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PubMed2001

Hemodynamic effects on atherosclerosis-prone coronary artery: wall shear stress/rate distribution and impedance phase angle in coronary and aortic circulation.

The objective of the present study was to evaluate the hemodynamic characteristics of an atherosclerosis-prone coronary artery compared to the aorta. We describe three- dimensional spatial patterns of wall shear stress (WSS) according to the impedance phase angle in pulsatile coronary and aorta models using in vivo hemodynamic parameters and computed numerical simulations both qualitatively and quantitatively. Angiography of coronary arteries and aortas were done to obtain a standard model of vascular geometry. Simultaneously to the physiologic studies, flow-velocity and pressure profiles from in vivo data of the intravascular Doppler and pressure wire studies allowed us to include in vitro numerical simulations. Hemodynamic variables, such as flow-velocity, pressure and WSS in the coronary and aorta models were calculated taking into account the effects of vessel compliance and phase angle between pressure and flow waveforms. We found that there were spatial fluctuations of WSS and in the recirculation areas at the curved outer wall surface of the coronary artery. The mean WSS of the calculated negative phase angle increased in the coronary artery model over that in the aorta model and the phase angle effect was most prominent on the calculated amplitude of WSS of the coronary artery. This study suggests that the rheologic property of coronary circulation, such as the fluctuation of WSS/WSR induces several hemodynamic characteristics. A separation of flow-velocity, a difference in phase between pressure conductance and blood flow and prominent temporal and/or spatial oscillatory fluctuations of the shear forces as a function of pulsatile flow might be important factors in atherogenesis and progression of atherosclerosis.

Adult↗
PubMed1996

Effect of Doppler echocardiography on utilization of hemodynamic cardiac catheterization in the preoperative evaluation of aortic stenosis.

OBJECTIVE: To examine the use of Doppler echocardiography in preoperative assessment of aortic stenosis and to determine its effect on subsequent use of hemodynamic cardiac catheterization. MATERIAL AND METHODS: We retrospectively reviewed a consecutive series of 574 adult patients who underwent aortic valve replacement for aortic stenosis between 1990 and 1992 at our institution. The use of Doppler echocardiography and cardiac catheterization and the predictive factors for use of hemodynamic catheterization were analyzed. RESULTS: After Doppler echocardiography in 423 patients, invasive hemodynamic assessment of the severity of aortic stenosis was performed in only 42% (179 patients). The use of cardiac catheterization declined over time (54% in 1990, 40% in 1991, and 35% in 1992) (P = 0.003), whereas no significant change in the baseline clinical characteristics of the population or in severity of stenosis as determined by Doppler echocardiography occurred during that time. Multivariate analysis identified the following variables as independent predictors of use of cardiac catheterization after Doppler echocardiography: clinically not severe aortic stenosis, mean gradient of less than 50 mm Hg determined by Doppler echocardiography, Doppler-determined aortic valve area of more than 0.8 cm2 or not calculated, attending cardiologist not specialized in echocardiography, and earlier year of assessment. CONCLUSION: After Doppler echocardiography, less than 50% of our patients undergoing aortic valve replacement for aortic stenosis have cardiac catheterization preoperatively. The use of cardiac catheterization after Doppler echocardiography--thus, duplication of hemodynamic assessment--declined significantly over time during the study period. Decline in the use of catheterization is related to the degree of diagnostic certainty provided by Doppler echocardiography and to the level of familiarity of the attending cardiologist with the technique.

Adult↗
PubMed1989

Adverse hemodynamic and clinical effects of encainide in severe chronic heart failure.

STUDY OBJECTIVE: To evaluate the hemodynamic effects of the antiarrhythmic drug, encainide, in patients with severe chronic heart failure. DESIGN: Unblinded, before-after study. SETTING: Referral center for patients with heart failure. PATIENTS: Thirty patients with severe chronic heart failure and a left ventricular ejection fraction less than 40%. INTERVENTIONS: Invasive hemodynamic measurements were done (using a balloon-tipped thermodilution catheter) before and for 3 hours after a single oral dose of 50 mg of encainide. MEASUREMENTS AND MAIN RESULTS: Ninety to one hundred and twenty minutes after its administration, encainide produced a significant deterioration in cardiac performance, as reflected by a fall in cardiac index from 2.3 to 1.8 L/min.m2 body surface (mean change 0.5 +/- 0.1; P less than 0.001), a fall in stroke work index from 26 to 18 g.m/m2 (mean change 8 +/- 2; P less than 0.001), and an increase in left ventricular filling pressure from 19 to 22 mm Hg (mean change 3 +/- 2; P less than 0.05). These deleterious hemodynamic effects were accompanied by worsening symptoms of heart failure in 8 of the 30 patients. Serum levels of encainide and its metabolites, O-desmethylencainide and 3-methoxy-O-desmethylencainide, were within the therapeutic range in most patients. CONCLUSIONS: Encainide can cause adverse hemodynamic and clinical effects in patients with severe chronic heart failure.

Adult↗
PubMed1990

Bicarbonate does not improve hemodynamics in critically ill patients who have lactic acidosis. A prospective, controlled clinical study.

STUDY OBJECTIVE: To determine whether correction of acidemia using bicarbonate improves hemodynamics in patients who have lactic acidosis. DESIGN: Prospective, randomized, blinded, crossover study. Each patient sequentially received sodium bicarbonate and equimolar sodium chloride. The order of the infusions was randomized. SETTING: Intensive care unit of a tertiary care hospital. PATIENTS: Fourteen patients who had metabolic acidosis (bicarbonate less than 17 mmol/L and base excess less than -10) and increased arterial lactate (mean, 7.8 mmol/L). All had pulmonary artery catheters and 13 were receiving catecholamines. MEASUREMENTS AND MAIN RESULTS: Sodium bicarbonate (2 mmol/kg body weight over 15 minutes) increased arterial pH (7.22 to 7.36, P less than 0.001), serum bicarbonate (12 to 18 mmol/L, P less than 0.001), and partial pressure of CO2 in arterial blood (PaCO2) (35 to 40 mm Hg, P less than 0.001) and decreased plasma ionized calcium (0.95 to 0.87 mmol/L, P less than 0.001). Sodium bicarbonate and sodium chloride both transiently increased pulmonary capillary wedge pressure (15 to 17 mm Hg, and 14 to 17 mm Hg, P less than 0.001) and cardiac output (18% and 16%, P less than 0.01). The mean arterial pressure was unchanged. Hemodynamic responses to sodium bicarbonate and sodium chloride were the same. These data have more than 90% power of detecting a 0.5 L/min (7%) change in mean cardiac output after administration of sodium bicarbonate compared with that after sodium chloride. Even the 7 most acidemic patients (mean pH, 7.13; range, 6.90 to 7.20) had no significant hemodynamic changes after either infusion. CONCLUSIONS: Correction of acidemia using sodium bicarbonate does not improve hemodynamics in critically ill patients who have metabolic acidosis and increased blood lactate or the cardiovascular response to infused catecholamines in these patients. Sodium bicarbonate decreases plasma ionized calcium and increases PaCO2.

Acidosis, Lactic↗
PubMed1983

Physical examination for exclusion of hemodynamically important right ventricular infarction.

Fifty-three consecutive patients with inferior myocardial infarction were evaluated prospectively, by physical examination and right heart catheterization within 36 hours of the onset of symptoms, to determine whether physical findings can separate such patients into those with and without associated right ventricular infarction. Hemodynamic findings consistent with right ventricular infarction were defined as right atrial pressure of 10 mm Hg or greater and a right atrial: pulmonary artery wedge pressure ratio of 0.80 or greater. Eight patients (Group 1) had hemodynamic evidence of right ventricular infarction, whereas 45 patients (Group 2) did not meet these criteria. Group 1, compared with Group 2, had a lower cardiac index (1.8 +/- 0.3 versus 2.6 +/- 0.6 L/min X m2, p less than 0.001), and a lower right ventricular stroke work index (4.1 +/- 3.6 versus 7.3 +/- 3.2 g X m/m2, p less than 0.05). An elevated jugular venous pressure of 8 cm H2O or more was seen in 7 of 8 Group 1 and 14 of 45 Group 2 patients (p less than 0.01). In addition, a Kussmaul's sign, substantiated by hemodynamic findings, was seen in all 8 Group 1 and in no Group 2 patients (p less than 0.001). The absence of both an elevated jugular venous pressure and a Kussmaul's sign in patients with inferior myocardial infarction makes the presence of a hemodynamically significant right ventricular infarction highly unlikely.

Adult↗
PubMed1998

Grading and hemodynamic follow-up study of arteriovenous malformations with transcranial Doppler ultrasonography.

This study presents and tests the clinical validity of a hemodynamic grading system that depends on noninvasive transcranial Doppler ultrasonographic parameters. The suggested transcranial Doppler-based grading system was compared with the Spetzler-Martin anatomic grading for prognosticative validity and clinical dependability. We concluded the following: (1) The pulsatility index was shown to be a more dependable transcranial Doppler parameter in the clinical evaluation of an arteriovenous malformation because of two reasons: preoperative pulsatility index findings inversely correlated with arteriovenous malformation volume, and the pulsatility index returned to normal values before the mean blood flow velocity did. Therefore, hemodynamic arteriovenous malformation grading can be based on the pulsatility index. (2) A transcranial Doppler-based hemodynamic arteriovenous malformation grading system correlated highly with the Spetzler-Martin grading in predicting postoperative neurologic deficits and adverse radiologic findings. (3) The presented grading system may contribute to the standardization and quantification of the hemodynamic changes during multidisciplinary management of arteriovenous malformations.

Adolescent↗
PubMed1999

[Pathogenesis of systemic hemodynamic disorders and choice of optimal obstetrical strategy in pregnant patients with gestosis].

A total of 810 pregnant women were examined in order to elucidate the pathogenesis of hemodynamic disorders in gestosis. The main group consisted of 460 patients with gestosis of different severity and the control group included 150 women with uneventful pregnancy. Central and regional hemodynamics in normal pregnancy were studied in detail by modern diagnostic methods (echocardiography and dopplerometry) and the relationship between the detected shifts and the function of the utero-placento-fetal circulation was shown. The predominant type of central hemodynamics in gestosis is the hypokinetic. Disorders in renal and cerebral circulation contribute to the pathogenesis of severe gestosis. Pathogenetic variants of hemodynamics shifts in gestosis are analyzed and recommendations on the follow-up of pregnancy are offered. Indications for preterm delivery in the interests of the mother and fetus are defined.

Adult↗
PubMed1976

[Influence of pressure and duration of perfusion on functional properties and hemodynamics of isolated kidneys from dogs (author's transl)].

1. Changes in functional properties and hemodynamics of isolated kidneys were analysed with special regard to pressure and duration of perfusion. Observations were compared between pairs of kidneys taken from the same animal and placed in identical experimental situations, but respectively perfused at a pressure level of either 100 mm Hg or 160 mm Hg. 2. A method using 133Xenon wash-out to measure renal blood flow, suppressing early recirculation, is described. 3. Changes in functional properties were towards decreases of glomerular filtration and tubular transfer. Hemodynamic changes proceeded from decreases of total and regional renal vascular resistance. Both functional properties and hemodynamic changes were larger as the duration of the pressure of the perfusion became greater. 4. Renal blood flow was different when measured with an electromagnetic flowmeter and by the 133Xenon wash-out technique. Practical applications, theoretical basis and results of the latter method are criticized. 5. Possible mechanisms by which high perfusion pressure hastens and increases functional and hemodynamic changes of isolated kidneys are discussed.

Animals↗
PubMed1994

Lack of effects of trimetazidine on systemic hemodynamics in patients with coronary artery disease: a placebo-controlled study.

Trimetazidine has been shown to improve anginal symptoms and exercise tolerance in patients with coronary artery disease (CAD). To determine the hemodynamic effects of trimetazidine, systemic hemodynamics were studied in 15 patients suffering from CAD (12 male, 3 female, mean age +/- SEM = 58.6 +/- 1.8 years). Cardiac index was determined by thermodilution method. Left ventricular and aortic pressures were measured using micromanometers (Miller Instruments). After basal measurements, patients were randomly given either placebo (n = 5) or one of two therapeutic doses of trimetazidine 1 mg.kg-1 (n = 5) or trimetazidine 1.5 mg.kg-1 (n = 5) in a double-blind procedure. Data were recorded 5, 10 and 20 min after intravenous drug bolus. Throughout the procedure, the evolution of systemic hemodynamic parameters was not statistically different between the three groups, in particular heart rate, cardiac index, systolic, diastolic and mean aortic pressures, end-diastolic ventricular pressure, mean capillary wedge pressure, pulmonary artery pressures or systemic vascular resistances. We conclude that, unlike other antianginal drugs (particularly beta-blockers, nitrates and calcium-channel inhibitors), trimetazidine does not modify systemic hemodynamics in patients with CAD. These results are consistent with a direct effect of trimetazidine on the ischemic myocardial cell previously reported.

Angina Pectoris↗
PubMedDate not supplied

[Hemodynamics changes in children and adolescents with mitral valve replacement].

The authors analyze the pre and post-operative hemodynamic picture of 30 children and adolescents with mitral valve replacement, which corresponds to a group of 106 patients operated on from 1964 to 1974. At variable time periods, between 9 days and 48 months (average 28 months) from the valve replacement, a new catheterization was done. The majority of the studies were done in the period between 13 and 36 months. Of the 30 cases, 21 were carriers of the Starr-Edwards valve, and the rest of different types. The Starr-Edwards valves produced a lawering of the CVP from 23.0 to 11.0 mm. Hg (average values) whereas with the other types the average pre-operative figure was 21.0 and in the post-operative period it fell to 11.0 mm. Hg. In the group with SE valves, pre-operative SPP was an average of 64.3 and in the post-operative period it was 32.0 mm. Hg. In the cases of SE valves the pre-operative total pulmonary resistances were 12.3 units and post-operatively they fell to 3.7 units. With the other types of valves the pre-opeative average was 10.9 units and post-operatively it was 5.3 units. The hemodynamic results obtained over a period of time with valvular substitution were similar in the distinct types of valves. However in the SE the benefits resulted more constant. The value of radiological and electrocardiographic study in order to predict the early post-operative hemodynamic changes is discussed. These studies serve essentially for a long range evaluation, whereas the hemodynamic, and clinical improvement maintained a strict relationship. This work shows that, in children and adolescents, the presence of severe venous-capillary and arterial pulmonary hypertension, and the elevated pulmonary resistences, are not contraindications for surgical treatment. It equally proves the eficacy of the valvular replacement, when the surgical indication and the control of the patients are handled in the proper way.

Child↗
PubMed1997

[Relationship between the site of coronary artery occlusion and degree of hemodynamic abnormality of right ventricular myocardial infarction].

Twenty one patients with acute inferior myocardial infarction underwent hemodynamic monitoring and coronary angiography study. 16 cases were diagnosed as having right ventricular myocardial infarction (RVMI) by the hemodynamic characteristics of RVMI and 5 cases no RVMI. In the 16 patients with RVMI, 15 (93.8%) had proximal or middle segment occlusion of right coronary artery (RCA) and the remaining one (6.3%) was caused by occlusion of left circumflex with no distal segment occlusion of RCA. According to the ratio of MRAP/PCWP, we divided the hemodynamic abnormality into two subgroups: MRAP/PCWP > or = 0.8 was considered severe and MRAP/PCWP 0.65-< 0.8 mild. In the 16 patients with RVMI, 10 cases were severe and 6 cases mild. The site of coronary artery occlusion in the severe group were 4/10 (40%) at proximal segmet of RCA and 5/10 (50%) at middle segmet of RCA and the remaining one case the site of occlusion was in circumflex, while in the mild group, 3/6 (50%) of the cases had occlusion at the proximal segment of RCA and 3/6 (50%) at middle segment of RCA. The results of this study showed that inferior myocardial infarction caused by proximal or middle segment occlusion of RCA might be accompanied by RVMI, but there was no relationship between the degree of hemodynamic abnormality and the site of RCA occlusion.

Adult↗
PubMed1999

Hemodynamic and metabolic alterations associated with intravenous infusion of a combination of adenosine triphosphate and magnesium chloride in conscious horses.

OBJECTIVE: To determine hemodynamic and metabolic effects of IV infusion of ATP-MgCl2 combination and maximal safe IV infusion rate in conscious horses. ANIMALS: 6 adult female horses. PROCEDURE: All horses received an IV infusion of ATP-MgCl2 combination, beginning at a rate of 0.05 mg of ATP/kg of body weight/min, which was increased by 0.05 mg/kg/min increments at 10-minute intervals until a rate of 1.0 mg/kg/min was achieved. Data were collected prior to the start of the infusion, at the end of each infusion rate, and at 15-minute intervals for the next hour after discontinuation of the infusion. Measured or calculated hemodynamic variables included cardiac output, cardiac index, heart rate, stroke volume, systemic and pulmonary arterial pressures, and systemic and pulmonary vascular resistances. Arterial blood gas tensions, CBC, plasma biochemical profiles, urine volume and specific gravity, and selected clinical signs of disease also were evaluated. RESULTS: Intravenous infusion of ATP-MgCl2 significantly increased cardiac output, decreased systemic vascular resistance, and caused mild pulmonary hypertension. Magnitude of the hemodynamic alterations was dependent on rate of infusion. Maximal safe infusion rate for these horses was 0.3 mg/kg/min. All horses became lethargic, and their appetites diminished during the infusion; 5 horses had mild signs of abdominal discomfort. Flank sweating was observed in all horses as infusion rate increased. Urine volume and specific gravity and hematologic, biochemical, and arterial blood gas alterations were detected during and after infusion. CONCLUSIONS AND CLINICAL RELEVANCE: Intravenous administration of ATP-MgCl2 in healthy, conscious, adult horses caused various metabolic and hemodynamic alterations that were without appreciable detrimental effects.

Adenosine Triphosphate↗
PubMed1999

Exercise hemodynamic performance of the pulmonary autograft following the Ross procedure.

BACKGROUND AND AIMS OF THE STUDY: The Ross procedure, in which the aortic valve is replaced with the patient's own pulmonary valve (pulmonary autograft), is considered an excellent alternative for younger patients requiring elective aortic valve replacement. Although resting pulmonary autograft hemodynamics are excellent, exercise hemodynamic data are lacking. The study aim was to measure the hemodynamic performance of the pulmonary autograft with exercise Doppler echocardiography (DE). METHODS: Twenty-four Ross procedure patients (20 males, four females; mean age 46 +/- 11 years) were studied at 25 +/- 14 months after aortic valve replacement with a pulmonary autograft. Patients had baseline supine DE to measure the maximum velocity (Vmax), and the peak and mean pressure gradient across the pulmonary autograft. Effective orifice area was calculated from the continuity equation and indexed to body surface area (EOAi). Patients then underwent symptom-limited upright bicycle exercise with supine DE repeated immediately on stopping exercise. For comparison, 10 normal controls (age 41 +/-10 years) and five mechanical aortic valve patients (mean age 55 +/- 10 years) were studied. RESULTS: At rest: Ross procedure patients had similar Vmax (1.2 +/- 0.2 m/s), peak gradient (6 +/- 2 mmHg), mean gradient (4 +/- 1 mmHg) and EOAi (1.7 +/- 0.4 cm2/m2) to those of normal controls. Mechanical-valve patients had significantly higher Vmax (2.5 +/- 0.2 m/s, p <0.001), peak gradient (25 +/- 4 mmHg, p <0.001) and mean gradient (14 +/- 3 mmHg, p <0.001) than Ross patients and normal controls. At exercise: Ross procedure patients had similar Vmax (1.8 +/- 0.4 m/s versus 2.1 +/- 0.2, p = NS), peak gradient (14 +/- 6 mmHg versus 17 +/- 4, p = NS) and mean gradient (8 +/- 4 mmHg versus 10 +/- 2, p = NS) to normal controls, with no significant change in EOAi. Mechanical-valve patients had significantly higher Vmax (3.4 +/- 0.3, p <0.001), peak gradient (48 +/- 7 mmHg, p <0.001) and mean gradient (30 +/- 5 mmHg, p <0.001) than Ross patients and normal controls. CONCLUSIONS: Aortic valve replacement using the Ross procedure provides excellent hemodynamic results at rest and on exercise, with DE parameters indistinguishable from those of normal controls. This study provides further support for the use of the Ross procedure as a preferred method of aortic valve replacement in younger patients.

Adult↗
PubMed1999

Hemodynamic changes in patients with Alagille's syndrome during orthotopic liver transplantation.

UNLABELLED: Children with Alagille's syndrome are at increased perioperative risk during orthotopic liver transplantation due to the cardiopulmonary abnormalities and the hemodynamic changes associated with this procedure. We studied 16 children with Alagille's syndrome who underwent 21 orthotopic liver transplantations. Peripheral pulmonary stenosis was present in all subjects. Right ventricular pressures were increased in 15 cases. Caval clamping resulted in a mean decrease of 15 +/-9 mm Hg in systolic blood pressure, 5 +/- 3 mm Hg in mean pulmonary artery pressure, and 4 +/- 3 mm Hg in central venous pressure. Systolic blood pressure decreased by 16 +/- 13 mm Hg, whereas mean pulmonary artery pressure and central venous pressure increased by 3 +/- 4 mm Hg and 1 +/- 4 mm Hg, respectively, at portal vein unclamping. There was no correlation between severity of pulmonary artery stenosis and hemodynamic changes. Veno-venous bypass used in four cases resulted in smaller hemodynamic changes. Time to extubation and duration of intensive care unit stay were unrelated to severity of pulmonary artery stenosis. IMPLICATIONS: Some children with Alagille's syndrome require liver transplantation. In our study, associated pulmonary artery stenosis did not dramatically increase perioperative risk. Veno-venous bypass decreased intraoperative hemodynamic changes in these patients.

Alagille Syndrome↗
PubMed1999

Accuracy of leveling hemodynamic transducer systems.

Critically ill patients frequently have invasive catheters placed to monitor hemodynamic pressures and to calculate hemodynamic indices. Correct leveling to the appropriate anatomical structure is critical as the pressure readings guide management of fluids, drug administration, and other interventions. The authors of this study investigated the accuracy with which registered nurses and respiratory technologists were able to level hemodynamic transducers to the phlebostatic axis using visual checks, a carpenter's level, and a laser leveling device. The results indicate that both groups were unable to accurately level transducers with visual checks alone. Use of a leveling tool improved accuracy. The laser level was superior for accuracy and speed and preferred for dexterity required, ease of use and patient safety. The data supports the need for a tool to accurately level hemodynamic transducer systems and suggests that the laser leveling device is the tool of choice.

Analysis of Variance↗
PubMed2000

[Parameters of hemodynamics and red cell redox-status in old patients with ischemic heart disease].

Red cell redox-status and hemodynamic changes were studied in 60 old patients with ischemic heart disease. The treatment consisted of standard therapy (ST), ST + amino acid composition (glutaminic acid, glycine, cysteine) or preductal (15, 30 and 15 patients, respectively). Glutathione levels, activity of glutathione-transferase, reductase, peroxidase, catalase, Cu-, Zn-superoxide dismutase, red cell levels of malonic dialdehyde, hemodynamic parameters according to echo-CG and ECG monitoring were estimated before the treatment and 20 days after it. Endogenic antioxidant defense/hemodynamic parameters correlation coefficients were calculated. Close correlations were not found. However, ST + amino acid composition demonstrated the weakest correlations between the antioxidant defense and hemodynamics, while ST + preductal produced the greatest number of correlations. It is suggested that amino acids promote search for the antioxidant system's optimum while ST + preductal promotes closer correlations between red cell redox status and hemodynamic parameters.

Aged↗
PubMed2000

Correlative assessment of hemodynamic parameters obtained with T2*-weighted perfusion MR imaging and SPECT in symptomatic carotid artery occlusion.

BACKGROUND AND PURPOSE: Perfusion MR imaging and single-photon emission CT (SPECT) are commonly used to evaluate hemodynamic status in patients with symptomatic occlusive cerebrovascular disease. These techniques rely on different underlying physiological mechanisms, and the data may not correspond. We studied the relationship between hemodynamic parameters obtained with these two methods. METHODS: We performed perfusion MR imaging and SPECT in 10 patients with symptomatic unilateral internal carotid artery occlusion. Relative cerebral blood volume (rCBV) and uncorrected mean transit time (uMTT) were obtained with dynamic contrast-enhanced T2*-weighted MR imaging. Relative cerebral blood flow (rCBF) and vascular reserve capacity were measured with 99mTc-HMPAO SPECT; vascular reserve capacity was calculated by the difference in CBF before and after acetazolamide challenge. Ratios of these hemodynamic parameters between the affected and contralateral vascular territories were calculated and compared. RESULTS: Normal-to-increased CBV, prolonged uMTT, decreased CBF, and normal-to-diminished vascular reserve capacity were observed in the affected vascular territories. Reduction of vascular reserve capacity corresponded well with uMTT but not with CBF and CBV. CBF, CBV, and uMTT did not correspond to one another. CONCLUSION: uMTT is more sensitive than the other parameters in estimating vascular reserve capacity. The relationship between parameters obtained with perfusion MR imaging and SPECT should be considered in assessing the hemodynamic status of patients with symptomatic occlusive cerebrovascular disease.

Aged↗
PubMedDate not supplied

Dominant hemodynamic parameters of chronic ischemic mitral regurgitation.

The study included 128 patients treated at the Institute of Cardiovascular Diseases in Sremska Kamenica within a year after the first posteroinferior myocardial infarction. On the basis of hemodynamic measurements, patients were divided into 2 groups. Group I (examinees) included 64 patients (58 males and 6 females, mean age 54.42 +/- 6.70 years) with proven mitral regurgitation and group 2 (control) included 64 patients (56 males and 8 females, mean age 51.71 +/- 8.84 years) without mitral regurgitation, but with stenotic changes in the right coronary artery and left circumflex coronary artery without significant stenotic lesions at the anterior descending left coronary artery. According to Sellers classification mitral regurgitation in group I was as follows: I grade 37.5%, II grade 31.3%, III grade 21.9% and IV grade 9.3%. Measured hemodynamic parameters in basal conditions (systolic, diastolic and mean pulmonary pressure, capillary pulmonary pressure and wave V, left ventricular end-diastolic pressure) point to significant impairment of diastolic function in group I apart from similar values of systolic function (cardiac output, cardiac index and ejection fraction). Dimension of the left atrium and left ventricle determined by transthoracic echocardiography confirm this. There was a positive correlation of examined parameters (pulmonary capillary and total pulmonary resistance) and the degree of mitral regurgitation, as well as the correlation between the degree of mitral regurgitation and hemodynamic parameters. It may be concluded that postinfarction mitral regurgitation in examined patients is of II degree on the average; total and capillary pulmonary resistance are most sensitive hemodynamic parameters for examining the severity of mitral regurgitation, whereas the size of the left atrium is the most sensitive echocardiographic parameter.

Chronic Disease↗