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ABSTRACT: The recognition of dysfunctional but viable myocardium after acute myocardial infarction (MI) may be of importance for both patient prognostication and the decision for revascularization. Low-dose dobutamine echocardiography (LDDE) has been shown to be a reliable technique in detecting reversibility of dysfunctional myocardium. The aim of the present study was to assess by LDDE possible time-dependent changes in myocardial viability and to evaluate the value of LDDE used in the postinfarction period. Twenty-seven patients with acute MI underwent LDDE on day 6, 30, and 90. At LDDE day 6, 41% of the affected segments showed a positive response to LDDE. At later examination on day 30 and 90, only 32% and 18%, respectively, of the dysfunctioning segments responded to dobutamine stimulation, with a significant decline in response (p < 0.0001), indicating loss of viability. Spontaneous segmental outcome was significantly better for LDDE-responding segments than for nonresponding segments (p = 0.0001). This study indicated that myocardial viability may be temporary and that a time-dependent loss of viability may take place during the first months after MI.
American Heart Journal 01/1998; 135(1):51-7. · 4.65 Impact Factor
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ABSTRACT: To study the prognostic significance of left ventricular diastolic function evaluated by transmitral and pulmonary venous flow velocities obtained in the early phase of a first acute myocardial infarction in relation to later development of congestive heart failure.
Pulsed Doppler echocardiography of transmitral and pulmonary venous flow was assessed in 65 consecutive patients with a first myocardial infarction within 1 h of arrival in the coronary care unit.
A univariate regression analysis identified age, left ventricular ejection fraction < or = 45%, mitral E deceleration time < or = 130 ms, E/A ratio > 1.5, peak pulmonary venous atrial flow velocity > or = 30 cm.s-1 and a difference between mitral and pulmonary venous atrial flow duration < 0 ms as variables significantly related to the development of congestive heart failure. However, in a multivariate analysis only mitral E deceleration time < or = 130 ms and age were significant independent variables related to the development of congestive heart failure during the first week following a first acute myocardial infarction.
Assessment of left ventricular diastolic function complements measurements of systolic function in the evaluation of cardiac function, and mitral deceleration < or = 130 ms best identifies patients at risk of development of congestive heart failure following acute myocardial infarction.
European Heart Journal 12/1997; 18(12):1882-9. · 10.48 Impact Factor
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ABSTRACT: Two echo-Doppler cardiographic investigations were performed 7 years apart in 17 insulin-dependent diabetic children without hypertension or nephropathy in order to detect early signs of cardiac abnormalities in this group without ischaemic heart disease. Relative to two matched control groups, the patients had reduced increase in left ventricular size (p < 0.01) and stroke volume (p < 0.05). An initially reduced end systolic wall stress and increased fractional shortening (p < 0.003) was normalized during the 7 years. Concomitant with early signs of autonomic neuropathy and aortic stiffening, left ventricular filling changed with increased velocity during atrial contraction (p < 0.01) correlating to the decreased stroke volumes (r = -0.57, p = 0.016). These early changes could suggest left ventricular restriction but could also reflect a changed sympathetic/parasympathetic balance in diabetic children. A reduced left ventricular cavity size and increased atrial ejection has thus been described in these insulin-dependent children without hypertension, nephropathy or evidence for ischaemic heart disease, suggesting the existence of a metabolically-induced cardiomyopathy.
Diabetic Medicine 09/1996; 13(9):834-40. · 2.90 Impact Factor
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ABSTRACT: Left ventricular diastolic dysfunction is currently recognized in patients with different heart diseases. Three abnormal filling patterns of the left ventricle detected by pulsed-Doppler echocardiography are observed in patients with heart disease. Each filling pattern is characterised by different symptoms, and by differences in function and dimension of the left atrium and filling pressures. Mitral and pulmonary venous flow velocities and durations obtained by pulsed Doppler technique can be used to evaluate left ventricular diastolic function in patients with different heart diseases. However, several factors affect the transmitral and pulmonary venous flow such as age, heart rate, positioning of the sample volume and aortic- and mitral valve insufficiency. These factors must be taken into consideration when the diastolic function is evaluated by pulsed Doppler technique.
Ugeskrift for laeger 09/1996; 158(33):4631-7.
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ABSTRACT: In order to elucidate further the abnormal myocardial Ca2+ metabolism in diabetes mellitus, voltage-gated Ca2+ channels and beta-receptors were quantified in myocardial membranes of short- and long-term diabetic rats. Diabetes was induced by an injection of streptozotocin (STZ). Animals were killed 2, 4, 7, 90 and 200 days after STZ. A group of diabetic animals were treated with insulin for 20 days following 180 days of untreated diabetes. Diabetic animals developed low triiodothyronine syndrome. During short-term diabetes, the maximum binding capacity (MBC) for Ca2+ channels was reduced by 25% at day 4 (p < 0.05) and the beta-receptor MBC was reduced by 48% (p < 0.05). A normalizing tendency was observed at day 7 for both receptor types; insulin-treated rats did not differ from controls at that time. After 90 and 200 days of untreated diabetes the Ca2+ channel MBC had increased by 36% and 27%, respectively (p < 0.05). Twenty days of strictly regulated blood glucose following 180 days of untreated diabetes totally normalized the Ca2+ channel MBC. This is in contrast to a previous report where insulin treatment did not normalize the Ca2+ channel MBC. Total beta-receptor MBCs did not differ from control values 90 and 200 days after STZ. In conclusion, an increase in rat myocardial Ca2+ channel MBC during long-term diabetes was fully normalized by short-term insulin treatment. The increase in sarcolemmal Ca2+ channels could serve to compensate for a defect coupling of the beta-receptor to adenylate cyclase. An elevated Ca2+ channel number may, at least theoretically, lead to increased Ca2+ flow across the cardiac sarcolemma and in this way contribute to the diabetic cardiomyopathy by increasing the intracellular Ca2+ concentration.
European Journal of Endocrinology 01/1996; 134(1):107-13. · 3.42 Impact Factor
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ABSTRACT: 1. Insulin-dependent diabetes mellitus is a known risk factor for congestive heart failure and an early diastolic dysfunction has been described. In order to see if diabetes itself and not complications like hypertension, nephropathy or ischaemic heart disease can be considered responsible for the abnormal diastolic function of the left ventricle, 17 young patients with uncomplicated insulin-dependent diabetes mellitus and 12 control subjects were exposed to a cold pressor test. 2. Blinded echo-Doppler examination was performed before and during the test. During basal conditions, left ventricular dimensions and volumes were smaller in diabetes and atrial contributions to left ventricular filling were increased. 3. During the cold pressor test, isovolumic relaxation time increased, peak early filling velocity (E) decreased, E deceleration time decreased and atrial contribution (A) increased significantly in diabetes, while only A increased in the control group. A marked increase in left atrial ejection force was seen in diabetes only (P < 0.002). This difference was seen in spite of comparable reductions in mitral area and atrioventricular compliance in the two groups. 4. The hyperfunction of the left atrium in diabetes is hypothesized to be due to reduce size of the left ventricle combined with incipient autonomic neuropathy.
Clinical Science 12/1995; 89(5):461-5. · 4.61 Impact Factor
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ABSTRACT: To study the left ventricular (LV) diastolic function in uncomplicated insulin-dependent diabetic patients without hypertension (n = 25) and comparable controls (n = 15), the effect of acute administration of nitroglycerin and nifedipine on cavity dimensions and transmitral flow pattern was investigated by Doppler echocardiography. At baseline no significant differences in any of the LV Doppler echocardiographic parameters were seen in the two groups. Only in diabetics did nitroglycerin diminish LV diastolic and systolic diameter significantly (p < 0.0002 and 0.004, respectively), reducing the stroke volume from 70 +/- 16 to 64 +/- 20 ml, p < 0.01. The decrease in stroke volume correlated significantly to hemoglobin (Hb) A1c level (r = 0.42, p = 0.036). An excessive preload reducing effect on venous capacitance vessels is assumed in diabetes, and this preload reducing effect was also reflected in transmitral flow pattern where E-wave/A-wave ratio decreased significantly only in the diabetic subjects (p < 0.0005). Nifedipine induced the same degree of sympathetic activation in the two groups, but an increase in LV early peak filling rate (E wave) was seen in diabetes only (63.3 +/- 13.5 to 66.8 +/- 13.5 mm, p < 0.01). The atrial filling of LV (A wave) was increased significantly in both groups. Thus an abnormal LV diastolic function can be disclosed by these pharmacologic challenges. Regulation of preload and its influence on transmitral flow pattern in diabetes deserves further investigation, as does the influence of calcium antagonists on early relaxation in the diabetic myocardium.
American Heart Journal 01/1994; 126(6):1417-26. · 4.65 Impact Factor
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ABSTRACT: Twenty-three children with diabetes mellitus, their ages ranging from 0.2-9.8 years, but with no sign of diabetic microvascular disease were investigated by M-mode and Doppler echocardiography, along with a comparable group of control subjects. In the diabetics, the fractional shortening and the mean velocity of fractional shortening were 14 and 18% higher, respectively, whereas the left ventricular end-systolic wall stress, an indicator of left ventricular afterload, was markedly reduced (22%). Assuming an unchanged preload in the two groups, this indicates a reduced afterload in these children. Systolic and diastolic time intervals, heart rate, and blood pressure were similar in diabetics and controls. Doppler-derived transmitral left ventricular filling indices were also similar. Thus, in these diabetic children no signs of left ventricular diastolic abnormality were detected. The state of hypercontractility of the left ventricle is considered to be due to a reduced afterload in early insulin-dependent diabetes.
Pediatric Cardiology 05/1991; 12(2):69-73. · 1.30 Impact Factor
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ABSTRACT: In order to elucidate the day-by-day development of low T3 syndrome, we made rats diabetic by an injection of streptozotocin. Untreated controls killed at day 0 and rats treated for 8 days with insulin after they had received streptozotocin served as controls. Sub-groups of animals were killed 1, 2, 3, 4 and 8 days after streptozotocin. In serum, heart and liver, T3 was depressed to less than 50% of controls at day 4, whereas the insulin-treated rats differed from controls only as to heart T3. Heart iodothyronine 5'-deiodinase activity was depressed to a minimum at day 3 and depression was not prevented by insulin. Liver iodothyronine 5'-deiodinase activity had not reached a minimum at day 8, and again, insulin treatment did not normalize this parameter. T3 contents and iodothyronine 5'-deiodinase activity in brown adipose tissue did not differ from values in controls at any point of time. Thus, in the rats with low T3 syndrome induced by streptozotocin-diabetes, a lowered iodothyronine 5'-deiodinase activity is not fully inhibited by insulin treatment, whereas the T3 content in the liver is re-established during an observation period of 8 days. A direct toxic effect of streptozotocin seems unlikely as an in vitro study showed no influence of streptozotocin on iodothyronine 5'-deiodinase activity in the liver. The study thus indicates that iodothyronine 5'-deiodinase activity in the heart and liver is depressed in experimental diabetes, despite near optimal regulation of blood glucose, and we suggest that lowered intracellular T3 production could, after some time, result in a hypothyroid state in different tissues.
Acta endocrinologica 08/1990; 123(1):67-71.
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ABSTRACT: Glycogen nephrosis, i.e. the Armanni-Ebstein lesion which manifests itself by intracellular accumulation of beta-glycogen has been studied in two groups of streptozotocin diabetic rats and compared to controls. One diabetic group was left untreated and the other diabetic group received pancreatic islet transplantation after 4 weeks duration of diabetes. The kidneys were studied after another 4 week period with normoglycemia. In the non-transplanted diabetic animals glycogen containing tubules comprised 43% of the distal tubule length in the cortex but in the transplanted animals no abnormal, glycogen containing cells could be recovered at the light microscope level. Measurements of the total distal tubule length in the non-transplanted diabetic animals showed that the distal tubules increased in length by 24%. In the transplanted diabetic animals distal tubule length remained the same as in the non-transplanted diabetic animals in spite of normalization of the tubular morphology. This finding could possibly be responsible for the incomplete normalization of kidney weight after treatment.
Apmis 09/1988; 96(8):749-54. · 1.99 Impact Factor
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O. Gøtzsche
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ABSTRACT: The acute effect of insulin treatment on the earlier reported protective effect of streptozotocin diabetes against the cardiotoxic effect of high dosis of isoproterenol (ISO) was investigated in rats. Thirty to 135 min after the injection of crystalline insulin, ISO was given subcutaneously and when ISO induced fibrosis in the myocardium was morphometrically analyzed 7 days later, a highly significant correlation (r= 0.83, 2 p=0.006) to the slope of the fall in blood glucose after insulin treatment appeared. The myocardial content of catecholamines was estimated in these 8 day diabetic rats. The norepinephrine content was significantly increased while epinephrine remained unchanged. An enhanced sympathetic nervous system activity with a consequent down regulation of the myocardial-adrenergic receptors could, therefore, explain this catecholamine resistance. The rapid reversion after insulin treatment excludes the possibility that streptozotocin in itself causes the ISO resistance and points towards a direct insulin effect on myocardial catecholamine sensitivity in diabetic rats. The phenomenon described might elucidate pathogenetic mechanisms behind toxic myocardial cell degeneration and may possibly have relevance for acute cardiovascular complications in diabetic patients.
Archiv für Pathologische Anatomie und Physiologie und für Klinische Medicin 05/1985; 405(2):193-201. · 2.49 Impact Factor
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ABSTRACT: A quantitative morphologic study of the glomeruli in rats after 4 wk of streptozotocin-induced diabetes showed a number of glomerular changes, as previously described. Of particular interest was the increase in the total amount of glomerular basement membrane material [from 0.94 +/- 0.13 (SD) mm3 to 1.26 +/- 0.14 mm3 per kidney]. This parameter did not change after 4 wk of normoglycemia following islet cell transplantation (1.19 +/- 0.17 mm3), nor was the total glomerular volume normalized. The contralateral kidney was weighed and used for estimating the total amounts of protein, RNA, and DNA. Four weeks of diabetes expectedly resulted in a 50% increase in kidney weight, and islet cell transplantation diminished this to 15% in excess of normal. The average cell size (protein/DNA ratio) paralleled the kidney size after diabetes and following transplantation. The average amount of RNA per cell (RNA/DNA) increased significantly after induction of diabetes and was totally normalized after transplantation. Kidney protein concentration (mg protein/mg kidney) remained constant throughout the experiment. Considering that a few weeks of diabetes provokes a large increase in basement membrane material, it is especially noteworthy that 1 mo of normoglycemia is quite insufficient to reverse the accumulation.
Diabetes 07/1981; 30(6):481-5. · 8.29 Impact Factor
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Acta endocrinologica. Supplementum 02/1981; 242:19-21.
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ABSTRACT: A considerable enlargement of the renal glomeruli is present very early after the acute onset of juvenile diabetes mellitus. In the hypertrophied glomeruli the surface area of the capillary walls, the filtration surface, is increased, and thereby also the amount of basement membrane in the capillary wall. The rate of development of this type of diabetic basement membrane accumulation has been studied in streptozotocin diabetic rats with 4- and 47-day duration of diabetes. During the first 4 days a 40% increase in the total amount of peripheral basement membrane material occurs, whereas the following period up to 47 days shows no further change. The structural changes of the glomerular capillaries seen in conjunction with the basement membrane accumulation comprise an enlargement of the filtration surface and capillary luminal volume. In another experiment, 4-week diabetic animals were transplanted with pancreatic islets. The renal structures were studied quantitatively after 4 weeks of normalization. It was found that the increased amounts of basement membrane material were still present.
Renal physiology 02/1980; 3(1-6):298-302.
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Nordisk medicin 12/1979; 94(11):291-2, 298.
