Biomedical subjects

M Iwase

Publications and source records attributed to M Iwase.

At least 91 records · Page 5Linked to original sources

PubMed1998

[Relationship between mitral valve echo score and hemodynamic variables in patients with mitral stenosis].

Mitral valve echo score has been proposed as a predictor or of the outcome of balloon mitral valvotomy in patients with mitral stenosis. The relationship between mitral echo score and the hemodynamic variables was evaluated. In 41 patients with pure mitral stenosis (nine men and 32 women, aged 57.9 +/- 9.4 years), mitral echo score was estimated from two-dimensional echocardiographic findings, and mitral valve area was measured by planimetry on the two-dimensional short-axis view. Apex phonocardiography and continuous-wave Doppler echocardiographic recording of transmittral flow were simultaneously performed to measure left atrial/left ventricular mean transmittral pressure gradient, pressure half-time and (Q-1)-(2-OS) interval. Linear regression analysis revealed that both mitral echo score and mitral valve area were significantly correlated with mean transmittral gradient (r = 0.522, p = 0.0005 and r = -0.651, p < 0.0001, respectively), pressure half-time (r = 0.491, p < 0.005 and r = -0.757, p < 0.0001) and (Q-1)-(2-OS) interval (r = 0.551, p < 0.0005 and r = -0.487, p < 0.005, respectively). Mitral echo score has a significant correlation with hemodynamic variables, which were comparable to but slightly different from mitral valve area, in patients with mitral stenosis.

Adult↗

PubMed1998

New sensitive method for the detection of the A3243G mutation of human mitochondrial deoxyribonucleic acid in diabetes mellitus patients by ligation-mediated polymerase chain reaction.

An adenine-to-guanine mutation at nucleotide position (np) 3243 in the mitochondrial tRNALeu(UUR) gene is closely associated with various clinical phenotypes of diabetes mellitus. Because the mutation creates a new restriction site for the restriction enzyme ApaI, the mutation is usually detected and quantified by ApaI cleavage of the PCR products including np 3243. The sensitivity of the conventional method is, however, 5-10% heteroplasmy. The percentage of heteroplasmy of the mutation is usually highest in the affected tissues and is much lower in peripheral blood cells, which are used most frequently for the analysis. The sensitivity of the conventional method, however, is not sufficient to detect the mutation from peripheral blood cells. Utilizing ligation-mediated polymerase chain reaction, we have developed a feasible and sensitive method to detect 0.01% heteroplasmy of the 3243 mutation in peripheral leukocytes.

Adenine↗

PubMed1997

Adrenergic control of the force-frequency and relaxation-frequency relations in patients with hypertrophic cardiomyopathy.

BACKGROUND: Exercise-induced enhancement of the force-frequency and relaxation-frequency relations has been studied in conscious animals but not in intact diseased human hearts. METHODS AND RESULTS: We evaluated left ventricular (LV) isovolumic contraction (dP/dt(max)) and relaxation (tau) during atrial pacing and dynamic exercise in 13 patients with nonobstructive hypertrophic cardiomyopathy (HCM) and 7 control subjects to investigate the influence of exercise on the force-frequency and relaxation-frequency relations. Group A consisted of 6 patients in whom the heart rate (HR)-dP/dt(max) relation was markedly enhanced during exercise (88+/-30%) compared with during pacing (34+/-15%). Group B consisted of 7 patients in whom the HR-dP/dt(max) relation showed similar enhancement during exercise (28+/-7%) and atrial pacing (28+/-11%). There was no difference in the HR-tau (derivative method [TD] and pressure half-time method [T(1/2)]) relation between pacing and exercise in groups A and B. Both the mean maximal wall thickness and the hypertrophy score in group B were greater than in group A (27+/-5 versus 19+/-2 mm and 7+/-1 versus 5+/-1 points, respectively; both P<.01). There was no difference in the LV peak systolic pressure, end-diastolic pressure, or the plasma level of catecholamines at baseline, at 50 W of exercise, and at peak pacing between groups A and B. The HR-dP/dt(max) relation in the control group was markedly enhanced during exercise (80+/-27%) compared with during pacing (32+/-14%). The HR-tau relation in the control group was enhanced during exercise (TD, 35+/-9%; T(1/2), 34+/-8%) compared with during pacing (TD, 12+/-7%; T(1/2), 14+/-7%). CONCLUSIONS: Exercise-induced enhancement of the relaxation-frequency relation was inhibited in all HCM patients, regardless of the degree of LV hypertrophy. The patients without exercise-induced enhancement of the force-frequency relation had more severe LV hypertrophy than the patients with the enhancement, indicating that the adrenergic control of the force-frequency relation may, at least in part, depend on the severity of LV hypertrophy or the stage of HCM.

Adult↗

PubMed1997

Early detection of successful coronary reperfusion based on serum concentration of human heart-type cytoplasmic fatty acid-binding protein.

Both human heart-type cytoplasmic fatty acid-binding protein (H-FABPc) and myoglobin are low molecular weight proteins that are abundant in the cytoplasm of myocardial cells. Unlike myoglobin, H-FABPc content in the skeletal muscle is less than in cardiac muscle. To investigate the usefulness of the serum concentration of H-FABPc in the early detection of successful coronary reperfusion, we measured serum concentrations of H-FABPc and myoglobin in 45 patients with acute myocardial infarction treated with intracoronary thrombolysis or direct percutaneous transluminal coronary angioplasty. Coronary angiography was performed every 5 min for reperfusion therapy to identify the onset of reperfusion. Reperfusion, defined as a TIMI grade 2 or 3, was achieved within 60 min of the initiation of reperfusion therapy in 30 patients (the reperfused group), but was not achieved in 15 patients (the non-reperfused group). Blood samples were obtained before initiation of treatment and 15, 30 and 60 min after initiation of treatment in the non-reperfused group. In the reperfused group, samples were obtained before reperfusion and 15, 30 and 60 min after reperfusion. The H-FABPc ratio (the ratio of value after to value before the initiation of treatment or reperfusion) increased sharply after the onset of reperfusion, peaking at 41 +/- 18 min, and decreased rapidly thereafter. The predictive accuracy of an H-FABPc ratio of > 1.8 for the detection of reperfusion within 60 min of the initiation of treatment was 93% at 15 min after reperfusion, 98% at 30 min, and 100% at 60 min. Similar rates of predictive accuracy were observed for a myoglobin ratio > 2.4. The H-FABPc ratio detected successful reperfusion as early as 15 min after the onset of reperfusion and was highly accurate in detecting reperfusion within 60 min of the onset of reperfusion. The predictive accuracy of the H-FABPc ratio was similar to that of the myoglobin ratio for the early detection of successful coronary reperfusion.

Adult↗

PubMed1997

Effect of bezafibrate on hypercoagulability assessed by fluorogenic prothrombin time in hyperlipidemic patients with non-insulin-dependent diabetes mellitus.

We investigated the usefulness of the fluorogenic prothrombin time (FPT) for detection of hypercoagulability and its association with hyperlipidemia in 19 patients with non-insulin-dependent diabetes mellitus (NIDDM) and 10 healthy control subjects, compared with plasma levels of fibrinogen, plasminogen activator inhibitor-1 (PAI-1) and D-dimer. We also evaluated the effect of bezafibrate on hypercoagulability in 10 hyperlipidemic NIDDM patients. The plasma levels of FPT and fibrinogen were significantly higher in hyperlipidemic NIDDM patients than in normolipidemic NIDDM patients and controls. Plasma levels of PAI-1 and D-dimer were significantly higher in normolipidemic and hyperlipidemic NIDDM patients compared with controls. The FPT was correlated with the HbA1c, the body mass index, and levels of total cholesterol, fibrinogen and PAI-1. Six-months therapy with bezafibrate reduced the levels of FPT, triglycerides and basal insulin, but did not alter levels of fibrinogen, PAI-1 and D-dimer. Our results showed that the FPT was useful for detection of hypercoagulability and evaluation of the effect of drugs. The increased FPT in patients with NIDDM suggested that hypercoagulability was present in association with hyperlipidemia.

Aged↗

PubMed1997

Effects of chronic beta-adrenergic receptor stimulation in mice.

The goal of the present study was to determine the effects of chronic beta-adrenergic receptor stimulation with isoproterenol (ISO) on cardiac tissue, systemic trophic changes and on beta-adrenergic receptor desensitization in mice. Mice (n=36) received continuous ISO (30 microg/g/day) via osmotic minipump for 13 days. Left ventricle (LV)/body weight (BW) ratio was increased by 27% in ISO v control (CON) mice. The extent of cardiac hypertrophy induced by chronic ISO was offset in part by concomitant increases in body weight, which were greater in ISO than CON mice (22 v 8%), and occurred with increases in both muscle mass and brown fat to BW ratios. Histological analysis of mice revealed a three-fold increase in subendocardial interstitial connective tissue with no evidence of acute cellular necrosis or chronic inflammation. Acute i.v. ISO challenges induced dose-dependent increases in LV fractional shortening (FS) and ejection fraction (EF) using echocardiography (9 MHz), which were attenuated after chronic ISO, i.e. physiological desensitization was observed. Cellular mechanisms of beta-adrenergic receptor desensitization included decreases in beta-adrenergic receptor density (-49%) and decreased basal (-45%) and ISO-stimulated (-61%) adenylyl cyclase activities. Lesser decreases in forskolin-stimulated adenylyl cyclase activity (-16%) and adenylyl cyclase mRNA levels for both type V (-17%) and type VI (-23%) isoforms were observed following chronic ISO. Thus, chronic ISO (30 microg/g/day) induced cardiac hypertrophy without cellular necrosis, increased weight gain and clear physiological desensitization in mice, with more extensive biochemical mechanisms than expected from simple catecholamine-specific (homologous) desensitization.

Adenylyl Cyclases↗

PubMed1997

Reduced tissue oxygenation and its reversibility by glycemic control in diabetic patients.

Relationship of transcutaneous oxygen pressure (TcP(O2)) to glycemic control and diabetic complications was investigated in patients with non-insulin dependent diabetes mellitus. TcP(O2) was measured in 103 patients with non-insulin dependent diabetes mellitus. Correlation of TcP(O2) to HbA1c, fasting blood sugar (FBS), age, duration of diabetes, serum lipids, hypertension, and diabetic complications were examined. We divided the patients into three groups according to their glycemic control: good control group (HbA1c < 7.0%), fair control group (HbA1c, 7.0-8.9%) and poor control group (HbA1c > or = 9.0). We compared TcP(O2) of these three groups with 19 non-diabetic controls. In 103 patients, TcP(O2) at baseline correlated with HbA1c, FBS and age (P < 0.001, P < 0.01 and P < 0.05, respectively), but did not correlate with duration of diabetes mellitus, neuropathy, nephropathy or retinopathy. TcP(O2) of good and fair control group was not reduced comparing to the non-diabetic control (63 +/- 11, 59 +/- 10 and 64 +/- 12 mmHg, respectively). The poor control group had significantly reduced TcP(O2) (55 +/- 10 mmHg) comparing to non-diabetic control (P < 0.005) and good control group (P < 0.005). Furthermore, in an independent study, TcP(O2), arterial oxygen pressure (Pa(O2)), oxygen pressure of dorsal pedal vein (PV(O2)) and erythrocyte 2,3-diphosphoglycerate (2,3-DPG) in eight patients with poor glycemic control were followed prospectively. Six patients with improvement of glycemic control showed a significant increase of TcP(O2) and Pa(O2) (P < 0.001 and P < 0.005, respectively). However, two patients without improvement of hyperglycemia had no change in TcP(O2) and Pa(O2). PV(O2) and 2,3-DPG levels of erythrocytes were not changed in six patients. These findings suggest that tissue oxygenation in diabetic patients was deteriorated in relation to hyperglycemia and was reversed with glycemic control. Improvement of Pa(O2) might contribute partly to the increase of TcP(O2).

2,3-Diphosphoglycerate↗

PubMed1997

Clinical trial of recombinant granulocyte colony-stimulating factor for chemotherapy-induced neutropenia patients with oral cancer.

PURPOSE: This study was undertaken to evaluate the efficacy and toxicity of recombinant human granulocyte colony-stimulating factor (rhG-CSF) in reducing neutropenia in patients with oral cancer undergoing intensive chemotherapy. MATERIALS AND METHODS: Patients with chemotherapy-induced neutropenia (< 1 x 10(9)/L) were divided into two groups: control group (n = 13) and rhG-CSF administration group (n = 16). rhG-CSF was administered subcutaneously at a dose of 75 micrograms/day on consecutive days. Peripheral blood cell counts and oral complications were investigated in each group. RESULTS: The duration of neutropenia and absolute neutrophil nadir counts were significantly improved by administration of G-CSF. No consistent effect on thrombocytopenia was noted. Administration of rhG-CSF also reduced the duration and degree of oral complications associated with chemotherapy-induced neutropenia. Intolerable side effects associated with administration of rhG-CSF were not observed. CONCLUSION: It was concluded that rhG-CSF is effective in shortening the duration of neutropenia after chemotherapy at a dose of 75 micrograms/day.

Adult↗

PubMed1997

Positional changes in the mandibular condyle and amount of mouth opening after sagittal split ramus osteotomy with rigid or nonrigid osteosynthesis.

PURPOSE: The purpose of this study was to investigate postoperative positional changes in the mandibular condyle and mouth opening in patients undergoing sagittal split ramus osteotomy with either rigid or nonrigid osteosynthesis. PATIENTS AND METHODS: The forty-six patients with mandibular prognathism underwent sagittal split ramus osteotomy for mandibular set back followed by fixation with one of four methods: circumferential wire (n = 11), lag screw technique (n = 10), positional screw technique (n = 10), or miniplates (n = 15). The changes in the condylar position were assessed by measuring the angle of the condylar long axis (the condylar angle) on submentovertex radiographs. Mouth opening was evaluated by measuring the interincisal distance immediately after the release of maxillomandibular fixation and by monitoring the duration of trismus. RESULTS: Regardless of the procedure used the condylar angle increased in most patients after surgery (80 of 92 condyles). Although the amount of increase tended to be higher with rigid osteosynthesis than with nonrigid osteosynthesis, no significant differences were observed among the groups. Mouth opening was not significantly influenced by the type of osteosynthesis, and no patient complained of limitation 1 year after surgery. CONCLUSIONS: Although inward rotation of the condyle frequently occurs after osteosynthesis regardless of the procedure used, the changes in condylar position are within the range of adaptability of the patient.

Adaptation, Physiological↗

PubMed1997

Effect of dobutamine and OPC-18790 on diastolic chamber stiffness in patients with idiopathic dilated cardiomyopathy.

We investigated the acute effects of the positive inotropic agents (dobutamine and a novel phosphodiesterase inhibitor OPC-18790) on left ventricular diastolic chamber stiffness in patients with idiopathic dilated cardiomyopathy (DCM). We obtained pressure-volume (PV) data before and after drug administration in 17 patients with DCM by using a conductance catheter with a micromanometer tip. Patients were randomly assigned to receive intravenous infusions of dobutamine (2.5-7.5 micrograms/kg body weight per min, n = 8) or OPC-18790 (5-10 micrograms/kg body weight per min, n = 9). The dynamic diastolic chamber stiffness constant was calculated from a steady-state beat. The passive diastolic chamber stiffness constant was determined from the end-diastolic PV relation determined during transient inferior vena caval occlusion. Dobutamine and OPC-18790 similarly improved left ventricular end-systolic elastance (Ees) and left ventricular isovolumic relaxation time constants. The dynamic diastolic chamber stiffness constant decreased significantly in both the dobutamine (0.0934 +/- 0.0271 to 0.0685 +/- 0.0248; p < 0.01) and OPC-18790 (0.0843 +/- 0.0477 to 0.0569 +/- 0.0246; p < 0.05) groups. The passive diastolic chamber stiffness constant decreased significantly in the OPC-18790-treated group (0.0211 +/- 0.0114 to 0.0144 +/- 0.0117; p < 0.005) but not in the dobutamine-treated group (0.0197 +/- 0.0130 to 0.010186 +/- 0.0102; p > 0.05). Thus both dobutamine and OPC-18790 reduced the dynamic diastolic chamber stiffness constant, but only OPC-18790 reduced the passive diastolic chamber stiffness constant. OPC-18790 had a favorable effect on diastolic function in patients with DCM, compared with that of dobutamine. The passive diastolic chamber stiffness obtained from the end-diastolic PV relations represents more likely passive chamber properties than the dynamic diastolic chamber stiffness obtained from traditional single-beat analysis.

Adult↗

PubMed1997

Cardiomyopathy induced by cardiac Gs alpha overexpression.

The goal of this study was to determine whether chronic endogenous sympathetic stimulation resulting from the overexpression of cardiac stimulatory G protein alpha subunit (Gs alpha) in transgenic mice (15.3 +/- 0.1 mo old) resulted in a clinical picture of cardiomyopathy. The left ventricular ejection fraction, measured by echocardiography, was reduced in older mice with Gs alpha overexpression (50.4 +/- 5.4%) compared with age-matched control mice (70.9 +/- 1.6%; P < 0.05). When ejection fractions were compared at similar heart rates, the Gs alpha mice exhibited a greater left ventricular end-diastolic dimension than control mice (4.3 +/- 0.2 vs. 3.7 +/- 0.1 mm; P < 0.05). Baseline heart rates were elevated in conscious Gs alpha mice (722 +/- 27 beats/min; n = 5) compared with control mice (656 +/- 28 beats/min; n = 5). Moreover, electrocardiographic monitoring demonstrated a high incidence of arrhythmias. Increased mortality compared with control mice (31.6 vs. 3.0%; P < 0.01) was also observed. Thus older mice with Gs alpha overexpression exhibit many of the features of dilated cardiomyopathy. This study supports the concept that chronic sympathetic stimulation over an extended period of time, i.e., over the life of an animal, is deleterious and actually may result in cardiomyopathy.

Animals↗

PubMed1997

[Extramedullary plasmacytoma with multiple metastasis following a maxillary plasmacytoma].

A 67-year old man noticed swelling of left maxillary in October 1992. Surgical biopsy of the left maxillary tumor revealed the plasmacytoma at the department of oral surgery. The Tumor disappeared after radiation therapy. He was admitted with dizziness and tarry stool in June 1994. We found left cervical and abdominal paraaortic lymph node swellings by the computer tomography. He died inspite of chemotherapy in December. Autopsy showed that plasma cells diffusely and nodularly invased in all alimentary tract with multiple ulcerations. Invasion was also observed in the liver, lungs, thyroid, heart, kidneys, and adrenals. The plasma cells in the liver showed IgG kappa type by tissue immunostain. Diffuse invasion of extramedullary plasmacytoma is very rare in alimentary tract and many other organs. This case may be value to delineate the nature of this disease.

Aged↗

PubMed1997

[Echocardiographic prediction of risk for embolism in patients with infective endocarditis].

The relationship between two-dimensional echocardiographic findings of vegetation and embolic events was investigated in 26 patients with infective endocarditis (17 males and 9 females, mean [+/-SD] age 51 +/- 17 years). The size and the other morphologic characteristics of vegetation (mobility, extent and consistency) were analyzed retrospectively according to the criteria by Sanfilippo, et al., and parameters were assigned scores from 1 to 4 to provide a total score. Patients with a maximum vegetation diameter > 10 min had a significantly higher incidence of embolic events than those with < or = 10 mm (p < 0.05). Each parameter of vegetation showed no significant difference between patients with and without embolic events; but the total score was significantly higher in patients with embolic events (p < 0.05). Particularly, all patients with a total score > or = 10 had embolic events, whereas those without embolic events had a total score < or = 9. There were no significant differences in the frequency of emergent valve replacement between patients with aortic value and mitral valve endocarditis. However, the incidence of heart failure was higher, but not significantly, in patients with aortic valve (67%) and combined valve endocarditis (67%) than in those with mitral valve endocarditis (36%). The maximum size and total score reflecting mobility, extent and consistency of vegetation using two-dimensional echocardiography provide useful information to predict the occurrence of embolic events in patients with infective endocarditis.

Adult↗

PubMed1997

Serum concentrations of myoglobin vs human heart-type cytoplasmic fatty acid-binding protein in early detection of acute myocardial infarction.

We compared the diagnostic utility of serum concentrations of human heart-type cytoplasmic fatty acid-binding protein (H-FABPc), myoglobin, and their ratio for the early diagnosis of acute myocardial infarction (AMI) in 104 healthy volunteers and 165 patients at admission within 6 h of the onset of chest pain. The ROC curves of the H-FABPc [0.946, 95% confidence interval (CI) = 0.913-0.979] and myoglobin (0.895, 95% CI = 0.846-0.944) between patients with AMI and healthy volunteers were significantly greater than the area under the ratio of myoglobin to H-FABPc (0.823, 95% CI = 0.765-0.881). In 165 patients, the sensitivity (81.8%, 95% CI = 74.2-89.4%), specificity (86.4%, 95% CI = 78.1-94.6%), and predictive accuracy (83.6%, 95% CI = 78.0-89.3%) of H-FABPc > 12 micrograms/L in diagnosing AMI were significantly higher than those of myoglobin, and were similar to those of the combination of H-FABPc > 12 micrograms/L and the ratio < or = 14. We conclude that H-FABPc is a more sensitive and specific marker than myoglobin for the early diagnosis of AMI, and that their ratio cannot give a clear advantage over the measurement of H-FABPc alone.

Adult↗

PubMed1997

Three-dimensional echocardiography by semi-automatic border detection in assessment of left ventricular volume and ejection fraction: comparison with magnetic resonance imaging.

The feasibility of three-dimensional echocardiographic reconstruction by semi-automatic border detection to assess left ventricular volume and function was investigated in a clinically applicable setting in 23 patients with various cardiac diseases and 7 normal volunteers. The commercial equipment permits digital acquisition of three apical orthogonal views, manual tracing of end-diastolic and end-systolic endocardium, semi-automatic border extractions of other frames, three-dimensional echocardiographic reconstruction and dynamic display within 20 min in a low resolution mode. Correlation of measurements with data obtained by magnetic resonance imaging (MRI) using the biplane modified Simpson method showed left ventricular end-diastolic volume (y = 0.894x - 0.456, r = 0.925, p < 0.001), end-systolic volume (y = 1.09x - 8.98, r = 0.959, p < 0.001), and ejection fraction (y = 0.956x + 1.93, r = 0.851, p < 0.001). In addition, a dynamic three-dimensional "movie-like" image displayed the shape, geometry, and regional wall motion abnormality, and change in global shape and size of the left ventricle. Three-dimensional echocardiographic analysis by three apical orthogonal views and dynamic display of the left ventricle provides reliable data comparable to MRI measurements within a reasonable period of time, and is now clinically feasible.

Adult↗

PubMed1997

[Comparison of effects of thrombolytic therapy followed by elective coronary intervention and direct coronary intervention in acute myocardial infarction: usefulness of dobutamine stress echocardiography].

The effects of intravenous administration of tissue plasminogen activator (t-PA) followed by elective percutaneous transluminal coronary angioplasty (PTCA) were compared to those of direct PTCA (d-PTCA) in patients with acute myocardial infarction using dobutamine stress echocardiography 1 week and 1 month after the acute episode. There were 12 patients in the t-PA group and nine patients in the d-PTCA group. Dobutamine was infused at incremental doses (5 micrograms/kg/min for each 5 min step). Wall motion changes were classified during infusion into four patterns, improvement, biphasic, worsening and no change. One week after the acute episode, seven of 12 patients in the t-PA group showed biphasic the pattern and five showed the improvement pattern. The biphasic pattern was observed in three patients in the d-PTCA group, worsening in one and improvement in five. One month later, the biphasic pattern in five patients in the t-PA group changed to the improvement pattern. No patients in the d-PTCA group showed changes in the wall motion pattern. There was no difference between the two groups in the frequency of the change of wall motion patterns 1 week and 1 month after infarction, but the improvement pattern was significantly increased from five to 10 patients in the t-PA group after 1 month (p < 0.05). The sensitivity, specificity and accuracy of the biphasic pattern in the t-PA group for indicating remnant coronary stenosis were 78%, 100% and 83%, respectively. Evaluation of wall motion pattern by dobutamine stress echocardiography is useful for assessment of reperfusion therapy for acute myocardial infarction. The administration of t-PA followed by elective PTCA has similar efficacy to d-PTCA.

Angioplasty, Balloon, Coronary↗

PubMed1997

Depressed mechanoenergetics and compensatory responses in idiopathic dilated cardiomyopathy.

The aim of this study was to clarify that the depressed mechanoenergetics in patients with idiopathic dilated cardiomyopathy (DCM) resulted from compensation for the decreased contractility. The study population consisted of eight control subjects, with normal left ventricular size and ejection fraction and 31 patients with DCM. Left ventricular end-systolic elastance (Ees), effective arterial elastance (Ea), external work (EW), and the pressure-volume area (PVA) were measured, using a dual-field volume conductance catheter equipped with a micromanometer-tipped catheter. Ea/Ees was evaluated as ventriculoarterial coupling. Normal hearts worked at almost optimal condition (defined as Ea/Ees = 1/2), while ventriculoarterial coupling was far from the optimum (Ea > Ees) in patients with DCM. Ees in patients with DCM was less than that in control subjects; however, Ea was similar in the two groups. The mismatch of Ea/Ees observed in DCM leads to depressed mechanoenergetics as a result of the compensatory response to maintain adequate blood pressure. Volume enlargement plays an important role in maintaining adequate blood pressure and cardiac output in the course of chronic deterioration of contractility.

Blood Pressure↗

PubMed1997

Dynamic exercise-induced changes in diastolic properties of the regional myocardium in hypertensive left ventricular hypertrophy.

We investigated the effect of mild exercise on global and regional diastolic function in patients with hypertensive left ventricular hypertrophy (LVH), using simultaneous measurement of micromanometric left ventricular pressure and echocardiographic indexes. Although left ventricular end-diastolic pressure (LVEDP) at rest in the hypertensive LVH group was similar to that in the control normotensive group, who had no abnormality on echocardiography or cardiac catheterization, LVEDP showed a marked increase during exercise only in the hypertensive LVH group. The pressure-dimension relation was shifted upward during exercise in all patients with hypertensive LVH. We utilized a new index of regional diastolic myocardial stiffness, KDM, which is derived from the diastolic relation between the mean wall stress and the natural logarithm of the reciprocal of wall thickness. Although KDM at rest was similar in the two groups, KDM increased significantly during exercise, both in the septum and posterior wall in patients with hypertensive LVH. The present results imply that even low-grade exercise may have deleterious effects on regional myocardial performance in patients with hypertensive LVH.

Diastole↗