disease detected non-invasively by electron beam tomography (EBT). We investigated the correlation between ASI and CAC in a group of patients. METHODS: CAC and ASI measurements were determined with EBT and a VitalVision device, respectively, on the same day in 97 asymptomatic patients. Patients with calcium scores above 0 were classified as CAC+ and those with calcium scores equal to 0 were classified as CAC-. The ASI index was divided into three groups - mild, moderate, and high - according to the H-value, provided by the VitalVision device. RESULTS: In patients below 51 years of age, no correlation between the ASI and CAC was found. In patients over 50 years of age, a moderate positive and significant correlation was found between the CAC score and ASI measurements (r=0.40, p=0.001). CONCLUSIONS: The presence of a correlation between the CAC and ASI in patients over 50 shows that the ASI can be used to investigate atherosclerotic risk.

Journal Article↗
PubMed2004

An ultrasound-based method for determining pulse wave velocity in superficial arteries.

In this paper, we present a method for estimating local pulse wave velocity (PWV) solely from ultrasound measurements: the area-flow (QA) method. With the QA method, PWV is estimated as the ratio between change in flow and change in cross-sectional area (PWV = dQ/dA) during the reflection-free period of the cardiac cycle. In four anaesthetized dogs and 21 human subjects (age 23-74) we measured the carotid flow and cross-sectional area non-invasively by ultrasound. As a reference method we used the Bramwell-Hill (BH) equation which estimates PWV from pulse pressure and cross-sectional area. Additionally, we therefore measured brachial pulse pressure by oscillometry in the human subjects, and central aortic pulse pressure by micro-manometry in the dogs. As predicted by the pressure dependency of arterial stiffness, the estimated PWV decreased when the aortic pressure was lowered in two of the dogs. For the human subjects, the QA and BH estimates were correlated (R=0.43, p<0.05) and agreed on average (mean difference of -0.14 m/s). The PWV by the BH method increased with age (p<0.01) whereas the PWV by the QA method tended to increase with age (p<0.1). This corresponded to a larger residual variance (residual = deviation of the estimated PWV from the regression line) for the QA method than for the BH method, indicating different precisions for the two methods. This study illustrates that the simple equation PWV = dQ/dA gives estimates correlated to the PWV of the reference method. However, improvements in the basic measurements seem necessary to increase the precision of the method.

Adult↗
PubMed2004

Anesthetic and physiologic effects of tiletamine, zolazepam, ketamine, and xylazine combination (TKX) in feral cats undergoing surgical sterilization.

Tiletamine (12.5 mg), zolazepam (12.5 mg), ketamine (20 mg), and xylazine (5 mg) (TKX; 0.25 ml, IM) combination was evaluated as an anesthetic in 22 male and 67 female adult feral cats undergoing sterilization at high-volume sterilization clinics. Cats were not intubated and breathed room air. Oxygen saturation (SpO(2)), mean blood pressure (MBP), heart rate (HR), respiration rate (RR), and core body temperature were recorded. Yohimbine (0.25 ml, 0.5 mg, IV) was administered at the completion of surgery. TKX produced rapid onset of lateral recumbency (4+/-1 min) and surgical anesthesia of sufficient duration to complete surgical procedures in 92% of cats. SpO(2) measured via a lingual pulse oximeter probe averaged 92+/-3% in male cats and 90+/-4% in females. SpO(2) fell below 90% at least once in most cats. MBP measured by oscillometry averaged 136+/-30 mm Hg in males and 113+/-29 mm Hg in females. MBP increased at the onset of surgical stimulation suggesting incomplete anti-nociceptive properties. HR averaged 156+/-19 bpm, and RR averaged 18+/-8 bpm. Neither parameter varied between males and females or over time. Body temperature decreased significantly over time, declining to 38.0+/-0.8 degrees C at the time of reversal in males and 36.6+/-0.8 degrees C at the time of reversal in females. Time from anesthetic reversal to sternal recumbency was prolonged (72+/-42 min). Seven cats (8%) required an additional dose of TKX to maintain an adequate plane of anesthesia at the onset of surgery, and this was associated with significantly longer recovery times (108+/-24 min).

Anesthesia↗
PubMed2006

Lung function in preschool children: applications in clinical and epidemiological research.

During recent years there has been significant development of pulmonary function tests for use in preschool children. A range of tests including multiple inert gas washout, plethysmography, spirometry, interrupter resistance and impulse oscillometry have been shown to be feasible and to be able to identify diminished lung function in children with lung disease such as asthma or cystic fibrosis. An overview of these applications in clinical and epidemiological research is given. Future applications to investigate the longer term effect of preterm delivery, intra-uterine growth retardation, smoking and assessing the response to therapeutic intervention would strengthen the scientific basis for the prevention and treatment of respiratory disease in early life.

Airway Resistance↗
PubMed2004

Single-isomer R-salbutamol is not superior to racemate regarding protection for bronchial hyperresponsiveness.

Bronchial hyper-reactivity (BHR) has been suggested to follow cessation of regular medication with racemic salbutamol. This study aimed at investigating the effects from medication with R,S- and R-salbutamol on bronchial response to provocation with isocapnic hyperventilation of cold air (IHCA). Twenty-six patients with mild to moderate asthma were enrolled in a double-blind, randomised, cross-over study. Bronchial response to provocation was measured before and after 1 week's medication. Doses of 0.63 mg R-salbutamol or 1.25 mg R/S-salbutamol were inhaled three times daily during medication-weeks and a wash-out week intervened. Tests were performed 6 h after the last dose of test drug. Impulse oscillometry and forced expiratory volume during one second were methods used to identify bronchial response to provocation. Two patients withdrew from the investigation due to side-effects, one from R- the other from R,S-salbutamol. Comparable resting bronchial conditions were indicated by differences in baseline lung function values of <2% between study days. No statistically significant medication-dependent differences in BHR could be demonstrated between treatment groups. However, 15 patients exhibited higher (P = 0.03) post-treatment BHR after pure R-salbutamol than after R,S-salbutamol. Furthermore, plasma concentrations of R-salbutamol tended to be lower (P = 0.08) after medication with R- than after R,S-salbutamol despite equal doses of R-salbutamol given during the two separate treatment periods. We also found that considerable amounts of S-salbutamol were retrieved in plasma after medication with pure R-salbutamol. We conclude that we were unable to demonstrate favourable effects of R-salbutamol over R,S-salbutamol regarding response to provocation with IHCA after regular medication of 1 week's duration.

Adult↗
PubMed1998

Comparative accuracy of three automated techniques in the noninvasive estimation of central blood pressure in men.

Automated devices have regularly replaced manual sphygmomanometry for the determination of blood pressure not only in homes and clinics, but also in emergency and critical care settings. Few studies exist that correctly assess the accuracy of these devices, and even fewer that specifically compare commercially available units that rely on different physiologic events for measurement. Six hundred pressure measurements were obtained from 120 subjects using 1 of 3 randomly selected blood pressure monitors. In addition, central arterial pressure measurements were obtained simultaneously and directly from the ascending aorta of each subject. Overall, these devices tended to overestimate diastolic (+2.5 mm Hg, p < 0.0001) and mean (+3.8 mm Hg, p < 0.0001) pressures, but not systolic (+0.7 mm Hg, p = NS) pressure. Compared with the other 2 devices, device I, relying on oscillometric detection, demonstrated a significantly smaller mean absolute error for diastolic pressure (4.9 +/- 3.0 vs 7.0 +/- 4.8 and 6.2 +/- 5.3 mm Hg, p < 0.0001) and mean pressure (4.0 +/- 3.2 vs 7.8 +/- 5.9 and 8.6 +/- 7.5 mm Hg, p < 0.0001), and a trend toward smaller error with systolic pressure (6.8 +/- 6.5 vs 7.3 +/- 6.8 and 8.0 +/-5.6 mm Hg, p = 0.19). Clinically significant (+/-10 mm Hg) errors were common with each device (24.8% overall), but serious (+/-20 mm Hg) errors were unusual (3.2%) and did not occur at all with device I during diastolic and mean pressure measurement. All of the devices tested could be expected to perform satisfactorily in most clinical settings provided that an average error of 4.0 to 8.6 mm Hg is tolerable. This level of accuracy typically extended throughout the range of pressures anticipated in most noncritical clinical situations. As implemented in the devices tested, noninvasive measurement by oscillometry with stepped deflation is more accurate than automated auscultation.

Adult↗
PubMed2003

Influence of the concentration of a gelling agent and the type of surfactant on the rheological characteristics of oleogels.

The investigation on the influence of components that contribute diverse degrees of viscosity to the formulations is of great interest in medicines for topical use. It is such the case of a derivative of the cellulose--ethylcellulose--that participates in the formula of the oleogels of olive oil as a gelificant agent. Surfactant agents--Olivem--can also modify the rheological characteristics of oil gels. In this work, it is studied how the variation of the concentration of ethylcellulose (3-5%) notably changes the viscosity of the prepared ones. The most concentrated preparations in gelling agent are the most viscous and also present a plastic material, whereas the minor concentration awards a Newtonian character to the prepared ones. On the other hand, the influence of the temperature has been investigated--25 and 37 degrees C--verifying that the viscosity of the samples diminishes with the increase of temperature. The influence of the addition of surfactant products--Olivem 900, 700 and 300--has given a result that prepared with major viscosity are those which include Olivem 900 that can be qualified like plastic. The most fluid prepared are those which have been elaborated with Olivem 300, and their liquid character has been confirmed by rheological measurements--viscometry, oscillometry and creep-recovery. Many applications can be foreseen in pharmaceutical as well as in the cosmetic area where the use of natural vegetable oils as vehicles for drugs is large.

Gels↗
PubMed2003

Value of the micropig model of menopause in the assessment of benefits and risks of postmenopausal therapies for cardiovascular and reproductive tissues.

OBJECTIVE: To extend the comparative database demonstrating the cardioprotective benefits of estrogen therapy to an additional relevant species and to assess the usefulness of this model for studies designed to assess benefits and risks of postmenopausal therapies. DESIGN: Prospective, randomized, controlled periclinical trial. SETTING: Medical university animal facility. ANIMAL(S): Fifteen sexually mature Yucatan micropigs and 15 ovariectomized micropigs. INTERVENTION(S): Oral conjugated equine estrogens (CEE), 0.625 mg/d, or levormeloxifene, 37.5 mg/d, for 182 days. MAIN OUTCOME MEASURE(S): Coronary artery atherosclerosis was measured by digitization, uteri were weighed, and uterine and mammary tissues were evaluated histologically and morphometrically. Mean blood pressure was measured by oscillometry, C-reactive protein by enzyme-linked immunosorbent assay, and serum lipids by enzymatic methods. RESULT(S): Coronary artery atherosclerosis was reduced 51% in animals that received CEE compared with controls. Levels of C-reactive protein increased by 12% with both treatments. Serum lipid levels and mean blood pressure did not differ among groups. Levormeloxifene produced a 5.9-fold increase in the uterine-to-body weight ratio. Histologic and morphometric data indicate that levormeloxifene has uterotrophic and mammotrophic effects. CONCLUSION(S): The micropig model extends the comparative evidence for cardioprotection provided by estrogen therapy to an additional highly relevant species, thus supporting the rationale for a clinically beneficial role of estrogen for the heart. The marked uterine effects of levormeloxifene detected by this model are probably highly predictive of the adverse events that would be encountered in clinical trials.

Animals↗
PubMed1997

Influence of thoracoabdominal pattern of breathing on respiratory resistance.

The purpose of this study was to test the hypothesis that voluntary changes in thoracoabdominal pattern of breathing may increase total respiratory resistance. Thirty-one normal subjects were asked to control their thoracoabdominal pattern of breathing by using a visual feedback. Thoracic and abdominal volume changes were measured by inductance plethysmography. Respiratory resistance and elastance were measured by forced oscillometry. The mean (+/-SD) percent thoracic contributions to tidal volume during thoracic or abdominal breathing were 75 (+/-11) and 25% (+/-9), respectively. These changes induced small but significant increases in resistance (P < 0.005) and elastance (P < 0.002). The increased resistance was observed in 22 subjects for thoracic breathing (P < 0.016) and in 21 subjects for abdominal breathing (P < 0.043). The mean value (+/-SD) of individual increases in resistance during thoracic or abdominal breathing, compared with normal breathing, were 9.2 +/- 17.5 and 9.4 +/- 19.9%, respectively. The fact that departing from spontaneous pattern increases respiratory resistance is consistent with the notion that breathing pattern is optimally adjusted on the basis of mechanical criteria.

Abdomen↗
PubMed1998

Long-term postoperative cognitive dysfunction in the elderly ISPOCD1 study. ISPOCD investigators. International Study of Post-Operative Cognitive Dysfunction.

BACKGROUND: Long-term postoperative cognitive dysfunction may occur in the elderly. Age may be a risk factor and hypoxaemia and arterial hypotension causative factors. We investigated these hypotheses in an international multicentre study. METHODS: 1218 patients aged at least 60 years completed neuropsychological tests before and 1 week and 3 months after major non-cardiac surgery. We measured oxygen saturation by continuous pulse oximetry before surgery and throughout the day of and the first 3 nights after surgery. We recorded blood pressure every 3 min by oscillometry during the operation and every 15-30 min for the rest of that day and night. We identified postoperative cognitive dysfunction with neuropsychological tests compared with controls recruited from the UK (n=176) and the same countries as study centres (n=145). FINDINGS: Postoperative cognitive dysfunction was present in 266 (25.8% [95% CI 23.1-28.5]) of patients 1 week after surgery and in 94 (9.9% [8.1-12.0]) 3 months after surgery, compared with 3.4% and 2.8%, respectively, of UK controls (p<0.0001 and p=0.0037, respectively). Increasing age and duration of anaesthesia, little education, a second operation, postoperative infections, and respiratory complications were risk factors for early postoperative cognitive dysfunction, but only age was a risk factor for late postoperative cognitive dysfunction. Hypoxaemia and hypotension were not significant risk factors at any time. INTERPRETATION: Our findings have implications for studies of the causes of cognitive decline and, in clinical practice, for the information given to patients before surgery.

Abdomen↗
PubMed1991

[Controlled trial of a non-invasive continuous blood pressure monitor: Cortronic AMP 770].

The performances of a Cortronic AMP 770 monitor, a new apparatus for non invasive continuous blood pressure monitoring was assessed. Its working principle is derived from oscillometry. The blood pressure cuff is kept at a low pressure (about 20 mmHg), and the oscillations induced by the arterial pulse are converted into blood pressure. Systolic, mean and diastolic blood pressure was measured in 9 healthy volunteers, under physiological conditions, using both the AMP 770 and a traditional oscillometer (Physiogard SM 785 NI, Odam). A group of 124 paired measurements was obtained, with values ranging from 87 to 150 mmHg for systolic pressure, from 48 to 97 mmHg for diastolic pressure, and from 63 to 114 mmHg for mean pressure. The mean differences (APM 770-Physiogard) were -1.2 +/- 10 mmHg for systolic pressure, 3.2 +/- 8 mmHg for diastolic pressure, and -3.8 +/- 8 mmHg for mean pressure. There was no correlation between blood pressure levels and discrepancy in the measurements obtained with the two methods. The Cortronic AMP 770 was reliable under normal circumstances, when compared with a traditional oscillometer. However further studies are required to assess its reliability under pathological circumstances (severe hypotension or hypertension, arrhythmias and sudden changes in blood pressure).

Adult↗
PubMed2005

Predictors of body mass index and associations with cardiovascular risk factors in Australian children: a prospective cohort study.

OBJECTIVE: To examine predictors of body mass index (BMI) at the age of 8 y in a prospective study of Australian children. DESIGN: Longitudinal survey of a cohort of Australian children followed from the 16th week of gestation to 8 y. SUBJECTS: In total, 741 boys and 689 girls who attended the survey as 8 y olds. MEASUREMENTS: Weight and height, blood pressure measured by automated oscillometry, fasting blood lipids and glucose. Questionnaire assessment of activity and diet. RESULTS: Proportions of overweight including obesity in boys and girls were, respectively, 22 and 25% at 1 y, 14 and 14% at 3 y, 13 and 18% at 5 y and 15 and 20% at 8 y. At the age of 1, 3, 6 and 8 y, children with overweight including obesity showed significantly more adverse cardiovascular risk factors. Blood pressure (BP) was significantly higher by 2/3 mmHg (systolic/diastolic) at 1 y, 3/2 mmHg at 3 y, 4/2 mmHg at 5 y and 6/2 mmHg at 8 y; HDL was significantly lower (P=0.002) by 8% and triglycerides were significantly higher by 27% (P<0.001). In multivariate regression, BMI at the age of 8 y was significantly predicted positively by birth weight, mother's BMI and hours spent in watching television at the time of the survey of 6 y olds. Mothers being ex-smokers or non smokers and children being 'slightly active' and 'active' negatively predicted BMI in 8 y olds. In a subset of 298 children with information about fathers, paternal BMI was an additional independent predictor. Maternal or paternal overweight including obesity each independently increased risk of overweight including obesity at the age of 8 y three-fold. A food factor with consumption of cereals and breads as the major components derived from a Food Frequency Questionnaire in a subset of 340 children was also an independent negative predictor of BMI in multivariate models. CONCLUSION: The increasing rate of overweight including obesity, particularly in girls, is associated with an increase in cardiovascular risk factors very early in life. Improvement of health-related behaviours within the family and a focus on promotion of activity in children should be priorities in achieving weight control.

Birth Weight↗
PubMedDate not supplied

Mean arterial pressures during the first 24 hours of life in < or = 600-gram birth weight infants.

OBJECTIVE: To determine mean arterial pressure values during the first 24 hours for "stable" and "unstable" extremely low birth weight (ELBW) infants and to ascertain its association with perinatal factors. BACKGROUND: In ELBW infants, hypotension is diagnosed by nonspecific clinical signs together with reference arterial pressure values extrapolated from regression models or from scarce actual observations. DESIGN: Retrospective cohort study. METHODS: 101 ELBW (< or = 600 g) infants born in our medical center (1989-2000). Considered stable were 36 infants with umbilical cord hemoglobin > or = 14 g/dl who, although mechanically ventilated, had normal acid-base balance, no patent ductus arteriosus, had not received indomethacin, steroids, muscle relaxants, narcotics, were never treated for hypotension and survived at least 7 days. The remaining 65 infants constituted the unstable group. Arterial pressures were determined by oscillometry (OBP) and direct transducer readings through an umbilical line (MAP). All admission and 10% of the readings were by OBP; the remaining 1877 measurements were by MAP. RESULTS: Stable and unstable infants were similar in birth weight, demographics, history of chorioamnionitis, antepartum steroids, low Apgar scores, administration of epinephrine during resuscitation, and sepsis. Stable infants were different from unstable in gestational age (27+/-2 vs 25+/-2 weeks' gestational age [w GA]), history of preterm labor, preeclampsia, and neonatal mortality (22 vs 68%). Admission OBP (30+/-7 vs 29+/-10 Torr) were similar and 1-hour MAP were different (30+/-6 vs 27+/-7 Torr) between both groups. MAP for stable infants was higher throughout the 24 hours. Greater differences were noted between 3 and 6 hours when 34 of 65 unstable infants were treated for hypotension. Mean MAP and 10 percentile values for stable infants at 1, 3, 6, 12, and 24 hours were 30 (22), 31 (24), 32 (25), 34 (24), and 35 (28) Torr, respectively. MAPs did not correlate with birth weight, but they were lower among 19 stable infants < or = 26 w GA than among 17 stable infants > or = 27 w GA. History of preeclampsia, antenatal steroids, intratracheal epinephrine and cord hemoglobin did not influence MAP. Low 1-minute Apgar score and intracranial hemorrhage were associated with low MAP during the first day. CONCLUSION: There is a wide variation of GA among ELBW infants. MAPs increase with GA and with postnatal age. Shortly after birth, arterial pressures are similar for stable and unstable infants. Failure to increase MAP between 3 and 6 hours of life should create concern. MAP < or = 28 Torr at 3 hours of life is a reasonable, but not absolute, predictor of the need for hypotension treatment.

Apgar Score↗
PubMedDate not supplied

Mean arterial pressure in extremely low birth weight concordant and discordant twins during the first day of life.

OBJECTIVE: To determine mean arterial pressure (MAP) values during the first 24 hours for stable concordant and discordant extremely low birth weight (ELBW) twins and to ascertain its association with perinatal factors. BACKGROUND: In ELBW infants, whether singletons or concordant or discordant twins, hypotension is diagnosed by nonspecific clinical signs together with reference arterial pressure values extrapolated from regression models or from scarce actual observations. DESIGN: Retrospective cohort study. METHODS: We studied 26 sets of concordant and 29 sets of discordant twins, one of whom in each set weighed < or = 800 g at birth. Infants with umbilical cord hemoglobin > or = 14 g/dl and who, although mechanically ventilated, had normal acid-base balance, no patent ductus arteriosus, had not received indomethacin, steroids, muscle relaxants, narcotics, were never treated for hypotension, and survived at least 7 days were considered stable. Arterial pressures were determined by oscillometry (OBP) and direct transducer readings using an umbilical line (MAP). All admission and 10 % of the subsequent readings were measured by OBP; the remaining were measured by MAP. RESULTS: Concordant and discordant twins were similar in demographics, history of chorioamnionitis, preeclampsia, antepartum steroids, cesarean delivery, and neonatal morbidity, but were different in mean birth weight (700 and 789 g), and gestational age (GA) (25 and 27 weeks). Forty-four (82%) of all concordant and 14 (26%) of 58 discordant twins were treated empirically for hypotension. Head ultrasounds were normal or showed Grade I/II in 74% concordant, 81% discordant, and 80% discordant infants with twin-to-twin transfusion syndrome (TTTX). Neonatal mortality was 46%, 45%, and 47%, respectively. There were 14 stable concordant and 22 stable discordant. Their MAPs were different at 1 hour (29 and 34 Torr), 3 hours (29 and 35 Torr), 6 hours (30 and 37 Torr), 12 hours (31 and 36 Torr), 18 hours (33 and 35 Torr), and 24 hours (34 and 36 Torr), respectively. Twenty-six small and 26 large concordant infants had similar MAP from the 1st (27 and 28 Torr) to the 24th hour of life (43 and 43 Torr). Concordant males (often not stable) had lower MAP than concordant females. Seventeen small discordant twins had lower MAP from 1 to 24 hours (28 and 33 Torr) than 17 large discordant twins without TTTX (32 and 38 Torr). Small discordant twins with (donors) and without TTTX had similar trends and MAP values. Large discordant twins with TTTX (recipient) had the highest MAP from birth to 24 hours than any other subgroup of infants and, unlike the others, the MAP trend decreased over time. MAP correlated with GA but not with very low birth weight (< or = 750 g), although with the same GA, those with higher birth weights had higher MAP, and at the same birth weight younger GA twins had lower MAP values. CONCLUSION: MAP increases from birth to 24 hours in all concordant and discordant twins regardless of condition (stable or unstable), birth weight (large or small) or GA. Recipient TTTX twins had higher MAP throughout but, unlike the other twins, it declined over 24 hours. Small discordant and donor TTTX infants should be considered intrauterine growth restricted and are expected to have MAP commensurable to their GA and not to their birth weight.

Apgar Score↗
PubMed2003

Mean arterial pressure in very low birth weight (801 to 1500 g) concordant and discordant twins during the first day of life.

OBJECTIVE: To determine retrospectively mean arterial pressure (MAP) for stable and unstable concordant and discordant very low birth weight (VLBW: 801 to 1500 g) twins during the first 24 hours of life. BACKGROUND: Morbidity and mortality are much higher for extremely low birth weight (ELBW < or =800 g) than for VLBW twins. Recently, we reported MAP trends and reference values in concordant and discordant ELBW twins. No comparable information is available for VLBW infants. DESIGN: Retrospective cohort study. METHODS: We studied 48 sets of concordant and 40 sets of discordant (birth weight difference > or =20%) consecutively born VLBW twins. Stable patients were defined as having umbilical cord hemoglobin > or =14 g/dl, nonacidotic blood gases, never treated for hypotension and survived at least 7 days. MAPs (Torr) were measured by oscillometry in 3163 and by transducer via umbilical artery in 2028 instances. RESULTS: Concordant and discordant twins were similar in demographics, history of twin-twin transfusion (TTTX), antenatal steroids, chorioamnionitis, pre-eclampsia, cesarean delivery, cord hemoglobin, normal head ultrasounds or I to II intracranial hemorrhage (97 and 99%) and neonatal mortality (4 and 5%), but were different in incidence of preterm labor (83 and 58%), birth weight (1227 and 1509 g) and gestational age (GA) (30 and 32 weeks). In all, 66 (69%) concordant twins and 61 (76%) discordant twins were stable. Stable concordant twins, whether small or large, had comparable MAP on admission that increased to 24 hours. Twins of < or =32 weeks GA had lower MAP throughout than those of > or =33 weeks GA. Although their mean birth weights were similar (1262 and 1274 g), 23 stable concordant males had significantly higher MAP than 43 concordant females. Stable discordant twins were divided into 31 small (1241 g) and 30 large (1845 g); their MAPs were different (p<0.05): 35 and 39 (admission), 35 and 39 (1 hour), 36 and 46 (6 hours), 38 and 41 (12 hours), 40 and 41 (18 hours) and 42 and 42 (24 hours) Torr. In all, 88% of small discordant twins were IUGR and 91% of large discordant twins had normal growth. TTTX syndrome occurred in 12 monochorionic sets. Nine of 12 donors were IUGR while 10 of 12 recipients had normal growth. Four of 12 donors had grades III to IV intracranial hemorrhage, eight donors and all 12 recipients had normal ultrasounds. Although their cord hemoglobin levels were similar, donor and recipient MAPs were higher than in any other group and, opposite to concordant and discordant twins, their values decreased from birth to 24 hours. CONCLUSION: In stable concordant, stable discordant, and small and large discordant twins, MAP correlates with birth weight, GA and postnatal age, and increases during the first 24 hours. In recipient and donor twin-twin transfusion infants, MAP is higher throughout and declines over time.

Birth Weight↗
PubMed2005

Mean arterial pressure in concordant and discordant triplets during the first week of life.

OBJECTIVE: To retrospectively determine mean arterial pressure (MAP) for stable concordant and discordant triplets during the first 7 days of life. BACKGROUND: Morbidity and mortality for prematurely born triplets is high, therefore, MAP monitoring during the first day of life is important for their clinical management. MAP reference values for special populations such as triplets have not been published. Recently, we reported that in stable discordant twins MAP values during the first day of life were significantly lower in the smaller than in their larger siblings. Comparable information for triplets is not available. DESIGN: Retrospective cohort study. METHODS: We studied 30 sets of concordant and 29 sets of discordant (birth weight difference > or =20%) consecutively born triplets. Stable patients were defined as those having umbilical cord hemoglobin > or =13 g/dl, normal blood gases, who were never treated for hypotension, and survived at least 7 days. MAP (torr) were measured by oscillometry in 3410, and by transducer via an umbilical arterial catheter in 1251 instances. RESULTS: Concordant and discordant triplets were similar in demographics, history of preterm labor (63 and 63%), chorioamnionitis (10 and 10%), pre-eclampsia (53 and 48%), cesarean delivery (100 and 100%), antenatal steroids (77 and 73%), cord hemoglobin (16 and 16 g/dl), combined triplets birth weight (4922 and 4732 g), gestational age (32 and 33 weeks), normal head ultrasounds or Grade I intracranial hemorrhage (96 and 100%) and neonatal mortality (2 and 1%), but were different in the number of infants requiring mechanical ventilation (57 and 31%). A total of 80 (89%) concordant triplets and 77 (88%) discordant triplets were stable according to our definition. Concordant stable triplets, whether small, medium or large, had similar MAP at birth. Their MAP values increased noticeably from birth to 24 hours and more subtlely to 7 days. Triplets of < or =32 weeks GA had lower MAP throughout than those of > or =33 weeks GA. Discordant stable triplets were divided into 27 small (1382 g), 26 medium (1683 g) and 27 large (1969 g); during the first 24 hours, medium and smaller triplets had MAP values that were lower than those of their larger siblings. From the second to the seventh day of life, all MAP values and trends were similar. Among discordant triplets, 86% of the smallest, 13% of the medium and 13% of the largest infants had asymmetrical intrauterine growth restriction. CONCLUSION: In stable concordant and stable discordant triplets, MAP correlates with birth weight, gestational age and postnatal age. MAP values increase noticeably during the first 24 hours and more subtlely during the next 7 days. Concordant or discordant, small, medium, and large triplets have similar MAP values and trends to that of their siblings. Small and medium discordant triplets have lower MAP values during the first day of life than their larger siblings but by the second day there MAP trends and values were no longer different.

Age Factors↗
PubMed2007

Isometric handgrip training does not improve flow-mediated dilation in subjects with normal blood pressure.

Isometric HG (handgrip) training lowers resting arterial BP (blood pressure), yet the mechanisms are elusive. In the present study, we investigated improved systemic endothelial function as a mechanism of arterial BP modification following isometric HG training in normotensive individuals. This study employed a within-subject repeated measures design primarily to assess improvements in BA FMD (brachial artery flow-mediated dilation; an index of endothelium-dependent vasodilation), with the non-exercising limb acting as an internal control. Eleven subjects performed four 2-min unilateral isometric HG contractions at 30% of maximal effort, three times per week for 8 weeks. Pre-, mid- and post-training resting ABP and BA FMD (exercised arm and non-exercised arm) were measured via automated brachial oscillometry and ultrasound respectively. BA FMD (normalized to the peak shear rate experienced in response to the reactive hyperaemic stimulus) remained unchanged [exercised arm, 0.029+/-0.003 to 0.026+/-0.003 to 0.029+/-0.004%/s(-1) (pre- to mid- to post-training respectively); non-exercised arm, 0.023+/-0.003 to 0.023+/-0.003 to 0.024+/-0.003%/s(-1) (pre- to mid- to post-training respectively); P=0.22]. In conclusion, improved systemic endothelial function is unlikely to be responsible for lowering arterial BP in this population.

Adult↗
PubMed2002

Influence of lipoprotein(a) on restenosis after femoropopliteal percutaneous transluminal angioplasty in Type 2 diabetic patients.

OBJECTIVE: The influence of vascular morphology and metabolic parameters including lipoprotein(a) (Lp(a)) on restenosis after peripheral angioplasty has been compared in Type 2 diabetes (DM) vs. non-diabetic patients (ND). RESEARCH DESIGN AND METHODS: The clinical course and risk profile of 132 (54 DM vs. 78 ND) patients with peripheral arterial occlusive disease (PAD) were observed prospectively following femoropopliteal angioplasty (PTA). Clinical examination, oscillometry, ankle brachial blood pressure index (ABI) and the toe systolic blood pressure index (TSPI) were used during follow-up. Duplex sonography and reangiography were also used to verify suspected restenosis or reocclusion. RESULTS: At the time of intervention patients with DM had a lower median Lp(a) of 9 vs. 15 mg/dl (P < 0.01) in patients without diabetes. Recurrence within 1 year after PTA occurred in 25 diabetic (= 46%, Lp(a) 12 mg/dl) and 30 non-diabetic (= 38%, Lp(a) 48 mg/dl) patients. DM patients with 1 year's patency had a median Lp(a) of 7 vs. 11 mg/dl in non-diabetic patients (P < 0.05). However, 12 months after angioplasty Lp(a) correlated negatively with the ABI (r = -0.44, P < 0.01) in diabetic and in non-diabetic patients (r = -0.20, P < 0.05). The probability of recurrence after PTA continuously increased with higher levels of Lp(a) in each subgroup of patients. CONCLUSIONS: Our data indicate that Lp(a) is generally lower in those with peripheral arterial occlusive disease and Type 2 diabetes than in non-diabetic individuals. The increased risk for restenosis with rising levels of Lp(a) is set at a lower Lp(a) in diabetes and may be more harmful for diabetic patients.

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