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PubMed1999

Doppler-derived mitral deceleration time: an early strong predictor of left ventricular remodeling after reperfused anterior acute myocardial infarction.

BACKGROUND: The relation between remodeling and left ventricular (LV) diastolic function has not yet been fully investigated. The aim of this study was to determine whether early assessment of Doppler-derived mitral deceleration time (DT), a measure of LV compliance and filling, may predict progressive LV dilation after acute myocardial infarction (AMI). METHODS AND RESULTS: Fifty-one patients (aged 61+/-11 years; 6 women) with anterior AMI successfully treated with direct coronary angioplasty underwent 2-dimensional and Doppler echocardiographic examinations within 24 hours of admission, at days 3, 7, and 30 and 6 months after the index infarction. Mitral flow velocities were obtained from the apical 4-chamber view with pulsed Doppler. End-diastolic volume index (EDVI) and end-systolic volume index (ESVI) were calculated with the Simpson's rule algorithm. Patients were divided according to the DT duration assessed at day 3 in 2 groups: group 1 (n=33) with DT >130 ms and group 2 (n=18) with DT </=130 ms. Patency and restenosis rate at 6 months were similar between the 2 groups (94% group 1 vs 89% group 2; P=0.52; 27% group 1 vs 33% group 2; P=0.64, respectively). LV volume indexes were similar in both groups at baseline (EDVI: 71+/-3 group 1 vs 70+/-3 mL/m2 group 2, P=0.42; ESVI: 43+/-3 group 1 vs 48+/-3 mL/m2 group 2, P=0.13, respectively). From day 3 on, LV volume indexes progressively increased in group 2 and were significantly larger than those of group 1 at 6 months (LVEDVI 61+/-3 group 1 vs 104+/-6 mL/m2 group 2, P=0.00001; LVESVI 31+/-3 group 1 vs 73+/-6 mL/m2 group 2, P=0.00001, respectively). A significant inverse correlation was found between DT and changes in EDVI at 6 months (r=-0.68; P<0.0000001). By stepwise multiple regression analysis among several clinical, demographic, angiographic, and echocardiographic variables, DT was the most powerful predictor of EDVI changes at 6 months (P=0.02). CONCLUSIONS: These data suggest that early estimation (day 3) of Doppler-derived mitral DT provides a simple and accurate mean to predict late LV dilation after reperfused AMI.

Adult↗
PubMed1988

Cycle length dependence of human action potential duration in vivo. Effects of single extrastimuli, sudden sustained rate acceleration and deceleration, and different steady-state frequencies.

Using a new method for long-term recording of monophasic action potentials from the human heart, we studied in 17 patients the effects on ventricular action potential duration (APD) of three clinically pertinent cycle length perturbations: (1) single extrastimuli, (2) abrupt sustained rate acceleration and deceleration, and (3) different steady-state cycle lengths. Results were: (a) APD after single extrastimuli at progressively longer cycle lengths were related to the extrastimulus cycle length with a biphasic electrical restitution curve which after an initial steep rise and a subsequent transient descent rose again more gradually to a plateau at cycle lengths above 800-1,000 ms. (b) After a sustained step decrease in cycle length, the first APD shortened abruptly while final steady-state adaptation required up to several minutes. The transition between the rapid and slow phase of APD change was characterized by a variable alternans of APD which correlated inversely with the preceding diastolic interval. (c) In the steady state, APD correlated linearly with cycle length, increasing an average of 23 ms per 100 ms cycle length increase (r = 0.995). The divergence between steady-state and non-steady-state APD, and the slowness of steady-state adaptation, are important factors to be considered in clinical electrophysiologic studies and in rate correction algorithms of APD or QT intervals, respectively.

Action Potentials↗
PubMed2003

Normalization of glucose concentrations and deceleration of gastric emptying after solid meals during intravenous glucagon-like peptide 1 in patients with type 2 diabetes.

The effects of different i.v. doses of glucagon-like peptide 1 (GLP-1) on glucose homeostasis and gastric emptying were compared in patients with type 2 diabetes. Twelve patients with type 2 diabetes received three different infusion rates of GLP-1 (0.4, 0.8, and 1.2 pmol/kg x min) or placebo in the fasting state and after a solid test meal (containing [(13)C]octanoic acid). Blood was drawn for glucose, insulin, C-peptide, glucagon, and GLP-1 determinations. The gastric emptying rate was calculated from the (13)CO(2) excretion rates in breath samples. Statistics were determined using repeated measures ANOVA and Duncan's post hoc test. Plasma glucose concentrations were equally normalized with all GLP-1 doses (P < 0.001). Insulin and C-peptide concentrations dose-dependently rose during GLP-1 infusion in the fasting state (P < 0.05), but were dose-dependently reduced by GLP-1 after meal ingestion (P = 0.0031 and 0.0074, respectively). Glucagon secretion was suppressed with GLP-1. Gastric emptying was decelerated by GLP-1 in a dose-dependent fashion (P < 0.001). Despite a dose-dependent stimulation of insulin secretion, glucose normalization can be achieved even with 0.4 pmol GLP-1/kg x min. Due to the dose-dependent inhibition of gastric emptying, lower GLP-1 doses than previously used may be as suitable for glucose control in patients with type 2 diabetes.

Aged↗
PubMed1989

[Study of umbilical cord coiling and variable deceleration].

Using cardiotocogram and umbilical arterial gas analysis, the presence or absence and variations of umbilical cord coiling were examined with relation to the incidence of variable deceleration (V.D.) and neonatal asphyxia. The results obtained were as follows. 1) The incidence of V.D. with cord coiling was higher than that without cord coiling (p less than 0.005). The incidence of severe V.D. with cord coiling was also higher than that without cord coiling (p less than 0.005). 2) The mean Apgar scores of cases with cord coiling were lower than that without cord coiling (p less than 0.02). 3) On the umbilical arterial gas analysis, the mean pH of cases with cord coiling was lower than that without cord coiling (p less than 0.05). And the mean pCO2 of cases with cord coiling was higher than that without cord coiling (p less than 0.005). So neonate with cord coiling showed a tendency towards respiratory acidosis in comparison with that without cord coiling. 4) The incidence of neonatal asphyxia with cord coiling was 16.0% (Apgar score less than or equal to 7), 20.0% (pH less than 7.20) and that without cord coiling was 8.8%, 13.2%, respectively. Although there was no statistically significant difference, a tendency was observed towards a higher rate of neonatal asphyxia with cord coiling. 5) The incidence of neonatal asphyxia with severe V.D. was 44.4% (Apgar score less than or equal to 7), 36.1% (pH less than 7.20) and that without severe V.D. was 5.7%, 8.6%, respectively. There was a statistically significant difference (p less than 0.005, p less than 0.005). In addition, the incidence of neonatal asphyxia with repeated V.D. was 35.3% (Apgar score less than or equal to 7), 44.1% (pH less than 7.20) and without repeated V.D. was 3.8%, 6.5%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Asphyxia Neonatorum↗
PubMed1988

Paradoxic heart rate deceleration during exercise. Relationship to a mid-right coronary artery stenosis.

A patient developed paradoxic deceleration of his heart rate at a high exercise level. Angioplasty of a right coronary artery stenosis distal to the sinoatrial branch and institution of diltiazem therapy resulted in normal cardioacceleration during repeated exercise testing. This unique pathophysiologic response appears to be due to direct or indirect effects of ischemia.

Coronary Disease↗
PubMed1983

Growth deceleration in Japanese schoolchildren with special reference to those in the city of Sendai.

From the national and regional statistics on the body dimensions of schoolchildren at the 6th year grade in primary schools (i.e., 11-year-olds) and at the 3rd year grade in junior high schools (i.e., 14-year-olds), the secular gains in height and weight by the children of the same age were calculated for the three periods of 1960-4, 1972-76 and 1976-81. Compared with the first period (i.e., 1960-4) when the growth acceleration was maximal, the secular gain was apparently reduced in the second and third study periods (i.e. 1970's) to the level of 1/2 to 1/3 of that in the first period, and was next to nil in some districts. Such deceleration was coupled with changes in seasonal growth patterns and diminution of urban-rural gaps both in the body size and the secular gain. For example, the body dimensions of the children in the City of Sendai did not differ in 1981 between the core part of the city and the surroundings, while the difference had been observed till late 1970's. The 1979 measurements of height and weight of Japanese children are compared with counterpart values observed in other countries.

Adolescent↗
PubMed1978

An analysis of the relationship between cardiac deceleration and correct performance under conditions of constant task difficulty.

Previous analyses of the relationship between cardiac deceleration and correct performance suffered from a confounding of task difficulty with performance accuracy. The present analysis indicates that the relationship between these variables still holds and is, in fact, more general under conditions which control difficulty of the task at a constant level.

Achievement↗
PubMed1992

Pinealectomy decelerates the circadian food intake rhythm of cervically sympathectomized rabbits.

Long-term records of the free-running food intake rhythms were obtained from 26 young adult blinded rabbits that were subjected in the course of recording to bilateral superior cervical ganglionectomy (sympathectomy). This always resulted in acceleration of the rhythm (mean delta tau = -0.35 h). Some 4 months afterwards, 12 rabbits were pinealectomized and after another 4 months sham pinealectomized also. In the other 14 animals, these operations were performed in the reverse order. It appeared that suctioning away part of the ventricular walls during sham pinealectomy was followed by a slight reduction in tau (mean = -0.07 h) that could be largely attributed to the spontaneous gradual reduction of tau that occurred throughout all experiments. On the other hand, total pinealectomy in these already sympathectomized blinded rabbits always resulted in a substantial deceleration of the rhythms (mean delta tau = +0.23 h). These observations on blinded rabbits suggest that a sympathetically denervated pineal gland releases appreciable amounts of melatonin or of another hormone with a melatonin-like accelerating effect on the circadian pacemaker (SCN).

Animals↗
PubMed1975

Prolonged end stage fetal heart rate deceleration.

With the use of routine monitoring of all patients in labor, a number of confusing, seemingly ominous fetal heart rate tracings in otherwise normal, healthy patients have been observed. This report described one such type of pattern called prolonged end stage deceleration.

Female↗
PubMed1975

Food satiation as a procedure to decelerate vomiting.

A food satiation procedure was used in two experiments to decelerate the frequency of vomiting responses in two profoundly retarded adults who exhibited well-defined vomiting-ruminatory response chains. For several years prior to this study, the subjects had exhibited a history of vomiting behavior. Satiation was accomplished during regular meals and consisted of allowing the subjects to eat until a satiation criterion of food refusal was achieved. The results revealed a 94 percent reduction of vomiting in Experiment 1 and a 50 percent response reduction in Experiment 2. Ten-day follow-up sessions indicated that the response reduction was maintained in both experiments. In Experiment 1 the subject exhibited a 4.99 kg weight gain at the 10-day follow-up with a total of 13.61 kg weight gain at a 4-week posttreatment weight check.

Feeding Behavior↗
PubMedDate not supplied

[Deceleration of vital activity as a universal biochemical mechanism ensuring adaptation of microorganisms to stress factors: a review].

The review deals with a major problem of contemporary biology, i.e., the strategy of persistence of organisms affected by stressors. The primary mechanism of biochemical adaptation of cells is their transition to a specific surviving state, which is characterized by deceleration of vital activity (DVA), a process related to decreased metabolism. According to the latest classification, there are four DVA types: quiescence (endogenous or exogenous), cryptobiosis, anabiosys, and latent life. These states are viewed from a new standpoint, as depending on both the stage of growth and development of the organism and the type of stressor. A brief characterization of cryptobiosis and anabiosys is provided. Quiescence, which is a specific type of DVA, is characterized in greater detail, with emphasis on differences between fungi and bacteria. Endogenous and exogenous quiescence is compared in two types of cells (spores). Changes in the composition of quiescent cells (spores) as compared to their vegetating counterparts involve lipids (membrane-associated and neutral), cytosolic carbohydrates (which serve as a reserve supply of nutritives or act as protectors), water content, RNA/protein synthesis, and cyclic nucleotides (e.g., cAMP). Biochemical mechanisms controlling reversion of DVA (the transition from spores to germinating cells) are also analyzed. In conclusion, consideration is given to the role of DVA in evolution and to the implications of DVA studies for biotechnology, cryogenic preservation, utilization of interstellar space and permafrost territories.

Adaptation, Physiological↗
PubMed2004

[Doppler index of myocardial performance and its relationship with mitral E wave deceleration time in acute Q-wave myocardial infarction].

OBJECTIVE: The objectives of the study were to assess myocardial systolic and diastolic functions by myocardial performance index (MPI) and its relationship with E - wave deceleration time (DT) in early phase of acute Q-wave myocardial infarction (MI). METHODS: We performed nongeometric Doppler-derived echocardiography to assess combined systolic and diastolic functions using myocardial performance index in 50 patients with acute Q-wave MI at early phase of events, (25 pts with anterior MI and 25 pts with inferior MI). The index is defined as the sum of the isovolumic contraction and isovolumic relaxation times divided by ventricular ejection time and was obtained by Doppler measurement from the diastolic mitral inflow and left ventricular outflow velocity-time intervals. RESULTS: As a result, the index was 0.54+/-0.1 in all patients with MI. We also estimated the higher MPI and DT values in anterior than in inferior MI (MPI: 0.61+/-0.07 vs. 0.46+/-0.06, p<0.001; DT: 244+/-64 msec vs. 204+/-31.2 msec, p=0.005, respectively). Myocardial performance index was positively correlated with DT in inferior MI (r=0.42, p<0.035) and negatively correlated with anterior MI; (r=- 0.72, p=0.0001). CONCLUSION: These data suggest that Doppler-derived MPI reflects severity of global left ventricular dysfunction in early phase of acute MI and may be a useful parameter in these patients.

Echocardiography, Doppler↗
PubMed2004

[Deceleration of vascular growth--a cause of varus hip deformity].

The aim of this study was to examine the peculiarities of femoral proximal epiphysis formation following the early disruption of its blood supply. The experiments were performed using 20 albino rats that were operated at postnatal day 18 having their diaphysis and acetabular arteries cut in one extremity (the other extremity serving as control). Starting at postoperational month 2 and up to month 12, 1-2 animals were sacrificed monthly by ether overdosage. Femoral and pelvic bones were removed from both control and experimental extremities, fixed in neutral formalin, decalcified, dehydrated and embedded in celloidin. The sections were stained with hematoxylin and eosin. It was established that a deceleration of vascular growth compromised the nutrition of the cartilage of the femoral proximal epiphyseal growth plate. This resulted in the delay of chondrocyte differentiation and prevented the timely formation of the bone in the area of femoral collum, causing the development of varus deformity.

Animals↗
PubMedDate not supplied

The influence of beta-agonists on normal and clonidine-decelerated noradrenaline turnover in the rat brain.

The effect of some beta-adrenoceptor agonists, such as clenbuterol, salbutamol, isoprenaline and formoterol on the NA turnover (estimated on the basis of NA disappearance after inhibition of its synthesis by FLA-63) in various regions of the rat brain was examined. All the used beta-agonists (given ip) accelerated the FLA-63 induced disappearance of NA in the cortex, limbic system and brain stem. That effect of the beta-agonists was antagonized by propranolol. The obtained results indicate that beta-adrenoceptors are involved in regulation of the NA turnover. After chronic treatment with salbutamol (5 mg/kg, twice a day for 10 days, the last dose--10 mg/kg), tolerance to acute affects of that substance developed. In turn, salbutamol given chronically prevented the clonidine-induced deceleration of NA disappearance. The effects observed after chronic salbutamol treatment may be due to developed adaptive changes in beta-, as well as in alpha 2-adrenoceptors.

Adrenergic beta-Agonists↗
PubMed1979

Decelerating the aging process.

Diseases whose incidence and prevalence are increased in the elderly and whose cytopathology, hormones, and immunogenesis differ, generally are included in the field of geriatrics. These conditions may be precipitated or accelerated in quantity or type by a wide variety of genetic and environmental factors. Chronological and progressive deterioration of selected cells, organs, and tissues, and their functions may occur without major specific pathology. These processes are referred to as senescence and its study, is gerontology.Geriatrics includes senility and diseases of the elderly. Terms associated with gerontology include benign agism or senescence, as a normal consequence of the aging processes common to all biological forms of life.The age period, 65 to 85 years, does not necessarily imply senility, but the normal chronological aging of an individual in an industrialized, urbanized society. This paper emphasizes recommendations for deceleration of the normal aging process.

Aged↗
PubMed1993

[The remote noninvasive assessment of left ventricular diastolic pressure by pulsed Doppler echography--the importance of the time of mitral protodiastolic deceleration].

UNLABELLED: To find a possible correlation between the transmitral diastolic flow, obtained by pulsed Doppler echocardiography, and left ventricular end-diastolic pressure (LVedP), we studied 95 patients (p) (58 +/- 9 years), with coronary artery disease (76 p) and dilated cardiomyopathy (19 p). P with atrial fibrillation, heart rate > 100 b/m or mitral regurgitation > 2+/4+ were excluded. We analyzed E and A wave peak velocities (v), time-velocity integrals (i) and diastolic filling intervals. Restriction to filling pattern was considered in the presence of an E wave deceleration time (DecT) < or = 120 ms (Group B- 22 p); the other 73 p (group A) ranged from abnormal relaxation to normal diastolic patterns, with DecT > 120 ms. RESULTS: -LVedP ranged from 3 to 38 mmHg in group A and from 16 to 39 mmHg in group B. In group A, the Ai/Ei ratio showed a significant linear correlation with the LVedP (r = 0.83, y = 14 chi + 2); Ai/El ratio > 1.0 identified pts with LVedP > 18 mmHg with a sensitivity of 85% and a specificity of 98%. In group B, there was a correlation between LVedP and the inverse ratio of integrals (Ei/Ai) (r = 0.72), as well as Ev/Av ratio (r = 0.69). CONCLUSIONS: In myocardial active relaxation abnormalities, Ai/Ei ratio increases proportionally to LVedP. A short DecT (< or = 120 ms) identifies a subgroup of p with predominant impairment of LV compliance and high filling pressures, in which the atrial contribution decreases as LVedP rises. Thus, whatever the prevailing mechanism of diastolic dysfunction, echo-Doppler transmitral diastolic flow can provide a noninvasive assessment of LVedP.

Adolescent↗
PubMed1951

Human decelerator.

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Aerospace Medicine↗