Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “REST”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,693 records · Page 94Linked to original sources
PubMed2000

Progressive resistance exercise and resting blood pressure : A meta-analysis of randomized controlled trials.

Hypertension is a major public health problem affecting an estimated 43 million civilian, noninstitutionalized adults in the United States (24% of this population). The purpose of this study was to use the meta-analytic approach to examine the effects of progressive resistance exercise on resting systolic and diastolic blood pressure in adult humans. Studies were retrieved via (1) computerized literature searches, (2) cross-referencing from original and review articles, and (3) review of the reference list by 2 experts on exercise and blood pressure. Inclusion criteria were as follows: (1) trials that included a randomized nonexercise control group; (2) progressive resistance exercise as the only intervention; (3) adult humans; (4) journal articles, dissertations, and masters theses published in the English-language literature; (5) studies published and indexed between January 1966 and December 1998; (6) resting systolic and/or diastolic blood pressure assessed; and (7) training studies lasting a minimum of 4 weeks. Across all designs and categories, fixed-effects modeling yielded decreases of approximately 2% and 4% for resting systolic and diastolic blood pressure, respectively (mean+/-SD systolic, -3+/-3 mm Hg; 95% bootstrap CI, -4 to -1 mm Hg; mean+/-SD diastolic, -3+/-2 mm Hg; 95% bootstrap CI, -4 to -1 mm Hg). It was concluded that progressive resistance exercise is efficacious for reducing resting systolic and diastolic blood pressure in adults. However, a need exists for additional studies that limit enrollment to hypertensive subjects as well as analysis of data with an intention-to-treat approach before the effectiveness of progressive resistance exercise as a nonpharmacological intervention can be determined.

Adult↗
PubMed2005

Resting myocardial blood flow is impaired in hibernating myocardium: a magnetic resonance study of quantitative perfusion assessment.

BACKGROUND: Although impairment in perfusion reserve is well recognized in hibernating myocardium, there is substantial controversy as to whether resting myocardial blood flow (MBF) is reduced in such circumstances. Quantitative first-pass cardiovascular magnetic resonance (CMR) perfusion imaging allows absolute quantification of MBF. We hypothesized that MBF assessed at rest by quantitative CMR perfusion imaging is reduced in hibernating myocardium. METHODS AND RESULTS: Twenty-seven patients with 1 or 2-vessel coronary disease and at least 1 dysfunctional myocardial segment undergoing PCI were studied with preprocedure, early (24 hours), and late (9 months) postprocedure CMR imaging. First-pass perfusion images at rest were acquired in 3 short-axis planes by use of a T1-weighted turboFLASH sequence. In each slice, MBF was determined for 8 myocardial segments in mL . min(-1) . g(-1) by deconvolution of signal intensity curves with an arterial input function measured in the left ventricular blood pool. Cine MRI for assessment of global and segmental function and delayed enhancement MRI for detection of viability were also obtained. All coronary lesions were 80% to 95% stenosis in severity. Over all segments, mean MBF normalized by rate-pressure product ("corrected MBF") was 1.2+/-0.3 mL . min(-1) . g(-1) . (mm Hg . bpm/10(4))(-1) in segments without significant coronary stenosis and 0.7+/-0.2 mL . min(-1) . g(-1) . (mm Hg . bpm/10(4))(-1) in segments with coronary stenosis before PCI (mixed model controlling for slice and segment z=-23.9, P<0.001). Early after the procedure, the MBF was 1.2+/-0.2 mL . min(-1) . g(-1) . (mm Hg . bpm/10(4))(-1) in revascularized segments and 1.3+/-0.2 mL . min(-1) . g(-1) . (mm Hg . bpm/10(4))(-1) in nondiseased segments (z=-6.1, P<0.001). Late after PCI, the systolic wall thickening and end-diastolic wall thickness both increased significantly more (both P<0.001) in the myocardial segments subtended by severe coronary stenosis (8+/-17% to 40+/-19% and 6.5+/-1.1 to 9.3+/-2 mm, respectively) than in the myocardial segments supplied by nondiseased vessels. Mean MBF in dysfunctional segments with significantly improved contraction after revascularization was 0.8+/-0.2 mL . min(-1) . g(-1) . (mm Hg . bpm/10(4))(-1) before PCI and 1.2+/-0.2 mL . min(-1) . g(-1) . (mm Hg . bpm/10(4))(-1) after PCI (z=2.0, P=0.04). CONCLUSIONS: CMR perfusion imaging detects impaired resting MBF in hibernating myocardial segments.

Aged↗
PubMed1998

Reduced gas transfer at rest and during exercise in school-age survivors of bronchopulmonary dysplasia.

School-age children who survive bronchopulmonary dysplasia (BPD) may have a permanent reduction in alveolar surface area that could limit gas transfer both at rest and during exercise. To test this hypothesis, 10 survivors of BPD, 10 children born prematurely without BPD, and 10 healthy children born at term, 6 to 9 yr of age, underwent treadmill exercise studies. During a three-phase protocol we measured intrabreath acetylene (C2H2) and carbon monoxide (CO) transfer, pulmonary function, and SaO2. Both at rest and during exercise, C2H2 transfer corrected for body surface area was lower in survivors of BPD than it was in children born prematurely without BPD or children born at term. With exercise the transfer of both gases increased sharply over resting values in children born prematurely and at term. In survivors of BPD C2H2 transfer with exercise did increase, but not as much as it did in control subjects, and corrected CO transfer did not change at all. In survivors of BPD and children born prematurely, FEV1 fell during recovery from exercise, but this did not correlate with C2H2 transfer or DL(CO)/VA. Thus, soluble gas transfer at rest and during acute exercise is reduced in children who survive BPD. This is likely explained either by long-term derangements in lung structure or residual right ventricular dysfunction affecting cardiac output.

Acetylene↗
PubMed1985

Determination of cardiac output at rest and during exercise by carbon dioxide rebreathing method in obstructive airway disease.

We evaluated the accuracy of the CO2 rebreathing method (CO2rb) for measuring cardiac output at rest and during steady-state exercise in 15 patients (mean +/- SD age, 59.7 +/- 7.5 yr) with obstructive airway disease. At rest, there was a significant correlation between direct Fick and CO2rb methods using measured arterial PCO2 (r = 0.70; p = 0.002), but not with using end-tidal PCO2 (r = 0.38; p = NS). During exercise, there was greater correlation with CO2rb using arterial PCO2 (r = 0.79; p = 0.001) than using end-tidal PCO2 (r = 0.63; p = 0.007) compared with the direct Fick determination. Correlation between the CO2rb and direct Fick methods was greater with moderate air-flow obstruction (n = 6) than with severe airway disease (n = 9), and the CO2rb method was more accurate during exercise than at rest. The CO2rb method using either end-tidal or arterial PCO2 underestimated the direct Fick measurement in 13 of 15 patients at rest, which may reflect inadequate equilibration between alveolar and oxygenated mixed venous PCO2. However, no consistent error was observed during exercise when higher CO2 production and an increased venoarterial PCO2 difference would diminish potential inaccuracies. We concluded that the CO2rb technique is an acceptable method for measuring cardiac output during exercise in patients with moderate and severe obstructive airway disease as long as arterial PCO2 is directly measured rather than estimated from end-tidal PCO2.

Aged↗
PubMed1990

Adrenergic regulation of lipolysis in situ at rest and during exercise.

The adrenergic regulation of lipolysis was investigated in situ at rest and during standardized bicycle exercise in nonobese healthy subjects, using microdialysis of the extracellular space in subcutaneous adipose tissue. The glycerol concentration was about two times greater in adipose tissue than in venous blood. At rest, the glycerol concentration in adipose tissue was rapidly increased by 100% (P less than 0.01) after the addition of phentolamine to the ingoing perfusate, whereas addition of propranolol did not alter the adipose tissue glycerol level. Glycerol in adipose tissue and plasma increased during exercise and decreased in the postexercise period. Propranolol in the perfusate almost completely inhibited the increase in the tissue dialysate glycerol during the exercise-postexercise period. Phentolamine, however, was completely ineffective in this respect. During exercise, the lipolytic activity was significantly more marked in abdominal than in gluteal adipose tissue; this was much more apparent in women than in men. Thus, in vivo lipolysis in subcutaneous adipose tissue is regulated by different adrenergic mechanisms at rest and during exercise. Alpha-adrenergic inhibitory effects modulate lipolysis at rest, whereas beta-adrenergic stimulatory effects modulate lipolysis during exercise. In addition, regional differences in lipolysis are present in vivo during exercise, which seem governed by factors relating to sex.

Adipose Tissue↗
PubMed2003

Resting regional cerebral blood flow and gambling task performance in cocaine-dependent subjects and healthy comparison subjects.

OBJECTIVE: Orbitofrontal cortex regional cerebral blood flow (rCBF) is lower in cocaine-dependent subjects than in non-cocaine-dependent subjects. Performance on the Gambling Task, a test of decision making, is a putative correlate of orbitofrontal cortex activity and is reportedly impaired in drug-dependent subjects. The authors tested the hypothesis that lower Gambling Task scores would be associated with lower resting orbitofrontal cortex rCBF in cocaine-dependent subjects. METHOD: Fifteen healthy comparison subjects and 13 abstinent cocaine-dependent subjects underwent resting single photon emission computed tomography to measure rCBF, after which they completed the Gambling Task. RESULTS: Resting anterior cingulate and left dorsolateral prefrontal cortex rCBF significantly correlated with performance on the Gambling Task, but orbitofrontal cortex rCBF did not. Left dorsolateral prefrontal cortex rCBF was lower in the cocaine-dependent subjects than in the comparison subjects. CONCLUSIONS: Resting anterior cingulate and dorsolateral prefrontal cortex rCBF is significantly related to decision making, as assessed by the Gambling Task.

Adult↗
PubMed1998

Effect of felodipine on arterial blood flow and venous function at rest in patients with mild essential hypertension.

Felodipine is a second-generation dihydropyridine calcium antagonist used to treat mild to moderate arterial hypertension. The authors used venous occlusion plethysmography to study the effect of this drug on lower limb arterial inflow and venous outflow in 10 at rest patients with mild essential hypertension. They also sought correlations between changes in district blood flow and blood pressure. Plethysmography was carried out at 8 AM and 4, 8, and 24 hours later at baseline (after washout), on the first day of treatment with a single daily administration of 10 mg felodipine ER, and after 7 and 30 days of treatment. The drug was given after the 8 AM evaluation. The authors determined rest flow, maximal venous incremental volume (MVIV) at 40 mmHg and 60 mmHg, and gradient of venous volume between 60 and 40 mmHg divided by the pressure difference (DV/DP) as index of venous distensibility. On the days of plethysmographic evaluation, arterial blood pressure and heart rate were measured continuously over 24 hours by the ABPM (Ambulatory Blood Pressure Monitoring). The results were analyzed by ANOVA. Rest flow, MVIV, and DV/DP were stable at the baseline evaluation. On days 1, 7, and 30 of treatment the rest flow after 4 and 8 hours was significantly greater than at 8 AM but had always returned to normal after 24 hours. No other plethysmographic parameters changed significantly; in particular venous outflow remained unchanged. Mean arterial, systolic, and diastolic blood pressure were significantly reduced, compared with baseline, following treatment on the first day and after 7 and 30 days' treatment. There was no effect on heart rate. The authors conclude that felodipine is useful for the treatment of mild essential hypertension, since it reduces arterial resistance without altering venous capacitance or distensibility.

Aged↗
PubMedDate not supplied

Calf muscle area and strength changes after five weeks of horizontal bed rest.

Nine male volunteers participated in a 10 week metabolic study in which subjects underwent 5 weeks of ambulatory control and 5 weeks of complete horizontal bed rest. Bed rest is a model commonly used to simulate space flight. The changes in muscle area and strength of the calf dorsiflexors and plantar flexors were measured before and after bed rest using magnetic resonance imaging (MRI) and a Cybex II dynamometer. The muscle area of the plantar flexors (gastrocnemius and soleus) decreased 12%, whereas the muscle area of the dorsiflexors was not significantly decreased. The maximal muscle strength of the plantar flexors decreased 26%; the muscle strength of the dorsiflexors was not significantly decreased. These results, which demonstrate differential muscle atrophy and a larger loss in strength relative to muscle area, have important implications in the development of exercise counter-measures to be implemented during space flight. The results also have implications for patients who have severe orthopaedic disorders and must be bed rested for long periods of time, and for persons who are voluntarily inactive (a large number of the elderly).

Adult↗
PubMed2006

Multiple gestation: side effects of antepartum bed rest.

The birth rate for higher order multiples has dramatically increased in recent decades. Multiple gestation pregnancies are considered to be at high obstetric risk. Antepartum bed rest is often prescribed to offset complications despite the lack of evidence for its effectiveness in preventing complications. This longitudinal repeated-measures study identified side effects of antepartum bed rest treatment for 31 hospitalized women with twin or triplet gestation. Maternal weight gain and infant birth weight were recorded. Antepartum stressors were measured by the Antepartum Stressors Hospital Inventory, and depressive symptoms were measured by the Center for Epidemiologic Studies Depression Scale (CES-D). Antepartum and post-partum side effects of bed rest were also assessed by the Antepartum and Postpartum Symptom Checklists. The weekly rate of maternal weight gain during hospitalization was significantly less than recent recommendations for multiple gestation weight gain (t = - 2.14, p = .04). Infant birth weights were appropriate for gestational age. There were fewer than expected small-for-gestational-age infants. Concerns regarding family status and separation from family were the major antepartum stressors. Women reported a high number of symptoms during bed rest (M = 22), which did not significantly change across 2 weeks. CES-D scores for depressive symptoms were high on antepartum hospital admission. Postpartum symptoms were initially high but had significantly declined by 6 weeks: F(1, 27) = 15.68, p = .00. These findings suggest that interventions are needed to reduce antepartum maternal weight loss, stress, physiologic and psychosocial symptoms, and depressive symptoms, as well as reduce postpartum symptoms of maternal morbidity.

Adolescent↗
PubMed1998

Haemodynamics in children during rest and exercise: methods and normal values.

Measuring haemodynamic performance in children is either invasive, and thus unacceptable, or noninvasive when the measured variable is often remote from the true variable. Measuring only maximum performance variables relies too heavily on motivation, especially in disease groups. We describe a method for the measurement of haemodynamic performance using respiratory mass spectrometry during rest, exercise and recovery therefrom. One hundred and six healthy children (55 male, 51 female) aged 8-16.9 yrs underwent an identical exercise protocol. Following studies at rest, they initially bicycled at 25 W x m(-2), increasing every 3 min by 15 W x m(-2) until exhaustion, after which measurements were made during recovery. Effective pulmonary blood flow, stroke volume, oxygen consumption, arteriovenous oxygen difference and functional residual capacity (FRC) together with estimates of pulmonary capillary blood volume and transit time were assessed at every exercise stage using inert gas rebreathing techniques. Haemodynamic performance is highly dependent on surface area, age, gender and pubertal stage. Many parameters, for example transfer factor, demonstrate pubertal stage-dependent differences at identical workloads even after correction for size. Females have a lower capillary blood volume at rest compared to age and size-matched males, but it is equalized during exercise. FRC unexpectedly rose with exercise, and peak exercise was associated with a falling stroke volume in 91% (95% CI 84-96%) of children, a possible demonstration of Starling's law of the heart. Oxygen pulse (oxygen consumption/cardiac frequency) is a very poor marker for pulmonary blood flow. Normal values are provided for all haemodynamic parameters for rest and every exercise stage for all subgroups of children. This should allow accurate comparison of normal and disease groups in future.

Adolescent↗
PubMed1991

Prostaglandin F2 alpha-induced calcium transient in ovine large luteal cells: II. Modulation of the transient and resting cytosolic free calcium alters progesterone secretion.

A previous study demonstrated that prostaglandin F2 alpha (PGF2 alpha) stimulates a transient increase in cytosolic free Ca2+ levels [( Ca2+]i) in ovine large luteal cells. In the present study, the magnitude of the PGF2 alpha (0.5 microM)-induced calcium transient in Hanks' medium (87 +/- 2 nM increase above resting levels) was reduced (P less than 0.05) but not completely eliminated in fura-2 loaded large luteal cells incubated in Ca2(+)-free or phosphate- and carbonate-free medium (10 +/- 1 nM, 32 +/- 6 nM, above resting levels; respectively). Preincubation for 2 min with 1 mM LaCl3 (calcium antagonist) eliminated the PGF2 alpha-induced calcium transient. The inhibitory effect of PGF2 alpha on secretion of progesterone was reduced in Ca2(+)-free medium or medium plus LaCl3. Resting [Ca2+]i levels and basal secretion of progesterone were both reduced (P less than 0.05) in large cells incubated in Ca2(+)-free medium (27 +/- 4 nM; 70 +/- 6% control, respectively) or with 5 microM 5,5'-dimethyl bis-(O-aminophenoxy)ethane-N,N,N'N'-tetraacetic acid (40 +/- 2 nM; 49 +/- 1% control; respectively). In addition, secretion of progesterone was inhibited (P less than 0.05) by conditions that increased (P less than 0.05) [Ca2+]i; that is LaCl3 ([Ca2+]i, 120 +/- 17 nM; progesterone, 82 +/- 8% control) and PGF2 alpha ([Ca2+]i, 102 +/- 10 nM; progesterone, 82 +/- 3% control). In small luteal cells, resting [Ca2+]i levels and secretion of progesterone were reduced by incubation in Ca2(+)-free Hanks ([Ca2+]i, 28 +/- 2 nM; progesterone, 71 +/- 6% control), however, neither LaCl3 nor PGF2 alpha increased [Ca2+]i levels or inhibited secretion of progesterone. The findings presented here provide evidence that extracellular as well as intracellular calcium contribute to the PGF2 alpha-induced [Ca2+]i transient in large cells. Furthermore, whereas an adequate level of [Ca2+]i is required to support progesterone production in both small and large cells, optimal progesterone production in large cells depends upon an appropriate window of [Ca2+]i.

Animals↗
PubMed2001

Uncoupling protein-3 is a molecular determinant for the regulation of resting metabolic rate by thyroid hormone.

Thyroid hormones increase energy expenditure, partly by reducing metabolic efficiency. The control of specific genes at the transcriptional level is thought to be the major molecular mechanism. However, both the number and the identity of the thyroid hormone-controlled genes remain unknown, as do their relative contributions. Uncoupling protein-3, a recently identified member of the mitochondrial transporter superfamily and one that is predominantly expressed in skeletal muscle, has the potential to be a molecular determinant for thyroid thermogenesis. However, changes in mitochondrial proton conductance and resting metabolic rate after physiologically mediated changes in uncoupling protein-3 levels have not been described. Here, in a study on hypothyroid rats given a single injection of T(3), we describe a strict correlation in terms of time course between the induced increase in uncoupling protein-3 expression (at mRNA and protein levels) and decrease in mitochondrial respiratory efficiency, on the one hand, and the increase in resting metabolic rate, on the other. First, we describe our finding that uncoupling protein-3 is present and regulated by T(3) only in metabolically relevant tissues (such as skeletal muscle and heart). Second, we follow the time course (at 0, 6, 12, 24, 48, 65, 96, and 144 h) of both uncoupling protein-3 mRNA levels and mitochondrial uncoupling protein-3 density in gastrocnemius muscle and heart. In both tissues, the maximal (12-fold) increase in uncoupling protein-3 density was reached at 65 h. The resting metabolic rate [lO(2)(kg(0.75))(-1)h(-1)] showed the same time course, and at 65 h the increase vs. time zero was 45% (1.316 +/- 0.026 vs. 0.940 +/- 0.007; P < 0.001). At the same time point, gastrocnemius muscle mitochondria showed a significantly higher nonphosphorylating respiration rate (nanoatoms of oxygen per min/mg protein; increase vs. time zero, 40%; 118 +/- 4 vs. 85 +/- 9; P < 0.05), whereas the membrane potential decreased by 8% (168 +/- 2 vs. 182 +/- 4; P < 0.05). These data are diagnostic of mitochondrial uncoupling. The results reported here provide the first direct in vivo evidence that uncoupling protein-3 has the potential to act as a molecular determinant in the regulation of resting metabolic rate by T(3).

Animals↗
PubMed2003

High dose growth hormone exerts an anabolic effect at rest and during exercise in endurance-trained athletes.

The anabolic actions of GH in GH-deficient adults and children are well documented. Replacement with GH in such individuals promotes protein synthesis and reduces irreversible loss of protein through oxidation. Although GH is known to be self-administered by athletes, its protein metabolic effects in this context are unknown. This study was designed to determine whether 4 wk of high dose recombinant human GH (r-hGH) administration altered whole body leucine kinetics in endurance-trained athletes at rest and during and after 30 min of exercise at 60% of maximal oxygen uptake. Eleven endurance-trained male athletes were studied, six randomized to receive r-hGH (0.067 mg/kg.d), and five to receive placebo. Whole body leucine turnover was measured at rest and during and after exercise, using a 5-h primed constant infusion of 1-[(13)C]leucine, from which rates of leucine appearance (an index of protein breakdown), leucine oxidation, and nonoxidative leucine disposal (an index of protein synthesis) were estimated. Under resting conditions, r-hGH administration increased rate of leucine appearance and nonoxidative leucine disposal, and reduced leucine oxidation (P < 0.01). This effect was apparent after 1 wk, and was accentuated after 4 wk, of r-hGH administration (P < 0.05). During and after exercise, GH attenuated the exercise-induced increase in leucine oxidation (P < 0.05). There were no changes observed in placebo-treated subjects compared with the baseline study. We conclude that GH administration to endurance-trained male athletes has a net anabolic effect on whole body protein metabolism at rest and during and after exercise.

Adult↗
PubMed2004

Elevated resting and exercise-induced cortisol levels after mineralocorticoid receptor blockade with canrenoate in healthy humans.

Activation of central nervous mineralocorticoid receptors (MRs) has been shown to inhibit the activity of the hypothalamo-pituitary-adrenocortical (HPA) axis in animals. Here, we examined whether MRs in humans likewise regulate HPA activity in response to a physiological stressor. In a balanced, randomized, double-blind, cross-over trial, 12 healthy men were treated with either two injections of 200 mg canrenoate or placebo 24 and 8 h before an intense physical exercise taking place between 1600 and 1700 h. Exercising was preceded by a 60-min rest period and followed by another 90-min rest. Blood was collected in regular intervals to determine ACTH, cortisol, and human GH (hGH). Exercise induced a significant rise in cortisol, ACTH, and hGH. Cortisol levels, however, were significantly higher after canrenoate, compared with placebo, whereas ACTH and hGH concentrations did not differ. The increase in cortisol was already significant during rest before exercise and continued to be elevated throughout the whole experiment. We conclude that MR blockade leads to a tonically increased cortisol secretion both during rest and under stimulation. The undiminished concentration of ACTH in the presence of elevated cortisol levels suggests that blockade of MR shifts the set point for cortisol feedback inhibition of the HPA axis toward higher cortisol levels.

Adrenocorticotropic Hormone↗
PubMed1985

Parasympathetic control of resting heart rate: relationship to aerobic power.

The degree of parasympathetic control of resting heart rate (PC) was assessed by measurement of variation in heart period (VHP) during cardiopulmonary synchronization of respiration. Respiratory period was arbitrarily preset and standardized at 7 heart beats (3 beats inspiration, 4 beats expiration). The mathematical and experimental evidence for this technique is elucidated. Twenty-one healthy subjects were examined for the relationship of aerobic power (VO2max) to (1) VHP and (2) respiratory sinus arrhythmia (RSA) waveform amplitude and phase. Intraindividual variability in VHP was low (test-retest r = 0.97-0.98). VHP in msec was a logarithmic function of VO2max (ml X kg FFW-1 X min-1) according to the equation: 1n VHP = 0.27 + 0.082 X VO2max where r = 0.92, P less than 0.001). VHP was more closely related to VO2max than was resting HR (r = -0.75). In addition, a higher VO2max was associated with a leftward shift of the HR: respiratory cycle sinusoidal curve. These results illustrate the close relationship between aerobic power and vagal tone in control of resting heart rate. Individuals with a higher aerobic power maintain lower resting heart rates mainly via an increase in parasympathetic tone (as opposed to a decreased sympathetic tone). Previous correlations between RSA characteristics and age may be accounted for by age-related decreases in VO2max.

Adult↗
PubMed1978

Pathogenesis and treatment of angina pectoris at rest as seen from its response to various drugs.

To twenty six patients with angina at rest (including 13 patients with Prinzmetal's variant angina), propranolol 40--50 mg, dilitiazem 60--90 mg, dipyridamole 50 mg, atropine sulfate 0.6 mg and phenoxybenzamine 10--20 mg were given at 9:00 p.m. and 2:00 a.m. (except phenoxybenzamine which was given only at 9:00 p.m.) to examine the effect of these drugs on the attack. Propranolol was not only ineffective in suppressing the attack but rather tended to aggravate it in all the cases of Prinzmetal's variant angina. It was effective to some degree in 5 of 13 cases of angina at rest other than Prinzmetal's variant angina. Diltiazem suppressed the attack completely and dramatically in all the cases of angina at rest (including Prinzmetal's variant angina). Dipyridamole was ineffective in all the cases except one in suppressing the attack. Atropine sulfate and phenoxybenzamine suppressed the attack in 13 of 21 cases and in 6 of 12 cases respectively. Coronary arteriography was done before and after the intravenous administration of 10 mg of diltiazem in 8 patients and it was demonstrated that diltiazem dilates large coronary arteries in all these patients. It is concluded that diltiazem, a calcium antagonistic drug, is specifically effective in suppressing the attack of angina at rest by dilating large coronary arteries and that the autonomic nervous system plays a role in the genesis of the attack probably by constricting large coronary arteries by way of alpha adrenergic receptors.

Aged↗
PubMed1996

Exercise beta-methyl iodophenyl acid (BMIPP) and resting thalium delayed single photon emission computed tomography (SPECT) in the assessment of ischemia and viability.

To clarify the significance of exercise BMIPP (beta-methyl iodophenyl pentadecanoic acid) and resting T1 delayed single photon emission computed tomography (SPECT) in the assessment of ischemia and viability, we studied maximal exercise-loading BMIPP SPECT following rest-injected T1 3 h SPECT in 11 control subjects, 20 patients with effort angina and 38 patients with old myocardial infarction. The left ventricular wall on ECT was divided into 9 segments. BMIPP and T1 uptake were scored as 0 = normal, 1 = reduced, 2 = severely reduced, or 3 = absent. Discordance was defined as when segments with a reduced BMIPP uptake had a better resting T1 uptake. Significant coronary artery stenosis was defined as stenosis of 75% or greater on coronary arteriogram. Left ventricular wall motion was assessed as either normokinesis, hypokinesis, severe hypokinesis, akinesis or dyskinesis on left ventriculogram. When discordance was considered to be a marker of ischemia, the sensitivity and specificity in effort angina and control subjects were 95.2% and 84.6% for patients and 83.9% and 94.4% for diseased vessels, respectively. There were no differences between the sensitivity and specificity in left anterior descending artery (LAD), left circumflex artery (LCx) and right coronary artery (RCA) lesions (83.3%, 95.5% in LAD, 83.3%, 95.5% in LCx, 85.7%, 92.6% in RCA, respectively). All of the patients with old myocardial infarction had reduced exercise BMIPP uptake in infarcted regions. In old myocardial infarction, 35 patients had segments with discordant uptake. Discordance was observed in 75 (91.5%) of 82 segments with hypokinesis, and in 24 (92.3%) of 26 segments with severe hypokinesis. Even among the 36 segments with akinesis or dyskinesis, 25 (69.0%) had discordant uptake. When discordance in the infarcted region was considered to be a marker of viability, regions with severe asynergy showed a high possibility of viability. Thus, discordant uptake on exercise BMIPP and resting T1 delayed SPECT may be a useful marker of ischemia in effort angina and of viability in old myocardial infarction.

Aged↗
PubMed1992

The effects of powered air supply to the respiratory protective device on respiration parameters during rest and exercise.

The common chemical warfare protective masks impose an excessive respiratory load on the wearer due to elevated breathing resistance and increased dead space. For patients with severe respiratory disease, the excessive respiratory effort may be intolerable. Besides, the substantial negative pressure created within the mask during inspiration may result in an inward leakage in individuals having difficulties with proper facial fitting of the mask. The purpose of the current investigation was to evaluate the effects of a blower, actively driving air, through the mask's filter, at a flow (mean +/- SD) of 42 +/- 2 L/min, on respiratory parameters during rest and moderate exercise. Ten healthy subjects of either sex participated in two experimental sessions, wearing the mask with and without the blower. Each session included 6 min of sitting at rest and 6 min of walking on a treadmill (3.2 mph, and 10 percent grade). In nine of the subjects, the active air supply produced a positive inspiratory pressure at rest (5 +/- 4 vs -24 +/- 9 mm H2O peak inspiratory pressure with and without the blower, respectively, p < 0.0001). Inspiratory carbon dioxide concentration (FICO2) at rest was diminished (0.4 +/- 0.4 vs 1.3 +/- 0.7 percent with and without the blower, respectively; p < 0.01) while FIO2 increased from 19.5 +/- 0.7 percent to 20.6 +/- 0.4 percent with the device (p < 0.01). These changes were associated with a significant decrease in respiratory rate (15 +/- 2 vs 18 +/- 3 per minute, p < 0.01). During exercise the blower barely decreased the negative inspiratory pressures, had no effect on other respiratory parameters measured, but significantly shortened the inspiratory/cycle-length time ratio (0.46 +/- 0.03 vs 0.53 +/- 0.03, p < 0.005). The effects of active air supply were not different between male and female subjects. We conclude that the blower is expected to be a useful accessory to respiratory protective devices for patients with pulmonary disease.

Adult↗