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At least 739 records · Page 41Linked to original sources
PubMed1999

Repetitive acidosis protects the ischemic heart: implications for mechanisms in preconditioned hearts.

Repetitive brief ischemic episodes (ischemic preconditioning, PC) result in transient intracellular acidosis and protect the heart from subsequent ischemic injury, potentially through a protein kinase C (PKC)-dependent mechanism. We hypothesized that repetitive brief acidification of the heart without concomitant ischemia would also protect the heart from ischemic injury via a PKC-dependent mechanism. Isolated rat hearts underwent 30 min of global ischemia following control perfusion (CTL), or after PC or repetitive acidosis (RA), in the presence of absence of chelerythrine, a specific PKC inhibitor. Intracellular pH, PCr and ATP were measured using 31P NMR spectroscopy, while intracellular sodium [Na]i was measured using 23Na spectroscopy. Na,K-ATPase activity was measured prior to ischemia and on reperfusion. Both PC and RA resulted in transient acidification prior to ischemia. Ischemic injury, as assessed by creatinine kinase (CK) release on reperfusion, was reduced in both the PC and RA hearts [63+/-14 and 16+/-4 IU/g dry weight (dw) respectively, v 705+/-72 IU/gdw for control P<0.001], and was associated with improved functional recovery on reperfusion. PC and RA each significantly reduced Na,K-ATPase activity prior to ischemia (8.18+/-0.47 and 7.76+/-0.54 micromol ADP/h/mg protein) when compared to control (11.05+/-0.54 micromol ADP/h/mg protein P<0.05), limited the rate of ATP depletion during ischemia, and resulted in more rapid normalization of [Na]i on reperfusion. Chelerythrine resulted in intermediate CK release in PC and RA hearts (443+/-48 and 375+/-72 IU/gdw, P<0.001 v PC, P<0.01 v control), but did not alter the rate of ATP depletion or [Na]i kinetics in either PC or RA hearts. PC and RA each protect the ischemic heart, having in common ATP preservation during ischemia and more rapid normalization of [Na]i on reperfusion. These effects, not modulated by protein kinase C, are consistent with the hypothesis that ATP preservation during ischemia provides enhanced substrate for sodium efflux via the Na,K-ATPase on reperfusion.

Acidosis↗
PubMed1991

Principal considerations on the stroke volume-heart size relationship based on different heart models.

The aim of the present study was to show by hemodynamic investigations in a rat heart and by theoretical considerations based on different heart models that a chronic enlargement of the heart does not necessarily lead to an impairment of the stroke volume. In the experiments performed on rat hearts of various sizes, in situ pressure-volume diagrams were obtained which clearly demonstrate that, in principle, larger hearts are able to eject larger stroke volumes despite the fact that for geometrical reasons, they have to develop higher wall stress. These findings are supported by calculations of stroke volume-heart size relations being based on the assumption of different geometrical models for the left ventricle. By means of these relations, when applying them to pressure-volume data of a dilated or failing heart, it is in principle possible to differentiate between effects of altered geometry and of altered contractility. A simple lever-pump system is introduced which is appropriate to simulate transmission aspects in the transformation of myocardial shortening into ventricular ejection for hearts of variable size.

Animals↗
PubMedDate not supplied

Heart bioassay of effluent of isolated, perfused guinea pig hearts to examine the role of metabolites regulating coronary flow during hypoxia.

The concentrations of adenosine and other metabolic factors are known to be altered in the effluent of hypoxic hearts, but the relative contribution of these factors in elevating coronary flow has not been clarified. Langendorff prepared guinea pig hearts were perfused at constant pressure and were made mildly hypoxic so that flow increased but oxygen consumption remained unchanged. When the effluent of these hearts was reoxygenated and pH corrected and directed to perfuse similarly prepared recipient (bioassay) hearts, flow remained unchanged in recipient hearts. However, when donor hearts were made severely hypoxic so that oxygen consumption decreased, and recipient hearts were perfused at constant flow, the PO2, pH corrected effluent produced a large vasodilation in recipient hearts. This response was greatly attenuated in the presence of excess adenosine deaminase but completely abolished by theophylline. Thus the apparent loss of adenine compounds into the effluent may account for vasodilation during severe hypoxia, but not during mild hypoxia, if effluent levels of these compounds truly reflect perivascular levels.

Adenosine↗
PubMed1978

Relation of lipids, weight and physical activity to incidence of coronary heart disease: the Puerto Rico heart study.

The 2 1/2 year incidence of coronary heart disease was examined in relation to antecedent serum cholesterol and fasting triglyceride levels, physical activity status and relative weight in a cohort of 8,171 urban and rural men 45 to 64 years old participating in the Puerto Rico Heart Program. In this population with a low incidence rate of coronary heart disease, risk of coronary disease was related to serum cholesterol in both urban and rural groups, but this trend was statistically significant only in the urban population. Neither the urban nor the rural population showed a substantial or statistically significant association of serum triglyceride levels with incidence of coronary heart disease. Correlations among relative weight and serum triglyceride and serum cholesterol levels were noted. Despite small differences in incidence of coronary heart disease between urban and rural groups, values for serum cholesterol, triglycerides and relative weight were all significantly higher in the urban men. Only physical activity levels were higher in the rural men. Multivariate analysis, performed to sort out the net effects of these interrelated variables, revealed that serum cholesterol is related to the risk of coronary heart disease even when all variables are taken into account. Low levels of physical activity were significantly associated with a greater incidence of coronary heart disease only in urban men (P less than 0.05). Overweight, which was associated with higher lipid values and less physical activity, was not related to the development of coronary heart disease in either the urban or the rural cohort.

Body Weight↗
PubMed1994

Estimated contribution of coronary artery bypass graft surgery to the decline in coronary heart disease mortality: the Minnesota Heart Survey.

OBJECTIVES: This study assessed the possible contribution of coronary artery bypass graft surgery to the decline in coronary heart disease mortality in the Minneapolis-St. Paul metropolitan area population between 1970 and 1984. BACKGROUND: Coronary artery bypass graft surgery is a major contemporary therapeutic approach for coronary heart disease. Its use has increased over the past two decades because it provides relief of symptoms and, in certain circumstances, prolongs life. During the period that age-adjusted coronary heart disease mortality has decreased, the use of coronary artery bypass graft surgery has increased dramatically, suggesting a relation. METHODS: All 30- to 74-year old Minneapolis-St. Paul area residents undergoing coronary artery bypass graft surgery between 1970 and 1984 (9,548 patients) were registered; their medical records were abstracted; and their survival was ascertained. These data were used in a medical survival probability model using a multivariate analytical approach developed from registries of patients treated medically. The model assumed that coronary artery bypass graft surgery was not available. Two annual mortality rates were compared: the observed Minneapolis-St. Paul annual coronary heart disease mortality rate and the modeled annual coronary heart disease mortality rate. The difference between these rates was the estimated contribution of coronary artery bypass graft surgery to the decline in coronary heart disease mortality rates. RESULTS: Between 1970 and 1984, the estimated surgical contribution increased from 0.2% (increased mortality) to +6.6% of the annual decrease in Minneapolis-St. Paul coronary heart disease mortality. CONCLUSIONS: Between 1970 and 1984, the contribution of coronary artery bypass graft surgery to the decline in coronary heart disease mortality, although small, gradually increased. This change appeared to be related to an increased frequency of coronary artery bypass graft surgery, improved operative mortality and changes in the clinical mix of surgical patients.

Adult↗
PubMed1997

The isolated post ischaemic rat heart is more vulnerable to protamine sulphate than the non-ischaemic heart.

Protamine sulphate is currently used for the reversal of heparin anticoagulation but is known to cause direct myocardial depression. The purpose of this study was to compare the effects of protamine sulphate on the isolated heart with and without cardioplegic ischaemia. Isolated rat hearts (Langendorff preparation) were electrically paced at 300 beats/min and perfused with Krebs-Henseleit solution. Five groups were tested: (1) control: no ischaemia, no protamine; (2) no ischaemia, protamine; (3) no ischaemia, protamine (time-matched control to groups 4 and 5); (4) control: ischaemia, no protamine; and (5) ischaemia, protamine. Protamine sulphate was infused for 15 min at 10 microg/ml. In groups 4 and 5, cardioplegic ischemia was maintained for 30 min at 30 degrees C before protamine exposure. Protamine decreased myocardial performance in a time- and dose-dependent manner. Protamine depressed mean (s.d.) myocardial left ventricular pressure in both non-ischaemic hearts (groups 2 and 3, to 49(4)% and 50(4)% from baseline, respectively) and post ischaemic hearts (group 5, to 28(8%). Mean (s.d.) left ventricular-developed pressure only partially recovered after protamine in post-ischaemic hearts (to 55(13)% of baseline) compared with full recovery of the non-ischaemic group. Protamine depressed coronary flow to 70(5)% and 74(8)% in non-ischaemic hearts (groups 2 and 3, respectively) and to 58(7)% in group 5. Coronary flow recovered completely at the end of the experiments in all protamine-treated groups. In conclusion, isolated rat hearts subjected to cardioplegic ischaemia are more vulnerable to protamine than are non-ischaemic hearts.

Animals↗
PubMed2001

Increased plasma adhesion molecule levels in patients with heart failure who have ischemic heart disease and dilated cardiomyopathy.

BACKGROUND: Inflammatory mechanisms, including leukocyte activation, appear to play a pathogenetic role in the development of heart failure. Vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) are important mediators of leukocyte adhesion to vascular endothelium. The plasma levels of the soluble form of these molecules may be elevated in chronic inflammation. METHODS AND RESULTS: We measured plasma VCAM-1 and ICAM-1 levels (in nanograms per milliliter) with the commercially available enzyme-linked immunosorbent assay method in 12 patients (9 male, 3 female, aged 64 +/- 8 years) with dilated cardiomyopathy and heart failure, in 23 patients (23 male, aged 65 +/- 9 years) with ischemic cardiomyopathy and heart failure, and in 11 healthy control subjects (8 male, 3 female, aged 49 +/- 14 years). Plasma ICAM-1 levels were higher both in patients with dilated cardiomyopathy (363 +/- 77 ng/mL, P <.05) (mean +/- SEM) and in those with ischemic heart disease (320 +/- 32 ng/mL, P <.05) than in control subjects (225 +/- 29 ng/mL). VCAM-1 levels were also higher in both groups with heart failure (664 +/- 73 ng/mL) than in control subjects (551 +/- 60 ng/mL). VCAM-1 levels were higher in patients with class IV compared with those with class II and III heart failure. CONCLUSIONS: Plasma adhesion molecule levels are increased in patients with heart failure and are unrelated to the presence or absence of angiographically demonstrable atherosclerotic coronary artery disease. The plasma level of VCAM-1 correlates with the severity of heart failure.

Aged↗
PubMedDate not supplied

Endothelial function is preserved in Chagas' heart disease patients without heart failure.

Endothelium may be damaged, especially at the coronary microcirculation, in animal models of Chagas' disease by several mechanisms. Endothelial dysfunction has been reported in chronic Chagas' heart disease patients with heart failure. Nevertheless, peripheral endothelial function has never been studied in patients with Chagas' heart disease without heart failure and other conditions that could per se alter the endothelial function. Endothelial function was evaluated in 9 patients with Chagas' heart disease (44.8 +/- 1.5 years, 5 females, left ventricular ejection fraction > or = 60%) and 10 healthy matched controls (38.6 +/- 5.5 years, 5 females). Extreme caution was exercised to select patients with no other conditions that could per se alter the endothelial function. Forearm blood flow was measured at baseline and during intra-brachial artery infusion of crescent doses of acetylcholine (0.75, 5, and 15 microg/100 mL tissue/min) and nitroprusside (1, 2, and 4 microg/ 100 mL tissue/min), an endothelium-dependent and an endothelium-independent vasoactive drug, respectively. At baseline, blood pressure and heart rate (continuously recorded with Finapress) and the forearm blood flow were similar in both groups. Acetylcholine (ACh) and sodium nitroprusside (SNP) caused significant and similar dose-dependent increases in forearm blood flow of all subjects: maximum ACh response of 24.8 versus 23.7, and maximum SNP response 24.4 versus 23.7 mL/100 mL tissue/min, respectively, for control and chagasic Groups. No significant systemic hemodynamic changes were observed during the intra-arterial infusion of the drugs. The authors conclude that the peripheral endothelial function is preserved in Chagas' heart disease patients without heart failure.

Acetylcholine↗
PubMed1970

Interaction between heart rate and calcium concentration in the control of contractile strength of the frog heart.

1. The changes in twitch tension during the ascending and descending staircase of the frog heart have been examined under various experimental conditions including the hypodynamic and prehypodynamic state.2. The descending staircase resembles the tension change after reduction of external calcium concentration in showing two consecutive phases, an initial rapid and later slow phase of tension decline.3. The time course of the ascending staircase depends on the condition of the heart; it is slow after, and rapid before, development of the hypodynamic state. It is also rapid when elicited after conditioning periods of increased heart rate.4. The tension transients in response to brief concentration steps of external calcium concentration were examined at various levels of heart rate. The results indicate that at high heart rates the sensitivity of heart cells to external calcium is increased.5. The results are interpreted along the lines of a previous hypothesis relating tension development to the cooperative action of two intracellular calcium compounds. The additional assumption is made that an intermediary exists which facilitates calcium movements in heart cells to an extent depending on the level of heart rate.

Animals↗
PubMed2000

Do patients with suspected heart failure and preserved left ventricular systolic function suffer from "diastolic heart failure" or from misdiagnosis? A prospective descriptive study.

OBJECTIVES: To characterise the clinical features of patients with suspected heart failure but preserved left ventricular systolic function to determine if they have other potential causes for their symptoms rather than being diagnosed with "diastolic heart failure." DESIGN: Prospective descriptive study. SETTING: Outpatient based direct access echocardiography service. PARTICIPANTS: 159 consecutive patients with suspected heart failure referred by general practitioners. MAIN OUTCOME MEASURES: Symptoms (including shortness of breath, ankle oedema, and paroxysmal nocturnal dyspnoea) and history of coronary heart disease and chronic pulmonary disease. Transthoracic echocardiography, body mass index, pulmonary function tests, and electrocardiography. RESULTS: 109 of 159 participants had suspected heart failure in the absence of left ventricular systolic dysfunction, valvular heart disease, or atrial fibrillation. Of these 109, 40 were either obese or very obese, 54 had a reduction in forced expiratory volume in 1 second to </=70%, and 97 had a peak expiratory flow rate </=70% of normal. Thirty one patients had a history of angina, 12 had had a myocardial infarction, and seven had undergone a coronary artery bypass graft. Only seven patients lacked a recognised explanation for their symptoms. CONCLUSIONS: For most patients with a diagnosis of heart failure but preserved left ventricular systolic function there is an alternative explanation for their symptoms-for example, obesity, lung disease, and myocardial ischaemia-and the diagnosis of diastolic heart failure is rarely needed. These alternative diagnoses should be rigorously sought and managed accordingly.

Angina Pectoris↗
PubMed1990

Geographical clustering of risk factors and lifestyle for coronary heart disease in the Scottish Heart Health Study.

A large cross sectional study, the Scottish Heart Health Study, of 10,359 men and women from 22 districts of Scotland was undertaken to try to explain the geographical variation of coronary heart disease mortality. Analysis by district showed that of the classic risk factors only cigarette smoking was strongly associated with heart disease mortality among both men and women. Mean diastolic blood pressure was weakly associated with rates among men and high density lipoprotein cholesterol showed a strong negative association among women. Total cholesterol showed a weak negative association with heart disease mortality, but, because the serum concentrations of cholesterol were uniformly high in all districts, a strong association with mortality would not be expected. In both men and women many dietary factors showed moderate or strong associations with mortality from coronary heart disease in a district--of these a low consumption of vitamin C was most notable. Other factors associated with heart disease included alcohol consumption and serum triglycerides among men, and obesity, physical activity, and serum triglycerides among women. Many factors associated with heart disease showed strong intercorrelations. Clustering of risk factors (including smoking, alcohol, and diet among men, and smoking, diet, and obesity among women) was associated with much of the regional variation in heart disease mortality in Scotland.

Adult↗
PubMed1994

Ischaemic heart disease: association with haematocrit in the British Regional Heart Study.

OBJECTIVES: To assess the relationship between haematocrit and risk of major ischaemic heart disease events. DESIGN: Prospective study of a cohort of men followed up for 9.5 years. SETTING: General practices in 24 towns in England, Wales, and Scotland (British Regional Heart Study). SUBJECTS: Altogether 7735 men aged 40-59 years at screening, who were selected at random from one general practice in each of 24 towns, were studied. MAIN OUTCOME MEASURES: Fatal and nonfatal ischaemic heart disease events. RESULTS: Risk of major ischaemic heart disease events was significantly increased at haematocrit levels of > or = 46.0%. Men with raised haematocrit (> or = 46.0%) showed a 30% increase in relative risk (RR) of major ischaemic heart disease events (RR = 1.32; 95% confidence intervals (CI) 1.10,1.57, p < 0.01) compared with those with values below 46.0%, even after adjustment for age, social class, smoking, body mass index, physical activity, blood cholesterol, lung function (FEV1), and pre-existing evidence of ischaemic heart disease. Further adjustment for systolic blood pressure reduced the risk slightly (RR = 1.27; 95% CI 1.06,1.51, p = 0.02) but it remained significant. The relationship was seen in men with and without pre-existing evidence of ischaemic heart disease. The study suggests that an increased haematocrit level plays a part in the development of major ischaemic heart disease events.

Adult↗
PubMed1976

Excitation-contraction coupling in heart. XIX. Effect of hypoxia on calcium transport by subcellular particles in the isolated perfused rat heart.

To examine the role of changes in calcium transport by subcellular particles in the pathogenesis of contractile failure due to oxygen lack, both mitochondrial and microsomal fractions were obtained from the isolated hypoxic rat hearts and their calcium binding and uptake abilities were determined by the Millipore filtration technique. The contractile force decreased by about 40, 60 and 70% of the control within 5, 10 and 30 min respectively, of perfusing the heart with hypoxic medium containing glucose. In hearts perfused for 10 min with hypoxic medium containing glucose, calcium binding and uptake by the microsomal fraction decreased significantly. However, mitochondrial calcium binding, but not uptake, decreased significantly on perfusing the hearts with hypoxic medium containing glucose for 20 to 30 min when the microsomal calcium transport was markedly depressed. Reduction in contractile force, calcium binding and uptake by the microsomal fraction as well as calcium binding by mitochondria of hearts made hypoxic for 30 min recovered towards normal upon reperfusion with control medium for 15 min. On the other hand, omitting glucose from the hypoxic medium significantly decreased calcium binding by mitochondrial and microsomal fractions within 10 min of perfusion in comparison to the control and accelerated the effects of hypoxia upon contractile force and microsomal calcium uptake. In contrast to the hypoxic hearts, the mitochondrial calcium uptake decreased significantly and the magnitude of depression in the microsomal calcium binding was appreciably greater in hearts made to fail to a comparable degree upon perfusion with substrate-free medium. The observed defects in calcium transporting properties of microsomal and mitochondrial membranes appear secondary to the contactile failure in hypoxic hearts.

Adenosine Triphosphatases↗
PubMed1994

Physical activity and 23-year incidence of coronary heart disease morbidity and mortality among middle-aged men. The Honolulu Heart Program.

BACKGROUND: The purpose of the study was to examine the association between physical activity and 23-year incidence of coronary heart disease morbidity and mortality. This cohort study continues to follow 8006 Japanese-American men who were 45 to 68 years of age and living on Oahu, Hawaii, in 1965, for the development of coronary heart disease morbidity and mortality. METHODS AND RESULTS: The Framingham physical activity index was calculated by summing the product of average hours spent at each activity level and a weighting factor based on oxygen consumption. Study subjects were divided into tertiles of physical activity index at baseline. Relative risks and 95% confidence intervals (CI) for incidence of coronary heart disease morbidity and mortality were obtained using the Cox model. After age adjustment and using the lowest physical activity index tertile as a reference group, the relative risk for coronary heart disease incidence for the highest tertile of physical activity was 0.83 (CI, 0.70 to 0.99). After adjusting for age, hypertension, smoking, alcohol intake, diabetes, cholesterol, and body mass index, the relative risk was 0.95 and CI included 1 (CI, 0.80 to 1.14). For coronary heart disease mortality, the age-adjusted relative risk was 0.74 (CI, 0.56 to 0.97) and 0.85 (CI, 0.65 to 1.13) after risk factor adjustment. CONCLUSIONS: The results suggest that the impact of physical activity index on coronary heart disease is mediated through its effects on hypertension, diabetes, cholesterol, and body mass index. These findings support the hypothesis that physical activity is inversely associated with coronary heart disease morbidity and mortality and suggest that physical activity interventions in middle-aged men, by improving cardiovascular risk factor levels, may have significant public health implications in the prevention of coronary heart disease.

Aged↗
PubMed1990

HDL-cholesterol as a risk factor in coronary heart disease. An update of the Helsinki Heart Study.

The aim of the Helsinki Heart Study, a 5-year primary prevention placebo-controlled study involving 4081 dyslipidaemic men (aged 40 to 55 years), was to investigate if increasing high density lipoprotein (HDL)-cholesterol plasma levels and decreasing low density lipoprotein (LDL)-cholesterol levels would reduce the incidence of coronary heart disease. Gemfibrozil 600mg twice daily was administered to induce these changes in lipoprotein levels. Baseline HDL-cholesterol levels in the study group were similar to those in the general population. Data from patients treated with placebo were analysed to investigate the influence of HDL-cholesterol levels on the incidence of coronary heart disease. Using the number of cardiac end-points per 1000 person-years to indicate the risk of coronary heart disease, it was clear that elevated HDL-cholesterol levels reduced the risk of coronary heart disease while the incidence increased at low HDL-cholesterol levels. This relationship was not altered when the effect of HDL-cholesterol levels was analysed jointly with other coronary risk factors (age, smoking or blood pressure). A weaker association was seen between LDL-cholesterol and risk of coronary heart disease, and triglycerides appeared to have no significant effect on the incidence of the disease. The data clearly suggest that HDL-cholesterol is a strong predictor of the incidence of coronary heart disease in the placebo group of the Helsinki Heart Study.

Cholesterol↗
PubMed2000

Administration of sevoflurane and isoflurane prior to prolonged global ischemia improves heart function in isolated rat heart.

BACKGROUND: The Langendorff model was used to determine whether pretreatment with sevoflurane, isoflurane, or ischemic preconditioning (IP) could protect the myocardium of rats against global ischemia. METHODS: After 15-min perfusion, each isolated heart was assigned to (1) CONTROL GROUP: no pretreatment, (2) Sevoflurane group: 20-min exposure of 1.7% sevoflurane prior to ischemia, (3) Isoflurane group: exposure of 1.4% isoflurane prior to ischemia, or (4) IP group: two 5-min ischemic periods separated by 5-min perfusion. Following pretreatment, each heart was exposed to 20-min global normothermic ischemia followed by 60-min reperfusion. Heart rate (HR), left ventricular end-diastolic pressure (LVEDP), left ventricular developed pressure (LVDP), HR x LVDP, left ventricular contractility (+dLVP/dt), and coronary flow were recorded continuously. Myocardial damage was assessed by hematoxylin and eosin (H&E) staining. RESULTS: No significant differences (P > 0.05) in hemodynamic variables were recorded among the four groups before the experiment. After ischemia during reperfusion, sevoflurane, isoflurane and IP pretreated hearts recovered left ventricular function significantly better than control hearts. After 60-min reperfusion, +dLVP/dt recovered to 6.84 +/- 1.06%, 23.3 +/- 4.80%, 42.3 +/- 3.16%, and 59.6 +/- 5.75% of baseline values respectively for control, sevoflurane, isoflurane and IP groups. HR x LVDP recovered to 8.9 +/- 1.7%, 27.9 +/- 6.42%, 38.7 +/- 2.78%, and 59.6 +/- 3.98% respectively. H&E staining supported the hemodynamic data in that hearts pretreated with sevoflurane, isoflurane and IP showed significantly less ischemic damage when compared to control hearts. CONCLUSIONS: Our study shows pretreatment with sevoflurane or isoflurane provided moderate protection to the isolated heart against prolonged periods of global ischemia.

Anesthetics, Inhalation↗
PubMed1975

[The number of nuclei and the thickness of the media and intima of the coronary arteries of normal hearts in the second and third decades of life and in hearts with coronary sclerosis and hypertension].

The number of nuclei in the cells of smooth muscle of the media, and the thickness of the media and intima of coronary arteries were investigated by histometric measurements with regard to their behaviour in different stages of life In normal hearts and in hearts altered by disease. Seven normal hearts in the second decade of life, 7 normal hearts in the third decade, 5 hearts with coronary sclerosis (average age 33 years) and 5 hearts with hypertension (average age 47 years) had been examined. After fixing the coronary arteries under a pressure of 110-130 nm Hg and postmortem coronary angiography, the anterior descending and circumflex rami of the left coronary artery and the right coronary artery were cut into blocks of tissue 1 cm long from which frozen sections were made after embedding in gelatine and HE staining. The number of cell nuclei and the thickness of the media and intima were determined micrometrically along 8 radii of each cross-section. From the quantitative findings for the 3 arterial branches in the individual case, a mean value was obtained for each parameter, and from these, a mean value for each group. In normal hearts and in coronary scelrosis, the number of cell nuclei decreases steadily towards the periphery of the cross-sections. In hypertension, in which the highest numbers of cell nuclei are found, hyperplasia of the cell nuclei right into the periphery is marked. The mean number of nuclei/100 mu thickness of media remains the same in all cross-sections of normal and pathological hearts alike. The average number of nuclei in the first 4 cross-sections of the three arterial branches increases from the second to the third decade, through the casses with coronary sclerosis to the cases with hypertension in the proportions 5.6 : 6.7 : 10.7 : 11.7. The difference between the third decade and coronary sclerosis decreases from the first 4 cross-sections to half, while between the coronary sclerosis and hypertension it increases. Hypertrophy and atrophy of the muscle fibres are not taken into account in these measurements. The thickness of the media in the groups behaves like the number of nuclei: in hypertension with the highest values, there is no significant decrease as far as the 8th cross-section, while in the coronary sclerosis and third decade groups the values come closer together after the 6th cross-section. The difference in the middle and peripheral vascular sections are more distinct than in the proximal sections for coronary sclerosis and hypertension. The thickness of the media increases from the second decade to the hypertensive group in the first 4 cross-sections from 70 mu through 106 mu and 131 mu up to 167 mu. The thickness of the intima increases distinctly more rapidly in comparison to the media from 52 mu through 95 mu, 203 mu to 279 mu in hypertension. The media of the coronary arteries in coronary sclerosis and to a greater extent in hypertension, undergo an increase in functional material through hypertrophy and hyperplasia.

Adult↗
PubMed2004

A school-based intervention to teach 3-4 grades children about healthy heart; the Persian Gulf healthy heart project.

BACKGROUND: Cardiovascular health promotion in children has the potential to reduce the risk of atherosclerosis in both the individual child and the population at large. It thus seems eminently reasonable to initiate healthful lifestyle training in childhood to promote improved cardiovascular health in adult life. AIMS: To test the hypothesis that a year long, classroom-based education for the third and fourth graders could change their knowledge scores about healthy heart. SETTINGS AND DESIGN: A randomized, controlled trial in elementary schools of Bushehr/Iran. METHODS AND MATERIALS: A total of 14 elementary schools, categorized by socioeconomic types and male and female setting were selected and randomized into control or intervention groups. Subjects were 1128 third and fourth graders, aged 9 to 10 years (49.1% boys and 50.9% girls). Over a course of 8 weeks, health educators and sport teachers of the elementary schools presented two hours sessions per week on heart function, nutrition, and exercise for healthy heart and living tobacco free for the intervention group. The education program was based on HeartPower! Program, an American Heart Association program. STATISTICAL ANALYSIS: Mann-Whitney U test and Wilcoxon matched-pairs signed rank test and Bonferroni correction for the two pair wise comparisons were used. RESULTS: Total heart knowledge at posttest was 25% correct higher in the intervention than in the control group (p< 0.001). Difference in means of total healthy heart knowledge scores between control and intervention group increased from 1.43 points in baseline to 4.02 points in posttest (p< 0.001). CONCLUSION: It can be concluded that the classroom-based cardiovascular health promotion had a significant effect on the heart healthy knowledge. Therefore, schools provide an excellent setting for introducing comprehensive healthy heart education and promotion of cardiovascular health to the general population.

Cardiovascular Diseases↗