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PubMed1997

Clinical and echocardiographic correlates of mitral E-wave transmission inside the left ventricle: potential insights into left ventricular diastolic function.

The mitral inflow wave is initially directed to the left ventricular apex and then turns around facing the left ventricular outflow tract. The E and A waves are transmitted to the left ventricular outflow tract where they are registered as Er and Ar waves, respectively. We hypothesized that the E-wave transit time to the left ventricular outflow tract recorded as the E-Er interval may depend on left ventricular early diastolic performance such as relaxation. This hypothesis was tested in clinical settings known to have abnormal left ventricular relaxation. Mitral E and left ventricular outflow tract Er waves were recorded with pulsed wave Doppler technique in 63 subjects: 25 healthy subjects, 18 patients with secondary left ventricular hypertrophy, and 20 patients with hypertrophic cardiomyopathy. The E-Er interval was measured from the onset of E wave to the onset of Er wave timed to the R wave of the electrocardiogram. The E-Er interval ranged from 45 to 300 msec: 96 +/- 28 msec in the controls, 127 +/- 46 msec in patients with left ventricular hypertrophy (p = 0.0091 versus controls), and 179 +/- 57 msec in patients with hypertrophic cardiomyopathy (p < 0.0001 versus controls). It correlated with left ventricular free wall thickness (r = 0.42, p = 0.0006), thickness of the ventricular septum (r = 0.43, p = 0.0004), left ventricular end-diastolic diameter (r = -0.38, p = 0.0022), left ventricular end-systolic diameter (r = -0.55, p < 0.0001), left ventricular isovolumic relaxation time (r = 0.39, p = 0.0063), RR interval (r = 0.28, p = 0.045), mitral E/A velocity ratio (r = -0.33, p = 0.010), and E-wave deceleration time (r = 0.38, p < 0.0044) but not with age. Multivariate analysis with all the previously mentioned variables and the group the patient belonged to as the dichotomous variable showed that the grouping variable was the sole independent determinant of the E-Er interval (multiple r = 0.74). The E-Er interval is an easily measurable Doppler parameter which is increased in left ventricular hypertrophy and hypertrophic cardiomyopathy. It is related to left ventricular wall thickness, left ventricular isovolumic relaxation time, mitral E/A velocity ratio, and E-wave deceleration time and may provide useful insight into left ventricular early diastolic performance-possibly the relaxation process.

Aged↗
PubMed1997

Traumatic pseudoaneurysm of the left sinus of Valsalva: a case report.

Deceleration injuries of the aorta result in tears that often lead to exsanguinating hemorrhage. The site is most often at the aortic isthmus, with injuries of the aortic root being rare. A minority of patients survive long enough to reach the hospital where prompt diagnosis and treatment are essential for survival. We hereby report on a patient who had a pseudoaneurysm of the left sinus of Valsalva 13 years after a deceleration accident, presumably caused by a contained rupture of the aortic root. Transesophageal echocardiography was of great value in studying the features of the pseudoaneurysm and its relation to the left main coronary artery and left upper pulmonary vein.

Accidents, Traffic↗
PubMed2003

Influence of low high-density lipoprotein cholesterol on left ventricular hypertrophy and diastolic function in essential hypertension.

BACKGROUND: Left ventricular (LV) hypertrophy and LV diastolic dysfunction, which are common cardiac changes in hypertensive patients, are modified by several nonhemodynamic (eg, genetic, neurohumoral, and metabolic) factors. However, the influence of serum lipids on these LV changes has not been sufficiently studied. Although low high-density lipoprotein (HDL) cholesterol is well known to be a major risk factor for coronary heart disease, it is unclear whether HDL cholesterol plays a role in hypertensive heart disease. METHODS: In 274 patients with treated essential hypertension, two-dimensional and Doppler echocardiography were performed, and LV mass, ratio of peak velocity of atrial filling to early diastolic filling (A to E ratio [A/E]), and deceleration time of the E-wave were evaluated. The relationship of dyslipidemia, especially low HDL cholesterol, to LV hypertrophy and diastolic function was investigated in these patients. RESULTS: In a univariate regression analysis, HDL cholesterol was inversely associated with LV mass, A/E, and deceleration time. The association of HDL cholesterol with LV diastolic function was observed in both men and women. Its association with LV mass was gender-dependent, being significant only in women. Triglycerides were weakly correlated with LV mass and A/E, but total and low-density lipoprotein cholesterol had no correlations with these indices. In a multiple regression analysis, only low HDL cholesterol among several lipid levels was an independent predictor of both LV mass and LV diastolic dysfunction. CONCLUSIONS: Our findings suggest that low HDL cholesterol may unfavorably modify LV structure and diastolic function in patients with treated essential hypertension.

Aged↗
PubMed2001

Regulation of microcin C51 operon expression: the role of global regulators of transcription.

Expression of the microcin C51 operon in Escherichia coli cells is regulated as a function of the phase of growth; it is stimulated during the decelerating phase of growth. Using single-copy P(mcc)-lac transcriptional fusion (the promoter region of the microcin C51 operon fused to a promoterless lac operon in lambda phage), we showed that transcription from the microcin operon promoter is dependent on sigma(s) (RpoS) factor. However, some level of P(mcc)-lac expression is possible in rpoS null mutants, indicating that another sigma factor might be involved in transcription of the microcin C51 operon. Overproduction of sigma70 decreased Pmcc-directed transcription, presumably as a result of competition of sigma factors for the limited amount of core RNA polymerase. The cyclic AMP-CRP complex was shown to stimulate transcription from Pmcc: the absence of CRP or cAMP in crp or cya mutant cells strongly decreased the level of P(mcc)-lac expression. The production of C51 microcin decreased or was absent in rpoS, crp and cya mutant cells. Leucine-responsive protein Lrp and histone-like protein H-NS repressed P(mcc)-lac expression in the exponential and decelerating phases of growth. In studies of P(mcc)-lac expression in double mutant cells, we showed that proteins CRP, Lrp and H-NS acted in rpoS-dependent and rpoS-independent ways in transcription of the microcin C51 operon. Mutation hns(-) resulted in an increase in P(mcc)-lac expression in crp, rpoS and lrp mutant cells, as in wild-type cells.

Bacterial Proteins↗
PubMed2002

[Respiratory distress syndrome, early postnatal corticoid therapy and periventricular leukomalacia].

UNLABELLED: The aetiology of cavitating periventricular leukomalacia (cPVL) involves pre and perinatal factors. Early postnatal dexamethasone has been associated with an increase in cerebral palsy but its role in the development of PVL remains uncertain. OBJECTIVES: (1) Reevaluate major factors associated with cPVL, (2) Evaluate the potential effect of early postnatal dexamethasone. METHOD: This retrospective case-control study (matched for gestational age, birth weight, twin pregnancy and date of birth) compared 50 premature infants with cPVL diagnosed between D7 and D45 from 1995 to 2000 and 50 matched control newborns with normal serial neurosonograms. A data base with 97 selected perinatal variables was used to perform logistic regression analysis in controlling confounding variables, the results are expressed as adjusted Odds Ratio (OR) with 95% confidence interval. RESULTS: The two populations were comparable for gestational age (median: 29.3 weeks, range: 24.4-34.7) and birth-weight (1297 g, 645-2130 g). The annual incidence of cPVL in preterm infants with a gestational age < 33 weeks varied from 1995 to 2000: 1.3%, 4.5%, 13.4%, 2.1%, 3%, 2.9%. Early postnatal dexamethasone was used in 23 of the newborns who developed cPVL (between november 1996 and march 1998). The only antenatal factor associated with cPVL was cardiac decelerations (28% vs 14%, OR = 3.4, 1.1-11.3). The postnatal risk factors were respiratory distress syndrome requiring the use of rescue surfactant (78% vs 38%, OR = 4.2, 1.4-11.9) and early postnatal dexamethasone at the time it was used (78% vs 17%, OR = 17.1, 3.9-73). CONCLUSION: The use of rescue surfactant and of early postnatal dexamethasone in preterm infants with respiratory distress syndrome were independently associated with the subsequent occurrence of cPVL. Cardiac deceleration was the only antenatal factor associated with cPVL.

Analysis of Variance↗
PubMed2004

Body, head, and facial growth: comparison between macaques (Macaca fuscata) and chimpanzee (Pan troglodytes) based on somatometry.

Chimpanzees and macaques were compared in their growth of head, face and body, based on a large-scale somatometrical database. Their growth stages, i to v, were determined by inflection points in velocity curves. Sex differences in their growth are shown both by elongated stages in juvenile and adolescent and by the greater velocity in males in the stages. Chimpanzees need longer to get their full growth, especially in the later infantile and juvenile stages. The growth patterns are classified into three types of "sigmoid", "parabolic", and "fast & slow" in distance curves, and in velocity curves, they correspond to "convex", acceleration in mid-growth stage; "linear", linear deceleration with age; and "concave", rapid deceleration in earlier stages and slow velocity in later stages. Great differences between chimpanzees and macaques were found in their growth patterns of upper facial height and facial height, which are "linear" or intermediate of "linear" and "concave" in macaques and "concave" in chimpanzees. These differences in their growth patterns explain the characteristic development of craniofacial proportions.

Animals↗
PubMed1998

Sudden turns and stops while walking: kinematic sources of age and gender differences.

Background: Significant age and gender differences were found among healthy young and older adult subjects in their abilities to quickly turn or stop in order to avoid obstacles that suddenly appear in the gait path (Cao C, Ashton-Miller JA, Schultz AB, Alexander NB. Abilities to turn suddenly: effects of age, gender and available response time. J Gerontol Med Sci 1997;52A:M88-M93; Cao C, Ashton-Miller JA, Schultz AB, Alexander NB. Abilities to stop suddenly: effects of age, gender, gait phase, and available response time. Submitted for publication, 1997 (also available as a chapter in Cao C. Biomechanics of forward momentum arrest when walking: age and gender differences. PhD Dissertation, University of Michigan, 1996). The present study quantified the extent to which age and gender differences in those subjects' response kinematics affected the total time they needed to suddenly arrest their forward momentum. Methods: Age- and gender-group means of four measures of forward movement of the anterior surface of the abdomen were obtained: the duration of the first post-cue response phase, from the visual cue that initiated the arrest response to reaching peak velocity (T1); acceleration (A1) during this phase; and decelerations (D2 and D3) during two subsequent post-cue response phases. A three-line-segment representation of this forward velocity history was constructed. This representation was used to predict the differences in response time needed (NRT) to suddenly arrest momentum that resulted from measured age and gender differences in each of the four response kinematics measures. Results: The largest contributor to the age group difference found in NRT was the increase in T1 among the older adults. Among the older males, the next largest contributor was their larger value of A1, and among the older females, their substantially smaller value of D2. Among the young adults in sudden turns, no single kinematic parameter seemed primarily responsible for the gender difference found in the NRT. Among the older adults, the gender difference in D2 was almost fully responsible for the gender difference in NRT, in both sudden stops and turns. Conclusions: Much of the older adults' need for longer response times than those of the young was attributable to the lengthened first phase of their responses. Older females, in addition, needed longer response times than young adults or older males because, during the second phase of their responses, their decelerations were substantially smaller. These age and gender differences may have arisen in part from known age and gender differences in abilities to develop lower extremity joint torque strengths rapidly. Copyright 1998 Elsevier Science B.V.

Journal Article↗
PubMed1997

Left ventricular remodelling and improvement in Freestyle stentless valve haemodynamics.

OBJECTIVE: To assess how left ventricular (LV) hypertrophy, geometry and function change after stentless aortic valve replacement for aortic stenosis, and to elucidate the physiological mechanism of the improvement in stentless valve haemodynamics. METHODS: 81 patients with aortic stenosis (age 75 +/- 6 years, 47 male) underwent aortic valve replacement (plus CABG in 33 patients) with a Freestyle stentless porcine valve (mean size 23 +/- 2 mm). They were prospectively investigated by Doppler echocardiography at 2 weeks, 3-6, 12, and 24 months after operation. Two hundred and forty-six echocardiograms were obtained and analysed. Aortic valve performance was assessed from its effective orifice area (EOA), the transvalvular increase in mean flow velocity (delta mV), the deceleration time of aortic flow velocity, and mean pressure drop (mPG). LV hypertrophy was assessed from LV mass index; LV geometry, from the ratio of wall thickness to the radius (T/R ratio) and LV function, from stroke volume index (LVSVI) and myocardial stroke work (SW). RESULTS: By 2 years after operation, LV mass index had fallen from 162 +/- 64 to 109 +/- 36, g/m2, and T/R ratio from 0.61 +/- 0.25 to 0.43 +/- 0.10. LVSVI increased from 29.4 +/- 10 to 42 +/- 17, ml/m2, and myocardial SW from 3.1 +/- 1.6 to 5.2 +/- 2.2, mJ/cm3 (all P < 0.001 by ANOVA), while LV outflow tract diameter remained unchanged. At the same time, stentless valve EOA increased from 1.59 +/- 0.75 to 2.2 +/- 0.72, cm2, and delta mV (from 82 +/- 31 to 49 +/- 24, cm/s) and mPG (from 9.7 +/- 5.0 to 5.2 +/- 3.7 mmHg) both fell significantly (all P < 0.001 by ANOVA): as the deceleration time of aortic flow velocity increased from 153.6 +/- 64.1 to 202.7 +/- 37.6 ms (P < 0.001 by ANOVA). CONCLUSION: After stentless aortic valve replacement, LV mass index and wall thickness both fall towards normal, and myocardial stroke work increases. These ventricular remodelling processes are accompanied by a more physiological flow jet at valve cusp level, which permits a greater stroke volume to be ejected with a smaller transvavular velocity increase, so that effective orifice area increases.

Aged↗
PubMed1999

Prevalence of left ventricular diastolic filling abnormalities in adult cardiac surgical patients: an intraoperative echocardiographic study.

The incidence of left ventricular (LV) diastolic abnormalities in adult cardiac surgical patients has not previously been adequately investigated. The present study was performed to characterize LV diastolic filling patterns by performing transesophageal Doppler echocardiographic (TEE) studies in patients undergoing cardiac surgical procedures and thus indirectly assess diastolic function in these patients. Doppler TEE studies were performed and transmitral flow (TMF) and pulmonary venous flow (PVF) velocities were recorded in 104 patients intraoperatively. Peak early (E) and late (A) TMF velocities and systolic (S) and diastolic (D) forward PVF velocities were assessed and deceleration time (DT) was measured in all patients. For analysis, the study patients were classified into three groups according to the ratio of the TMF E to A velocity curves: group I with E/A ratio less than 1.0, group II with E/A ratio of 1.0 to less than 2.0, and group III with E/A ratio of 2.0 or greater. A filling pattern of abnormal LV relaxation was found in 73 patients (E/A < 1.0), a normal or pseudonormal pattern was present in 27 patients (1.0 < or = E/A < or = 2.0), and restrictive filling in 4 patients (E/A > 2.0). Patients with impaired relaxation had a greater incidence of recent myocardial infarction and congestive heart failure (CHF) than those with normal or pseudonormal filling patterns. Within group II, patients with CHF had higher TMF E deceleration rates and lower PVF S/D ratios compared with those without CHF (P < .05). Doppler echocardiographic examination of TMF and PVF velocities suggests that abnormalities in diastolic function are prevalent in adult cardiac surgical patients.

Aged↗
PubMed1999

Transesophageal echocardiographic area and Doppler flow velocity measurements: comparison with hemodynamic changes in coronary artery bypass surgery.

OBJECTIVE: Changes in transesophageal echocardiography (TEE)-derived Doppler flow velocities through the mitral valve and pulmonary veins occur after cardiopulmonary bypass and are believed to reflect left ventricular (LV) diastolic functional impairment. The aim of this study was to determine the time-coincidence between these Doppler flow velocity parameters, LV two-dimensional (2D) short-axis area measurements, and hemodynamic parameters in patients after coronary artery bypass grafting. DESIGN: Prospective clinical study. SETTING: University hospital. PARTICIPANTS: Twenty patients with normal ejection fraction undergoing elective cardiac surgery. INTERVENTIONS: At multiple intervals during surgery and 6 hours postoperatively, mitral inflow velocity and pulmonary venous flow velocity were measured with pulsed Doppler TEE. LV short-axis area by echocardiography and cardiac output by thermodilution were simultaneously obtained. MEASUREMENTS AND MAIN RESULTS: Time-coincidence was found in the immediate postbypass period between a decreased E/A ratio from 1.16 (95% confidence interval, 1.0 to 1.31) to 0.64 (95% confidence interval, 0.47 to 0.81, p < 0.01), a decreased E-wave deceleration time, and a significantly increased heart rate (HR) and cardiac index. End-diastolic area (EDA) and stroke volume index (SVI) decreased after sternal closure. HR, E-wave deceleration time, and SVI remained altered until 6 hours postoperatively. No change was found in pulmonary venous flow velocity parameters and systolic LV function. CONCLUSION: In patients with normal systolic ventricular function and no inotropic support, Doppler flow velocity patterns alone did not sufficiently reflect hemodynamic changes, whereas 2D LV area, especially EDA measurements, provided useful information about hemodynamically significant LV filling impairment.

Aged↗
PubMedDate not supplied

Dynamic stability of the elbow: electromyographic analysis of the flexor pronator group and the extensor group in pitchers with valgus instability.

The medical collateral ligament is a common site of injury in baseball pitchers, causing substantial morbidity and loss of pitching time. Twenty-six skilled baseball pitchers with medial collateral ligament insufficiency were studied before surgery with high-speed cinematography and fine-wire electromyography of eight muscles around the elbow. Data from the pitchers with injured elbows were compared with data obtained from uninjured pitchers. The flexor carpi radialis muscle in the pitchers with medial collateral ligament deficiencies revealed significantly decreased firing during the acceleration and deceleration phase of the fastball when compared with that of the pitchers with normal elbows, and the flexor carpi radialis muscle was significantly depressed during the early cocking and deceleration phases. The extensor muscles revealed slightly increased activity in the injured elbows; however, this was not statistically significant. Although the muscles of the flexor pronator group (especially the flexor carpi ulnaris muscle and the flexor digitorum superficialis muscles) are anatomically positioned to provide dynamic stability of the elbow, they did not demonstrate increased electrical activity in pitchers with medial collateral ligament deficiencies. This finding suggests that the muscles on the medial side of the elbow do not supplant the role of the medial collateral ligament during the fastball pitch.

Baseball↗
PubMed1995

Effects of enalapril on left ventricular mass and diastolic function in essential hypertension: special reference to duration of hypertension.

Using M-mode and pulsed Doppler echocardiography, the effects of enalapril on left ventricular (LV) hypertrophy and diastolic dysfunction in essential hypertension and the relation between improvement in these two parameters and duration of hypertension were evaluated. The subjects, 30 previously untreated hypertensive patients, were divided into nonhypertrophy (18 patients) and hypertrophy (12 patients) groups. All patients received enalapril at a daily dose of 5 to 10 mg for 6 months. Left ventricular mass by M-mode echocardiography and LV inflow (LVIF) velocity by transthoracic pulsed Doppler echocardiography were measured before and after enalapril therapy. In the nonhypertrophy group, enalapril significantly increased peak early diastolic LVIF (E) velocity (P < .05), slightly lowered peak atrial systolic LVIF (A) velocity, significantly decreased their ratio (A/E) (P < .01), and significantly shortened both the deceleration time, from the peak of the early diastolic wave, and isovolumic relaxation time (P < .05 and P < .01, respectively). In the hypertrophy group, enalapril significantly increased E (P < .05), slightly lowered A, significantly decreased A/E (P < .05), slightly shortened the deceleration time and isovolumic relaxation time, and slightly decreased LV mass. The administration of enalapril correlated significantly and positively with the duration of hypertension and the rates of change in A/E and LV mass in all of the hypertensive patients (P < .01 and P < .05, respectively). These results suggest that long-term administration of enalapril to hypertensive patients improves LV diastolic hemodynamics regardless of the presence or absence of LV hypertrophy and that the effects are most remarkable in patients with the shortest duration of hypertension.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1995

Effect of a main renal artery stenosis on the downstream Doppler waveform in dogs.

RATIONALE AND OBJECTIVES: We evaluated the changes in the down-stream Doppler waveforms caused by a proximal stenosis in the main renal artery of dogs. METHODS: Renal parenchymal arterial waveforms downstream from mild (< 50%), moderate (50-75%), and severe (76-95%) stenoses were compared with nonstenotic baseline waveforms in five mongrel dogs. Waveform shapes were categorized as biphasic or monophasic. The percentage of biphasic and monophasic waveforms was determined for each stenosis. The acceleration index (AI) and the acceleration time (AT) were determined using traditional and modified calculations (AI' and AT'). Late systolic deceleration (DS), diastolic deceleration (DD), and the resistive index (RI) also were measured. RESULTS: AT, AI', and AT' demonstrated significant differences between the severe stenoses and nonstenotic baselines (p < .05); however, there was no difference between the mild and moderate stenoses versus baselines. The percentage distribution of monophasic and biphasic waveforms was highly correlated with the degree of stenosis. Monophasic waveforms increased on average from 22.5% of baseline waveforms to 76.5% of waveforms in the severe stenoses. Biphasic waveforms decreased on average from 69.9% of baseline waveforms to 18.7% of waveforms in the severe stenoses. CONCLUSION: Quantitative evaluation of the downstream waveform parameters (AI, AT, AI', AT', DS, DD, and RD in the dog kidney is not sufficiently accurate, but calculation of the percentage of the monophasic and biphasic waveforms present may be useful to predict a hemodynamically significant renal artery stenosis (> or = 50%).

Animals↗
PubMed1997

Favourable native-like helical local interactions can accelerate protein folding.

BACKGROUND: Extensive studies of peptide conformation have provided reasonable knowledge of the rules determining helix stability. This knowledge can be used to stabilize proteins against chemical and thermal denaturation. This has been done in two proteins: the chemotactic protein from Escherichia coli, Che Y (a 129 aa alpha/beta parallel protein with five alpha-helices, which shows an accumulating intermediate during refolding) and the activation domain of human procarboxypeptidase A2, ADA2h (a 81 aa alpha + beta protein domain, with two alpha-helices, which follows a two-state mechanism). As the introduced stabilizing interactions are local in nature, the energy balance between the contribution of local and nonlocal interactions changes considerably. Recent theoretical analyses of protein folding using simplified models have indicated that optimization of folding speed requires this balance to be biased towards nonlocal interactions. To determine whether this is the case, we study here the folding kinetics of two ADA2h mutants in which alpha-helix 1 (mutant M1) or 2 (mutant M2) has been stabilized through local interactions, as well as the equilibrium and kinetic behaviour of a double mutant (DM) in which both helices have been stabilized. RESULTS: The stability of DM is considerably enhanced with respect to wild type (WI) and this mutant can be considered as a thermoresistant protein (Tm > 363 K). The thermodynamic parameters obtained by chemical denaturation (urea and GdnHCl) show that DM is approximately 2.6 kcal mol-1 more stable than WT. The effects on folding kinetics are different in each of the single mutants. M1 shows very little effect in refolding, while its unfolding is greatly decelerated with respect to WT. M2 shows, together with a deceleration in unfolding, a significant acceleration in refolding. As with equilibrium parameters, the kinetics of the double mutant can be explained by the simple addition of the effects found in each single mutant. Interestingly enough, the refolding slope mkf in mutants M2 and DM is smaller than in the wild-type and M1 mutant. CONCLUSIONS: Thermoresistance can be achieved, in some cases, by increasing favourable native local interactions. The balance between local and nonlocal interactions can be significantly changed in some proteins and still keep a cooperative unfolding transition similar to that of the wild type. The introduction of favourable local interactions by mutational redesign can also be used to increase the folding speed of certain proteins, showing that not all proteins in nature have been optimized for rapid folding, contrary to what has been theoretically indicated. This behaviour is probably also shared by other polypeptides with highly unstructured denatured states. All these phenomena have been shown experimentally in ADA2h by mutations that increase helix stability. However, the effects promoted for such an approach in proteins with residual structure and/or intermediates in the denatured ensemble could be different. This has been shown by experiments performed on CheY in which the cooperativity of the folding process was greatly affected.

Adaptor Proteins, Signal Transducing↗
PubMed2002

Doppler-echocardiographic indices of diastolic function in heart failure admissions with preserved left ventricular systolic function.

Many patients admitted to hospital with heart failure have preserved left ventricular (LV) systolic function. The incidence of isolated diastolic dysfunction as a cause of such admission remains unclear. We aimed to examine diastolic function in unselected admissions from the community with heart failure using the European Study Group on Diastolic Heart Failure (ESGDHF) Doppler-echocardiographic indices of diastolic dysfunction. Primary heart failure was confirmed in 210 of 309 sequential admissions with suspected heart failure. Doppler echocardiography was used to assess left ventricular ejection fraction, wall thickness and parameters of diastolic function including E:A ratio, E-wave deceleration time and isovolumic relaxation time. Of 210 patients studied (118 female), ejection fraction was <45% in 111, leaving a population of 99 with preserved systolic function. We excluded those with significant valvular disease, leaving 56 patients (mean age=77 years) with an ejection fraction >45% and no other relevant abnormality. Twenty were in atrial fibrillation. E-wave deceleration time was >280 ms in 42%. E:A was reversed in 30 of 36 patients in sinus rhythm, but only seven met the ESGDHF criterion of E:A<0.5. Isovolumic relaxation time was >105 ms in 38%. Wall thickness was increased in 75% of cases. The ESGDHF Doppler-echocardiographic criteria for diastolic heart failure were fulfilled in 43%. In clinically confirmed heart failure, 27% of patients had preserved systolic function and no significant valvular disease. Only 43% of this group had confirmed diastolic heart failure by these ESGDHF criteria. The pathophysiological basis of the syndrome in the remaining 57% remains unclear.

Aged↗
PubMed1999

An analysis of movement and discomfort of the female breast during exercise and the effects of breast support in three cases.

Breast pain is common during exercise, occurring in up to 56% of subjects in some surveys. This pain is mainly associated with the movement of breast tissue. In an attempt to analyse this movement and the resulting pain, the movement of the female breast tissue was quantified in four conditions of breast support ("sports bra", "fashion bra", "crop top" and bare breasted) during four different activities (running, jogging, aerobics march and walking). These activities represented general patterns of exercise for adult females in Australian society. All three subjects were healthy, active, young women of varying breast size (12B, 14B & 14C) that were typical of young women. Two of the subjects had noted breast pain whilst exercising. The results showed that wearing external support for the breast tissue reduced absolute vertical movement and maximum downward deceleration force on the breast. Support also reduced perceived pain. When compared to other forms of breast support a "sports bra" (brassiere designed for breast support whilst exercising) provided superior support for the breast in relation to the amplitude of movement, deceleration forces on the breast, and perceived pain. The data indicates that adult females should wear appropriate breast support to reduce perceived breast discomfort or pain. Of the three garments examined in this study, the fitted sports bra provided superior support and pain reduction.

Adult↗
PubMed2004

Control of reaching movements in children and young adults with myelomeningocele.

The aim of the present study was to analyze the ability to programme and execute reaching movements in individuals with myelomeningocele (MMC) and in a control group. Thirty-one participants (18 males, 13 females; mean age 12 years 11 months, SD 2 years 7 months, range 9 to 19 years) with MMC and 31 participants (matched for age and sex) without disabilities were investigated. Reaching was performed with and without visual feedback toward three targets displayed on a computer screen and data were collected using a digitizing tablet linked to a computer. The kinematics of reaching were analyzed and analysis of variance was used for statistical analysis. Results showed that both groups were able to programme reaching movements under both visual conditions. Although the execution of reaching was poor in the MMC group compared with the control individuals, as indicated by larger end-point errors (p=0.002), less straight movements (p=0.018), and shorter deceleration phases (p=0.004), movement time was not prolonged in the MMC group. Those with shunt treatment (n=21) had more difficulties when visual feedback was provided. Those with symptoms of early brainstem dysfunction (n=5) had shorter deceleration phases under both visual conditions.

Adolescent↗
PubMed2000

Developmental change in auditory selective attention as reflected by phasic heart rate changes.

Heart rate was recorded from five different groups of children (ages 7, 10, 12, 14, and 20 years) while they were performing an auditory selective attention task. The participants were instructed to count rare tone pips embedded in a series of standard tone pips presented at one (attended) ear while ignoring rare and standard stimuli presented at the other (unattended) ear. A pattern of anticipatory heart rate deceleration followed by acceleration was associated with rare tone pips at the attended ear but not with rare tone pips that should be ignored. The absence of differential sensitivity of heart rate responses to rare tone pips presented at the unattended ear was observed for all age groups. These findings were interpreted to suggest that the ability to ignore irrelevant target stimuli has reached mature levels during middle childhood. The depth of anticipatory deceleration increased until age 14, suggesting that the ability to maintain attentional set continues to develop beyond childhood.

Acoustic Stimulation↗