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Resumo Fundamento: A Sauromatum guttatum (S. guttatum) é utilizado no tratamento de doenças do sangue e supostamente tem atividade espasmolítica através da inibição dos canais de Ca2+. Objetivos: O objetivo deste estudo foi investigar o potencial anti-hipertensivo de S. guttatum em modelo de rato Sprague-Dawley (SD) com hipertensão induzida por dieta com alto teor de sal (HIDATS). Métodos: Ratos SD foram divididos em normotensos, hipertensos e grupos tratados com verapamil e S. guttatum. Extrato bruto de S. guttatum (Sg.B) (100, 150 e 300 mg/kg/dia) e verapamil (5, 10 e 15 mg/kg/dia) foram administrados por via oral junto com NaCl. Anéis aórticos e faixas do átrio direito de ratos normotensos foram utilizados para investigar os mecanismos subjacentes. O nível de significância estatística adotado foi de 5%. Resultados: A pressão arterial média diminuiu nos grupos hipertensos tratados com Sg.B e verapamil de forma dose-dependente (p <0,001). No estudo de reatividade vascular, a acetilcolina induziu relaxamentos com valor CE50 de 0,6 µg/mL (0,3-1,0) em ratos hipertensos tratados com Sg.B (300 mg/kg), sugerindo preservação endotelial. Em aorta isolada de rato normotenso, o Sg.B exibiu vasorrelaxamento com valor de CE50 de 0,15 mg/mL (0,10-0,20), após ablação por desnudamento endotelial ou pré-tratamento com L-NAME e atropina. O tratamento com Sg.B causou relaxamento contra contrações induzidas por K+ alto, como o verapamil. O Sg.B mostrou efeitos inotrópicos (82%) e cronotrópicos (56%) negativos em preparações isoladas atriais de ratos reduzidas com atropina. A avaliação fitoquímica indicou a presença de alcaloides, flavonoides e taninos. Conclusão: O S. guttatum possui efeito vasodilatador através da preservação da função endotelial, liberação de NO mediada pelo receptor muscarínico e inibição do movimento de Ca2+, enquanto o efeito depressor do miocárdio atrial pode estar ligado ao receptor muscarínico. Esses achados fornecem a base farmacológica para o uso do extrato de S. guttatum como um medicamento anti-hipertensivo.
Abstract Background: Sauromatum guttatum (S. guttatum) is used in the treatment of blood disorders and reportedly has a spasmolytic activity through Ca2+ channel inhibition. Objectives: The aim of this study was to investigate the antihypertensive potential of S. guttatum in high salt-induced hypertensive Sprague-Dawley (SD) rat model (HSHRs). Methods: SD rats were divided into normotensive, hypertensive, S. guttatum and verapamil treated groups. S. guttatum crude extract (Sg.Cr) (100, 150 and 300 mg/kg/day) and verapamil (5, 10 and 15 mg/kg/day) were administered orally along with NaCl. Aortic rings and right atrial strips from normotensive rats were used to investigate the underlying mechanisms. The level of statistical significance was set at 5%. Results: Mean arterial pressure decreased in the Sg.Cr and verapamil-treated hypertensive groups in a dose-dependent manner (p < 0.001). In the vascular reactivity study, acetylcholine induced relaxations with an EC50 value of 0.6 µg/mL (0.3-1.0) in Sg.Cr-treated hypertensive rats (300 mg/kg), suggesting endothelial preservation. In isolated normotensive rat aorta, Sg.Cr-treated rats showed vasorelaxation with an EC50 value of 0.15 mg/mL (0.10-0.20), ablated by endothelial denudation or pretreatment with L-NAME and atropine. Sg.Cr treatment caused relaxation against high K+-induced contractions, like verapamil. Sg.Cr showed negative inotropic (82%) and chronotropic effects (56%) in isolated rat atrial preparations reduced with atropine. The phytochemical investigation indicated presence of alkaloids, flavonoids and tannins. Conclusion: S. guttatum has a vasodilatory effect through endothelial function preservation, muscarinic receptor-mediated NO release and Ca2+ movement inhibition, while atrial myocardial depressant effect can be linked to the muscarinic receptor. These findings provide pharmacological base for using S. guttatum extract as an antihypertensive medication.
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RESUMEN Introducción: Las enfermedades cardiovasculares constituyen la primera causa de muerte en Cuba y la mayoría de los países desarrollados. La ecocardiografía con rastreo de marcas o speckle-tracking bidimensional (ST-2D) es una técnica reciente en la evaluación de la función cardíaca. Objetivo: Determinar la relación entre la deformación miocárdica (strain) circunferencial (GCS) medida por ST-2D y el estado de la circulación coronaria, en pacientes con cardiopatía isquémica. Método: Se realizó un estudio analítico, transversal, con 55 pacientes con indicación de coronariografía a los que se les realizó ecocardiograma para medir la GCS mediante ST-2D, en el Centro de Investigaciones Médico Quirúrgicas (CIMEQ, La Habana, Cuba), durante un año. Se crearon dos grupos: con enfermedad coronaria significativa (ECS=32) y no significativa (ECNS=23). Se utilizó SSPS para análisis de los resultados. Resultados: La edad promedio fue mayor en ECS (55,6 ±9,3 vs. 61,8±8,8; p=0,014). Predominaron los hombres con ECS (47,3%), los hipertensos (ECS=90,6% y ENCS=65,2%; p=0,02) y los fumadores (ECS=59,4% y ENCS=17,4%; p=0,002). El diagnóstico más frecuente fue la angina crónica estable (87%). En ECS predominó la enfermedad de tres vasos (75%). La GCS fue menor en ECS [(-19,5±3.8 vs. -25,2±5,7; p=0,033); área bajo la curva = 0,208]. No hubo diferencias en GCS, según el número de vasos significativamente enfermos. Conclusiones: Los resultados encontrados no justifican el empleo de la GCS por ST-2D para discriminar la presencia o no de ECS.
ABSTRACT Introduction: Cardiovascular diseases are the top cause of death in Cuba as well as in most developed countries. Two-dimensional speckle-tracking (2D-ST) echocardiography is a recent technique in the evaluation of cardiac function. Objective: To determine the relationship between global circumferential strain (GCS) measured through 2D-ST echocardiography and the state of coronary circulation in patients with ischemic heart disease. Method: An analytical, cross-sectional study was carried out on 55 patients with indication of coronary angiography, who underwent echocardiography to measure the GCS through 2D-ST at the Centro de Investigaciones Medico Quirúrgicas (CIMEQ, Havana, Cuba), during one year. Two groups were created: with significant coronary artery disease (SCAD = 32) and non-significant coronary artery disease (NSCAD = 23). The statistical package for the social sciences (SPSS) was used to analyze the results. Results: Mean age was higher in the SCAD group (55.6 ± 9.3 vs. 61.8± 8.8, p=0.014). Men with SCAD (47.3%), patients with high blood pressure (SCAD = 90.6% and NSCAD = 65.2%, p = 0.02) and smokers (SCAD = 59.4% and NSCAD = 17.4%, p = 0.002) predominated. The most frequent diagnosis was chronic stable angina (87%). Three-vessel disease predominated in the SCAD group (75%). The GCS was lower in the SCAD group [(-19.5.0 ± 3.8 vs. -25.2 ± 5.7, p = 0.033); area under the curve = 0.208]. There were no differences in GCS according to the number of significantly diseased vessels. Conclusions: The results found do not justify the use of GCS through 2D-ST echocardiography to discriminate the presence or nor of SCAD.
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Ecocardiografía , Isquemia Miocárdica , Pruebas de Función CardíacaRESUMEN
Objective:To establish a nomogram prediction model for the prognosis of patients with septic cardiomyopathy (SCM) based on afterload-corrected cardiac performance (ACP), in order to identify septic patients with poor outcomes and treatment.Methods:The data of patients admitted to the department of critical medicine of the Second Affiliated Hospital of Guangzhou Medical University from June 2016 to June 2019 were analyzed. All patients were monitored by pulse indication continuous cardiac output (PiCCO) monitor more than 24 hours and diagnosed as SCM with ACP less than 80%. The predictors of 30-day death risk of SCM patients were screened by univariate Cox regression analysis. Multivariate Cox regression analysis was used to establish the prediction model for 30-day death risk of SCM patients, which was displayed by the nomogram. Finally, the discrimination and calibration of the model were analyzed by receiver operator characteristic curve (ROC curve) and consistency index (C-index).Results:A total of 102 patients with SCM were included and the 30-day mortality was 60.8% (62 cases). Among 102 patients with SCM, 57 patients (55.9%) had mild impairment of cardiac function (60%≤ACP < 80%), and the 30-day mortality was 43.9% (25/57); 39 patients (38.2%) had moderate impairment of cardiac function (40%≤ACP < 60%), and the 30-day mortality was 79.5% (31/39); 6 patients (5.9%) had severe impairment of cardiac function (ACP < 40%), and the 30-day mortality was 100% (6/6). There was significantly difference in mortality among the three groups (χ 2 = 24.156, P < 0.001). The potential risk factors for 30-day death of SCM patients screened by univariate Cox regression analysis were included in multivariate Cox regression analysis. The results showed that the independent risk factors for 30-day death of SCM patients were acute physiology and chronic health evaluation Ⅱ [APACHEⅡ, risk ratio ( HR) = 1.031, 95% confidence interval (95% CI) was 1.002-1.061, P = 0.039], vasoactive inotropic score (VIS, HR = 1.003, 95% CI was 1.001-1.005, P = 0.012), continuous renal replacement therapy (CRRT; HR = 2.106, 95% CI was 1.089-4.072, P = 0.027), and ACP ( HR = 0.952, 95% CI was 0.928-0.977, P < 0.001). The nomogram model was established based on the above independent risk factors and age, and the area under the curve (AUC) was 0.865 (95% CI was 0.795-0.935), P < 0.001; C-index was 0.797 (95% CI was 0.747-0.847), P > 0.05. Conclusions:The nomogram model based on age, APACHEⅡ score, VIS score, CRRT and ACP has a certain clinical reference significance for the prediction of 30-day mortality of SCM patients. The discrimination and calibration are good, however, further verification is needed.
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Objective To investigate the application value of afterload-related cardiac performance(ACP) in patients with sepsis-induced cardiomyopathy.Methods A total of 148 patients with septic shock admitted by the department of critical care of Wuhan fourth hospital from April 2013 to March 2018 were retrospectively included,all included patients were divided into LVEF ＜ 50％ group and LVEF ≥ 50％ group according to left ventricular ejection fraction (LVEF),the mortality rate at 28 days and ACP value were compared in the 2 groups.All included patients were divided into normal group (ACP ＞ 80％),mild heart function impairment group (60％ ＜ ACP ≤ 80％),moderate heart function impairment group (40％ ＜ ACP ≤ 60％),and severe heart function impairment group (ACP ≤ 40％) according to ACP value,the mortality rate at 28 days was compared in the 4 groups.The measurement data were compared by grouped t test,the rates were compared by chi-square test.Results The mortality rate was 58.2％ in the LVEF ＜ 50％ group,and 30.9％ in the LVEF ≥ 50％ group,with statistically significant differences (x2=11.171,P＜0.01).The values of ACP in the LVEF ＜ 50％ group were (39.3±16.4) ％,and those in the LVEF ≥ 50％ group were (69.1±14.9) ％,with statistically significant differences (t=l 1.571,P＜0.01).The mortality rate was 14.81％ in the normal group,44.00％ in the mild,58.82％ in the moderate and 90.00％ in the severe group.The differences between the normal group and the mild and moderate groups were statistically significant,while those between the severe group and the mild and moderate groups were statistically significant.Conclusion Aflerload-related cardiac performance is of great value for the diagnosis and prognosis in patients with sepsis-induced cardiomyopathy.
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Objective@#To investigate the application value of afterload-related cardiac performance(ACP) in patients with sepsis-induced cardiomyopathy.@*Methods@#A total of 148 patients with septic shock admitted by the department of critical care of Wuhan fourth hospital from April 2013 to March 2018 were retrospectively included, all included patients were divided into LVEF < 50% group and LVEF≥50% group according to left ventricular ejection fraction (LVEF), the mortality rate at 28 days and ACP value were compared in the 2 groups. All included patients were divided into normal group (ACP > 80%), mild heart function impairment group (60% < ACP≤80%), moderate heart function impairment group (40% < ACP≤60%), and severe heart function impairment group (ACP≤40%) according to ACP value, the mortality rate at 28 days was compared in the 4 groups. The measurement data were compared by grouped t test, the rates were compared by chi-square test.@*Results@#The mortality rate was 58.2% in the LVEF < 50% group, and 30.9% in the LVEF≥50% group, with statistically significant differences (χ2=11.171, P<0.01). The values of ACP in the LVEF < 50% group were (39.3±16.4) %, and those in the LVEF≥50% group were (69.1±14.9) %, with statistically significant differences (t=11.571, P<0.01).The mortality rate was 14.81% in the normal group, 44.00% in the mild, 58.82% in the moderate and 90.00% in the severe group. The differences between the normal group and the mild and moderate groups were statistically significant, while those between the severe group and the mild and moderate groups were statistically significant.@*Conclusion@#Afterload-related cardiac performance is of great value for the diagnosis and prognosis in patients with sepsis-induced cardiomyopathy.
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OBJECTIVE: To observe the effect of moxibustion on cardiac function and the expression of B-cell lymphoma-2 (Bcl-2), Bcl-2 associated X (Bax), Fas, Fas ligand (FasL) in cardiomyocytes of chronic heart failure (CHF) rats, so as to explore its underlying mechanisms in preventing and treating CHF. METHODS: SD rats were randomly divided into normal control, model, moxibustion, Captopril and moxibustion ＋ Captopril (M＋C) groups (n＝12 rats/group). The CHF model was established by intraperitoneal injection of Adriamycin (ADR, from 1 to 4 mg/kg, once every other day for 15 days). Mild moxibustion was applied to bilateral"Feishu"(BL 13) and "Xinshu"(BL 15). Rats of the Captopril group was treated by gavage of Captopril suspension (5 mg/mL, 25 mL/kg), and those of the M＋C group treated by the combined two methods. All the treatments were given once a day for 3 weeks. The general conditions and behaviors of rats were observed. The left ventricular mass index (LVMI) and right ventricular mass index (RVMI) were detected for assessing the cardiac performance. Morphological changes of myocardium were observed by HE staining. Enzyme linked immunosorbent assay (ELISA) was used to detect the concentrations of B-type natriuretic peptide (BNP) and precursor N-terminal pro-brain natriuretic peptide (NT-pro BNP) in the serum. The expression levels of Bcl-2, Bax, Fas and FasL of the left ventricle of heart were detected by Western blot. RESULTS: After modeling, the pathological changes of myocardium (as myocardial cell swelling with vacuoles, myocardial fibre breakage, etc.) were obvious, the LVMI, RVMI, serum BNP and NT-pro BNP concentrations, and myocardial Bax, Fas and FasL protein expression levels were significantly increased in the model group compared with the normal group (P0.05)．. CONCLUSION: Moxibustion can reduce myocardial injury and improve cardiac function in CHF rats, which may be related to its effects in down-regulating the expression of myocardial Bax, Fas and FasL proteins, and up-regulating the expression of Bcl-2 protein to inhibit cardiomyocyte apoptosis.
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Abstract The aim of this work was to evaluate whether the heart function of bullfrog tadpoles (25 Gosner stage) is affected by their acute exposure (48 h) to a sub-lethal concentration (10 µg.L–1) of the active principle of the organophosphorus pesticide Folisuper 600R (methyl parathion - MP). Our results demonstrated that MP causes not only a reduction in tadpoles’ cardiac ventricular mass, resulting in a marked reduction in their cardiac twitch force, but also impairs their swimming performance, irrespective of increasing their heart rate. Together, these findings indicate that low and realistic concentration of MP have a negative impact on tadpoles’ performance, jeopardizing their survival.
Resumo O objetivo do presente estudo foi avaliar se a função cardíaca de girinos de rãs-touro (estágio 25 de Gosner) é afetada pela exposição aguda (48h) a uma concentração sub-letal (10 µg.L–1) do princípio ativo do pesticida organofosforado Folisuper 600R (metil paration – MP). Nossos resultados demonstraram que o MP ocasionou não apenas uma redução na massa ventricular cardíaca dos girinos, como também provocou uma redução na sua força de contração cardíaca e de seu desempenho natatório, a despeito de ter sido observado um aumento de sua freqüência cardíaca. Conjuntamente, os achados aqui obtidos indicam que uma baixa e realística concentração de MP exerce um impacto negativo sobre o desempenho dos girinos, ameaçando sua sobrevivência.
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Animales , Corazón/efectos de los fármacos , Insecticidas/toxicidad , Metil Paratión/toxicidad , Rana catesbeiana/fisiología , Corazón/fisiopatología , Larva/efectos de los fármacos , Larva/crecimiento & desarrollo , Larva/fisiología , Rana catesbeiana/crecimiento & desarrollo , NataciónRESUMEN
Abstract The aim of this work was to evaluate whether the heart function of bullfrog tadpoles (25 Gosner stage) is affected by their acute exposure (48 h) to a sub-lethal concentration (10 µg.L1) of the active principle of the organophosphorus pesticide Folisuper 600R (methyl parathion - MP). Our results demonstrated that MP causes not only a reduction in tadpoles cardiac ventricular mass, resulting in a marked reduction in their cardiac twitch force, but also impairs their swimming performance, irrespective of increasing their heart rate. Together, these findings indicate that low and realistic concentration of MP have a negative impact on tadpoles performance, jeopardizing their survival.
Resumo O objetivo do presente estudo foi avaliar se a função cardíaca de girinos de rãs-touro (estágio 25 de Gosner) é afetada pela exposição aguda (48h) a uma concentração sub-letal (10 µg.L1) do princípio ativo do pesticida organofosforado Folisuper 600R (metil paration MP). Nossos resultados demonstraram que o MP ocasionou não apenas uma redução na massa ventricular cardíaca dos girinos, como também provocou uma redução na sua força de contração cardíaca e de seu desempenho natatório, a despeito de ter sido observado um aumento de sua freqüência cardíaca. Conjuntamente, os achados aqui obtidos indicam que uma baixa e realística concentração de MP exerce um impacto negativo sobre o desempenho dos girinos, ameaçando sua sobrevivência.
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BACKGROUND: The issue of using phenylephrine in hemorrhagic shock treatment has been controversial because it is known that phenylephrine improves the tissue perfusion by increasing arterial blood pressure but deteriorates the myocardium by increasing afterload and decreasing myocardial oxygen delivery via coronary vasoconstriction. This study was aimed to assess the effects of phenylephrine on hemodynamic variables, cardiac performance, and myocardial oxygen balance in resuscitation from hemorrhagic shock. METHODS: Twenty anesthetized dogs were randomly divided into phenylephrine group and control group. After inducing hemorrhagic shock, resuscitation was done with phenylephrine and 0.9% normal saline respectively. We measured hemodynamic indices, blood gas parameter and cardiac enzymes which indicate myocardial demage. RESULTS: In both groups, cardiac output and hemodynamic indices improved. In phenylephrine group, the systemic oxygen delivery and consumption was much higher and the myocardial oxygen extraction ratio was maintained at the lower level than the control group. In addition, the CK-MB was higher at the early phase of resuscitation and the troponin T was also higher than the control group during the whole period of resuscitation. Creatine kinase-MB increased during early resuscitation in phenylephrine group but kept decreasing after that and there's no difference between two groups. Troponin T was higher in the phenylephrine group after resuscitation. CONCLUSIONS: We concluded that phenylephrine improves myocardial oxygen balance and contractility without serious myocardial demage during resuscitation from hemorrhagic shock.
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Animales , Perros , Presión Arterial , Gasto Cardíaco , Creatina , Hemodinámica , Miocardio , Oxígeno , Perfusión , Fenilefrina , Resucitación , Choque Hemorrágico , Troponina T , VasoconstricciónRESUMEN
BACKGROUND: It has been well recognized that exercise tolerance and angina threshold in patients with coronary artery disease (CAD) are reduced after a meal. But precise mechanism leading to the postprandial worsening of angina has yet to be adequately defined. This study was undertaken to determine the effect of a mixed meal on cardiac performance and heart rate variability (HRV) in patients with CAD. METHODS: 24 patients with angina or myocardial infarction were studied. Echocardiographic examination and heart rate variability test were performed in the fasting state and the other 40-60 minutes after a 600-800 kcal mixed meal. RESULTS: In the postprandial state, resting heart rate was significantly increased by 5.2% from 64.8+/-10.69 beats/min to 68.2+/-10.2 beats/min (p<0.01), stroke volume by 8.1% from 59.6+/-17.3 ml to 64.4+/-18.1 ml (p<0.01), cardiac output by 14.2% from 3.8+/-1.06 to 4.3+/-1.21 (p<0.01). E wave and A wave of mitral filling flow and E/A ratio were not significantly different in the fasting and postprandial tests. But DT and IVRT were significantly increased in the postprandial state (p<0.05, p<0.01 respectively). HRV was not different in the fasting and postprandial state. CONCLUSIONS: In patients with CAD, a 600-800 kcal mixed meal significantly increased resting heart rate, stroke volume, cardiac output, DT and IVRT.
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Humanos , Gasto Cardíaco , Enfermedad de la Arteria Coronaria , Ecocardiografía , Tolerancia al Ejercicio , Ayuno , Frecuencia Cardíaca , Comidas , Infarto del Miocardio , Volumen SistólicoRESUMEN
A hemodialysis arteriovenous fistula may cause high output cardiac state by volume overload and decreased systemic vascular resistance. Arteriovenous fistulas for hemodialysis consist usually of either a radiocephalic fistula at the wrist or a more proximal brachiocephalic fistula at the antecubital fossa. In this study the contribution of arteriovenous fistula to cardiac function has been evaluated by comparing cardiac performance before and after the point occlusion of the anastomotic site. The results suggest that the occlusion of arteriovenous fistula may decrease end-diastolic left ventricular volume (VOLd), increase end-systolic left ventricular volume (VOLs), decrease stroke volume (SV), decrease ejection fraction (EF) and decrease cardiac output (CO). This study shows that arteriovenous fistula influences directly to cardiac performance, so careful determination of dialysis option is required for the end stage renal failure patients with marginal heart function.
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Humanos , Fístula Arteriovenosa , Gasto Cardíaco , Diálisis , Fístula , Corazón , Diálisis Renal , Insuficiencia Renal , Volumen Sistólico , Resistencia Vascular , MuñecaRESUMEN
Volume replacement is a vital therapy in patient with circulatory shock, but the type of fluid that should be infused remains in controversy. This study is designed to compare the cardiopulmonary effects of a colloid solution and a crystalloid solution in dogs subjected to severe hemorrhagic shock. Twelve dogs were bled into shock and mean arterial pressure(MAP) were maintained at 60 mmHg for 1 hour followed by further hemorrhage to 40 mmHg for additional one hour, Animals were randomized to fluid challenge with 10% pentastarch(group P) or 0.9% normal saline(group S) to restore MAP. Complete hemodynamic and blood gas parameters and plasma lactate concentration were measured at pre-shock, during shock and after resuscitation for 2 hours. Cardiac function and hemodynamic stability were restored to higher level than the control level on the completion of fluid challenge with each type of solution, but hemodynamic parameters decreased as time goes after resuscitation. Especially in group S, hemodynamic parameters decreased more significantly and rapidly than group P. Considering the relation of left ventricular stroke work index(LVSWI) and pulmonary capillary wedge pressure(PCWP), the cardiac performance was well maintained to normal level in group P during post-resuscitation period, but rapidly deteriorated in group S. There was a significant increase in intrapulmonary shunt fraction with pentastarch that was maximal on the completion of fluid challenge but which normalized over the next 1 hour. Assessment of tissue perfusion was measured by mixed venous oxygen tension(PVO2) and plasma lactate concentration. In group P, PVO. was restored to higher than the control level and maintained to the cantrol level during post-resuscitation period, but in group S, it was not restored to control level at the completion of fluid challenge, moreover after then, it decreased progressively. Plssma lactate concentration was recovered to control level in group P at the completion of fluid challenge, but in group S, it was recovered lately. It means that tissue perfusion was more rapidly and effectively restored in group P than group S. In conclusion, infusion of pentastarch at severe hemorrhagic shock restored the hemodynamic parameter more rapidly and maintained cardiac performance more effectively during post-resuscitation period than normal saline. Infusion of pentastarch also maintained tissue perfusion more effectively but it increased intrapulmonary shunt fraction transiently.
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Animales , Perros , Humanos , Capilares , Coloides , Hemodinámica , Hemorragia , Derivados de Hidroxietil Almidón , Ácido Láctico , Oxígeno , Perfusión , Plasma , Resucitación , Choque , Choque Hemorrágico , Accidente CerebrovascularRESUMEN
The systolic time intervals (STI's) and the diastolic time (DT) as functions of the RR interval during exercise were proved to be described by cubic regression equations that converge to the origin of the coordinates. Using the equations, we compared I) the systolic time and DT of trained and untrained men, and II) examined the relations between parameters of STI's. I) Forty healthy male subjects aged 19-22 years old were divided into three groups, i, e., 8 long distance runners (group LD), 16 men with relatively high fitness (group A) and 16 men with relatively low fitness (group B) . They performed submaximal exercise test using a cycle ergometer for measuring the time of electromechanical systole (QS<SUB>2</SUB>) and DT. After test, maximal exercise test was conducted to determine the maximal heart rate (HRmax) in each subject. Means±SD of the minimum QS<SUB>2</SUB> and the minimum DT of the 40 subjects predicted from the regression equations at the HRmax were 209.7±12.5 and 108.2±15.6 ms, their ratio being about 2: 1. The QS<SUB>2</SUB> was significantly shorter, whereas DT was longer in the group LD than in the groups A and B at the HR of more than 120 bpm. II) Ten healthy male subjects aged 19-22 years old performed submaximal exercise to clarify the relations between any two of QS<SUB>2</SUB>, the left ventricular ejection time (LVET) and the preejection period (PEP) at the same HR: there were positive and negative significant correlations between QS<SUB>2</SUB> and LVET, and between LVET and PEP, respectively, at the HR of more than 100 bpm. These results reveal that, when the HR is increased in exercise, the left ventricular systolic time (QS<SUB>2</SUB>) is shortened while the diastolic time is lengthened for the subjects trained as long distance runners. The shortening of the systolic time is mainly caused by shortening of LVET. The changes in the systolic and diastolic times suggest that contractility of cardiac muscle is enhanced during exercise of above moderate intensity after an extensive period of the aerobic training.
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In order to study the characteristics of the early cardiovascular responses following the occlusion of the superior mesenteric artery, occlusion of the artery was perfomed on 7 dogs, and sham operation on 6 dogs to serve as control- It was found that after the release of the occlusion 2 hours later, the mean arterial pressure and the central venous pressure of the experimental group dropped significantly. Comparable changes could not be observed in the controls. Meanwhile, the parameters of left ventricular functions such as left ventricular systolic pressure, + dp/dt max, = dp/dt max, Q-dp/dt max interval, and the product of 3 items(cardiac rate, Q-dp/d max interval and the peak value of left ventricular pressuure) showed no difference between the 2 groups.The results suggest that the general functional derangement of the cardiovascular system can be ascribed to the pooling of blood and/or fluid in the splanchnic area, and the adnormal myocardial performance does not appear in the initial phase of superior mesentric artery occlusion.
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The purpose of this clinical investigation is to analyse the growth of the ventricular volumes and the changes of indices of cardiac performance during infancy and childhood. The materials were composed of 129 healthy infants and children (4 months to 13 years of age), who had a history of Kawasaki disease and without any evidence of coronary artery lesion. All the cases underwent cardiac catheterization and cineangiography under sedation. Volumes of the left and right ventricles were calculated by integration methods in tow frames for end-diastole and end-systole from biplane cineangiograms. Left ventricular mass was calculated in 120 infants and children by Rackley's method.<BR>All the volumes and masses were deviled by body surface area in order to normalize the crude values for infants and children of different size. The mean values of left ventricular end-diastolic volume index (LVEDVI), right ventricular end-diastolic volume index (RVEDVI) and stroke index (SI) for each age were less in the younger children than those in the older children, and abrupt stepwise increase was observed at 1 year, 6 years and 10-11 years of age in the values of LVEDVI, RVEDVI and SI.<BR>The infants and chidren were divided into four groups according to age (under 1 year, 1 to 5 years, 6 to 10 years and more than 11 years) . The values of LVEDVI, RVEDVI, SI and LVmass index were less in the younger age groups than those in the older age groups, and the difference of each age groups was statistically significant. The value of left ventricular ejection fraction (LVEF) was less in the youngest group (under 1 year) than those in the another groups (p<0.01) . The value for right ventricular ejection fraction (RVEF) was not significantly different in the age groups. End-systolic pressure-volume ratio was normalized with left ventricular mass (LVESP/ (LVESV/LVmass) ) . This normalized ratio was the lowest in the youngest group (under 1 year) and the highest in the oldest group (more than 11 years) .<BR>As mentioned before, abrupt stepwise increase was observed in the“normal”values of LVEDVI, RVEDVI and SI in infancts and children. The explanation of this fact may be difficult at present. By the evidence of the normalized end-systolic pressure-volume ratio, it can be said that the contractility of the left ventricle in“healthy”infants and children was increased according to age. The reason why the value of LVEF was less in the youngest group than those in the another groups can be attributed to the lower contrac-tility in the youngest group. A possible factor that the value of RVEF was not significantly different between the youngest group and the another groups is; because the right ventricle works under higher pressure during fetal and neonatal period, then the right ventricular performance developed already in infancy.
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0. 05) The above results show that TFH canstrengthen myocardial contractility and pumpfunction of the heart, reduce total peripheral vas-cular resistance and increase vascular clasticity innormal subjects