Toshikazu Aoki

Late development of an aneurysm of a saphenous vein used as an aortocoronary conduit

A case of a large saphenous vein aortocoronary aneurysm that developed late after coronary artery bypass grafting is presented. This is the first case of a large saphenous vein aortocoronary aneurysm identified by serial angiography and 3-dimensional computed tomographic scanning.

Differences in direction-dependent shortening of the left ventricular wall in hypertrophic cardiomyopathy and in systemic hypertension

To determine whether patients with hypertrophic cardiomyopathy (HC) have an altered mode of contraction of the left ventricular (LV) wall related to underlying myocardial abnormalities, geometric changes in the LV wall were analyzed at 2 points of the cardiac cycle (end-diastole and end-systole) using 2-dimensional echocardiography. The relations between meridional and circumferential shortening of the LV midwall, mean wall thickening, and the changes in the short-axis cross-sectional area of the LV wall at the level of chordae tendineae were determined in 18 patients with nonobstructive HC, and were compared with those in 31 normal subjects and 19 patients with essential systemic hypertension. In normal subjects, no significant difference was observed between meridional (16.3 +/- 2.4%) and circumferential (17.1 +/- 4.0%) shortening, whereas cross-sectional LV wall area increased significantly at end-systole (p < 0.001). In patients with hypertension, all measured indexes were not different from those in normal subjects. In contrast, patients with HC had significantly reduced meridional shortening (p < 0.001) and mean wall thickening (p < 0.01). Consequently, a striking difference was observed between meridional (8.9 +/- 2.4%) and circumferential (16.9 +/- 3.2%) shortening (p < 0.001). Furthermore, no increase in cross-sectional LV wall area was observed at end-systole. Thus, echocardiographic detection of direction-dependent contraction can be a useful index for distinguishing HC from systemic hypertension.

Influence of age on left ventricular performance during exercise in normal Japanese subject: Assessment by radionuclide ventriculography

To assess the effects of age on left ventricular performance, multistage supine ergometer exercise radionuclide ventriculography (RNV) was performed in 92 normal subjects. The subjects ranged in age from 24 to 86 years and were free of cardiopulmonary disease and diabetes. Age-related changes in exercise duration, left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), cardiac output (CO) left ventricular ejection fraction (LVEF), left ventricular dv/dt, systolic and diastolic time indexes of dv/dt, and peak systolic pressure/left ventricular end-systolic volume (PSP/LVESV) were analyzed at rest and during the peak exercise stage.Age-related decrease in LVEDV and peak diastolic dv/dt were significant at rest. The time indexes of ECG R to peak systolic dv/dt and time of end-systole to peak diastolic dv/dt also were prolonged with age. Both maximum heart rate and exercise duration were shown to decline with age. No age-related difference was observed in LVESV, LVEF or PSP/LVESV either at rest or during exercise. However, the change of LVEF and LVESV during exercise was less in subjects aged 60 or more. These results indicate decreased left ventricular function during exercise in elderly subjects.

Dipyridamole radionuclide ventriculography in patients with coronary artery disease : comparison with ergometer exercise

Intravenous administration of dipyridamole during radionuclide ventriculog raphy (RNV) was performed in 26 consecutive patients with symptomatic coro nary artery disease. The authors compared the results of dipyridamole-RNV with those of ergometer exercise-RNV in detecting myocardial ischemia. During exercise, ST depression, regional wall motion (RWM) abnormalities, and de creased left ventricular ejection fraction (LVEF) were observed in 21 (81%), 23 (88%), and 20 (77%) patients, respectively. However, after intravenous di pyridamole, ST depression, RWM abnormalities, and decreased LVEF were observed in 14 (54%), 15 (58%), and 2 (8%) patients, respectively. Although LVEF usually decreases during myocardial ischemia, LVEF did not decrease (57 ± 11% to 58 ± 10%), even in patients with ST depression, after intravenous dipyridamole. Maintained left ventricular ejection fraction is considered to be a hemodynamic effect of the potent arterial vasodilatation induced by di pyridamole. These results from dipyridamole-RNV in myocardial ischemia seem to con flict with the results from dipyridamole-thallium studies carried out to deter mine the capacity to detect coronary artery disease. Unknown mechanisms of dipyridamole other than the coronary steal phenomenon may be operative in the genesis of myocardial ischemia.

Echocardiographic Assessment of Cardiac Structural and Functional Abnormalities in Patients With End-Stage Renal Disease Receiving Chronic Hemodialysis

BACKGROUND The aim of this study was to assess the echocardiographic characteristics of chronic hemodialysis (HD) patients with end-stage renal disease (ESRD) in a multicenter prospective cohort study.Methods and Results:Three hundred and fifteen patients with ESRD (67.9±10.6 years, 47.6% male) on chronic HD for ≥1 year were examined on transthoracic echocardiography, including Doppler-derived aortic valve area (AVA) measurement. Only 11.5% and 3.4% of all patients had normal left ventricular (LV) geometry and normal LV filling pattern, respectively. The majority of patients had aortic and mitral valvular calcification, and approximately 50% of all 315 patients had aortic valve narrowing with AVA <2.0 cm2. Patients were divided into 3 groups according to AVA index tertile: group 1, highest tertile; group 2, middle tertile; and group 3, lowest tertile. Group 3 was older, had a greater cardiothoracic ratio on chest X-ray, higher plasma brain natriuretic peptide and total LV afterload, and lower stroke volume index than the other 2 groups. Age and intact parathyroid hormone (PTH) level were independently associated with low AVA index. CONCLUSIONS Patients with ESRD on chronic HD have a high prevalence of cardiac structural and functional abnormalities including calcified aortic sclerosis. High age and PTH were associated with aortic valve narrowing in these patients.

A case report of a family of serum cholinesterase deficiency.

自他覚症状を全く欠く健康な54才の男性が健康診断において,血清コリンエステラーゼの測定不能な低値を指摘され,肝生検を含む入院精査を受けたが血清コリンエステラ-ゼ低値以外,何ら異常所見を示さず,その家族調査がなされた.その結果,血清コリンエステラーゼ欠損症遺伝子ESI1のホモ接合型,ヘテロ接合型それぞれ3名が発見され,この家系が血清コリンエステラ-ゼ欠損症家系である事が判明した.