摘要:

Height, weight, total body fat, lean body mass, size of fat cells and total number of lipid-containing fat cells were compared in two groups of children, ages 2-6 years, with congenital heart disease. Twelve children who developed heart failure in infancy made up one group and 14 asymptomatic patients made up the other. No patient was cyanotic or had undergone surgical repair.Patients with heart failure were shorter and lighter than asymptomatic patients. Whereas both fat and lean tissues were less in the heart failure group, reduction in body fat was more important in producing underweight. Although there was no difference in the size of fat cells, the number of lipid-laden fat cells was diminished in the children who had early heart failure. Thus hypocellularity of fat cells appeared to be the major determinant of diminished body fat with heart failure. Because shortness and decreased lean tissue were associated with these adipose tissue abnormalities, it is likely that widespread changes are caused by early heart failure. As previously reported with hypoxemia, the early development of heart failure seems to produce tissue changes that handicap growth.

ISSN:0009-7322    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

long-term survivors of intrapericardial surgery in the pediatric age group. We evaluated clinical evidence of syndrome and concurrent appearance of antiheart antibody (AHA) by indirect immunofluorescence and antiviral antibody (AVA) by complement fixation in sera preoperatively and serially postoperatively. Incidence of PPS was 27% overall in 400 subjects, but only 3.5% in infants younger than 2 years of age. AHA in high titer appeared in all patients with PPS. A fourfold or greater rise in titer to AVA was found in 70% of these but in only 5% of those with negative AHA and no PPS. AVA rise, tested in 280 consecutive patients, was to no single one of the eight viruses studied (adenovirus, cytomegalovirus, and coxsackievirus B 1-6). Instead, the rise and fall, consistent with antiviral response to a recent infection, was exhibited usually to one but occasionally to two or more viruses, and the viral prevalence changed from year to year, as did that in the community. The study suggests that concurrent fresh or reactivated viral illness plays a role in triggering the immunologic response that characterizes the PPS.

ISSN:0009-7322    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

Morphologic analyses of lungs from infants who died of severe aortic stenosis shortly after birth have shown increased pulmonary vascular smooth muscle and an increased number of pulmonary resistance vessels. These findings have been thought to be caused by in utero pulmonary venous, pulmonary arterial or right ventricular hypertension. To study this problem in the fetus, we created aortic stenosis in 10 fetal lambs (97-115 days gestation). Fetuses were reoperated upon at 133-141 days gestation (mean 32.6 days aortic stenosis). The left ventricular-to-systemic arterial systolic blood pressure difference was measured in three fetuses and was abnormal (18, 22 and 22 mm Hg). Pulmonary arterial blood pressure was measured in three fetuses and was normal (54-58 mm Hg mean). At autopsy, aortic stenosis was severe and the aortic diameter reduced (1.7 ± 1.0 mm vs 6.1 ± 0.7 mm for controls,p< 0.01). Heart weight was greater in aortic stenosis (21.5 ± 8.8 g) compared with control (17.2 ± 5.8 g,p< 0.01). This was the result of increased left ventricular free wall weight (aortic stenosis 9.79 ± 7.73 g vs control 5.46 ± 2.26 g,p< 0.01) and thickness (aortic stenosis 7.3 ± 1.5 mm vs control 5.1 + 1.7 mm,p<0.05). Lungs of six fetuses were fixed by perfusion and 331 fifth-generation resistance vessels were measured. Medial width (m) was decreased in aortic stenosis (4.82 ± 0.66 μ) compared with vessels from six control fetuses (6.19 ± 1.70μ, n = 529,p< 0.002). External diameter (d) was also decreased in aortic stenosis (22.18 ± 1.37μ) compared with control vessels (39.05 ± 10.15 μ,p< 0.01), resulting in an increased m/d ratio in aortic stenosis (0.22 i 0.03) compared with control vessels (0.16 ± 0.04,p< 0.007). The number of small muscular vessels per cm' lung tissue was decreased in aortic stenosis (74.3 ± 27.2/cm') compared with control lungs (167.3 ± 3.9/cm',p< 0.004). Differences between these findings and findings in human infants' lungs may be the result both associated lesions and age at time of death in human infants.

ISSN:0009-7322    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

The physiologic response to the chronic administration of digoxin was studied in 12 adult and 13 newborn sheep. Vascular pressures, cardiac output, isovolumic contraction phase indexes and systolic time intervals were measured before and after 2 weeks of digoxin therapy. Physiologic measurements were correlated with drug levels in plasma and myocardium. Resting myocardial function in newborns exceeded that in ewes. In ewes, the heart rate decreased from 98 to 74 beats/min, the preejection period (PEP) decreased from 76 to 57 msec, the ratio of PEP to left ventricular ejection time (LVET) decreased from 0.323 to 0.223 and dP/dt max increased from 2415 to 3460 mm Hg. sec-' as plasma concentrations of digoxin increased to a mean of 1.8 ng/ml. Although the final steady-state plasma concentration of digoxin in newborn lambs averaged 1.7 ng/ml, cardiac output, PEP, PEP/LVET and dP/dt max did not change significantly from baseline values. These studies suggest that developmental differences in the physiologic response to digoxin are due either to a limited capacity for improvement in myocardial contractility shortly after birth or to an agerelated difference in the effect of digoxin on myocardial tissue.

ISSN:0009-7322    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

To develop standards for distinguishing antiarrhythmic drug effect from spontaneous variability of premature ventricular complexes (PVCs), 21 males (mean age 56 ± 8 years) with chronic ischemic heart disease and PVCs underwent symptom-limited treadmill exercise testing and 24-hour ambulatory monitoring before and after 2 weeks of placebo medication. Linear regression analysis was used to describe the relationship between baseline and placebo PVC frequency for various indexes of ventricular ectopic activity and to establish 95% and 99% one-tailed confidence intervals for this relationship within the group of 21 patients. The lower limit of baseline PVC frequency for which the procedure could distinguish a placebo from a true drug response, termed the “sensitivity threshold,” was an average frequency of 2.2 PVCs/hour for ambulatory electrocardiographic monitoring and 1.2 PVCs/min for treadmill exercise testing. All patients exceeded the sensitivity threshold on baseline ambulatory ECGs, but only 38% of patients did so on baseline treadmill exercise tests. To establish antiarrhythmic efficacy with 95% confidence, the minimal percent reduction of PVCs between baseline and placebo visits was 68% for treadmill exercise testing and 65% for ambulatory electrocardiography. Although these standards were developed in patients with chronic ischemic heart disease, the model can be used to establish antiarrhythmmic drug efficacy in any patient group.

ISSN:0009-7322    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

We evaluated the effects of acebutolol, a cardioselective β-adrenergic blocking agent, on the anginal pattern and exercise tolerance in 44 patients with chronic stable angina. There were 43 males and one female, with a mean age of 57 years (range 48-73 years).The study consisted of an initial 4-week, single-blind placebo control phase, followed by a 3-week, singleblind dose-titration phase using increasing doses of acebutolol and by two 5-week double-blind phases that included randomization to acebutolol or placebo and crossover. A 1-week withdrawal schedule followed each treatment phase. All patients kept a diary of anginal frequency and nitroglycerin consumption. Capsule counts of returned medication were made at each visit. Exercise treadmill tests were performed at entry into the study and on the final day of each of the four phases.Acebutolol produced a significant decrease in the frequency of angina attacks, consumption of nitroglycerin and exercise capacity. Resting and peak exercise values were significantly reduced. Heart rates were reduced by 16% and 18%, respectively (p<0.002) and rate-pressure products by 17% and 30%, respectively (p< 0.002). At effective antianginal dosages, acebutolol had no significant adverse effects on pulmonary functions. No clinical side effects of acebutolol necessitated drug discontinuance.Acebutolol is a well-tolerated β-blocking drug that significantly reduces spontaneous anginal frequency, decreases consumption of nitroglycerin and increases exercise capacity in patients with chronic stable angina. It is a useful therapeutic addition to the group of /-adrenergic blocking agents. Further, its lack of deleterious effects on the bronchial smooth muscle suggests that acebutolol may be safely used in patients in whom angina is associated with obstructive pulmonary disease.

ISSN:0009-7322    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

Coronary artery stenoses that limit blood flow below demand are considered critical. In this comparative study we investigated whether the same degree of stenosis in either the proximal third of the right coronary artery (RCA) or the proximal third of the left anterior descending artery (LAD) causes critical floweduction. Lesions were quanltified from 35-mm cinefilms in multiple projections using a vernier caliper. These morphometric measurements were correlated with various manifestations of critical flow reduction, such as angina pectoris, development of collateral vessels and segmental wall motion abnormalities. In 13 patients with anginal pain and isolated RCA stenosis, the mean degree of obstruction was 63% area stenosis, which was significantly lower (p< 0.05) than that measured in 17 symptomatic patients who had isolated obstructions of the LAD (77% area stenosis). In patients with an identical degree of obstruction (78%) in either the LAD or RCA, collateral vessels were angiographically demonstrable in 53% of the RCA stenoses but in only 29% of the LAD stenoses. Furthermore, when the stenoses were less than 63% in the RCA and LAD, regional wall motion abnormalities were more frequently (p < 0.05) associated with RCA than with LAD stenoses. These observations indicate that a significantly smaller percent area of stenosis is critical in the RCA than in the LAD.

ISSN:0009-7322    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

To determine the predictive accuracy of fluoroscopically detected coronary artery calcification (CAC) and a positive submaximal exercise test, 129 asymptomatic men were screened; 13 had both coronary artery calcification and positive exercise test (≥ 1.0 mm ST-segment depression). These 13 men were studied at coronary arteriography. They had a mean age of 44 years (range 41–56 years); none had history or symptoms of heart disease and all had normal resting ECGs at entry.CAC was detected in one artery in 10 men, in two arteries in two men, and in three arteries in one man. Coronary artery disease (CAD) was considered clinically significant if any major coronary branch was narrowed > 50%. Coronary arteriography revealed 12 men with clinically significant CAD (one-vessel CAD in four, two-vessel CAD in five and three-vessel CAD in three men) and one man with minor one-vessel CAD. The predictive accuracy was 100% for minor CAD and 92% for clinically significant CAD. The location of CAC and CAD correlated, but the absence of CAC did not rule out the presence of CAD at coronary arteriography. Furthermore, CAC did not indicate the location of the highest stenotic (most occlusive) lesions seen at arteriography. Follow-up for the 13 patients was 36 months; three patients developed typical angina and one patient developed a transmural myocardial infarction.This study suggests that the predictive accuracy of CAC and a positive exercise test in the middle-aged nonhyperlipidemic asymptomatic male is very high (100% for CAD and 92% for clinically significant CAD) and that CAC and a positive exercise test predict an early appearance of angina or myocardial infarction in previously asymptomatic men.

ISSN:0009-7322    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

The diagnostic accuracy of the Bruce multistage exercise treadmill test (ETT) and changes in left ventricular function assessed by radionuclide angiocardiography (RNA) during rest and maximal exercise were compared in 72 patients who underwent coronary arteriography for evaluation of chest pain. Significant coronary artery disease was defined as a 75% or greater stenosis of the diameter of any of the three major coronary arteries. The coronary arteriographic results were used to categorize each patient according to the number of vessels with a significant lesion. As a result, 15 patients had insignificant disease and 57 had significant lesions of one or more coronary arteries. ETT results were defined as positive if ST-segment changes occurredwith exercise, negative if ST-segment changes did not occur at target heart rate, and indeterminate if ST-segment abnormalities existed at rest or if no ST-segment changes developed at a heart rate below the target heart rate. Abnormal changes in left ventricular function by RNA were an exercise-induced wall motion abnormality, a less than 5% increase in ejection fraction, and a greater than 25% increase in end-diastolic volume and an increase in end-systolic volume with exercise.RNA results were normal in 11 of 15 patients with insignificant disease and abnormal in four, all of whom had 50% lesions of a major coronary artery. In this group, ETT results were indeterminate in seven patients, negative in six and positive in two. In the 57 patients with significant coronary disease, RNA results were abnorinal in 55 and normal in two. ETT results were indeterminate in 12 patients, negative in nine and positive in 36.RNA had a sensitivity of 97% and a specificity of 73% for the 72 patients. By comparison, ETT had a sensitivity of 80% and a specificity of 66% for the 53 patients with adequate studies. These results suggest that exercise-induced changes in left ventricular function defined by RNA have a greater diagnostic accuracy than the ST-segment response during ETT in the patient population studied.

ISSN:0009-7322    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

The relationship between the configuration of agarose-gel lipoprotein electrophoresis patterns and the extent of coronary artery disease (CAD) was studied in consecutive patients undergoing diagnostic coronary angiography. Three groups were identified: patients with normal coronary arteries (group 1), patients with minor luminal irregularities (group 2) and patients with significant coronary artery obstructions (group 3). Densitometric scans of the electrophoretograms were studied to determine the relative proportion of lipoproteins in each major fraction and the configuration of the pre β-3 complex. The presence of multiple subfractions within the pre-β lipoprotein complex had a sensitivity of 66% for the presence of CAD and a specificity of 99%. A decreased level of αalipoproteins, defined as less than 25% of total lipoproteins, occurred almost entirely in groups 2 and 3, whereas an increased level (> 28%) of pre-β lipoproteins was less specific for CAD. The proportions of α and pre-β lipoproteins were inversely related (r = 0.677). Although abnormalities of serum cholesterol and/or triglycerides were common in groups 2 and 3, the detailed study of lipoprotein patterns provided a more sensitive index of disordered lipoprotein metabolism. The angiographic severity of CAD was significantly related to age and to levels of serum triglycerides,αalipoproteins, and pre-β lipoproteins. The lipoprotein electrophoretogram, in conjunction with serum lipid levels, is a valuable tool for demonstrating abnormalities of lipoprotein metabolism associated with CAD.

ISSN:0009-7322    

出版商:OVID    

年代:1980

数据来源: OVID