RESUMEN
BACKGROUND: Intense physical stress might promote inflammatory responses, whereas a regular physical exercise has positive influence. Little is known on the acute metabolic and inflammatory responses to different levels of strenuous exercise in trained athletes. AIM: To compare the short-term effect of two different ultra-endurance competitions on the inflammatory profile in male triathletes. METHODS: We studied 14 Ironman (IR) and 13 Half Ironman (HIR) before and after their own specific race. We assessed body composition and measured blood cells, lipids, iron metabolism and plasma levels of some acute-phase cytokines and inflammatory markers. RESULTS: After the race, IR showed reduced total body water and fat-free mass, not related with the duration of exercise, and increased white cells and platelets; high-density lipoprotein levels also increased. IR, but not HIR, showed reduced iron levels, increased ferritin and transferrin, reduced % saturated transferrin. HIR showed higher basal interleukin (IL)-6, tumour necrosis factor (TNF)-α, IL-10, IL-1ß than IR; however, the post-performance rise was greater in IR. Irisin increased only in HIR and osteocalcin decreased in IR. In the whole study group, delta of white blood cells was directly related with delta of monocyte chemoattractant protein 1, and Δ ferritin was inversely related with Δosteocalcin. CONCLUSIONS: A single ultra-endurance competition induces an inflammatory response depending on the duration of physical effort, with increased acute-phase cytokines, and an altered iron metabolism. Irisin, whose biological meaning is still uncertain, seems to be associated with acute variations of some metabolic parameters.
Asunto(s)
Biomarcadores/sangre , Citocinas/sangre , Inflamación/sangre , Esfuerzo Físico/fisiología , Atletas , Composición Corporal , Voluntarios Sanos , Humanos , Inflamación/fisiopatología , MasculinoRESUMEN
BACKGROUND AND AIM: A certain degree of impaired kidney function is related to an increased cardiovascular risk. The cardiovascular protection exerted in the postmenopausal state by the hormone replacement therapy (HRT) is debated. No studies have so far explored the relationship between menopause, renal function and cardiovascular risk profile in healthy menopausal women in relation with HRT. SUBJECTS AND METHODS: A total of 362 postmenopausal healthy women with normal albumin excretion rate were recruited and divided into two groups (HRT+ and HRT-) according to the presence or absence of HRT. All participants underwent a complete routine biochemical analyses and an echocardiogram. RESULTS: Clinical characteristics of the two groups were similar, but HRT+ showed a significantly higher estimated glomerular filtration rate (GFR; by CKD-EPI formula). Regarding the heart ultrasonography, HRT+ had a significantly lower size of the aortic root and left atrium diameter (p = 0.038 and p = 0.012, respectively); no differences were found in the ejection fraction and Left Ventricular Mass Index (LVMI). In the whole study group, eGFR correlated inversely with LVMI and with the size of the aortic root (both p < 0.0001), being GFR the only determinant of the former by a stepwise regression. Dividing the study population according to an eGFR cut-off (> 80 and < 80 ml/min/1.73 m(2)); > 80 women, in comparison with < 80, showed a significantly lower LVMI and lower size of aortic bulb, further reduced in the HRT+. CONCLUSION: In a cohort of healthy, drug-naïve, postmenopausal women, HRT seems to positively affect glomerular filtration and is associated with lower values of left ventricular mass and aortic root size, thus offering a further mechanism through female hormones exert cardioprotection.
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Estrógenos/farmacología , Tasa de Filtración Glomerular/efectos de los fármacos , Corazón/efectos de los fármacos , Terapia de Reemplazo de Hormonas , Posmenopausia , Anciano , Aorta/diagnóstico por imagen , Aorta/efectos de los fármacos , Biomarcadores/sangre , Enfermedades Cardiovasculares/prevención & control , Estudios Transversales , Ecocardiografía , Femenino , Atrios Cardíacos/diagnóstico por imagen , Atrios Cardíacos/efectos de los fármacos , Ventrículos Cardíacos/diagnóstico por imagen , Ventrículos Cardíacos/efectos de los fármacos , Humanos , Persona de Mediana Edad , Análisis de RegresiónRESUMEN
This study was undertaken to elucidate the still debated question of the relationship between cardiac volume and QRS voltage amplitude. The authors studied 14 healthy men, aged 24-61 years (mean age, 41.2 +/- 12.1 years). They underwent a reduction in venous return, produced by simultaneously inflating sphygmomanometric cuffs placed around the most proximal portion of each of the four limbs. In basal conditions and 5 minutes after cuff inflation, two-dimensional and M-mode echocardiograms were recorded with vectorcardiographic loops and scalar Frank leads. The reduction of the venous return to the heart induced a significant decrease of the end-diastolic left ventricular diameter (from 52.4 +/- 4.2 to 48.5 +/- 4.6 mm, P < .001), of the R wave amplitude in leads X and Y, of the sum of the R wave amplitudes in the three leads,and of the maximal vector in the frontal and horizontal planes. No significant changes in the heart rate or arterial blood pressure were observed. These results support Brody's theory concerning the relationship between cardiac blood volume and QRS voltage.
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Ventrículos Cardíacos/anatomía & histología , Vectorcardiografía , Función Ventricular , Adulto , Volumen Sanguíneo , Ecocardiografía , Humanos , Masculino , Persona de Mediana EdadRESUMEN
The aim of this study was to evaluate the effects of preload reduction on the Doppler transmitral flow pattern in the presence of diastolic dysfunction (hypertensive patients) and normal diastolic function (normal subjects) to identify, if present, one or more indexes of abnormal diastolic ventricular filling independent of variations in preload. For this purpose Doppler echocardiography was performed in 17 patients with hypertension and in 18 normal subjects under basal conditions and after 5 minutes of blood pressure cuff inflation at the root of the four limbs. The two groups showed a similar response to preload reduction: a significant reduction in peak velocity and the time-velocity integral of the E wave and in the ratio of peak velocities of E and A waves. Therefore the differences in left ventricular filling patterns between hypertensive and normal subjects observed under basal conditions were still present after preload reduction. The comparison between normal subjects after preload reduction and hypertensive patients in the basal state showed a higher peak velocity and time-velocity integral of the A wave in the latter (61.2 +/- 16.2 vs 46.2 +/- 9 cm/sec [p less than 0.002] and 5.4 +/- 1.8 vs 3.7 +/- 1 cm [p less than 0.002], respectively) with no differences in the ratios of peak velocities and time-velocity integrals of the E and A waves.(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
Diástole/fisiología , Hipertensión/fisiopatología , Función Ventricular Izquierda/fisiología , Adulto , Velocidad del Flujo Sanguíneo , Presión Sanguínea/fisiología , Ecocardiografía , Ecocardiografía Doppler , Femenino , Ventrículos Cardíacos/diagnóstico por imagen , Ventrículos Cardíacos/fisiopatología , Humanos , Hipertensión/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Válvula Mitral/diagnóstico por imagen , Válvula Mitral/fisiología , Válvula Mitral/fisiopatología , Flujo Sanguíneo Regional , Función VentricularRESUMEN
The normal values of the systolic time intervals (STI) in children and their possible relationship with heart rate have not been studied thoroughly. From a group of 9760 healthy school-children 10-12 years old, 488 subjects of both sexes were randomly selected in order to measure the STI and calculate the respective indices. The final population study was composed of 479 children, 249 males and 230 females, aged from 10/1 to 12/2 years/months (mean age 11/1 +/- 0/4 years/months). In each child, the following STI were measured: total electromechanical systole (Q-S2), left ventricular ejection time (LVET), mechanical systole (S1-S2), preejection period (PEP), PEP/LVET ratio and isovolumic contraction time (ICT). For each parameter, the regression equation with heart rate was calculated using a linear model and was verified if a real difference existed between linear regressions of males and females. Moreover, for each parameter, the index from the respective regression equation was calculated as well as its normal value and the standard deviation. Finally, the diastolic time (% diastole) and its correlation with heart rate were calculated. Our results demonstrate that in children, a close correlation exists between the STI and heart rate, although less striking than in adults; only the PEP/LVET ratio appears independent from heart rate, as in adults. The % diastole versus heart rate non-linear relationship shows the same behaviour as in adults. Finally, in agreement with other authors, our results show that in childhood the relationship between the STI and heart rate behaves alike in males and females.
Asunto(s)
Frecuencia Cardíaca , Sístole , Niño , Electrocardiografía , Estudios de Evaluación como Asunto , Femenino , Humanos , Italia , Modelos Lineales , Masculino , Contracción Miocárdica , Valores de Referencia , Volumen Sistólico , Factores de TiempoRESUMEN
In the last few years, alterations in transmitral diastolic flow pattern have been used to assess changes in left ventricular diastolic properties. However, since diastolic flow primarily reflects the atrioventricular pressure gradient, loading conditions, as well as intrinsic left ventricular properties, should be able to affect this pattern. This study was selectively designed to decrease preload (a major determinant of the atrioventricular pressure gradient) in normal subjects to observe the effects on the Doppler transmitral flow pattern without pharmacologic interventions that may also affect left ventricular diastolic properties. In 12 normal subjects, preload was reduced by inflation of blood pressure cuffs placed at the level of the root of the 4 limbs. The peak velocity of early mitral flow (E wave) decreased from 62 +/- 8 to 51 +/- 7 cm/s (p less than 0.001), while no changes were found in the maximal velocity after atrial contraction; this caused a significant decrease in the ratio of these 2 velocities (the E to A ratio) from 1.5 +/- 0.3 to 1.1 +/- 0.1 (p less than 0.001). The time-velocity integral of early diastolic inflow decreased from 7.8 +/- 1.3 to 6.1 +/- 1.3 cm (p less than 0.001) with no significant changes of the time-velocity integral of inflow after atrial contraction. Therefore, preload reduction in normal subjects significantly reduces transmitral flow in early diastole with preserved late ventricular filling, producing a pattern that can mimic the changes previously described in left ventricular diastolic dysfunction.
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Diástole/fisiología , Hemodinámica/fisiología , Válvula Mitral/fisiología , Adulto , Anciano , Velocidad del Flujo Sanguíneo , Ecocardiografía , Ecocardiografía Doppler , Electrocardiografía , Humanos , Masculino , Persona de Mediana Edad , Presión , Valores de ReferenciaRESUMEN
Beta-endorphin and beta-lipotropin plasma concentrations were evaluated in 24 patients with congestive heart failure (CHF) (10 patients had chronic CHF and 14 an acute episode superimposing on chronic CHF), and in 35 age matched controls. Beta-endorphin and beta-lipotropin were significantly lower (P less than 0.005 and P less than 0.001 respectively) in patients with CHF than in controls. A significant decrease of both peptides vs controls was observed also in the two subgroups of patients, with chronic and acute CHF, without statistical differences between the subgroups. Beta-endorphin and beta-lipotropin showed a close and significant correlation (r = 0.88, P less than 0.001) amongst the whole series of patients as well as in both subgroups with chronic and acute CHF. In consideration of the long duration of the disease the decreased concentrations of beta-endorphin and beta-lipotropin can be considered to be due to a depletion of the releasable pool of the peptides, as it was previously shown for chronic stress.
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Insuficiencia Cardíaca/sangre , betaendorfina/sangre , beta-Lipotropina/sangre , Enfermedad Aguda , Enfermedad Crónica , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
The effects of ibopamine and furosemide on renal function given alone and in combination at single doses were studied in 6 men and 6 women aged 45 to 73 years with chronic congestive heart failure of NYHA class II. After 3 days of dietary stabilization, the patients received either ibopamine 200 mg, furosemide 40 mg, or furosemide 40 mg plus ibopamine 200 mg with 2-day washout between treatments, according to a double-blind, balanced three-way crossover design using all possible treatment sequences. On each treatment day urine collections were performed at 2-hourly intervals from 2 h before to 6 h after dosing, and urine volume and Na+, K+, Cl-, and creatinine concentrations were measured for every period. The patients received a standardized breakfast 3 h before treatment and then were allowed 250 ml tap water to drink before starting each urine collection period. Venous blood samples were taken before breakfast and midway between each urine collection period for analysis of serum Na+, K+, Cl-, creatinine, and glucose. Heart rate, blood pressure, and physical signs were recorded 2, 1 h, immediately before, and then 0.5, 1, 2, 3, 4, 5, and 6 h after treatment. At the same times the patients were asked for any symptoms. The time course of the diuretic effect of furosemide 40 mg was consistent with the data reported by other authors.(ABSTRACT TRUNCATED AT 250 WORDS)
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Desoxiepinefrina/análogos & derivados , Dopamina/análogos & derivados , Furosemida/uso terapéutico , Insuficiencia Cardíaca/tratamiento farmacológico , Riñón/fisiopatología , Anciano , Glucemia/metabolismo , Cloruros/orina , Creatinina/sangre , Desoxiepinefrina/administración & dosificación , Desoxiepinefrina/uso terapéutico , Quimioterapia Combinada , Electrólitos/orina , Femenino , Furosemida/administración & dosificación , Insuficiencia Cardíaca/fisiopatología , Humanos , Pruebas de Función Renal , Masculino , Persona de Mediana Edad , Micción/efectos de los fármacosRESUMEN
In order to investigate the prevalence of vectorcardiographic bites, expression of small areas of fibrosis, atrophy or degeneration of the myocardium, we studied, using the vectorcardiograms (VCG) of 101 diabetic patients (35 with insulin-dependent and 66 with non-insulin-dependent diabetes mellitus, aged from 25 to 60 years, without hypertension, coronary artery disease, or intraventricular conduction defects) and 228 normal control subjects, matched for age and sex. The prevalence of bites was 38.6% in diabetic patients and 10.0% in the control group (p less than 0.001). Diabetic patients were also subdivided into groups according to age, sex, metabolic control, risk factors for coronary heart disease, type of diabetes, duration of diabetes and diabetic microangiopathy. No correlation was found between any of the variables investigated nor of a combination of these, and the presence of bites. We conclude that VCG is a sensitive test for cardiac involvement in diabetic patients but that it cannot be used to identify any specific factor able to influence the onset and evolution of this involvement.
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Cardiomiopatías/complicaciones , Complicaciones de la Diabetes , Adulto , Cardiomiopatías/fisiopatología , Diabetes Mellitus Tipo 1/complicaciones , Diabetes Mellitus Tipo 1/fisiopatología , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/fisiopatología , Angiopatías Diabéticas/fisiopatología , Electrocardiografía , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Twelve patients with chronic cor pulmonale due to chronic obstructive pulmonary disease have been examined with 2D echocardiography, performing four-chamber view by apical and subcostal approaches, and the right ventricular outflow tract view by the subcostal approach. These views have permitted evaluation of right ventricular volumes, and hence right ventricular ejection fraction, by the use of three different geometrical formulae: the biplane area-length method, Simpson's rule and the pyramidal method. The ejection fraction values obtained from each method have been compared to those obtained by equilibrium radionuclide angiocardiography. Four-chamber apical and subcostal views were satisfactorily recorded in 10 of the 12 patients (83.3%), and right ventricular outflow tract view in 8 patients (66.6%). No significant statistical differences have been found between measurements obtained from the three different echocardiographic examinations performed on each subject by the same operator, so demonstrating a satisfactory reproducibility of the technique. The highest correlation coefficient for ejection fraction was shown by Simpson's rule (r = 0.96, p less than 0.001), with a very narrow confidence intervals, while the r values for the biplane area-length method was 0.63 (p less than 0.05) and for the pyramidal method 0.50 (not statistically significant), with increasingly wider confidence intervals. The statistically significant difference between the three correlation coefficients demonstrates the higher accuracy of Simpson's rule for the determination of right ventricular ejection fraction.
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Ecocardiografía/métodos , Volumen Sistólico , Anciano , Femenino , Ventrículos Cardíacos/diagnóstico por imagen , Ventrículos Cardíacos/fisiopatología , Humanos , Interpretación de Imagen Asistida por Computador , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Enfermedad Cardiopulmonar/fisiopatología , Angiografía por Radionúclidos , Reproducibilidad de los ResultadosRESUMEN
The effects of acute changes in cardiac volumes determined by hemodialysis on cardiac voltages were assessed in 18 chronically uremic patients by means of a vectorcardiographic and scalar Frank leads recording, immediately before, at the 90th and 180th minute, and immediately after hemodialysis. The following parameters were simultaneously monitored: body weight, systolic and diastolic blood pressure, heart rate, hematocrit and, in eight patients, echocardiographic systolic and diastolic diameters of the left ventricle. During hemodialysis all voltages considered except R wave in X lead increased significantly. They were inversely correlated with body weight, blood pressure, and systolic and diastolic diameters and directly with hematocrit (volemia-dependent parameters). The maximal vector on the left sagittal plane and the R wave amplitude in Z lead, representing left ventricular posterolateral wall activation, showed the greatest increase. When, at the end of hemodialysis, an amount of fluids ranging from 300 to 800 ml was restored, these cardiac voltages decreased paralleling the increase of left ventricular diameters. In conclusion, these results demonstrate that cardiac voltage and volumes are inversely related.
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Arritmias Cardíacas/fisiopatología , Volumen Cardíaco , Electrocardiografía , Fallo Renal Crónico/fisiopatología , Diálisis Renal , Vectorcardiografía , Adulto , Anciano , Femenino , Sistema de Conducción Cardíaco/fisiopatología , Ventrículos Cardíacos/fisiopatología , Hemodinámica , Humanos , Masculino , Persona de Mediana EdadRESUMEN
In the aim to clarify the magnitude and features of alterations in left ventricular function observed in patients with mitral valve prolapse syndrome (MVPS), we studied 41 patients with MVPS with M-mode echocardiography and computerized reading of recordings (with particular regard to the diastolic phase), and compared them with a control group of 15 healthy subjects matched for age and sex. Routine morphological and functional echocardiographic parameters were evaluated and, in addition, peak rates of movement of left ventricular endocardia, of wall thicknesses change and of cavity dimensions variations were obtained. Finally, a detailed analysis of various diastolic phases have been performed, according to the method proposed by Hanrath et al. There were no significant statistical differences in the morphological echocardiographic parameters (ventricular diameters, wall thicknesses) between the two groups. Patients with MVPS showed (compared to the control group) a significant increase in the peak rate of posterior wall endocardium movement during systole (1.64 +/- 0.42 vs 1.29 +/- 0.30, p less than 0.01) and a reduction of peak rate of interventricular septum thickening (1.21 +/- 0.36 vs 1.45 +/- 0.46, p less than 0.05). The comparison of all other systolic function parameters did not show statistical differences. As far as diastolic phase is concerned, no significant differences were found in the analysis of the peak velocities. However, evaluation of the diastolic phases demonstrated, in MVPS group, a significantly shorter slow filling period, both in absolute value (185.88 +/- 78.91 vs 303.15 +/- 117.58, p less than 0.001) and in percent of the whole diastole (37.42 +/- 11.88 vs 52.50 +/- 10.61, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)
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Ecocardiografía , Prolapso de la Válvula Mitral/diagnóstico , Contracción Miocárdica , Adolescente , Adulto , Diástole , Femenino , Ventrículos Cardíacos , Humanos , Masculino , Prolapso de la Válvula Mitral/fisiopatología , Procesamiento de Señales Asistido por Computador , SístoleRESUMEN
Thyroid function alterations induced by amiodarone treatment (200-400 mg/day for 5 days/week) were studied in 50 patients with heart disease (age 34-75 years, mean age 55.5 +/- 11.8) for 25.6 +/- 15.0 months. Statistical analysis was made of the results obtained from the 14 patients who underwent all of the schedule examinations during the same 16-month period. A reduction in T3 was observed after 7 days' treatment; this became statistically significant at 12 and 16 months. FT3 fell significantly only after 7 days; rT3 showed an opposite trend to that of T3 (low T3 syndrome), with significant increases at all observation times. TSH rose at 7 days, then fell gradually to below baseline values after 12 months. No evidence of clinical hyperthyroidism accompanied the significant increases of T4 and FT4 observed at 1, 3, 6, and 16 months; when this complication occurred (in 6% of the cases) it was associated with a rise or lack of reduction in T3 levels. In these cases treatment was withdrawn. Amiodarone was also discontinued in 2 other cases (4%) with elevated thyroid function indices but without clinical symptoms. Seven patients who showed an isolated increase of FT3 were carefully monitored; only in one case did clinical hyperthyroidism develop with a simultaneous rise in the T3 level. A diagnosis of hypothyroidism may be considered only if there is a reduction in T4 levels, since an isolated increase in TSH is not as reliable; treatment had to be suspended for this reason in 2 cases (4%), both without clinical symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
Amiodarona/efectos adversos , Síndromes del Eutiroideo Enfermo/inducido químicamente , Adulto , Anciano , Amiodarona/uso terapéutico , Arritmias Cardíacas/tratamiento farmacológico , Femenino , Humanos , Hipertiroidismo/inducido químicamente , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Pruebas de Función de la TiroidesRESUMEN
For the purpose of assessing the cardiovascular effects of hemodialysis (HD), M-mode echocardiography was performed 24 hours before and 2 hours after this procedure in 15 patients with chronic renal failure. The results, which include computer analysis of digitized interventricular septum (IVS) and left ventricular posterior wall (LVPW), show the following statistically significant changes after HD: reduction of end-diastolic and end-systolic internal diameters of the left ventricle (LVID), increase of mean velocity of circumferential fiber shortening, of peak rate of systolic and diastolic LVID variation, of systolic and diastolic LVPW movement, and of IVS movement in systole. These results demonstrate that after HD the left ventricle not only decreases in size but also its performance improves in both contraction and relaxation. These changes did not correlate with the reduction in body weight and arterial pressure following HD; hence HD seems to act on left ventricular function by reducing mainly afterload and, possibly, by modifying some humoral parameters. In conclusion, M-mode echocardiography, especially when utilized in conjunction with the computerized analysis of the recordings, is useful and reliable in monitoring hemodynamic changes occurring during the dialytic session.
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Ecocardiografía , Corazón/fisiopatología , Diálisis Renal , Adulto , Anciano , Peso Corporal , Femenino , Ventrículos Cardíacos/patología , Ventrículos Cardíacos/fisiopatología , Hematócrito , Humanos , Masculino , Persona de Mediana Edad , Contracción MiocárdicaRESUMEN
Sixty patients with non-insulin-dependent diabetes underwent M-mode echocardiographic examination. They were all in good metabolic control under treatment with oral antidiabetic drugs and/or diet; none had clinical evidence of micro- or macroangiopathy, cardiovascular disease, arterial hypertension, or other associated risk factors. The control group consisted of 30 normal subjects. No significant differences were shown either with routine or computer-assisted evaluation of the echocardiograms; if there was a significant difference, there was a wide overlap with normal values. However, alterations of the systolic function of the left ventricle were shown by the reduction of the percentage fractional shortening during the first third of systole (9.14 +/- 5.85 vs 12.27 +/- 7.04, p less than 0.05); alterations of the diastolic function were shown by the marked mitral opening delay (54.15 +/- 20.64 msec vs 10.57 +/- 5.18, p less than 0.00001) and the presence of a B notch (50% of the diabetics). In particular, the B notch seemed to be associated with more severe impairment of left ventricular performance. Therefore, these data appear particularly useful in detecting even slight abnormalities in cardiac function in diabetic patients.
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Diabetes Mellitus Tipo 2/fisiopatología , Ecocardiografía/métodos , Corazón/fisiopatología , Adulto , Femenino , Ventrículos Cardíacos , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Potassium canrenoate (KCR) is widely used in cardiac patients as an aldosterone antagonist, antiarrhythmic and diuretic drug. According to experimental and clinical studies it can also elicit an inotropic action. It is not clear, however, whether this inotropic activity occurs in the absence of any treatment or after the myocardial contractility has already been improved with digitalis. In order to evaluate a possible interaction of this drug with digitalis we administered KCR intravenously to 41 anaesthetized dogs either untreated or treated with digitalis, in which aortic and left ventricular pressures were recorded and myocardial contractility was evaluated by calculating in real time the first derivative of ventricular pressure (Formula: see text) max and two other contractility indexes (Formula: see text) max and V.max. The results obtained showed that KCR given at doses of 10, 20 and 30 mg/kg i.v. did not elicit any inotropic effect in dogs not previously digitalized. 100 mg/kg i.v. first depressed cardiac contractility and then increased it. After cardiac performance had been improved by digitalis, KCR further increased all contractility indexes significantly. These results could explain previous observations that no inotropic effect was observed in human subjects not treated with digitalis after treatment with KCR.
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Ácido Canrenoico/farmacología , Glicósidos Digitálicos/farmacología , Contracción Miocárdica/efectos de los fármacos , Pregnadienos/farmacología , Animales , Presión Sanguínea/efectos de los fármacos , Digoxina/farmacología , Perros , Femenino , Frecuencia Cardíaca/efectos de los fármacos , Masculino , Estimulación QuímicaRESUMEN
We examined 106 VCGs of cancer patients receiving Adriamycin (ADM) to investigate the nature and meaning of bites. It is known that ADM causes patchy areas of myocardial degeneration and necrosis, the appearance of which is dose dependent. Thirty-eight cancer patients not yet receiving ADM were examined to provide controls. Patients were divided into six groups, according to total cumulative ADM dose received. The incidence of bites in the different groups was shown to be as follows: group 1 (controls, 38 patients) 13.1%; group 2 (1-100 mg/m2 of body surface ADM, 23 patients) 39.1%; group 3 (101-200 mg/m2, 33 patients) 42.2%; group 4 (201-300 mg/m2, 25 patients) 56%; group 5 (301-400 mg/m2, 15 patients) 66.6%; group 6 (greater than 400 mg/m2, 10 patients) 90%; groups 2-6 52.8%. These percentages show a trend which is highly correlated with the total cumulative dose of ADM (p=0.00005). The influence of age on the appearance of bites has been excluded by analyses of trends in patients below and over 50 years (p=0.08). In 80.35% of cases, bites appear on more than one plane and mostly close to the maximum vector (Vmax). We therefore think that these results favor the hypothesis that bites are the electrophysiologic expression of lesions, such as small fibrotic and necrotic areas, which interfere with the normal spread of the ventricular depolarization wavefront.