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Query: UMLS:C0018799 (heart disease)
 34,133 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Epidemiological data reviewed suggest that diabetes itself increases the cardiac risk of diabetics (types I and II), independently from the development of coronary heart disease and in addition to other risk factors (hypertension, hypercholesterolemia, hypertriglyceridemia, smoking and others), presumably by a specific myocardial disease called "diabetic cardiopathy", or according to the recommendations of the WHO, "diabetic heart muscle disease." Disturbances of the left and right ventricular function as well as the autonomic function of the heart can be understood as signs of this specific cardiopathy. The pathophysiological mechanisms underlying this disease are not yet fully known; however, recent evidence is presented that diabetes leads to a facet of metabolic dysfunctions regarding glucose and energy metabolism, calcium homeostasis and the expression of specific proteins that diminish the ability of the heart to respond to increased workload and increase the vulnerability of the heart in diabetes. Since preliminary experimental data indicate that inhibitors of the angiotensin-converting enzyme can protect the heart in diabetes, it is intriguing to suggest that increased release of angiotensin II plays a significant role in the change from reduced adaptability to irreversible damage of the heart in diabetes.
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PMID:[Diabetic cardiopathy. Pathophysiologic concepts and therapeutic approaches]. 161 89

Cardiac disorders are known to be associated with neutrophil infiltration. The central role of calcium in modulating neutrophil functions prompted us to examine whether Ca2+ channel blockers could affect vital neutrophil functions in mice. In vitro exposure of mice neutrophil to nifedipine resulted in inhibition of superoxide production in a dose-dependent manner. However, the inhibition of calcium uptake elicited by nifedipine did not appear to account for the observed effect since the extracellular Ca2+ enrichment and depletion did not produce a significant reversal of inhibition. In addition, there was significant inhibition (P less than 0.01) of nicotinamide adenine dinucleotide phosphate reduced (NADPH) oxidase activity. Cytosolic-free Ca2+, as measured by Quin-2AM fluorescence, showed no significant change indicating that the effect was independent of inhibition of Ca2+ influx. The hypothesis was substantiated by loss of neutrophilic functions following long-term administration of nifedipine. Our data indicate that nifedipine impairs neutrophil functions and support the hypothesis that Ca2+ antagonists also affect cellular functions by non Ca2+ mediated processes.
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PMID:Nifedipine affects neutrophil functions by a non-calcium-mediated mechanism. 165 39

The pharmacologic treatment of atrial fibrillation (AF) is aimed at controlling the ventricular response, restoring sinus rhythm, and preventing or delaying relapses. In the control of ventricular response, digitalis maintains a primary role when the arrhythmia is accompanied by heart failure. In ischemic, hypertensive, and degenerative (whose number is increasing at present) cardiopathies without evident ventricular dilatation, treatments with calcium antagonists (such as verapamil, gallopamil, or diltiazem) or beta-blocking agents must be preferred. In order to control the ventricular response in patients with chronic AF during physical activity, the association of digitalis with beta-blocking agents or calcium antagonists seems to provide satisfactory results. The drugs of the IC class, especially flecainide, represent a certain therapeutical progress in the restoration of sinus rhythm in the treatment of paroxysmal atrial fibrillation affecting subjects without evident alterations of ventricular function, particularly in subjects with Wolff-Parkinson-White syndrome, with forms of vagal origin, or with atrial fibrillation alone. A therapeutic combination of digitalis and quinidine may produce resolution of the arrhythmia in the presence of altered ventricular function or when AF is of an uncertain onset. In patients with hypertensive, ischemic, and/or degenerative cardiopathy without evident ventricular or advanced heart failure, the verapamil-quinidine association may also be effective and even quicker. The combination of drugs of the I and III class for restoration of the sinus rhythm in particularly resistant forms of AF without evident structural heart alterations is promising but must be verified in a greater number of patients. In the prevention of relapses amiodarone appears to have the widest spectrum of advantages from an electrophysiologic point of view; however, because of its many side effects, amiodarone represents a late therapeutical choice. The promising results obtained with flecainide are disputed by the results of the CAST, which limit the possibilities of using this drug to a low number of cases (W.P.W. syndrome, AF of vagal origin, atrial fibrillation alone). In the past, quinidine and disopyramide have been the drugs most widely used in the prophylaxis of AF. These drugs have a similar efficacy, and both of them provided some positive results. However, because of untoward side effects (especially for quinidine) during chronic treatment, the use of these drugs has been questioned. Perhaps in the majority of patients, the less dangerous therapeutic choice after the termination of the fibrillation is a combination of drugs slowly down AV node activity (digitalis or calcium antagonists and beta blockers) with class IA antiarrhythmics.
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PMID:The pharmacologic treatment of atrial fibrillation. 167 64

Because cystic fibrosis (CF) epithelia have ion transport abnormalities that may in part be regulated by intracellular calcium metabolism, and the kidney is actively involved in both ion transport and calcium homeostasis, we have investigated renal calcium handling in CF. Twenty-four-hour urine collections were analyzed in 34 CF patients (age 5 to 35 years) and kidney ultrasound studies were performed in 17 CF patients (age 6 months to 23 years). Renal histologic findings at postmortem examination of 14 CF patients (age 4 months to 23 years) were compared with those of 12 patients (age 11 months to 17 years) with other chronic illnesses (6 congenital heart disease, 6 malignancy). In 30 of the 34 CF patients urinary calcium excretion was normal (less than 4 mg (0.1 mmol)/kg/24 hr). Four CF patients had hypercalciuria (calcium excretion 4.4 to 8.8 mg (0.11 to 0.22 mmol)/kg/24 hr). However, these patients had other possible explanations for hypercalciuria, such as immobilization (n = 2), increased dietary sodium load (n = 1), and glucocorticoid therapy (n = 1). None of the 17 patients examined by renal ultrasonography had nephrocalcinosis. Five CF patients had histologic evidence of sparse nephrocalcinosis at autopsy. However, 6 of 12 autopsy kidney specimens from patients with other chronic illnesses and similar preterminal events also showed nephrocalcinosis. The hypercalciuria and nephrocalcinosis in CF and other chronic debilitating diseases may be explained by factors known to affect calcium handling. Our evidence does not support a primary renal defect as the basis of hypercalciuria and nephrocalcinosis in CF.
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PMID:Renal calcium handling in cystic fibrosis: lack of evidence for a primary renal defect. 169 Jul 95

Thrombus formation in the left atrium and left ventricle is primarily due to stasis of blood which causes activation of the coagulation system. Migration of thrombotic material into the circulation depends on the dynamic forces of the circulation. Atrial fibrillation is the commonest underlying cardiac disorder predisposing to thromboembolism. Rheumatic mitral stenosis, left atrial enlargement, prior myocardial infarction, hypertension, and echocardiographic left ventricular hypertrophy are risk factors for thromboembolic stroke in elderly patients with chronic atrial fibrillation. Non-valvular atrial fibrillation accounts for 45% of cardiac sources of thromboembolic stroke and includes patients with ischemic heart disease, hypertension, thyrotoxic heart disease, hypertrophic cardiomyopathy, chronic sinoatrial disorder, and idiopathic atrial fibrillation. 15% of cardiac sources of thromboembolic stroke are associated with acute myocardial infarction, 10% with left ventricular aneurysm and mural thrombi remote from an acute myocardial infarction, 10% with rheumatic valvular heart disease, and 10% with prosthetic cardiac valves. Mitral valve prolapse, mitral annular calcium, nonischemic cardiomyopathies, infective endocarditis, nonbacterial thrombotic endocarditis, left atrial myxoma, paradoxical embolism associated with congenital heart disease, calcific aortic stenosis, and complex atherosclerotic plaque within the proximal aorta also contribute to thromboembolism.
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PMID:Etiology and pathogenesis of thromboembolism. 176 43

Cardiological findings in athletes are often similar to those observed in clinical cases. Electrocardiographic and cardiac imaging abnormalities as well as physical findings may be the same in both of these groups. Bradycardia and rhythm disturbances are the most common abnormalities in athletes. Most athletes with abnormal electrocardiograms are asymptomatic and numerous investigators have failed to detect heart disease in association with such electrocardiograms. In contrast to cardiac dysfunction observed in clinical cases, enhanced or normal ventricular systolic and diastolic function have been reported in athletes. In endurance athletes, this is associated with very high values for maximal aerobic power (VO2max). Absolute and body size-normalised cardiac dimensions in most athletes do not approach values from chronic disease states, and may not exceed echocardiographic normal limits. In addition, pathological and physiological enlargement appear to be biochemically and functionally different. Myosin ATPase enzyme expression and calcium metabolism are different in rats with pathologically or physiologically induced enlargement. The reported biochemical differences underlie systolic and diastolic dysfunction in pathological enlargement. Conversely, trained rodents and humans have demonstrated enhanced systolic and diastolic function. It is important to note that cardiac enlargement observed in athletes is the result of normal adaptation to physical conditioning and/or hereditary influences. Conversely, pathological changes result from disease processes which can lead in turn to reduced function, morbidity and mortality. Since the mid 1970s echocardiography has been used to compare cardiac dimensions in male endurance- and resistance-trained athletes. A sport-specific profile of eccentric and concentric enlargement has been documented in endurance and resistance athletes, respectively. Subsequent studies of athletes have examined factors such as age, sex and degree of competitive success to determine their contribution to these sport-specific cardiac profiles. Unique athletic subgroups have also been analysed and have included ballet dancers, rowers, basketball players and triathletes. However, there is a paucity of data on cardiac dimensions in female athletes. Finally, physical conditioning studies have also examined echocardiographic dimensions before and after endurance and resistance training. Significant enlargement of internal dimensions, wall thickness or left ventricular mass have been reported but such increases are relatively small and by no means universal. Several conflicting explanations for enlarged cardiac dimensions appear in the literature. Chronic volume and pressure haemodynamic overloading during physical conditioning has been proposed to explain eccentric and concentric cardiac enlargement in endurance- and resistance-trained athletes respectively. However, twin studies suggest that hereditary factors may be important determinants of cardiac dimensions and/or the degree of cardiac adaptability to physical conditioning.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:The 'athletic heart syndrome'. A critical review. 182 49

In the absence of myocardial ischaemia, ventricular tachycardias occurring in patients with structural heart disease rarely respond to calcium antagonists like verapamil. In contrast, verapamil is markedly effective in the acute management of "supraventricular" tachycardias. Thus, intravenous verapamil has often been used for therapeutic and diagnostic purposes in patients with wide QRS complex tachycardias. This report details two unusual cases of ventricular tachycardia that are verapamil-sensitive. They highlight two major categories of "idiopathic" ventricular tachycardia, namely fascicular tachycardia and catecholamine-mediated ventricular tachycardia. The risks of verapamil administration for wide complex tachycardias are also reviewed.
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PMID:Verapamil and ventricular tachycardias. 187 19

Human myocytes were isolated from right atrial appendage, and contractile responses to inotropic agents were studied. Responses to inotropic agents of cells isolated from patients with mild heart disease [New York Heart Association (NYHA) classes I and II] were compared with those of myocytes from rabbit atria. Maximally effective concentrations of calcium, forskolin, and isoproterenol increased contraction amplitude to a similar extent (11.9, 11.5, and 11.3% change in cell length, respectively), but histamine produced a smaller effect (7.1%). The maximum responses of rabbit atrial cells to calcium (18.5%) and isoproterenol (15.0%) were significantly greater than human. In human cells, the velocity of contraction or relaxation was accelerated more by isoproterenol (P less than 0.05) or forskolin (P less than 0.01) than by high calcium. Only relaxation velocity was increased by isoproterenol in rabbit cells (P less than 0.05). Rabbit myocytes contracted and relaxed 10-30% faster than human (P less than 0.05). Cells from the atria of patients with New York Heart Association (NYHA) heart failure class III or IV were less responsive to isoproterenol than those from class I or II (P less than 0.01). Omitting data from patients who had been taking calcium-channel blockers or beta-adrenoceptor agonist or antagonist drugs did not affect the conclusions. Analysis of variance revealed a significantly greater between-patient than within-patient variation (P less than 0.001), indicating that cells from the same patient have a tendency to respond in a similar way. Responses to high calcium did not differ among NYHA classes. The effect of forskolin was not reduced in NYHA class III, although there was a decreased response in cells from two patients in NYHA class IV.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Reduced beta-agonist sensitivity in single atrial cells from failing human hearts. 197 24

We tested the hypothesis that intracellular Ca++ [( Ca++]i) overload underlies the diastolic dysfunction of patients with hypertrophic cardiomyopathy. Myocardial tissue was obtained at the time of surgery or transplantation from patients with hypertrophic cardiomyopathy and was compared with control myocardium obtained from patients without heart disease. The isometric contractions and electrophysiologic properties of all myocardial specimens were recorded by standard techniques and [Ca++]i was measured with the bioluminescent calcium indicator aequorin. In contrast to the controls, action potentials, Ca++ transients, and isometric contraction and relaxation were markedly prolonged in the hypertrophic myocardium, and the Ca++ transients consisted of two distinct components. At 38 degrees C and 1 Hz pacing frequency, a state of relative Ca++ overload appeared develop, which produced a rise in end-diastolic [Ca++]i, incomplete relaxation, and fusion of twitches with a resultant decrease in active tension development. We also found that drugs with increase [Ca++]i, such as digitalis, exacerbated these abnormalities, whereas drugs that lower [Ca++]i, such as verapamil, or agents that increase cyclic AMP, such as forskolin, prevented them. These results may explain why patients with hypertrophic cardiomyopathy tolerate tachycardia poorly, and may have important implications with regard to the pharmacologic treatment of patients with hypertrophic cardiomyopathy.
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PMID:Diastolic dysfunction in hypertrophic cardiomyopathy. Effect on active force generation during systole. 199 83

The role of calcium (Ca) and magnesium (Mg) was evaluated in pigs that died suddenly of microangiopathy (mulberry heart disease) characterized by myocardial and endothelial cell damage and capillary microthrombosis. Myocardial and hepatic Ca concentration in pigs with microangiopathy was significantly (p less than 0.001) higher than in pigs with other diseases and in healthy slaughter pigs. On the other hand, myocardial and hepatic Mg concentrations in pigs with microangiopathy was significantly (p less than 0.001) lower than in pigs with other diseases and in healthy slaughter pigs. The results indicate that increased Ca concentration was associated with decreased Mg concentration in pigs with microangiopathy. Altered Ca and Mg concentrations might reflect disturbed electrolyte homeostasis related to oxidative cardiovascular damage. The results encourage the study of the efficacy of antioxidants for prevention of myocardial Ca overload. The combined use of Mg and of Ca-antagonists with antioxidants should be evaluated for protection against experimental microangiopathy.
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PMID:Hypothesis: increased calcium and decreased magnesium in heart muscle and liver of pigs dying suddenly of microangiopathy (mulberry heart disease): an animal model for the study of oxidative damage. 203 Feb 54


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