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Biomedical subjects

T Chikamori

Publications and source records attributed to T Chikamori.

At least 37 records · Page 2Linked to original sources
PubMed1997

[Mechanism of silent myocardial ischemia in elderly patients with coronary artery disease--assessment by dipyridamole thallium scintigraphy].

To evaluate the clinical significance of silent myocardial ischemia in elderly patients with coronary artery disease, 147 patients (aged 65 years and older) underwent coronary angiography and dipyridamole thallium scintigraphy. Seventy-four patients (44 men, 30 women) who showed reversible defects (RD) and ischemic ST depression during scintigraphy were divided into two groups: 13 with silent RD (18%, 12 men, 1 woman), and 61 with painful RD (82%, 32 men, 29 women). Most patients with silent RD were men. The prevalence of myocardial infarction was similar in patients with silent RD (62%) and in patients with painful RD (49%). The prevalence of multivessel disease was also similar in the two groups: 85% in patients with silent RD and 82% in patients with painful RD. Among 38 patients with infarction, 8 had silent RD and 30 had painful RD. The prevalence of RD in the area of infarction was greater in patients with silent RD (63%) than in patients with painful RD (47%), but the difference was not statistically significant. The prevalence of extensive infarction (fixed defects) was greater in patients with silent RD (75%) than in patients with painful RD (30%, p < 0.05). Among 36 patients without infarction, there was no scintigraphic parameter which showed significant difference. Bypass grafting and angioplasty were initially performed in 23% of the patients with silent RD and in 36% of the patients with painful RD (ns). When the two groups were treated medically during the follow-up period of 29 +/- 22 months, the incidences of cardiac events were similar: 10% in patients with silent RD and 13% in patients with painful RD. The prevalence of silent RD is not high in elderly patients with significant coronary artery disease. Compared with the patients with painful RD, those with silent RD were more likely to have an old and extensive myocardial infarction, and they tended to have RD in the area of the infarct.

Aged↗
PubMed1997

[Usefulness of dipyridamole thallium scintigraphy in the diagnosis of coronary artery disease in elderly patients].

Patients suspected of having coronary artery disease (CAD) underwent dipyridamole thallium scintigraphy, exercise electrocardiography, and coronary angiography. Of the 500 patients studied, 163 were at least 65 years old, and 337 were less than 65 years old. Both CAD and multivessel CAD were more common in elderly than in younger patients (81% vs 69%, p < 0.01 for CAD; and 43% vs 26% p < 0.01 for multivessel CAD). In patients without myocardial infarction, the specificity of exercise electrocardiography was lower among elderly patients than among younger patients (52% vs 61%), but the sensitivity was higher (87% vs 75%). In contrast, both the sensitivity and the specificity of dipyridamole thallium scintigraphy were similar in the two age groups (86% vs 87% and 79% vs 74%). Among patients with myocardial infarction and a positive exercise test, reversible defects were equally common in the two age groups (60% vs 58%). The reversible defects were in areas remote from the area of infarction in half of the patients in both groups. Among patients with negative exercise-test results, reversible defects were more common in elderly patients than in younger patients (57% vs 38%). The reversible defects were in the infarcted area in 71% and 79% of these patients, respectively. These results indicate that dipyridamole thallium scintigraphy is a sensitive and specific method for detecting CAD, independent of age. It is particularly useful in identifying myocardial viability in the infarcted area.

Adult↗
PubMed1997

[Surgically treated unruptured sinus of Valsalva aneurysm: a case report].

A 73-year-old man was admitted because of progressive dyspnea. Echocardiography revealed a markedly dilated right sinus of Valsalva and severe aortic regurgitation. Coaptation loss of the aortic valve leaflets was thought to be the cause of regurgitation and congestive heart failure, a rare complication of the unruptured sinus of Valsalva aneurysm. Surgical treatment should be considered to prevent life-threatening heart failure and rupture of the aneurysm even in patients without overt heart failure.

Aged↗
PubMed1996

Diagnostic significance of an exercise-induced prominent U wave in acute myocardial infarction.

A prominent U wave induced by exercise testing in patients with anterior wall myocardial infarction is a highly specific but insensitive marker for the narrowing of the left circumflex or right coronary artery, although a U-wave increase alone with or without ST-segment depression may help better identify these coronary artery narrowings. In patients with inferior and/or posterior myocardial infarction, a prominent U wave is regarded as a simple electrocardiographic marker for inferior and/or posterior residual ischemia.

Adult↗
PubMed1996

Sympathetic hyperactivity in patients with vasospastic angina--assessment by spectral analysis of heart rate and arterial pressure variabilities.

The autonomic nervous system may play an important role in regulating coronary arterial tone. To evaluate the role of autonomic nervous activity in patients with vasospastic angina (VSA), we studied 10 VSA patients with patent coronary artery (mean; 56 yr, range; 44-66 yr) and 8 normal subjects (mean; 58 yr, range; 35-71 yr). ECG and arterial pressure were continuously recorded for 4 min in a supine position at 7:30 am, 10:30 am, and 4:30 pm. Low-frequency (LF; 0.04-0.15 Hz) and high-frequency (HF; 0.20 Hz) components of the beat-to-beat variabilities of the R-R interval (RRI) and systolic arterial pressure (SAP) were then estimated by autoregressive power spectral analysis. The LF-Normalized Power (LF-NP; [LF Power]/[Total Power]-[Direct Current Power]) of both the RRI and SAP variabilities were greater in VSA patients than in normal subjects (RRI: 0.51 +/- 0.07, 0.51 +/- 0.07, 0.53 +/- 0.06, vs 0.25 +/- 0.04, 0.31 +/- 0.05, 0.31 +/- 0.06, at 7:30 am, 10:30 am, and 4:30 pm respectively: p = 0.010, 0.044, 0.018. SAP: 0.62 +/- 0.06, 0.53 +/- 0.06, 0.57 +/- 0.06 vs 0.37 +/- 0.04, 0.30 +/- 0.06, 0.26 +/- 0.07, respectively: p = 0.006, 0.017, 0.003.). The LF-power of SAP variability also tended to be greater in VSA patients. There was no difference in the HF-component coefficient of variance (CCV (%) = 100 x (component power) (1/2)/ mean RR intervals) of the RRI variabilities between the 2 groups. These results indicate that increased sympathetic vasomotor tone and cardiac sympathetic predominance may play an important role in patients with VSA.

Adult↗
PubMed1996

[Two cases of Candida endocarditis associated with abdominal disease].

Two cases of Candida endocarditis are reported. The first case was of a 63-year-old man who had a positive blood culture for Candida albicans during treatment for liver abscess and early gastric cancer. He was transferred to our department, and aortic and tricuspid regurgitation due to Candida endocarditis was diagnosed. The patient was successfully treated with aortic valve replacement, tricuspid valve plasty and anti-fungal agents. The second case was of a 65-year-old man who complained of fever. Despite a diagnosis of common bile duct cancer and resection of the tumor, the fever persisted. He was transferred to our department and was diagnosed having aortic regurgitation due to Candida endocarditis, complicated by heart failure. Although intense medical therapy including antifungal agents, diuretics, catecholamines and digoxin was initiated, the patient died from multiple embolisms 9 days later. In the treatment of Candida endocarditis, early diagnosis and early decision-making for either surgical or medical therapy is indispensable. Although the prevalence of Candida endocarditis is low, the differentiation of this disease should be taken into account in febrile elderly patients with long-standing therapy with antibiotics.

Aged↗
PubMed1996

[An elderly patient with Leriche syndrome complicated by congestive heart failure and rhabdomyolysis].

A 64-year-old man, who had had bilateral intermittent claudication and leg pain for five years, was admitted because of sudden onset of severe leg pain, and acute respiratory failure. Laboratory data showed markedly elevated serum CK of 73,050 IU/L, and urinary myoglobin of 430,000 ng/ml. A diagnosis of rhabdomyolysis was made. Renal dialysis was required for the next two days because of acute renal failure. The aortogram was performed on the 32nd day and disclosed complete obstruction of the abdominal aorta immediately distal to the bilateral renal arteries. Good collateral flow was noted to the popliteal arteries. On the 49th day, the patient successfully underwent extra-anatomical bypass surgery (axillo-bifemoral bypass). The mechanism of rhabdomyolysis in this elderly patient was discussed.

Heart Failure↗
PubMed1996

[Infective endocarditis associated with vertebral osteomyelitis: report of two cases].

A 42-year-old man and a 65-year-old woman with infective endocarditis suffered onset of severe back pain. Magnetic resonance imaging and technetium-99 m bone scanning demonstrated osteomyelitis in the lumbar spine which is an unusual complication of infective endocarditis. The man was treated by antibiotics and finally aortic valve replacement and laminectomy with bone grafting. The woman had small patent ductus arteriosus and developed aortic regurgitation, but was treated by antibiotics and corset application with good result. The possibility of osteomyelitis in the lumbar spine should be considered in a patient with endocarditis complaining of severe back pain. The appropriate antibiotic therapy over a prolonged period is recommended.

Adult↗
PubMed1995

Determinants of exercise capacity in the hypertensive elderly--a study based on the assessment of cardiac reserve by dipyridamole radionuclide angiography.

To evaluate the determinants of exercise capacity in the hypertensive elderly with an assessment of cardiac reserve by dipyridamole radionuclide angiography, 31 elderly subjects (aged 62 to 78 years, 15 hypertensive and 16 normotensive) underwent symptom-limited maximum treadmill exercise with measurement of maximal oxygen consumption along with radionuclide angiography in list mode at rest and after dipyridamole infusion. In the normotensive elderly, maximal oxygen consumption correlated with relative filling volume during the rapid filling period at rest (r = 0.58; p < 0.05), and correlated inversely with the percent change in the peak ejection rate with dipyridamole (r = -0.63; p < 0.01). In contrast, maximal oxygen consumption correlated with atrial contribution at rest (r = 0.69; p < 0.005), and correlated inversely with the percent change in atrial contribution with dipyridamole (r = -0.87; p < 0.0001) in the hypertensive elderly. These results indicate that the mechanisms for maintaining exercise capacity are different in elderly subjects with or without hypertension.

Aged↗
PubMed1995

[Diagnosis and prognosis of elderly patients with coronary artery disease: assessment with dipyridamole thallium imaging].

Noninvasive evaluation of coronary artery disease is difficult in elderly patients because of their limited exercise-capacity. The diagnostic and prognostic value of dipyridamole perfusion scintigraphy was assessed in 147 patients aged 65 years and older. All patients underwent coronary angiography. Initially, 32 patients had percutaneous transluminal coronary angioplasty (PTCA) or coronary artery bypass grafting (CABG). The other 115 patients were first treated medically and followed for a mean of 29 +/- 22 months. Nine patients (7.9%) had cardiac events including cardiac death and coronary intervention (PTCA or CABG) during the follow-up. Dipyridamole perfusion scintigraphy was performed safely in all patients, whereas treadmill exercise testing could not be adequately performed in 24 patients, 18 of whom had multivessel disease. Multiple regression analysis showed that: fixed defect and reversible defect were powerful detectors of coronary lesions (p = 0.0001, p = 0.0027, respectively), all patients with fixed disease and 94% of patients with only reversible defect had significant coronary lesion; Diffuse slow washout and ST depression were statistically significant for detecting multivessel coronary lesions in patients with fixed disease (p = 0.0001, p = 0.017, respectively), the sensitivity and specificity of diffuse slow washout and/or ST depression for detecting multivessel coronary lesions ware 85% and 74%, respectively, and ST depression was statistically significant for detecting multivessel coronary lesions (p = 0.0002) in patients with only reversible defect, the sensitivity and specificity of ST depression were 88% and 64%, respectively. Cox survival analysis identified diffuse slow washout as the best predictor of future cardiac events among the scintigraphic variables.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1995

[Prognosis of patients with triple vessel disease and old myocardial infarction: relationship to the number of total coronary occlusions].

Patients with myocardial infarction (MI) and triple vessel coronary disease generally have poor prognoses. However, it is not known whether there are particular angiographic variables associated with the poor prognosis in MI patients with triple vessel disease. The angiographic variables for poor prognosis were investigated in 43 MI patients with triple vessel disease (32 men and 11 women, mean age 63 +/- 9 years) who were followed medically for a mean of 32 +/- 28 months. There were 13 cardiac deaths (30%) and 10 late-coronary artery bypass grafting (23%). Twenty patients were alive and well. The patients who died of cardiac causes had lower ejection fractions (42 +/- 18% vs 49 +/- 15%, p < 0.05), a higher prevalence of two vessel occlusion (77% vs 40%, p < 0.05), and a higher prevalence of coronary occlusion opposite the MI site (69% vs 25%, p < 0.01) when compared to survivors, although there were no significant differences in age, MI sites, or the prevalence of occlusion in the infarct-related artery. Multivariate analysis with the Cox proportional hazards model revealed that coronary occlusion opposite the MI site (hazards ratio 16.36) and an age of > or = 65 years (4.46) indicated a significantly high ratio. The hazard ratio of the ejection fraction and two vessel coronary occlusion were not significant. The poor prognosis of MI patients with triple vessel coronary disease may be related to impaired left ventricular function and to coronary occlusion opposite the MI site and greater age. This may have important clinical implications in the initial decision for interventional therapy.

Adult↗