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Biomedical subjects

K Haze

Publications and source records attributed to K Haze.

At least 91 records · Page 5Linked to original sources

Percutaneous transluminal coronary angioplasty and coronary artery bypass surgery--early and follow-up clinical results.

To evaluate the efficacies of percutaneous transluminal angioplasty (PTCA) and coronary artery bypass grafting (CABG) for angina pectoris, early and follow-up data were reviewed in 495 patients who had undergone these procedures from 1986 to 1988. In 173 patients with single vessel disease, there were no significant differences in initial success rate and early and late incidences of major complications or cardiac death between 152 patients with elective PTCA and 21 with urgent. When compared in 161 patients with multivessel disease, however, significant differences in success rate were found between 130 patients in the elective PTCA group and 31 in whom PTCA was urgent (81.6% vs. 64.5%, p less than 0.05). Significant differences were also found in early incidence of major complications (3.1% vs. 12.9%, p less than 0.01), early mortality (1.5% vs. 9.7%, p less than 0.01), and the late incidence of cardiac events (6.2% vs. 25.0%, p less than 0.01). These results show that freedom from cardiac death and overall cardiac events in the elective PTCA group as significantly better than that in the urgent group at 42 months of follow-up. Comparing early and follow-up results, on the other hand, there was no statistically significant difference between the elective and urgent CABG groups. Thus, there appear to be limitations on the urgent use of PTCA for refractory unstable angina caused by multivessel disease, and urgent CABG was recommended to high-risk patients of urgent PTCA.

Adult↗

[Clinical and anatomical features of acute myocardial infarction associated with double rupture of the interventricular septum and ventricular free wall].

Four patients with acute myocardial infarction (MI) complicating double rupture; interventricular septum and ventricular free wall ruptures, were studied. All patients had histories of hypertension, and pre-infarction angina pectoris of short duration less than 8 days without previous MI. The sites of infarction were anteroseptal in 2 patients and inferoposterior in the other 2. Only one case was complicated with mild pump failure (Killip class II). Blood pressure was adequately controlled after the onset of MI in all patients. Interventricular septal rupture occurred between 2 and 10 days after the onset of MI. Free wall rupture occurred between 2 and 22 days after MI. Types of free wall ruptures were oozing in 2 patients and blow-out in the other 2. Surgical repair was performed in 2 patients with the oozing type rupture, who however died soon after surgery. The autopsy findings were as follows: 3 patients had left ventricular free wall ruptures and one had right ventricular free wall rupture. One of the patients with left ventricular free wall rupture showed a secondary rupture of a pseudo-ventricular aneurysm. Postmortem coronary angiograms revealed 3 patients with single-vessel disease and one patient with double-vessel disease, indicating that coronary arterial lesions and complicated heart failure were not severe in these 4 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

[Non-supervised home exercise programs in a convalescent phase of acute myocardial infarction: their effectiveness and the usefulness of the heart rate at the anaerobic threshold].

The effectiveness of 2 different exercise programs in the convalescent phase of acute myocardial infarction (AMI) was assessed. One hundred and five patients with AMI were enrolled for one of these 2 non-supervised home exercise programs immediately after discharge from the hospital. Before discharge and one month later, they underwent submaximal graded treadmill exercise tests with the application of expiratory gas analysis. All patients were assigned to perform 2 km of walk-jog exercise daily for one month. The heart rate during exercise, duration of exercise and the total steps during 24 hrs were measured. Eighty patients (group A) underwent the exercise program in which their heart rates were maintained at 100-110 beats/min during exercise; while 25 patients (group B) underwent the other program in which their heart rates were maintained at 90-100% of those obtained at their anaerobic threshold (AT). The ventilatory AT was calculated by the standard technique using the Horizon System. In group A, AT increased from 13.4 ml/min/kg to 15.1 ml/min/kg (p < 0.01) after the exercise program and in group B, from 12.8 ml/min/kg to 14.9 ml/min/kg (p < 0.01). In group B, AT increased in all patients, while it remained unchanged in 30% of the patients in group A (p < 0.01). In conclusion, a non-supervised home exercise program can be effective and easily instituted for rehabilitation in a convalescent phase of AMI. The program using 90-100% of the heart rates at the anaerobic threshold seemed to be more suitable for obtaining better effects on exercise tolerance than that using 100-110/min heart rate.

Aged↗

[Medical therapy in patients with left main coronary artery stenosis].

To elucidate the long-term prognosis of medically-treated patients with left main coronary artery (LMCA) lesions, 119 consecutive patients with LMCA lesions undergoing coronary angiography were analyzed retrospectively. Among these, 3 patients died soon after angiography and were excluded from this study. Among the remaining 116 patients, 22 were treated medically (Group M) for the following reasons: profound left ventricular (LV) dysfunction (3 patients), effective pharmacological treatment (10), and patients' refusal of surgical therapy (9). Among 94 patients who underwent coronary artery bypass graft (CABG), 83 patients survived (Group S). During the follow-up period, cardiac events occurred in 5 patients in Group M; cardiac deaths in 3, non-fatal myocardial infarction (MI) in one and late application of CABG in one. Two-year cardiac event-free rate after diagnosis was 77%, which remained unchanged thereafter. The cumulative survival rate was 83%. The incidence of cardiac events in Group M was higher than that in Group S (p < 0.01). However, cardiac event rates were similar between these 2 groups for patients with good collateral circulations to the left coronary arteries, no preceding MI and LV end-diastolic pressure less than 15 mmHg. We concluded that the Japanese patients with severe LMCA lesions who respond favorably to pharmacological intervention have unexpectedly good prognoses, however, obstructed collateral circulation to the left coronary system, the presence of preceding MI and high LV end-diastolic pressure were all high-risk factors for medically-treated patients.

Adult↗

[Prognostic significance of scintigraphic silent myocardial ischemia detected by stress thallium scan in patients with recent myocardial infarction].

To evaluate the prognostic significance of scintigraphic silent myocardial ischemia (SMI) detected by stress thallium scan in patients with myocardial infarction (MI), we performed a retrospective investigation on cardiac events (CE) during a two-year follow-up period in 149 patients with MI within three months of onset (34 +/- 19 days). SMI was defined as asymptomatic redistribution (RD) in the infarcted area. The patients were divided into three groups based on results of stress thallium scan as follows: 50 patients with neither chest pain nor RD (Group A), 46 patients with SMI (Group B) and 53 symptomatic patients (Group C). In comparison of the incidence of CE, which included cardiac death, recurrent MI, chronic heart failure, angina pectoris, PTCA, CABG and severe ventricular arrhythmia (lown grade greater than or equal to 3) during two-year follow-up, Group C had significantly higher incidence of PTCA and CABG than Group B (p less than 0.01), but there was no significant difference of other CE between groups B and C except PTCA and CABG. In addition, Groups B and C had a significantly higher incidence of CE than Group A in cardiac event-free curves, but there was no significant difference for Groups B and C. We conclude that patients with SMI are associated with unfavorable prognosis as symptomatic patients and that these patients should undergo careful follow-up.

Aged↗

[Prognostic implications of exercise induced silent myocardial ischemia in patients with angina pectoris].

To clarify the prognostic implications of exercise induced silent myocardial ischemia (SMI) in patients with angina pectoris, the clinical characteristics and long-term prognosis after coronary angiography in 379 patients without prior myocardial infarction were investigated. According to the results of treadmill testing and/or Tl-201 exercise imaging after medical treatment, 50 patients with negative for ischemia were classified as control group, 110 patients with exercise induced SMI were classified as the SMI group, and 187 patients with painful ischemia formed the PI group. Thirty-two patients were excluded because of inconclusive exercise results. Single vessel disease and vasospastic angina were more frequent in the control group than in the SMI and PI groups. But there were no differences in baseline characteristics and extent of coronary lesions between the latter two groups. Heart rate, systolic blood pressure and rate-pressure product at end point in treadmill testing were higher in the control and SMI groups than in the PI group. The mean follow-up period was 4.8 years, and follow-up was completed in every case. Cardiac events, including cardiac death, nonfatal myocardial infarction and readmission from severe angina, occurred in 25 patients of the SMI group, 43 of the PI group and 7 of the control group. Cumulative cardiac event curves did not show any statistically significant difference between the SMI and PI groups. We conclude the presence or absence of angina during exercise test is no longer the principal prognostic index for determining a patient's risk of cardiac events.

Adult↗

[Clinical significance of ST segment shifts during chest pain in predicting the pathogenesis of impending myocardial infarction].

To know whether the pathogenesis of impending myocardial infarction(IMI) could be predicted by the direction of ST segment shifts during an ischemic chest pain, we studied 62 patients with IMI and undergoing emergent coronary angiography(CAG). They were selected from a consecutive number of 474 patients with unstable angina. IMI was defined when patients had more than 2 episodes of chest pain at rest under intensive pharmacological interventions after their CCU admission, and at least one of those was not relieved by nitroglycerin given intravenously. They were divided into 2 groups according to ST segment shifts during chest pain; 35 patients with ST elevation (G-1) and 27 patients with ST depression (G-2). The time of CAG was individually determined in each patient according to the severity of illness. Those with acute MI within 3 months before the study and 24 hours following the chest pain just before CAG were excluded from the study. New onset angina accounted for 49% in G-1 and 4% in G-2(p less than 0.01). Average history length of IMI, frequency of symptoms after CCU admission, and interval from the last symptom to CAG were similar in each groups. Single vessel disease was more predominant in G-1 than in G-2 (54% vs 11% p less than 0.01). Intracoronary thrombus(IT) in an ischemia related artery(IRA) was found in 97% of G-1 and 22% of G-2(p less than 0.001), while complex lesions(CL) proposed by Ambrose as another genesis of IMI were in 26% of G-1 and 74% of G-2(p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Angina, Unstable↗

Management and evaluation of non-supervised home exercise program in a convalescent phase of acute myocardial infarction.

Out of 636 patients with acute myocardial infarction (AMI) admitted to our institution, 183 patients enrolled in our non-supervised home exercise program immediately after their discharge from the hospital. The first 40 patients were randomized to control and training group, while the remaining 143 patients were included in the training group. Before and after the trial, all patients underwent cardiopulmonary exercise testing; submaximal graded treadmill exercise test with the application of expiratory gas analysis. In the training group, patients performed 2 km walk-jog exercise everyday for 1 month, keeping their heart rate (HR) at 90-100% of that in the anaerobic threshold. HR during exercise was monitored by patients themselves, using HR-meter. The anaerobic threshold significantly increased in the training group; while control group had no significant changes. VO2 and HR significantly increased at the same Borg's indices. Psychological improvement was also obtained in the training group compared to control group. It is concluded that non-supervised home exercise program is effective and easily applicable in the convalescent phase of AMI.

Aged↗

Newly developed myocardial imaging by using single photon emission computed tomography (SPECT).

Thallium myocardial imaging is a useful technique to evaluate myocardial perfusion and myocardial viability in ischemic heart disease. However, myocardial imaging using single photon emission computed tomography (SPECT) and gamma-emitting radiopharmaceuticals has been recently developed for more precise evaluation of myocardial infarction and ischemia. The present study evaluates animal experiments and the clinical applications of these new myocardial imaging techniques. Areas considered on 1) myocardial necrosis assessed using 111In-antimyosin, 2) myocardial fatty acid metabolism assessed using 123I-beta-methyl-iodophenyl pentadecanoic acid (BMIPP) and 3) myocardial sympathetic neural activity assessed using 123I-metaiodobenzyl guanidine (MIBG). Dual energy SPECT using these new agents and thallium gives precise characterization of the myocardial tissue in the infarcted and ischemic area.

3-Iodobenzylguanidine↗

Hyperlipoproteinemia as a risk factor for ischemic heart disease.

We analyzed serum lipoproteins and apolipoprotein E (apo E) from 199 patients in CCU, having ischemic heart disease, and from 211 healthy subjects. It was suggested that serum lipoprotein abnormalities, especially elevated low density lipoprotein (LDL) levels, are closely related to atherogenesis in relatively young patients and subjects with severe coronary lesions. The frequency of apo E-4 was higher and that of E-2 was lower in the CCU group than in the control group. Apo E mutants, E-7 (Glu244----Lys, Glu245----Lys) and E-5 (Glu3 (Glu3----Lys), were also frequent in the CCU group. Apo E isoproteins have higher pI in the order E-2, E-3, E-4, and we observed that LDL-cholesterol levels increased in the same order. The apo E mutants, E-5 and E-7, are also more basic than E-4. These findings suggest that basic apo Es were associated with the development of atherosclerosis. The prevalence of familial hypercholesterolemia (FH) in the CCU group was more than 10 times higher than the reported frequency of FH heterozygotes in normal population. The persistence of marked hypercholesterolemia from infancy probably makes FH patients susceptible to atherosclerosis. Based on the analysis of LDL-receptor protein synthesis, various types of mutations were observed even in phenotypically homozygous FH patients. FH homozygotes were divided into 2 groups, a receptor-negative group and a receptor-defective group. We found a great difference in the frequency of coronary heart disease depending on whether even a small number of receptors were present or not.

Apolipoproteins E↗

[Detection of restenosis after successful percutaneous transluminal coronary angioplasty (PTCA)--usefulness of exercise thallium scintigraphy].

We studied the efficacy of stress thallium scan in detecting restenosis after primary successful PTCA. There were 21 patients with angina pectoris and 16 patients with previous myocardial infarction. The sensitivity and the specificity of stress thallium scan in detecting restenosis were superior to those of stress electrocardiography or chest pain complained in follow-up period. In multi-vessel disease, we could assess the vessel developing restenosis more easily than stress electrocardiography. Initial thallium %UPTAKE RATIO was significantly improved after PTCA but redecreased in patients developing restenosis. In patients showing residual redistribution despite of not developing restenosis, we could judge vessel patency by gradually improving initial %UPTAKE RATIO after PTCA. Thus, stress thallium scan proved to be useful in detecting restenosis after PTCA.

Aged↗

[Serial assessment of denervated but viable myocardium following acute myocardial infarction by using 123I-MIBG and 201TlCl myocardial SPECT].

123I-MIBG is taken up by sympathetic nerve ending and provides a scintigraphic image of myocardial sympathetic innervation. We investigated the scintigraphic detection of denervated but viable myocardium following acute myocardial infarction by serial 123I-MIBG and 201TlCl myocardial SPECT. Fourteen patients were studied at acute (10 +/- 2 days) and chronic stage (86 +/- 10 days). Simultaneous dual SPECT was carried out after IV administration of 111 MBq (3 mCi) of 201TlCl and 123I-MIBG. The defect size of 123I-MIBG and 201TlCl were compared visually by using Bull's eye display generated from each myocardial SPECT. In all patients, 123I-MIBG defect showed larger compared to 201T1Cl defect at acute stage, which suggest the existence of denervated but viable myocardium. Of these patients, seven showed significant improvement of both defects, though 123I-MIBG defect showed slightly larger compared to 201TlCl defect, even at chronic stage. These patients had exercise induced thallium transient defect at infarcted area. The remaining 7 patients had no improvement of both defects at chronic stage, which suggest the complete scar at infarcted area. In addition to above study, 4 patients of old myocardial infarction demonstrated larger 123I-MIBG defect compared to 201TlCl defect even at old stage, which thought to be pathogenesis of ventricular tachycardia. In conclusion, 123I-MIBG could evaluate sympathetic denervation and reinnervation noninvasively in the patients with acute myocardial infarction.

3-Iodobenzylguanidine↗

[Clinical variables that can cause the underestimation of the viable myocardium in the infarcted area: results of the sequential exercise thallium-201 myocardial scintigraphy].

Clinical variables that can cause the underestimation of the viable myocardium were examined in the sequential exercise thallium-201 study before and after PTCA. Among 60 patients who had documented myocardial infarction with single coronary artery disease, 43 patients had successful PTCA. Compared to the initial images after PTCA, the 4 hour-delayed images before PTCA had larger and more severe defect in the infarcted area of 14 patients (33%). This underestimated group had shorter period from the infarction to the stress study. (3.4 +/- 2.4 M vs. 7.1 +/- 9.2 M; p less than 0.05), and attained more maximal heart rate during the stress study. The numbers of the patients who had severe stenosis (greater than or equal to 99%) were more in the underestimated group (79% vs. 34%; p less than 0.01). The patients who have recent myocardial infarction, especially within three months, are likely to be underestimated their viable myocardium in the infarcted area, and this variable is dependent from their workload during the stress study and the severity of the stenotic lesion which also affect the estimation of the myocardial viability.

Angioplasty, Balloon, Coronary↗

Clinical and prognostic significance of silent myocardial ischemia in survivors after acute myocardial infarction.

To clarify the clinical and prognostic significance of silent myocardial ischemia (SMI) after acute myocardial infarction (MI), the clinical characteristics and long-term prognosis after discharge in 525 medically treated survivors after acute MI were investigated. According to the presence of post-infarction angina and results of all exercise tests during hospitalization, 309 patients without ischemic episodes were classified into control group, 59 patients with SMI into SMI group and 157 patients with post-infarction angina into AP group. Previous MI (29%, 24%, 11%, respectively), non-Q wave MI (34%, 34%, 15%) and multivessel disease (69%, 61%, 33%) were more frequent in the SMI and AP groups than in the control group. These indicated clinical characteristics in patients with SMI were similar to those in patients with angina pectoris. The incidence of angina prior to MI onset in patients with SMI was lower than in patients with post-infarction angina. This may suggest that there is some common mechanism keeping them silent in the pre- and post-MI period. During the mean follow-up period of 5.5 years, 93 patients died and 78 had a recurrent MI. Cumulative total and cardiac mortality, and incidence of recurrent MI by actuarial method were higher in the SMI as well as AP group than in the control group. There was no statistically significant difference in prognosis between SMI and AP group. We conclude total ischemic burden, not only symptomatic but SMI, should be treated using currently available therapeutic modalities for further improvement of long-term prognosis in survivors after acute MI.

Actuarial Analysis↗

Serial assessment of myocardial infarction by using gated MR imaging and Gd-DTPA.

In order to assess the usefulness of Gd-DTPA in the evaluation of myocardial infarction, 17 patients were examined with gated MR imaging. Scans were made by using a spin-echo pulse sequence before and after IV administration of 0.15 mmol/kg of Gd-DTPA. The images were made at four intervals (average of 5, 12, 30, and 90 days) after the onset of the infarction. Gd-DTPA uptake at the infarcted area was graded as marked, moderate, or no increase in signal intensity by visual inspection. At these four time intervals, an area of increased signal intensity in the infarcted myocardium was detected on T1-weighted images after administration of Gd-DTPA in 14 (82%) of 17 cases, 16 (94%) of 17 cases, six (38%) of 16 cases, and three (21%) of 14 cases, respectively. Markedly increased signal intensity in infarcted areas was shown on T1-weighted images with Gd-DTPA at 5 and 12 days. The ratio of gadolinium uptake in the infarcted area to that in normal myocardium also was evaluated. At 5 and 12 days, the mean increase in signal intensity in the infarcted area was significantly higher than that in a normal area, but not at 30 and 90 days. Increased signal intensity also was apparent on T2-weighted images without Gd-DTPA at 5 and 12 days; however, the use of late echo reduced the signal-to-noise ratio, leading to image degradation. Uptake of Gd-DTPA was a positive marker in acute myocardial infarction, but no significant uptake of Gd-DTPA occurred in chronic myocardial infarction.

Contrast Media↗