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 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The purpose of this article was to review the clinical and experimental features of diabetic cardiomyopathy, with particular relevance to the Black population. One hundred thirty-seven studies were identified, of which 57 were selected as references for this article. Diabetes is associated with the development of cardiomyopathy, independent of coronary atherosclerosis. Pathological studies show myocardial hypertrophy and fibrosis; microvascular pathology is also present, but all of these pathological findings have an uncertain relationship to myocardial failure. Hemodynamic findings of both congestive and restrictive cardiomyopathy have been described. Noninvasive studies revealed abnormal systolic and diastolic function in many diabetic subjects, particularly in the presence of diabetic complications and/or hypertension. Experimental studies have focused on the mildly diabetic dog and the severely diabetic rat. One year of diabetes in dogs resulted in decreased left ventricular compliance and increased interstitial connective tissue. Studies in the diabetic rat showed a marked slowing of contraction and relaxation. Chronic insulin therapy reversed the changes in the rat model. Combining hypertension with diabetes in the rat resulted in increased myocardial and coronary microvascular pathology and greater changes in isolated muscle function, electrophysiology, and contractile protein biochemistry. Many hypertensive diabetic rats died spontaneously, showing signs of congestive heart failure. Diabetic cardiomyopathy is a significant cause of heart failure in diabetic subjects and occurs more frequently in those with microvascular complications and/or hypertension. Clinical studies are needed to clarify the natural history of this disorder, focusing on the benefits of tight control of hyperglycemia and treatment of associated hypertension. Experimental studies will clarify the pathophysiology and contribute to improved therapy. The high prevalence of diabetes and hypertension in Blacks makes these considerations especially relevant to this population.
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PMID:Diabetic cardiomyopathy. 226 38

The hearts obtained at autopsy of 67 patients with hypertension, diabetes mellitus, or both were examined microscopically and histochemically, and the amount of fibrosis was determined. Significant differences in heart weight, interstitial fibrosis, replacement fibrosis, and perivascular fibrosis were found among the groups. The mean heart weight of the hypertensive-diabetic patients was significantly greater than that of the hypertensive patients and the diabetic patients. The amount of microscopic fibrosis increased between the groups, the lowest in hypertensive hearts, midrange in diabetic hearts, and highest in hypertensive-diabetic hearts. Total fibrosis correlated with heart weight among diabetic and hypertensive-diabetic patients and was significantly greater among patients with congestive heart failure, most of whom had histories of both hypertension and diabetes. The microscopic grade of fibrosis correlated significantly (p less than 0.01) with a quantitative, histochemical determination of the amount of collagen per milligram of total noncollagenous protein in the heart tissue. Myocardial fibrosis may contribute to the diastolic dysfunction typical of hypertensive-diabetic cardiomyopathy, in which congestive heart failure is a common sequela. The importance of hypertension in the pathogenesis of severe diabetic heart disease is discussed.
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PMID:A comparison of the pathological spectrum of hypertensive, diabetic, and hypertensive-diabetic heart disease. 202 37

Diabetic heart disease (DHD) is one of the most important contemporary management problems confronting the entire diabetic management team. DHD is multifactorial and multifaceted. The three major problems are: coronary artery disease (CAD), autonomic cardiac denervation and a specific heart muscle disease in diabetes (diabetic cardiomyopathy). Various other ancillary problems include obesity, hypertension, lipid aberrations and rheological alterations etc. CAD and diabetes mellitus (DM) have a greater association; the disease is more severe, sets in early and has many atypical features including painless, silent onset, delayed arrival at intensive coronary care unit, increased incidence of pump failure and arrhythmias and high case fatality rate. Autonomic cardiac denervation is an important and a common companion of diabetic peripheral neuropathy and has serious repercussions in DHD. Simple, sensitive screening tests may identify such a group so as to exercise caution in management. Various clinical (non-invasive, invasive and autopsy) and experimental studies provide evidence for the existence of a specific diabetic heart muscle disease comprising of small vessel disease and metabolic aberrations. Recent advances in literature and our own experience are reviewed. The practical management aspects of each facet, such as maintenance of high index of suspicion, early diagnosis and referral, close monitoring, role of rigid blood glucose control and specific role of each member of the diabetic team is outlined. The possible preventative strategies are discussed.
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PMID:Diabetic heart disease--current problems and their management. 268 Nov 39

Experimental and clinical evidence points to the existence of a cardiomyopathy associated with diabetes mellitus that is not due to coronary atherosclerosis. The condition is characterized by distinct clinical presentations and physiologic and biochemical abnormalities. Potential mechanisms for the development of diabetic cardiomyopathy are complex but are probably associated, in part, with hyperglycemia and hyperlipidemia. Primary hypertension is also associated with the development of myocardial abnormalities. Many of these changes are similar to those seen in diabetic cardiomyopathy. It is now clear that the co-existence of hypertension and diabetes mellitus produces a more severe cardiomyopathy than that produced by hypertension or diabetes alone. Potential mechanisms for interaction are numerous. Treatment of hypertension in diabetic patients must be targeted to more specific needs. Antihypertensive drugs should not worsen cardiac risk factors or glucose control and should have favorable effects on left ventricular function. The calcium antagonists and angiotensin-converting enzyme inhibitors have pharmacologic profiles that make them attractive as monotherapy for diabetic patients.
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PMID:Myocardial disease in hypertensive-diabetic patients. 268 10

The effects of combined renovascular hypertension and diabetes mellitus on the rat heart were investigated in order to detect possible synergistic effects of the two conditions. Hypertensive diabetic and hypertensive nondiabetic young male Wistar rats were compared with diabetic and non-diabetic controls. Since the normal body weight increase of the diabetic animals was markedly suppressed a weight-matched nondiabetic control group was introduced in addition. Hypertension was established for eight weeks by a surgical stenosis of the left renal artery, diabetes mellitus was maintained for four weeks after a single intraperitoneal injection of 75 mg/kg streptozotocin. Light and electron microscopic stereological parameters were obtained for the left ventricular papillary muscles. The whole hearts were also investigated histologically. Qualitative morphology failed to substantiate synergistic effects in the hypertensive diabetic rats. Vascular abnormalities were not observed. The stereological parameters, however, revealed microstructural reactions which were observed exclusively in the hypertensive diabetic group: the volume ratio of mitochondria-to-myofibrils was decreased, the surface-to-volume ratio of mitochondria was increased (reduction of mitochondrial size) and the mean cross sectional area of capillaries was decreased. Similar quantitative mitochondrial changes have been frequently described in long-standing hypertension, but in the present investigation, they were not found in the nondiabetic hypertensive group. It is therefore concluded that diabetes mellitus potentiates the effects of chronic pressure overload on myocardial cells. However, the myocardial fibrosis which has been found by other groups at later stages of hypertension and/or diabetes mellitus was not detected in the present study. The reduced mean cross sectional area of capillaries in hypertensive-diabetic rats may be correlated with early molecular changes of the myocardial interstitium or with early abnormalities of small arteries. Thus our stereological results support the hypothesis that a non-coronary hypertensive diabetic cardiomyopathy occurs in mammalian hearts.
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PMID:Synergistic effects of diabetes mellitus and renovascular hypertension on the rat heart--stereological investigations on papillary muscles. 296 73

Quantitative electrocardiographic (ECG) and vectorcardiographic (VCG) analysis was carried out in 113 newly diagnosed, middle-aged, non-insulin-dependent diabetics (61 men, 52 women) and 125 non-diabetic control subjects (56 men, 69 women) in order to explore changes attributable to non-coronary heart disease (diabetic cardiomyopathy) in diabetics. Diabetic men had a prolonged PQ interval and women a more negative P-terminal force and a more leftward frontal QRS axis than their non-diabetic counterparts, but no other significant differences we found between diabetic and non-diabetic subjects in various quantitative ECG and VCG variables when the effect of confounding factors (age, obesity, coronary heart disease, hypertension, drugs) was taken into account. The more negative P-terminal force and left axis deviation in diabetic women could be explained by a concomitant left ventricular hypertrophy among them. Non-insulin-dependent (type 2) diabetes, which is commonly preceded by a long duration of asymptomatic hyperglycaemia, is not associated, early in its clinical course, with major ECG and VCG abnormalities suggestive of diabetic cardiomyopathy.
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PMID:Quantitative electrocardiographic and vectorcardiographic study on newly-diagnosed non-insulin-dependent diabetic and non-diabetic control subjects. 334 19

Non invasive methods for the exploration of myocardial function permit the demonstration of preclinical diabetic cardiomyopathy. In this study, we have tried to define the relationship between the degree of diabetic retinopathy and the presence of myocardial dysfunction. We have recorded echocardiogram and phonomechanograms on thirty two insulin dependent diabetics (IDD) less than 50 years of age, without evidence of arteriosclerosis. All patients had a normal baseline electrocardiogram and a normal bicycle exercise test. These diabetics were assigned to three groups: I = no retinopathy (9 patients); II = minimum retinopathy (12 patients); III = marked retinopathy (11 patients). They were compared to ten non-diabetic control subjects of similar age (group 0). None of the parameters of systolic function was modified in the different groups of diabetics in comparison with the control group. We found, however, a very significant reduction of the maximum rate of enlargement of left ventricule and reduction of the maximum narrowing rate of the left ventricular posterior wall during the protodiastolic period in group III, v.s. group 0, I and II. Group III contained 3 patients with borderline hypertension and 5 patients with diabetic glomerulopathy. Our results indicate a diminution of myocardial compliance and relaxation in those IDD with marked retinopathy, but it raises the question of the role of borderline elevations of arterial pressure or hypertension during physical exercise, which are frequently found in diabetics with retinopathy in causing these abnormalities.
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PMID:[Exploration of left ventricular function in insulin-dependent diabetics (relation with retinopathy)]. 373 80

The mechanism of heart failure in patients with diabetic cardiomyopathy is not clear. Previous studies suggested that vascular lesions specific for diabetes mellitus were present and that the lesions could be the basis for impaired cardiac function. We have investigated the histologic and histochemical characteristics of intramyocardial vessels (20 to 500 microns) in a group of diabetics using comparable groups of patients with hypertension, patients with hypertension and diabetes mellitus, and, as controls, patients with neither hypertension nor diabetes mellitus. Analysis of multiple blocks taken from the 42 study patients disclosed no lesions specific for diabetes mellitus or hypertension. The discrepancy between our findings and earlier reports is probably due to a lack of controls and the use of non-perfusion-fixed material in the earlier studies.
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PMID:Diabetic cardiomyopathy. A morphological study of intramyocardial arteries. 375 19

Diabetes mellitus is associated with a specific cardiomyopathy. This is evident from the clinical-pathological work and the epidemiologic data from the Framingham study. Noninvasive studies of diabetics have shown alterations in systolic and diastolic function that may ultimately lead to clinical heart failure. The relationship of these cardiac changes to the type of diabetes, its duration, and its severity is not settled. However, a correlation between changes in heart function and other complications of diabetes has been demonstrated. Insufficient prospective data is available from noninvasive studies to establish the frequency of progression from subclinical cardiac dysfunction to overt congestive failure. The pathogenesis of this disorder is still uncertain. Pathological studies have shown changes in the intramural arteries, arterioles, and capillaries but their functional significance is uncertain. Experimental studies have shown interstitial changes leading to an apparently less compliant left ventricle in the diabetic dog and monkey. In the diabetic rat reversible changes were found in myocardial function, related to changes in contractile proteins and intracellular calcium metabolism. In both species, the response to anoxia or ischemia was altered in the presence of diabetes. However, irreversible depression of the contractile element was not found in most animal studies of isolated diabetes. In contrast, the combination of hypertension and diabetes leads to substantial cardiac damage and circulatory congestion, both in clinical and experimental investigations. Clearly much more work must be carried out to understand the pathogenesis, treatment, and ultimately the prevention of diabetic cardiomyopathy.
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PMID:Diabetic cardiomyopathy. 388 Sep 19

We have assessed the presence of VIP/PHI/secretin receptors in heart by: (1) testing the ability of the corresponding peptides to activate adenylate cyclase in cardiac membranes from rat, dog, Cynomolgus monkey and man, and (2) examining the ability of the same peptides to exert inotropic and chronotropic effects on heart preparations from rat and Cynomolgus monkey in vitro. Based on their affinity for natural peptides and synthetic analogs, two types of VIP/PHI/secretin receptors were characterized: the relatively nonspecific "secretin/VIP receptor" of rat heart (that is "secretin-preferring" only in that secretin was more efficient than VIP in stimulating adenylate cyclase), and the "VIP/PHI-preferring" receptor of man, monkey and dog heart. Four physiopathological situations affecting secretin/VIP receptors in rat heart were explored: In male rats from the Okamoto strain and the Lyon strain, two strains presenting spontaneous hypertension, heart membranes exhibited a markedly decreased response of adenylate cyclase to secretin/VIP, with lesser alterations in the responses to isoproterenol and glucagon. This impairment developed in parallel with the occurrence of hypertension and was reproduced in normotensive rats submitted to chronic isoproterenol treatment (but not in Goldblatt hypertensive rats). These findings are consistent with a hyperactivity of norepinephrine pathways in spontaneously hypertensive rats, leading to a reduced number of cardiac post-junctional secretin/VIP receptors bound to adenylate cyclase. Heart membranes from genetically obese (fa/fa) Zucker rats also exhibited severely decreased responses to secretin/VIP with lesser alterations in the responses to glucagon and isoproterenol. These anomalies were specific for the heart, and developed in concomitance with obesity. The first anomaly could not be corrected by severe food restriction. Secretin stimulation of heart adenylate cyclase was also selectively altered in streptozotocin-diabetic rats. Thus, two types of diabetic cardiomyopathy were characterized by a severe local alteration of secretin/VIP receptors coupled to adenylate cyclase. Hypothyroidism, provoked in rat by thyroidectomy or propylthiouracil treatment, again induced a marked decrease in secretin-stimulated cardiac adenylate cyclase activity. In rat papillary muscle electrically stimulated in vitro, secretin exerted a positive inotropic effect. This effect was reduced in obese (fa/fa) Zucker rats. In rat right atrium, secretin also exerted a positive chronotropic effects.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Heart receptors for VIP, PHI and secretin are able to activate adenylate cyclase and to mediate inotropic and chronotropic effects. Species variations and physiopathology. 608 34


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