Increased negativity of interstitial fluid pressure contributes to development of oedema in rat skin following application of xylene.

Intradermal interstitial fluid pressure (Pi) has been studied in rat skin during formation of inflammatory oedema caused by application of xylene. Pi was measured with sharpened micropipettes connected to a servocontrolled counter-pressure system. Control Pi averaged -1.3 +/- 0.6 (SD) mmHg. Following xylene application Pi decreased to -5.0 mmHg after 5 min and then increased to stabilize at about 0 mmHg at 45-60 min and later. When the transvascular fluid shifts accompanying the inflammatory reaction were prevented by inducing circulatory arrest prior to xylene application, Pi fell to -7.5 mmHg within 5 min and remained at this level throughout the observation period of 90 min. Aprotinin in large doses (80,000 KIE kg-1) before xylene application reduced the fall in Pi, whereas indomethacin had no effect. The increased negativity in Pi will add directly to a normal transcapillary net filtration pressure of about 0.5 mmHg, resulting in a 10- to 20-fold increase in this pressure. The present experiments therefore suggest that the interstitium plays an active role in oedema formation in the initial phase of xylene-induced inflammation in rat skin through the development of an increased negativity of Pi.     

Oedema-preventing mechanisms in a low-compliant tissue: studies on the rat tail

The long-term effect of elevated tail venous pressure (Pv) on interstitial fluid pressure (Pi) and colloid osmotic pressure (COPi) was studied in rats. Measurements were performed on different rats after 1-5 days of congestion, and on a sham operated control group. Two different degrees of venous stasis were obtained by means of graded ligation of tail veins and skin. Moderate degree of ligation (group 1) caused no visual oedema. More extensive ligation (group 2) gave marked oedema already on day 1 and further progression and exudation from the skin during the following 3 days. Tail venous pressure was measured by micropuncture and interstitial fluid pressure by the wick-in-needle technique. Interstitial fluid was sampled by a dry wick method, and colloid osmotic pressure was measured with a membrane osmometer. In group 1, Pv had increased from 6.5 to 21.5 mmHg on day 1, and thereafter remained unchanged. Interstitial fluid pressure increased from 3.4 to 16.9 mmHg after ligation and to 19.2 mmHg on day 1. Colloid osmotic pressure fell from 11.7 to 5.8 mmHg. From day 1, both interstitial fluid pressure and colloid osmotic pressure remained largely unchanged. In group 2 rats, tail venous pressure increased to 33.0 and 36.3 mmHg on day 1 and 2 and then fell towards control level during the following 3 days. Interstitial fluid pressure increased to 22.9 and 31.4 mmHg before a rapid decline towards control level. Colloid osmotic pressure was reduced from 11.7 to 5.6 mmHg. We conclude that hydrostatic counterpressure may provide an oedema-preventing effect of up to about 15 mmHg.(ABSTRACT TRUNCATED AT 250 WORDS)     

Implantation of a Jarvik 2000 left ventricular assist device as a bridge to eligibility for refractory heart failure with renal dysfunction

A 55-year-old man, who previously underwent surgical ventricular restoration and mitral valve surgery, was referred to our department for management of refractory heart and multiple organ failure. At the time of admission to our hospital, he could not be registered as a candidate for heart transplantation because of severe renal failure with a serum creatinine level of 4.6 mg/dl. We considered that he was a marginal candidate for heart transplantation; thus, it was essential to understand the etiology of renal failure and estimate whether it was reversible. Cardiac catheterization revealed poor hemodynamic function with a systemic pressure of 107/60 mmHg, cardiac index of 2.5 l/min/m(2), and pulmonary artery pressure of 63/27 mmHg, despite intense medical treatment. Contrary to biochemical examination findings of blood, renal biopsy findings showed no significant glomerular abnormality. Furthermore, the severity of tubular atrophy and interstitial fibrosis in the cortex was mild. These pathological findings suggested that the renal dysfunction in this case was possibly attributable to a hemodynamic factor. His symptoms gradually deteriorated despite an increasing dose of inotropic support; thus, we planned implantation of a Jarvik 2000 axial-flow pump (Jarvik Heart Inc., New York, NY, USA) as a bridge to eligibility, and informed consent was obtained. Because of a tight adhesion on the anterior wall, we placed the device on the lateral wall of the left ventricle, making sure not to direct the pump at the septum. Postoperatively, the implantable left ventricular assist device provided relief from heart failure symptoms as well as recovery of renal function, with serum the creatinine level at 1.2 mg/dl, which allowed the patient to become an appropriate candidate for heart transplantation. At an 18-month follow-up examination, his status was uneventful, and he is now at home awaiting heart transplantation.     

The venous pump of the human foot

Pressures in the flexor digitorum muscle, posterior tibial and anterior tibial muscles and subcutaneous pressure in the lower leg were recorded in 18 volunteers with a non-infusion technique. The venous plexus of the sole of the foot was compressed by a pneumatic foot pump. Activation of this device creates oscillations of intramuscular and subcutaneous interstitial fluid hydrostatic pressure in the lower leg. The mechanism for this is explained by intermittent passive muscle stretch. The interstitial fluid pressure decreased following active muscle contractions during venous stasis of the limb, but not following activation of the pneumatic pump. Although the pneumatic foot pump may on theoretical grounds be useful in early treatment of postoperative and post-traumatic oedema of the leg, complementary studies are necessary to establish its effectiveness.     

Hemodynamics of a functional centrifugal-flow total artificial heart with functional atrial contraction in goats

Implantation of a total artificial heart (TAH) is one of the therapeutic options for the treatment of patients with end-stage biventricular heart failure. There is no report on the hemodynamics of the functional centrifugal-flow TAH with functional atrial contraction (fCFTAH). We evaluated the effects of pulsatile flow by atrial contraction in acute animal models. The goats received fCFTAH that we created from two centrifugal-flow ventricular assist devices. Some hemodynamic parameters maintained acceptable levels: heart rate 115.5 ± 26.3 bpm, aortic pressure 83.5 ± 10.1 mmHg, left atrial pressure 18.0 ± 5.9 mmHg, pulmonary pressure 28.5 ± 9.7 mmHg, right atrial pressure 13.6 ± 5.2 mmHg, pump flow 4.0 ± 1.1 L/min (left) 3.9 ± 1.1 L/min (right), and cardiac index 2.13 ± 0.14 L/min/m². fCFTAH with atrial contraction was able to maintain the TAH circulation by forming a pulsatile flow in acute animal experiments. Taking the left and right flow rate balance using the low internal pressure loss of the VAD pumps may be easier than by other pumps having considerable internal pressure loss. We showed that the remnant atrial contraction effected the flow rate change of the centrifugal pump, and the atrial contraction waves reflected the heart rate. These results indicate that remnant atria had the possibility to preserve autonomic function in fCFTAH. We may control fCFTAH by reflecting the autonomic function, which is estimated with the flow rate change of the centrifugal pump.     

The contribution of alterations in cardiac output to changes in arterial pressure reflexly evoked from the carotid sinus in the rabbit.

1. The reflex cardiovascular effects of changes in pressure within the vascularly isolated carotid sinus were examined in seventeen anaesthetized rabbits. The opposite sinus was denervated and both aortic nerves were divided, 2. Comparison of the mean values at sinus pressures of 40 and 200 mmHg showed a large reduction in systemic arterial pressure from 126 to 58 mmHg and a moderate reduction in heart rate, from 287 to 253 beats min-1. Cardiac output, measured by thermal dilution, showed only a small change, a fall from 160 to 148 ml. min-1 kg-1. 3. By contrast with this reduction in cardiac output of just over 7%, total peripheral resistance, derived by dividing mean arterial pressure by cardiac output, was halved, falling from 0-48 to 0-41 mmHg ml.-1 min kg. 4. Thus in the anaesthetized rabbit changes in cardiac output make only a small contribution to the changes in systemic pressure evoked by alterations in carotid sinus pressure. Changes in total peripheral resistance are principally responsible for the effect on systemic pressure. 5. Though the changes in output of the heart were small, there were considerable changes in the work done by the left ventricle which was approximately halved when carotid sinus pressure was raised from 40 to 200 mmHg.     

Portopulmonary hypertension due to schistosomiasis in two Malagasy patients

Portopulmonary hypertension is characterized by a chronic liver disease associated with a mean pulmonary artery pressure >25 mmHg at rest, an increased pulmonary vascular resistance and a capillary pulmonary pressure <15 mmHg with portal hypertension. Schistosomiasis may be an aetiology of this syndrome, however, few cases have been reported. We describe the first cases of portopulmonary hypertension with schistosomiasis in Malagasy patients. There were 2 men aged of 18 and 20 from hyperendemic area of schistosomiasis in Madagascar Both had a history of repeated water contact. They presented a dyspnea associated with ascites and oedema. Clinical examination showed portal and pulmonary hypertension with right ventricular heart failure. Cardiac examination revealed a systolic murmur and splint of the second heart pulmonary Pulmonary hypertension was confirmed by cardiac ultrasonogaphy Serology of bilharzias was positive. Parasitological examination showed eggs of S. mansoni. The treatment based on salt-free diet, spironolactone and praziquantel led to a better evolution of symptoms (case 1). Symptoms of right heart failure remained for the second patient even though improvement was noted. In tropical countries, schistosomiasis may be one of the cause of portopulmonary hypertension and may appear in early age. Its treatment remains difficult as the drugs recommended are not affordable.     

The heart-pump interaction: effects of a microaxial blood pump

BACKGROUND: When we use rotary blood pumps as an assist device, an interaction takes place between the pump performance and the native heart function (native heart influences pump performance and vice versa). The interaction between native heart and rotary blood pump can be useful to predict recovery of the failing heart. METHODS: The rotary blood pumps used were microaxial catheter-mounted pumps with an external diameter of 6.4 mm (Impella, Aachen, Germany). The pump-heart interaction was studied in five juvenile sheep with a mean body weight of 68.5 +/- 8.7 kg. The pumps were introduced via the left carotid artery and placed in transvalvular aortic position. Recorded parameters were pump speed (rpm), generated flow (L/min) and differential pressure (mm Hg) obtained at high frequency rate of data recordings (25 sets of data per second). This allowed continuous analysis of the pump performance during cardiac cycle. Under clinical conditions the interaction was studied in a 60-year-old male, in whom the device was applied due to postcardiotomy heart failure after myocardial infarction. RESULTS: Heart-pump interaction was analyzed based on pump flow differential pressure. This relationship, analyzed continuously during cardiac cycle, presents as a loop. The dynamic contribution of the heart to the flow generated by the pump leads to continuous fluctuation in the pressure head and the creation of hysteresis. The improved function of the failing heart under clinical conditions after seven days of mechanical support was expressed by: increased hysteresis of the loop caused by increased gradient of flow generated during cardiac cycle, a more pronounced venticular ejection phase that indicates more dynamic heart contribution to the generated flow, and finally increased gradient of the differential pressure during cardiac cycle, caused predominantly by increased aortic pressure and decreased left ventricle pressure during diastolic phase. CONCLUSIONS: The heart-pump interaction based on the pump flow-differential pressure relationship can be useful in predicting the possibility to wean the patient from the device.     

Brady- and tachycardia in light of the Valsalva and the Mueller maneuver (apnea)

With a computerized impedance cardiograph we measured stroke volume (sv), cardiac output and heart rate (HR) in four men, during apnea with positive or negative intrapulmonic pressure (i.e., Valsalva and Mueller maneuver) in air. During Valsalva maneuvers the sv was reduced, and the compensatory rise in HR failed to keep the cardiac output at the control level before apnea. During both types of apnea, the diastolic pressure was increased as was the total peripheral resistance (TPR). The vasoconstriction and tachycardia during Valsalva maneuvers can be explained as a sino-aortic baroreceptor phenomenon in man. The smaller changes occurring during Mueller maneuvers result in no change in the transmural arterial pressure in the thorax, compared to the control level. Thus, without a stimulus there is no change in heart rate. The alveolar oxygen uptake and carbon dioxide elimination during apnea at total lung capacity was much larger than in the control phase before both types of apnea. The arteriolar vasoconstriction with increased TPR during the Valsalva apnea, was accompanied by a reduction in the stroke work of the left ventricle to approximately 50% of the work in the control phase.     

Reevaluation of the needle method for measuring interstitial fluid pressure.

Inserting a needle into subcutaneous spaces should allow a subatmospheric pressure to be measured if interstitial fluid pressure is truly negative as measured by the capsule and wick techniques. Previous needle measurements of interstitial fluid pressure have produced a positive value, but in most instances fluid has been injected into the tissues prior to recording of pressure. Therefore, we measured subcutaneous needle pressure in anesthetized dogs without fluid injection into the tissues. Approximately 30 min are required for an equilibrium pressure after insertion of the needle. The mean 30-min pressure was 4.6 +/- 0.5 (SE) mmHg (n equals 41). With observable edema, interstitial fluid pressures as measured with the needle were always positive. However, the needle method for continuous recording of pressure lacks rapid sensitivity to changes in tissue fluid pressures. In order to develop a needle method that would follow changes in interstitial fluid pressure, 0.5-1 mul of saline was injected into or withdrawn from the tissue. With this method, pressure plateaued in 10-20 min. This plateau pressure increased with tissue hydration and decreased with dehydration.     

Loss or inhibition of uPA or MMP-9 attenuates LV remodeling and dysfunction after acute pressure overload in mice

Left ventricular (LV) hypertrophy is a natural response of the heart to increased pressure loading, but accompanying fibrosis and dilatation may result in irreversible life-threatening heart failure. Matrix metalloproteinases (MMPs) have been invoked in various cardiac diseases, however, direct genetic evidence for a role of the plasminogen activator (PA) and MMP systems in pressure overload-induced LV hypertrophy and in heart failure is lacking. Therefore, the consequences of transverse aortic banding (TAB) were analyzed in mice lacking tissue-type PA (t-PA(-/-)), urokinase-type PA (u-PA(-/-)), or gelatinase-B (MMP-9(-/-)), and in wild-type (WT) mice after adenoviral gene transfer of the PA-inhibitor PAI-1 or the MMP-inhibitor TIMP-1. TAB elevated LV pressure comparably in all genotypes. In WT and t-PA(-/-) mice, cardiomyocyte hypertrophy was associated with myocardial fibrosis, LV dilatation and dysfunction, and pump failure after 7 weeks. In contrast, in u-PA(-/-) mice or in WT mice after PAI-1- and TIMP-1-gene transfer, cardiomyocyte hypertrophy was moderate and only minimally associated with cardiac fibrosis and LV dilatation, resulting in better preservation of pump function. Deficiency of MMP-9 had an intermediate effect. These findings suggest that the use of u-PA- or MMP-inhibitors might preserve cardiac pump function in LV pressure overloading.     

Effect of longstanding venous stasis and hypoproteinaemia on lymph flow in the rat tail

This study was performed to provide information on the determinants of lymph flow by comparing the effect of venous stasis and hypoproteinaemia in the rat tail. This low-compliant tissue was chosen in an attempt to induce preferential changes in interstitial pressure or volume. The removal rate (kAlb) of 125I-labelled human serum albumin (I-HSA) injected subcutaneously was monitored with external gamma-counting equipment and used as a measure of lymph flow. Interstitial fluid hydrostatic pressure (Pi) was measured with wick-in-needle technique, and interstitial fluid was collected post mortem by dry wicks. Colloid osmotic pressure of plasma (COPp) and wick fluid (COPi) was measured with a colloid osmometer. In a separate group of experiments, 51Cr-EDTA and [125I]HSA were used to measure the interstitial fluid volume. Venous stasis, induced by bilateral ligation of the external tail veins, increased interstitial fluid hydrostatic pressure from 1.7 to 16 mmHg and kAlb from 0.030 to 0.063 h-1, whereas tail circumference was nearly constant. Interstitial volume averaged 1.17 ml/g dry weight in control animals and 1.27 ml/g during increased venous pressure. Daily injections of aminonucleoside in salt-loaded rats (0.3% NaCl as drinking water) reduced colloid osmotic pressure of plasma from 19.1 to 8.5 mmHg and of wick fluid from 11.2 to 2.9 mmHg, while interstitial fluid hydrostatic pressure increased to 5.2 mmHg. The removal rate of 125I-labelled human serum albumin increased to 0.113 h-1, compared to 0.051 h-1 in salt-loaded controls. The interstitial volume showed a marked increase in salt-loaded hypoproteinaemic rats, 1.75 ml/g dry weight, compared to 1.30 ml/g in salt-loaded controls.(ABSTRACT TRUNCATED AT 250 WORDS)     

Myocardial performance and collateral flow after transient coronary occlusion in exercising dogs.

Fourteen dogs with prior constriction of the left circumflex (LCf) coronary artery were studied at rest and during treadmill running. Hemodynamics were measured before and after a 1-min LCf occlusion. Coronary and collateral flows were quantitated during occlusion both at rest and during exercise. Group I consisted of 4 dogs with resting collateral flow exceeding one-half (average 78%) of normal flow, and group II consisted of 10 dogs with collateral flows less than one-half (average 30%) of normal. At rest LCf occlusion caused no hemodynamic changes in group I, but stroke volume fell significantly in group II. During running, collateral flow after LCf occlusion doubled in group I, and there was only a small rise in left atrial pressure to 18 mmHg. In group II, collateral flow increased by 50% during running and actually decreased in 4 dogs. Significant cardiac failure developed as stroke volume halved, and left atrial pressure rose to an average 30 mmHg. Therefore exercise-induced depression of left ventricular function in the ischemic heart can be correlated to the amount of coronary collateral flow.     

Influence of Age on Sensitivity and Effector Mechanisms of the Carotid Baroreflex

In 30 healthy subjects aged 20–48 years the hemodynamic response to carotid sinus stimulation (neck suction -40 mmHg) was studied. Heart rate, arterial pressure and cardiac output (dye dilution technique) were measured. In order to evaluate the effect of age on carotid sinus function the material was subdivided into two arbitrary subgroups, aged up to 30 years (n = 15) respectively 30 years and above (n = 15). Carotid sinus stimulation induced a significantly greater reduction in mean arterial pressure in the younger group compared to the older group. The heart rate reduction was, on the average, slightly greater in the younger group though the difference was not significant. In both groups a significant decrease in cardiac output contributed to the demonstrated reduction in mean arterial pressure. As the decrease in cardiac output was, on the average, slightly smaller in the younger group, the results indicate that the greater blood pressure response in the younger group was due to a greater reduction in peripheral vascular resistance. This is further supported by the finding of a significant correlation between changes in total peripheral vascular resistance, elicited by carotid sinus stimulation and age.     

Analysis of the relationship between left ventricular pressure and motor current for evaluation of native cardiac function during left ventricular support with a centrifugal blood pump

Control of the ventricular assist device (VAD) for native heart preservation should be attempted, and the VAD could be one strategy for dealing with the shortage of donors in the future. In the application of nonpulsatile blood pumps for ventricular assistance from the ventricular apex to the aorta, bypass flow and hence the motor current of the pumps change in response to the ventricular pressure change. Utilizing these intrinsic characteristics of the continuous-flow pumps, in this study we investigated whether motor current could be used as an index for continuous monitoring of native cardiac function. In study 1, a centrifugal blood pump (CFP) VAD was installed between the apex and descending aorta of a mock circulatory loop. In this model, a baseline with a preload of 10 mmHg, afterload of 40 mmHg, and LV systolic pressure of 40 mmHg was used. The pump speed was fixed at 1300, 1500, and 1700 rpm, and LV systolic pressure was increased up to 140 mmHg by steps of 20 mmHg while the changes in LV pressure, motor current, pump flow, and aortic pressure were observed. In study 2, an in vivo experiment was performed using three sheep. A left heart bypass model was created using a centrifugal pump from the ventricular apex to the descending aorta. The LVP was varied through administration of dopamine while the changes in LV pressure, pump flow, and motor current at 1500 and 1700 rpm were observed. An excellent correlation was observed in both in vitro and in vivo studies in the relationship between motor current and LV pressure. In study 1, the correlation coefficients were 0.77, 0.92, and 0.99 for 1300, 1500, and 1700 rpm, respectively. In study 2, they were 0.88 (animal no. 1), 0.83 (animal no. 2), and 0.88 (animal no. 3) for 1500 rpm, and 0.95 (animal no. 2) and 0.93 (animal no. 3) for 1700 rpm. These results suggest that motor current amplitude monitoring could be useful as an index for the control of VAD for native heart preservation.     

Measurement of hemodynamic changes with the axial flow blood pump installed in descending aorta

We have developed various axial flow blood pumps to realize the concept of the Valvo pump, and we have studied hemodynamic changes under cardiac assistance using an axial flow blood pump in series with the natural heart. In this study, we measured hemodynamic changes of not only systemic circulation but also cerebral circulation and coronary circulation under cardiac support using our latest axial flow blood pump placed in the descending aorta in an acute animal experiment. The axial flow blood pump was installed at the thoracic descending aorta through a left thoracotomy of a goat (43.8 kg, female). When the pump was on, the aortic pressure and aortic flow downstream of the pump increased with preservation of pulsatilities. The pressure drop upstream of the pump caused reduction of afterload pressure, and it may lead to reduction of left ventricular wall stress. However, cerebral blood flow and coronary blood flow were decreased when the pump was on. The axial flow blood pump enables more effective blood perfusion into systemic circulation, but it has the potential risk of blood perfusion disturbance into cerebral circulation and coronary circulation. The results indicate that the position before the coronary ostia might be suitable for implantation of the axial flow blood pump in series with the natural heart to avoid blood perfusion disturbances.     

肾交感神经去除术对心肌肥厚和心肌纤维化的影响

 目的:观察肾交感神经去除术（renal sympathetic denervation, RDN）对心肌肥厚和心肌纤维化的影响,并探讨其可能机制。方法:选用12周龄的健康SD雄性大鼠60只,随机分为假手术组、假手术+RDN组、主动脉缩窄组、主动脉缩窄+RDN组,8周后用介入生理记录仪检测血流动力学和心功能指标,HE染色、苦味酸-天狼星红染色分别观察心肌肥厚和心肌纤维化情况,放射免疫分析法测量血浆肾上腺素浓度、肾素活性、血管紧张素II浓度及心脏血管紧张素II含量。结果:与主动脉缩窄组相比,RDN可显著改善主动脉缩窄大鼠心脏舒张功能［左室舒张末期压力（LVEDP）：(8.03±1.66) mmHg vs(15.77±2.14) mmHg;等容舒张期左室压力下降最大速率（-dp/dt）：(7 793±587) mmHg/s vs(6 353±475) mmHg/s;P＜0.01］、防止其心肌肥厚和纤维化［左心室重量指数：3.340±0.121 vs4.244±0.102;心肌细胞面积：(332.9±28.9) μm2 vs(401.6±33.2) μm2;胶原容积分数：7.76%±0.85% vs12.48%±1.82%;P＜0.01］。然而,RDN不能降低主动脉缩窄大鼠的血压（P＞0.05）。RDN导致主动脉缩窄大鼠的血浆肾上腺素浓度、肾素活性、血管紧张素II浓度及心脏血管紧张素II含量均明显减少（P＜0.01）。结论: RDN可以通过降低交感和肾素-血管紧张素系统活性直接抑制心肌肥厚和心肌纤维化,从而改善心脏功能。     

Effect of “Vein Pump” Activation upon Venous Pressure and Blood Flow in Human Subcutaneous Tissue

The effect of “vein pump” activation upon superficial venous pressure and blood flow in human subcutaneous adipose tissue was studied in 6 normals and 2 patients with venous insufficiency. Blood flow in subcutaneous tissue was measured at the lateral malleolus by the local ¹³³Xenon washout technique. with the subject placed in a supine position. During passive lowering of the leg blood flow decreased 50 per cent and total vascular resistance increased 136 per cent. Activation of the vein pump by continuously tipping the foot up and down caused a decrease in venous pressure of 5 mmHg in horizontal position. Venous pressure increased only by 8 mmHg when the leg was lowered during exercise. In this situation blood flow remained constant corresponding to an increase in vascular resistance of 42 per cent. However increasing venous pressure to 28 mmHg by venous stasis in the lowered leg during exercise caused an additional increase in vascular resistance of 82 per cent. In the patients with venous insufficiency exercise did not prevent the decrease in blood flow during lowering of the leg. Hence venous pressure elevation of 25 mmHg or more caused an additional increase in vascular resistance in subcutaneous tissue, “vasoconstrictor response”. It is concluded that this “vasoconstrictor response” depends on a vasoconstrictor impulse transmission from veins to arterioles, veno-arteriolar reflex.     

慢性高输出量型心功能不全发展过程中心室舒、缩功能和顺应性的变化及其与心泵功能的关系

本文研究了大鼠慢性高输出量型心功能不全发展过程中心室舒,缩功能和顺应性的变化规律及其与心泵功能的关系。疾病模型采用动静脉造瘘(ACF)加单侧肾动脉缩窄(RAS)的方法建立。本实验中,全部ACF+RAS大鼠均呈现出慢性高输出量型心功能不全的特征,在静息状态下心脏指数(CI)显著升高,而心泵贮备功能(CORF)却不同程度地降低。结果表明:随心泵功能的恶化,心室的舒、缩功能进行性降低,心室的舒张顺应性显著升高,心室的舒,缩性能和顺应性在心功能不全发展的不同阶段对心泵功能所起的作用不同。     

Arm and ankle blood pressure response to treadmill exercise in normal people

Nineteen healthy volunteers, 10 men and nine women (mean age 38 and 30 years), exercised on a treadmill. The systolic blood pressure (BP) was measured at the ankle and in the arm after submaximal (8 min with a final load of 2 W kg-1 body weight) and maximal exercise. The BP was measured for 10 min after exercise, or until the elimination of a negative pressure difference between ankle and arm. The pre-study resting systolic arm and ankle pressures were 122 +/- 11 and 144 +/- 13 mmHg. One minute after submaximal exercise, arm and ankle BP were 147 +/- 18 and 159 +/- 19 mmHg (ankle-arm pressure difference 12 +/- 13 mmHg); 1 min after maximal exercise the corresponding figures were 182 +/- 26 and 153 +/- 35 mmHg (ankle-arm pressure difference -29 +/- 33 mmHg). We conclude that maximal exercise, but not an appropriately chosen submaximal exercise level, causes a negative BP difference between ankle and arm in normal people.