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Biomedical subjects

Teruo Takano

Publications and source records attributed to Teruo Takano.

At least 109 records · Page 6Linked to original sources

Assessment of myocardial washout of Tc-99m-sestamibi in patients with chronic heart failure: comparison with normal control.

BACKGROUND: In contrast to 201TlCl, 99mTc-sestamibi shows very slow myocardial clearance after its initial myocardial uptake. In the present study, myocardial washout of 99mTc-sestamibi was calculated in patients with non-ischemic chronic heart failure (CHF) and compared with biventricular parameters obtained from first-pass and ECG-gated myocardial perfusion SPECT data. METHODS AND RESULTS: After administration of 99mTc-sestamibi, 25 patients with CHF and 8 normal controls (NC) were examined by ECG-gated myocardial perfusion SPECT and planar data acquisition in the early and delayed (interval of 3 hours) phase. Left ventricular ejection fraction (LVEF, %), peak filling rate (PFR, sec(-1)), end-diastolic volume (LVEDV, ml) and end-systolic volume (LVESV, ml) were automatically calculated from the ECG-gated SPECT data. Myocardial washout rates over 3 hours were calculated from the early and delayed planar images. Myocardial washout rates in the CHF group (39.6+/-5.2%) were significantly higher than those in the NC group (31.2+/-5.5%, p < 0.01). The myocardial washout rates for the 33 subjects showed significant correlations with LVEF (r = -0.61, p < 0.001), PFR (r = -0.47, p < 0.01), LVEDV (r = 0.45, p < 0.01) and LVESV (r = 0.48, p < 0.01). CONCLUSION: The myocardial washout rate of 99Tc-sestamibi is considered to be a novel marker for the diagnosis of myocardial damage in patients with chronic heart failure.

Adult↗

Modification of the radial procedure in a patient with partial atrioventricular septal defect.

We successfully cured atrial fibrillation while preserving internodal conduction in a patient with a partial atrioventricular septal defect. Because the anterior and middle internodal tracts are interrupted by the defect, the lower right atrial incision of either the maze or the radial procedure may interrupt the remaining posterior tract, resulting in internodal conduction block. We deleted the posterior septal incision from the radial procedure and replaced it with a right-side left atriotomy. The patient resumed normal sinus rhythm with significant contraction of the right and left atria. The preserved internodal pathway through the posterior interatrial septum was confirmed by electrophysiologic study.

Adult↗

Pronounced effect of procainamide on clockwise right atrial isthmus conduction compared with counterclockwise conduction: possible mechanism of the greater incidence of common atrial flutter during antiarrhythmic therapy.

INTRODUCTION: It has been shown that the induction rates of common and reversed common atrial flutter are comparable during baseline control study, whereas the rate is significantly greater for common flutter than reversed common flutter during administration of antiarrhythmic agents. The mechanism of this discrepancy is not known. METHODS AND RESULTS: The study consisted of 15 patients (group 1) with clinically documented common atrial flutter either with (n = 10) or without (n = 5) Class I antiarrhythmic therapy, and 15 patients with paroxysmal supraventricular tachycardia (group 2). Bidirectional conduction velocity and minimal pacing cycle length of 1:1 conduction during incremental pacing from both the low lateral right atrium and coronary sinus were assessed. The response of these variables to procainamide was analyzed in correlation with the induction rate of each type of flutter during the pacing protocol. Conduction velocity in the clockwise (CW) direction was significantly slower for all pacing cycle lengths than conduction velocity in the counterclockwise (CCW) direction in group 1 but was similar in group 2. Minimal pacing cycle length of 1:1 conduction did not differ between CW and CCW conduction in either group. However, in group 1, minimal pacing cycle length of 1:1 conduction of CW conduction was prolonged to a greater degree after procainamide than that of CCW conduction. There also was a significant increase in the induction rate of common flutter. This preferential effect of procainamide on CW conduction was not observed in group 2. CONCLUSION: CW conduction over the isthmus is preferentially influenced by procainamide compared with CCW conduction, which may explain the greater incidence and induction probability of common flutter during antiarrhythmic therapy.

Adult↗

Effects of a single oral dose of cilostazol on epicardial coronary arteries and hemodynamics in humans.

Cilostazol, a novel cyclic adenosine monophosphate phosphodiesterase type III inhibitor, has been developed as an antiplatelet drug with a vasodilating action on peripheral arteries. The present study was designed to test, in humans, whether cilostazol can dilate the epicardial coronary arteries and what are its hemodynamic effects. Eight patients with chest pain syndrome were subjected to serial quantitative coronary arteriography immediately before and at 30, 60 and 150min after a single oral dose of cilostazol (200mg). Luminal cross-sectional areas (mm2) at the proximal and distal sites of major coronary arteries (6 segments at each sampling time) were significantly increased at 150 min after taking the drug. The percent increases relative to the baseline values were 25+/-7 (6.8+/-0.8-->8.3+/-1.0*) and 42+/-7% (2.1+/-0.3-->3.0+/-0.4*) in the right coronary artery, 24+/-5 (5.1+/-0.7-->6.1+/-0.8*) and 28+/-10% (1.6+/-0.31-->9+/-0.3*) in the left anterior descending artery, and 14+/-6 (5.9+/-0.9-->6.6+/-0.9*) and 24+/-10% (1.3+/-0.2-->1.5+/-0.2*) in the left circumflex artery, respectively (*p<0.05 vs baseline). This action, relative to that of nitroglycerine, was between 27% and 54%. Moreover, small but sustained decreases in systolic pulmonary pressure and stroke work index were observed. Thus, cilostazol has a mild coronary vasodilating action with minimal hemodynamic effects, thereby giving it a possible role in the treatment of coronary artery disease.

Administration, Oral↗

Clinical course, timing of rupture and relationship with coronary recanalization therapy in 77 patients with ventricular free wall rupture following acute myocardial infarction.

This study aimed to analyze the clinical course, timing of rupture and relationship with percutaneous coronary intervention (PCI) in patients with cardiac free wall rupture (FWR) following acute myocardial infarction (AMI). FWR was observed in 77 (2.3%) of 3, 284 patients with AMI in our CCU over 28 years. 47 (61.0%) cases were male and mean of age was 69.8 year old. Rupture occurred on Day 1 of infarction in 46 patients (59.7%). 22 cases (28.6%) had cardiogenic shock before FWR. 10 cases (13.0%) had double rupture preceded by ventricular septal perforation (VSP). 25 cases (32.5%) were treated with thrombolytic agents, and only 10 cases (13.0%) had percutaneous coronary intervention (PCI). Before 1981, when PCI was not indicated, incidence of FWR was 2.7%. After 1988 (the era of PCI), the incidence decreased to 1.1%. FWR and the era showed a significant negative correlation (r=0.519: P=0.0056). Rupture was abrupt in 51 cases (66.2%: abrupt type) and was gradual in 26 cases (33.8%: oozing type). The percentages of female, patients with cardiogenic shock before rupture, patients treated by thrombolytic agents and survival rate were significantly higher in the slow-onset rupture group than in the abrupt-onset rupture group. The percentage of patients treated by PCI was extremely low (7.8%) in abrupt-onset group. Of all patients, only 8 (10.4%) survived by emergency operation. One patient with abrupt type survived emergency pericardiotomy in the CCU. One patient with abrupt type and 4 patients with oozing type who had emergency operation in operation room survived. 2 patients with oozing type survived by pericardial drainage and strict blood pressure control. We conclude that early recognition and emergency surgery without thrombolytic therapy may substantially reduce mortality in oozing ruptures. Moreover, immediate and adequate reperfusion by PCI may prevent development of abrupt rupture following acute myocardial infarction.

Aged↗

Clinical significance of wide QRS complexes at the termination of paroxysmal supraventricular tachycardias.

BACKGROUND: A wide QRS complex is not a rare electrocardiographic phenomenon at the termination of paroxysmal supraventricular tachycardia (PSVT), but no plausible underlying mechanism has yet been proposed. The purpose of the present study was to elucidate the frequency and the underlying mechanism of the wide QRS complexes at the termination of PSVT. METHODS: We retrospectively reviewed 305 electrocardiograms (ECGs) from 100 patients, on which PSVT termination was recorded. The frequency of the wide QRS complexes was analyzed in 181 ECGs to avoid duplication, because there were 124 ECGs obtained from the same patients with same methods. The 181 ECGs were divided by morphology into three groups: Type A, termination with wide QRS complex without pause; Type B, wide QRS complex following initial pause after termination; Type C, wide QRS complex following the first narrow QRS after termination. RESULTS: The wide QRS complex was recorded in 81/181 (44.8%) ECGs (Type A; 3/81 (3.7%), Type B; 44/81 (54.3%), Type C; 62/81 (55.6%) ) and its frequency was not dependent on the mechanism of PSVT. It was more frequently observed after a long pause, and was frequently induced by procedures that increase vagal tone, such as intravenous adenosine 5'-triphosphate administration (16/22: 72.7%) and vagal stimulation maneuvers (16/32: 50%). There were a total of 41 wide QRS complexes (44.6%) which had a preceding sinus P wave, out of a total of 92 wide QRS complexes in all three types. These 41 wide QRS complexes included 30/44 (68.2%) Type B wide QRS, and 11 (24.4%) Type C wide QRS complexes. CONCLUSION: The aberrant conduction or escaped ventricular contraction was suggested to be the underlying mechanism of the majority of wide QRS complexes and ventricular premature contraction is less frequent.

Electrocardiography↗

Clinical significance of pleural effusion in acute aortic dissection.

STUDY OBJECTIVE: To clarify the clinical significance of pleural effusion in the clinical course of acute aortic dissection (AAD). DESIGN: Retrospective clinical series. SETTING: A university hospital. PATIENTS: Fifty-five patients strongly suspected of having AAD because of severe chest or back pain. Patients with obvious ischemic heart disease, lung disease, and pleural disease were excluded. INTERVENTIONS: An additional diagnosis of pleural effusion was made when evident by CT. MEASUREMENTS AND RESULTS: Pleural effusion was detected in 42 of 48 patients (88%) with AAD (mean plus minus SD age, 65 plus minus 12 years; 35 men and 13 women), but in only 1 of 7 patients (14%) who proved not to have AAD (mean age, 74 +/- 10 years; 6 men and 1 woman). Effusion appeared at a mean of 4.5 days after onset of dissection. Thoracentesis performed in six patients showed a bloody effusion in three patients and an exudative effusion in three patients. In the six AAD patients without pleural effusion, four patients underwent surgery within 3 days after onset of dissection. In patients with AAD, effusion was demonstrated on the first CT after hospital admission in 18 patients, and was bilateral in 32 patients. WBC count in blood, serum C-reactive protein concentration, and body temperature were higher in patients with effusion (13,400 +/- 3,600/microL, 18.4 +/- 11.5 mg/dL, and 38.2 +/- 0.7 degrees C) than in those without effusion (10,300 +/- 2,900/microL, 4.5 +/- 4.2 mg/dL, and 37.0 +/- 1.0 degrees C, respectively). CONCLUSIONS: Pleural effusion occurs frequently in patients with AAD, often in association with inflammatory reactions.

Acute Disease↗

Unusual petal-like fibromuscular dysplasia as a cause of acute abdomen and circulatory shock.

Fibromuscular dysplasia (FMD) is a nonatherosclerotic, noninflammatory segmental arterial occlusive disorder that involves primarily the renal and carotid arteries, and less often the coronary, iliac, and visceral arteries. We report the case of 78-year-old Japanese woman who presented with acute abdomen complicated by shock. Autopsy revealed hemorrhagic necrosis of the small intestine due to severe narrowing of the mesenteric arteries. Histologically, smooth muscles showed in-bundle hyperplasia surrounding the adventitia together with medial and perimedial fibrodysplasia of these arteries, forming the characteristic petal-like appearance of FMD. No occlusive thrombus was observed. Further, another medial fibrodysplasia type of FMD was also seen in the renal and left circumflex coronary arteries. Unusual proliferation of smooth muscles resulted in the petal-like atypical FMD at the superior mesenteric artery.

Abdomen, Acute↗

Cardiac pseudoaneurysm coupled with a rupture of the papillary muscle complicating myocardial infarction.

As a complication of myocardial infarction, dual rupture of the left ventricular myocardium and the papillary muscle is a rare condition. In such a case, the heart is predisposed to reduced output because of unloading of the ventricle during systole, resulting in the patient being in danger of deteriorating into a severe state or dying suddenly from cardiogenic shock. We report a rescued case of a 65-year-old woman, who had cardiogenic shock due to left ventricular pseudoaneurysm, coupled with partial rupture of the posteromedial papillary muscle three weeks after posterior myocardial infarction. Emergent left ventriculography revealed a large aneurysmal cavity and regurgitation towards the left atrium. The patient underwent emergent aneurysmectomy with mitral valve replacement.

Aged↗

Systemic lupus erythematosus related transverse myelitis presenting longitudinal involvement of the spinal cord.

Lupus-related transverse myelitis is a rare but serious complication. A 25-year-old Japanese woman with systemic lupus erythematosus (SLE) was admitted because of numbness of the face and left upper extremity, headache, and intermittent fever. Six days later, she developed tetraplegia. MRI of the spinal cord showed longitudinal high intensity signals from medulla oblongata to C5, and from Th12 to conus medullaris on T2-weighted image. These MRI findings were consistent with acute catastrophic neurological abnormalities. Despite administration of the combination of methylprednisolone and cyclophosphamide pulse therapies, as well as plasmapheresis, her condition did not improve. Any vasculopathy in addition to the autoimmune pathogenesis, and narrow therapeutic window may relate to the present refractory case.

Adult↗

Spontaneous isolated dissection of the superior mesenteric artery.

A case of a 63-year-old man with isolated dissection of the superior mesenteric artery (SMA), demonstrated by enhanced computed tomography (CT) and abdominal angiography, was admitted to our hospital. The severity of this disease varies from mild to severe; the severe cases require surgery. But the mild cases, like the one presented here, only need conservative therapy. This case demonstrated the usefulness of anticoagulation therapy and the indications for surgical and radiological intervention.

Aortic Dissection↗

Prognosis of economy class syndrome treated in intensive care unit.

OBJECTIVE: The aim of this study was to clarify the prognosis of economy class syndrome (pulmonary thromboembolism following long distance flight) patients discharged from the intensive care unit. METHOD: Medications, daily activities, recurrence of pulmonary thromboembolism, and quality of life were investigated for an average of 471 days following discharge from the intensive care unit. The information from the patients was obtained by means of a mailed questionnaire or telephone interview. PATIENTS: Ten patients with economy class syndrome were enrolled in this study. Nine were female and one was male (61+/-9 years). RESULTS: In addition to appropriate acute care, additional management was given including the placement of an inferior vena cava filter in 3 patients and a course of oral anticoagulation therapy in 7 patients. None of them died or had recurrence of pulmonary thromboembolism. Four patients took subsequent air flights. No thromboembolic episodes were seen during the follow-up period. CONCLUSION: The long-term prognosis in these patients can be favorable with appropriate management of the acute episode in conjunction with adequate preventive measures.

Acute Disease↗

[Clinical significance of plasma concentration of macrophage colony-stimulating factor in patients with vasospastic angina].

OBJECTIVES: The concentration of macrophage colony-stimulating factor (M-CSF), an inflammatory cytokine, increases with the progression of coronary lesions, but no clinical investigations have evaluated the relationship to coronary vascular tone. The present study investigated the relationship between M-CSF and vasoreactivity of the coronary arteries in patients with vasospastic angina. METHODS: Vasospastic angina (VSA) was characterized by transient chest pain and ischemic ST segment changes at rest, or by a positive result in spasm provocation testing with acetylcholine. The subjects were 24 patients with stable VSA(inactive VSA group) treated on an outpatient basis, 31 VSA patients hospitalized with unstable angina (active VSA group), and 13 healthy subjects(control group). The sensitivity of determination of plasma M-CSF in blood was 40 pg/ml. The levels of this factor in each group were compared. Based on the findings of the acetylcholine vasospasm-induction test, patients were divided into those with single-vessel vasospasm and those with multivessel vasospasm, and, according to the dose of acetylcholine required to induce spasm, into high- and low-dose groups. Plasma M-CSF levels in each group were compared. RESULTS: Mean plasma M-CSF was 598 +/- 180 pg/ml in the inactive VSA group, 775 +/- 194 pg/ml in the active VSA group, and 632 +/- 103 pg/ml in the control group. The mean plasma M-CSF level in the active VSA group was significantly higher than that in the inactive VSA group(p < 0.01). Mean plasma M-CSF level in the single-vessel and multivessel vasospasm groups was highest for active VSA patients with multivessel vasospasm (872 +/- 173 pg/ml). The relationship with the acetylcholine induction dose clarified that plasma M-CSF levels were highest in patients with active VSA in the acetylcholine low-dose group (825 +/- 177 pg/ml, p < 0.001). CONCLUSIONS: Plasma M-CSF concentration reflects the vasoreactivity of coronary spasm in the VSA group, and may be an indicator of the severity of coronary endothelial dysfunction.

Aged↗

[Left ventricular peak systolic pressure/end-systolic volume ratio change after dobutamine infusion for predicting left ventricular contractile reserve: comparison with Emax].

OBJECTIVES: Genuine left ventricular contractile function is difficult to assess in the clinical setting. Left ventricular peak systolic pressure/end-systolic volume (Pps/Ves) ratio may be misleading because this index takes no account of the left ventricular end-systolic point and V0 intercept in the pressure-volume relation geographic curve. End-systolic pressure-volume relation and maximum chamber elastance derived from left ventricular pressure-volume loops can provide reliable estimates of contractile function. However, the feasibility of this technique for clinical purposes is limited, because it requires instantaneous measurement of left ventricular pressure and volume. This study assessed the feasibility of using Pps/Ves ratio for predicting the left ventricular contractile reserve by direct comparison with maximum elastance (Emax) derived from left ventricular pressure-volume loops. METHODS: Studies were undertaken in 18 consecutive patients aged 60 +/- 9 years who underwent cardiac catheterization. On-line instantaneous left ventricular volume was derived from the acoustic quantification method by transthoracic echocardiography. Pps was determined by pressure manometer tipped wire and Ves was measured automatically from acoustic quantification software in an ultrasound system. Pps/Ves was compared with Emax derived from each simultaneous pressure-volume loop during inferior vena caval occlusion before and after dobutamine infusion. Emax was determined as the slope of end-systolic points for each loop with the use of an automated iterative linear regression technique. Left ventricular contractile reserve was assessed by evaluating its functional response to 10 micrograms/kg/min of dobutamine infusion. RESULTS: Pps/Ves showed significant correlation with Emax in all patients (r = 0.70, p < 0.0001). However, scattered distribution of V0 value differences were noted. Contractile reserve (Pps/Ves) showed strong correlation with contractile reserve (Emax) despite V0 value differences (r = 0.927, p < 0.0001). CONCLUSIONS: Pps/Ves change after dobutamine infusion may minimize individual V0 distribution. This simple index could be used to evaluate left ventricular systolic performance without requiring the left ventricular pressure-volume relationship and volume unloading maneuver.

Aged↗

[Potential role of leptin and insulin resistance assessed by the glucose clamp technique in coronary artery disease].

OBJECTIVES: Leptin may correlate with insulin resistance and be an important factor in patients with coronary artery disease. Therefore, we examined whether plasma leptin levels and insulin resistance are linked with coronary artery disease. METHODS: Plasma leptin levels and insulin resistance, assessed by the hyperinsulinemic euglycemic clamp technique, were measured in control subjects (n = 12, mean age 62 +/- 10 years), and in patients with obstructive coronary artery disease (n = 15, mean age 64 +/- 8 years) or vasospastic angina (n = 12, mean age 62 +/- 12 years). RESULTS: Plasma leptin levels were significantly higher (p < 0.017) in patients with obstructive coronary artery disease (8.4 +/- 2.7 ng/ml) and vasospastic angina (7.9 +/- 2.1 ng/ml) than in patients without obstructive coronary artery disease (4.7 +/- 1.4 ng/ml). Mean glucose infusion rate was significantly (p < 0.017) lower in patients with obstructive coronary artery disease (4.39 +/- 1.78 mg/kg/min) and vasospastic angina (3.57 +/- 1.72 mg/kg/min) than in patients without obstructive coronary artery disease (8.74 +/- 1.05 mg/kg/min). The plasma levels of leptin were negatively correlated with mean glucose infusion rate (r = -0.67, p < 0.01). The other coronary risk factors were similar in these three groups. CONCLUSIONS: Plasma leptin levels are correlated with insulin resistance and may be associated with coronary artery disease.

Aged↗