Parameters of the left ventricular performance were evaluated by echocardiographic examination in 66 normal subjects. Effects of pulse rate, systemic arterial pressure, peripheral resistance and left ventricular end-diastolic dimension on the parameters were also observed. Normal value(mean+/-SD) of fractional shortening was 34.0+/-5.2%, ejection fraction 0.71+/-0.07, mean rate of circumferential fiber shortening 1.15+/-0.19 circ/sec, mean posterior wall velocity 4.05+/-0.70cm/sec, maximal posterior wall velocity 6.31+/-1.26cm/sec, mean normalized posterior wall velocity 0.82+/-0.14/sec, and maximal normalized posterior wall velocity 1.28+/-0.24/sec. There were negative correlations of peripheral resistance to fractional shortening, ejection fraction and mean rate of circumferential fiber shortening. Pulse rate and left ventricular end-diastolic dimension did not have significant effects on these parameters. Mean and maximal posterior wall velocity had negative correlations to peripheral resistance and positive correlations to left ventricular end-diastolic dimension. But mean and maximal normalized posterior wall velocity had no correlations to any of them.
Arterial Pressure ; Echocardiography* ; Heart Rate ; Vascular Resistance

PURPOSE: The purpose of this study was to determine the value of the intrarenal resistive index (RI),measured by Doppler sonography, in order to assess intrarenal vascular resistance in autosomal dominant polycystickidney disease (ADPKD) patients. MATERIALS AND METHODS: In 26 patients with ADPKD, RI was measured by Dopplersonography and correlated with the presence of hypertension, renal function (creatinine clearance) and anatomicalrenal severity index (RSI), thus indicating renal morphologic abnormalities during B-mode sonography . RESULTS:RI was significantly higher in 18 hypertensive ADPKD patients (0.64+/-0.65) (Mean+/-1SD; range: 0.52-0.74) than ineight normotensive patients (0.59+/-0.50) ( 0.48-0.64) (p<0.05). Statistically significant inverse correlation wasfound between RI values and creatinine clearance (r=-0.45, p<0.05), and statistically significant correlation wasfound between RI values and RSI, indicating the degree of renal parenchymal involvement. CONCLUSION: RIcorrelates with the development of hypertension, renal function and renal morphologic abnormality scoring by RSIduring B-mode Doppler sonography, and measured in this way may thus be used to assess renal vaseular resistance inADPRD patients.
Creatinine ; Humans ; Hypertension, Renal ; Polycystic Kidney, Autosomal Dominant* ; Vascular Resistance

BACKGROUND: Vestibular reflexes, such as vestibulo-sympathetic reflex, have been considered as an important physiologic mechanism to maintain peripheral vascular resistance in case of orthostatic stress. Vestibular function may play an important role not only in maintaining spatial orientation, but also in determining G-tolerance. The purpose of this study was to investigate the possible contribution of vestibular function to G-tolerance. METHODS: Vestibular function was measured indirectly in 86 subjects by analyzing vestibulo-ocular reflex (VOR) using a rotating chair test. They were also exposed to +6Gz acceleration for 30 seconds with rapid onset run (1 G/sec). After G-exposure, they were classified into the Pass and the G-LOC group according to their success or failure to maintain consciousness during G-exposure. The VOR parameters of the G-LOC group were compared with those of the Pass group. RESULTS: While VOR gain values of one subset of the G-LOC group (low gain G-LOC group, N=8) were significantly lower than those of the Pass group at rotation frequencies of 0.02, 0.04, 0.08, and 0.32 Hz, VOR gain values of the other subset of the G-LOC group (high gain G-LOC group) were significantly higher than those of the Pass group at all rotation frequencies. There was no difference of VOR phase value between the Pass and the G-LOC groups. CONCLUSIONS:This study suggests the vestibular function may be involved in determining G-tolerance. According to VOR gain values, we were able to recognize two distinct G-LOC subgroups compared with the Pass group. The difference between afferent or efferent vestibular flows and target organ response can be a possible explanation for different VOR parameters of G-LOC subgroups.
Acceleration ; Consciousness ; Reflex ; Reflex, Vestibulo-Ocular* ; Unconsciousness* ; Vascular Resistance

Univentricular heart, or single ventricle, is characterized by the entire flow from the two atria being carried directly through the left and right AV valves into the single ventricular chamber. According to the morphologic structure of the ventricle, univentricular heart is classified as left ventricular type, right ventricular type and rarely intermediate type. Natural survival depends primarily on factors that limit pulmonary blood flow, such as an increase in pulmonary vascular resistance or the presence of pulmonic stenosis. Other variables of survival include the morphologic type of single ventricle, the great artery anatomy and the adequacy of the atrioventricular connection. To our knowledge, this is first report in our country of a patient with single ventricle of left ventricular morphology who naturally survived into the second decade of life.
Arteries ; Heart* ; Humans ; Pulmonary Valve Stenosis ; Vascular Resistance

The ocular vascular resistance of the ciliary choroidal network has been investigated on measurements of pulse amplitude(PA). The ocular pulse is derived from the ciliary choroidal blood flow which account for more than 90% of the total ocular blood flow(OBF). In 5 normal Cynomolgus monkeys with topical application(50 micro l) of 2% epinephrine, the PA revealed a significant reduction(0.32 +/- 0.06mmHg, mean +/- SEM, p<0.01). In the other 5 normal Cynormlgus monkeys with 4% pilocarpine, the PA revealed no significant increment(0.32 +/- 0.15mmHg, mean +/- SEM, p<0.10) by the OBF system. These results suggest that topical application of epinephrine produces a significant reduction of OBR but pilocarpine produces a mild increment of OBF.
Choroid ; Epinephrine* ; Haplorhini ; Macaca fascicularis ; Pilocarpine* ; Vascular Resistance

The ocular vascular resistance of the ciliary choroidal network has been investigated on measurements of pulse amplitude(PA). The ocular pulse is derived from the ciliary choroidal blood flow which account for more than 90% of the total ocular blood flow(OBF). In 5 normal Cynomolgus monkeys with topical application(50 micro l) of 2% epinephrine, the PA revealed a significant reduction(0.32 +/- 0.06mmHg, mean +/- SEM, p<0.01). In the other 5 normal Cynormlgus monkeys with 4% pilocarpine, the PA revealed no significant increment(0.32 +/- 0.15mmHg, mean +/- SEM, p<0.10) by the OBF system. These results suggest that topical application of epinephrine produces a significant reduction of OBR but pilocarpine produces a mild increment of OBF.
Choroid ; Epinephrine* ; Haplorhini ; Macaca fascicularis ; Pilocarpine* ; Vascular Resistance

Renal blood flow was measured by single injection technique of HippuranI13 in 13 patients with chronic glomerulonephritis and 11 control subjects. There was a significant decrease in renal blood flow in chronic glomerulonephritis particulary in those with elevated blood urea nitrogen. Renal blood flow was inversely proportionate to renal vascular resistance but no correlation was noted between renal blood flow and creatinine clearance.
Blood Urea Nitrogen ; Creatinine ; Glomerulonephritis* ; Humans ; Renal Circulation* ; Vascular Resistance

OBJECTIVETo investigate the impacts of metabolic syndrome (MS) on endothelial function and target organ damage in hypertensive patients.

METHODSPatients with essential hypertension (EH) were divided into two groups: hypertension and metabolic syndrome (EH + MS, n = 61), hypertension without metabolic syndrome (EH + nonMS, n = 95) and 31 healthy subjects served as normal control (NC). The change of brachial artery vascular diameter, blood flow volume and vascular resistance after reactive hyperemia were measured by color Doppler ultrasonography.

RESULTS(1) Triglyceride (TG), fasting blood glucose (FBG), body mass index (BMI) were higher in EH + MS group than that in EH + nonMS group (P < 0.05). (2) Endothelium-dependent Dilatation (FMD%) and rate of flow volume of reactive hyperemia were significantly lower in EH + MS group than that in EH + nonMS and NC group [(7.08 +/- 3.21)% vs. (8.18 +/- 1.74)% and (10.41 +/- 4.52)%, P < 0.05 and 0.01 respectively; (154.19 +/- 78.94)% vs. (196.44 +/- 64.22)% and (221.81 +/- 89.64)%, P < 0.05 and 0.01 respectively], while these parameters were similar between EH + nonMS and NC groups (P > 0.05). (3) The high sequence of forearm dilatation capability was also significantly reduced in EH + MS group compared to other groups. (4) The incidences of carotid atherosclerotic plaque and left ventricular hypertrophy (LVH) were significantly increased in EH + MS group compared to EH + nonMS group and NC group. (5) FMD was correlated with age, gender, smoking, SBP, DBP, TG, Fib respectively (P < 0.05). Intima-media thickness (IMT) of carotid artery was positively related with age, smoking, SBP, DBP, BMI, TG, Fib respectively. The left ventricular mass index (LVMI) was positively related with age, smoking, SBP, DBP, BMI, TG respectively. FMD was negatively related with IMT and LVMI respectively (P < 0.01).

CONCLUSIONMetabolic syndrome further aggravated endothelial dysfunction and target organ damage in patients with essential hypertension.

Adult ; Aged ; Aged, 80 and over ; Endothelium, Vascular ; physiopathology ; Female ; Humans ; Hypertension ; complications ; physiopathology ; Hypertrophy, Left Ventricular ; etiology ; Insulin Resistance ; Male ; Metabolic Syndrome ; complications ; physiopathology ; Middle Aged ; Vascular Resistance

Eisenmenger's syndrome includes any condition in which communication between the pulmonary and systemic circulations gives rise to pulmonary vascular disease causing a right to left shunt with peripheral cynosis. The theoretical risks of anesthesia in patients with Eisenmenger's syndrome are considerable. We report on the case of a 47-year-old female patient with Eisenmenger's syndrome secondary to ventricular septal defect for transabdominal hysterectomy. Of prime concern was the maintenance of sytemic vascular resistance, and this was achieved using an infusion of phenylephrine started before the induction of anesthesia; the infusion continued after the operation. We carefully performed general anesthesia with N2O-O2-ketamine-fetanyl-enflurane. The patient was discharged for home 8 days later without complications.
Anesthesia ; Anesthesia, General ; Eisenmenger Complex* ; Female ; Heart Septal Defects, Ventricular ; Humans ; Hysterectomy ; Middle Aged ; Phenylephrine ; Vascular Diseases ; Vascular Resistance

OBJECTIVETo study the differences of cardiovascular system between men and women in response to exercise stress.

METHODSForty healthy youth were tested according to Bruce protocol of exercise stress. They were detected by ultrasonography during the rest, peak exercise, and recovery stages, respectively. The left ventricular diastolic elastance (Ed), effective arterial elastance (Ea), left ventricular end-systolic elatance (Ees), ventricular-vascular coupling index (VVI), and total stiffness index (TSI) were measured and calculated according to the formulas. The results of all stages were compared according to genders.

RESULTSAll stages, the Ed, TSI, and VVI of women were higher than those of men, but the Ees was lower than that of men (all P<0.05); there was no significant difference in Ea between men and women. The Ed, Ees, Ea, and TSI were closely related with left ventricular oxygen consumption and heart function, and women showed more closely. Before and after exercise, the changes were different in Ed, Ees, Ea, TSI, and VVI (all P<0.05), and VVI changed least.

CONCLUSIONSBefore and after exercise, the ventricular stiffness matched well with arterial stiffness and maintained within a narrow range. For women, the tolerance of exercise was lower than that of men.

Adult ; Diastole ; physiology ; Exercise ; physiology ; Female ; Humans ; Male ; Sex Characteristics ; Vascular Resistance ; physiology ; Vascular Stiffness ; physiology ; Ventricular Function, Left ; physiology