Biomedical subjects
Publications and source records attributed to Y L Doi.
Thirty-four patients with idiopathic dilated and ischemic cardiomyopathy underwent a symptom-limited cardiopulmonary exercise testing to evaluate the significance of postexercise blood pressure (BP) response. The postexercise BP response was useful in assessing the impaired exercise capacity and increased sympathetic activity in patients with heart failure.
OBJECTIVES: To elucidate whether atherosclerotic aortic plaque detected by transesophageal echocardiography can be a clinically useful marker for coronary artery disease in the elderly. BACKGROUND: Atherosclerotic aortic plaque detected by transesophageal echocardiography has been reported to be a marker for coronary artery disease. Its significance may be important particularly in the elderly population, although to our knowledge, there are no data yet available. METHODS: We performed transesophageal echocardiography on 84 patients who had previously undergone coronary arteriography. The criteria used to diagnose atherosclerotic plaque on transesophageal echocardiography were the presence of focally or linearly increased echodensity of the aortic intima with lumen irregularity and thickening or ulceration. RESULTS: Significant coronary artery disease (> or = 50% stenosis) was detected in at least one major coronary artery in 27 of the 84 patients. Aortic plaques were detected by transesophageal echocardiography in 25 of the 27 patients (93%) with coronary artery disease and in 30 of 57 patients (53%) without coronary disease (p<0.001). Among 24 patients 70 years or older, aortic plaques were present in 13 of 14 (93%) patients with coronary artery disease and 9 of 10 patients (90%) without coronary disease. Among 60 patients younger than 70 years, aortic plaques were present in 12 of 13 patients (92%) with coronary artery disease and 21 of 47 patients (45%) without coronary disease (p<0.01). The independent association between coronary artery disease and the presence of aortic plaque, age, gender, and other coronary risk factors was examined by multiple logistic regression analysis. In patients 70 years or older, the presence of aortic plaque failed to be a predictor of significant coronary artery disease, although it was indeed a strong predictor of coronary artery disease in patients younger than 70 years (p<0.05). CONCLUSIONS: In elderly patients, atherosclerotic aortic plaque detected by transesophageal echocardiography is not useful in predicting significant coronary artery disease. It is useful only in a relatively younger population.
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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.
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To evaluate the diagnostic value of a transient dilatation of the left ventricle during dipyridamole-thallium imaging (DTI) for detecting significant coronary artery disease (CAD) in patients with negative DTI results, 81 consecutive patients were studied. Twenty one patients (26%) had CAD and 60 patients had normal coronary anatomy (NCA). The initial/delayed ratio of the left ventricular dimension, which was measured as the distance between the 2 peaks of a count profile curve on a 45 degrees left anterior oblique planar image, was defined as the dilatation ratio (DR) of the left ventricle. Patients with CAD had a higher incidence of chest pain after dipyridamole infusion (35 vs 13%; p < 0.05), and ST depression during exercise testing (50 vs 25%; p < 0.05) than those with NCA. DR was significantly greater in CAD patients than in NCA patients (1.08 +/- 0.10 vs 0.97 +/- 0.03; p < 0.0001). DR was considered abnormal (> 1.03) when it was greater than the mean +2 standard deviations of the DR in NCA patients. Seventy-six percent of CAD patients had an abnormal DR. A stepwise discriminant analysis revealed that an abnormal DR alone had the same ability to predict CAD (sensitivity 76%, specificity 98%, chi-square 80.9, p < 0.0001) as the best combination of abnormal DR, chest pain during exercise testing, age and gender (sensitivity 76%, specificity 98%, chi-square 98.5, p < 0.0001). When abnormal DR was excluded from this analysis, the best combination of the variables showed a reduced ability to predict CAD (sensitivity 81%, specificity 77%, Wilks' Lambda 0.71, chi-square 26.7, p < 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)
To evaluate the prognosis of patients with coronary artery disease treated medically using dipyridamole thallium scintigraphy, 277 consecutive patients were followed prospectively. During 2.8 +/- 1.8 years of follow-up, 21 patients experienced nonfatal myocardial infarction or died from cardiac causes. Stepwise discriminant analysis using clinical and angiographic variables revealed that the combination of ejection fraction, number of diseased vessels, previous myocardial infarction and left ventricular asynergic score was most statistically significant (chi-square = 24, p = 0.0001) in predicting events. After including scintigraphic findings, the analysis revealed that the combination of negative washout rate, ejection fraction, ST depression during dipyridamole loading, previous myocardial infarction, coronary artery narrowing of > 90%, left ventricular asynergic score and number of diseased vessels (chi-square = 39, p < 0.0001) was the best predictor of events. These results indicate that the addition of dipyridamole thallium scintigraphic data to established angiographic markers can help better identify patients with coronary artery disease who are at high risk of cardiac events.
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The purpose of this study was to noninvasively differentiate in patients with reduced global left ventricular function between those with idiopathic dilated cardiomyopathy (IDC) and coronary artery disease (CAD). Clinical features and findings of dipyridamole thallium-201 imaging in 55 consecutive patients with IDC were compared with those in 77 with CAD. Left ventricular ejection fraction was similar between the 2 groups (34 +/- 16% vs 39 +/- 7%). Patients with IDC had lower incidences of ischemic chest pain (11 vs 79%; p less than 0.0001), electrocardiographic evidence of myocardial infarction (24 vs 82%; p less than 0.0001), and reversible defects (4 vs 57%; p less than 0.0001) than did those with CAD. The lowest percent thallium uptake in the initial imaging was less with CAD than IDC (30 +/- 15% vs 59 +/- 10%; p less than 0.001). Patterns of perfusion defects were classified as: no defects, multiple small defects and large defects. Of patients with IDC, 15 had no defects, 19 had multiple small defects, and 21 had large defects, whereas all those with CAD had large defects (p less than 0.0001). Stepwise discriminant analysis, using chest pain and electrocardiography, revealed sensitivity of 89%, specificity of 87%, accuracy of 88%, and positive predictive value of 83% in the identification of patients with IDC.(ABSTRACT TRUNCATED AT 250 WORDS)
To assess the relation of exercise capacity to indexes of systolic and diastolic function in hypertrophic cardiomyopathy, 81 patients underwent two-dimensional echocardiography, technetium-99m equilibrium radionuclide angiography acquired in list mode and maximal, symptom-limited, treadmill exercise testing with measurement of maximal oxygen consumption (VO2 max). VO2 max for the group was 13.9 to 49.3 (mean 25.4) ml/min per kg. Thirty-six patients (44%) achieved less than or equal to 70% of age-predicted VO2 max. Patients with such a degree of limitation were more likely to be in New York Heart Association functional class II or III (23 of 36 vs. 14 of 45; p = 0.005); there was no such relation between VO2 and the incidence and magnitude of rest left ventricular outflow tract pressure gradient greater than 30 mm Hg (11 of 36 vs. 11 of 45; p = NS and 58 +/- 24 vs. 65 +/- 19 mm Hg; p = NS). In the 22 patients with a left ventricular outflow tract gradient, the ratios of peak ejection to peak filling rate and of atrial contribution to left atrial dimension were related to percent of the age-predicted VO2 max (r = 0.49, p = 0.02 and r = 0.54, p less than 0.02). These ratios reflect impaired left ventricular systolic performance and atrial systolic failure, respectively. Stepwise discriminant analysis revealed these two ratios to be the two strongest predictors (p = 0.0001) of patients with a left ventricular outflow tract gradient whose VO2 max was less than or equal to 70% of the age-predicted value (sensitivity 90%, specificity 100%).(ABSTRACT TRUNCATED AT 250 WORDS)
To evaluate the usefulness of dipyridamole thallium scintigraphy with low-level exercise for the identification of left main (LM) coronary artery disease (CAD), 466 consecutive patients with CAD were studied. Thirty-eight patients (8%) had LM stenosis (diameter narrowing greater than or equal to 50%). The LM scintigraphic pattern was present in 9 of 38 patients with LMCAD and 38 of 428 CAD patients without LMCAD (24 vs 9%; p less than 0.005). This pattern was present in 6 of 9 patients with LMCAD without right CAD and in only 3 of 29 patients with LM and right CAD (67 vs 10%; p = 0.0005). Patients with LMCAD had a higher incidence of premature cessation of low-level exercise (53 vs 21%; p less than 0.0001), chest pain (68 vs 48%; p less than 0.02), blood pressure decrease of greater than or equal to 20 mm Hg (44 vs 16%; p less than 0.002) and greater ST depression (0.17 +/- 0.13 vs 0.06 +/- 0.10 mV; p less than 0.001) during dipyridamole loading than patients without LMCAD. Stepwise discriminant analysis revealed that the LM scintigraphic pattern and markers of ischemia during dipyridamole loading best identified (p less than 0.0001) patients with LMCAD without right CAD (sensitivity 67%, specificity 91%), but this predictability is no better than the LM scintigraphic pattern alone. The combination of clinical markers of ischemia during dipyridamole loading and scintigraphic findings of diffuse slow washout, extensive fixed defects and the LM pattern best identified (p less than 0.0001) patients with LM and right CAD (sensitivity 72%, specificity 80%).(ABSTRACT TRUNCATED AT 250 WORDS)
To assess the prognostic significance of thallium-201 perfusion defects in patients with idiopathic dilated cardiomyopathy (IDC), 43 patients underwent thallium scintigraphy in addition to clinical, echocardiographic, angiographic and hemodynamic evaluation. Eleven patients had no significant thallium perfusion abnormality, 19 had multiple small defects and 13 had a large defect. During 3.2 +/- 2.2 years, 14 patients had disease-related mortality. The patients who died had a higher incidence of ventricular tachycardia (71 vs 31%; p less than 0.02), increased cardiothoracic ratio (60 +/- 6 vs 54 +/- 6; p = 0.005), decreased fractional shortening (11 +/- 6 vs 15 +/- 5; p less than 0.05), increased pulmonary wedge pressure (15 +/- 7 vs 10 +/- 6 mm Hg; p = 0.05), increased left ventricular end-diastolic pressure (21 +/- 8 vs 14 +/- 6 mm Hg; p = 0.02) and abnormal thallium perfusion defects (13 of 14 vs 16 of 26; p less than 0.05) compared with survivors. Age, gender, left ventricular end-systolic and end-diastolic dimensions, cardiac index and ejection fraction were not statistically different in the survivors versus the patients who died. Kaplan-Meier survival estimates at 1, 3 and 5 years were 100% in patients without significant perfusion abnormality; 89, 77 and 64%, respectively, in patients with multiple small defects; and 84, 76 and 30%, respectively, in patients with a large defect (p less than 0.025 by log rank test).(ABSTRACT TRUNCATED AT 250 WORDS)
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Cardiac complications, especially aortic regurgitation, are very rare in Behçet's disease. This report describes a patient with a complicated abnormality of the aortic valve apparatus and severe aortic regurgitation secondary to Behçet's disease. In the literature, flail prolapsed valve, perforated valves and ruptured pseudoaneurysms of the sinus of Valsalva have been reported. Echocardiography may be most useful to detect these anatomically complex abnormalities and therefore to elucidate the cause of aortic regurgitation in Behçet's disease.
A 44-year-old housewife was found to have coarctation of the abdominal aorta secondary to Takayasu's arteritis. Since she also had mitral stenosis, possible etiological relation between Takayasu's arteritis and mitral stenosis is suspected.