Kiyoshi Machii

Hypertrophic nonobstructive cardiomyopathy with giant negative T waves (apical hypertrophy): ventriculographic and echocardiographic features in 30 patients.

Abstract In 30 of 1,002 consecutive patients who had left heart catheterization and cineangiography for evaluation of either ischemic heart disease or cardiomyopathy the electrocardiogram showed giant negative T waves (greater than 10 mm) associated with high QRS voltage (R wave greater than 26 mm in lead V 5 or the sum of the S wave in lead V 1 and the R wave in lead V 5 35 mm or more) in the precordial leads despite absence of hypertension or significant coronary artery disease. In all 30 patients a characteristic spade-like configuration (concentric apical hypertrophy) was observed in the right anterior oblique ventriculogram at end-diastole as well as in the long axis two dimensional echocardiogram. The average apical thickness in these patients (24.8 ± 6.6 mm) was significantly greater than that in normal subjects (9.4 ± 3.1 mm) ( P P P P P It is concluded that these 30 patients have nonobstructive hypertrophic cardiomyopathy with marked concentric hypertrophy in the apex (apical hypertrophic type) and with a different septal shape and contraction pattern from those seen in the obstructive type. This type of hypertrophy appears to be a fairly common type of hypertrophic cardiomyopathy in Japan.

Prediction of pulmonary arterial pressure in adults by pulsed Doppler echocardiography.

Doppler echocardiography was used to estimate pulmonary artery (PA) pressure in 45 adult patients with various kinds of heart disease and the patterns were compared with those of 32 normal control subjects. Doppler signals obtained in the right ventricular (RV) outflow tract just proximal to the pulmonary valve and electrocardiogram were recorded simultaneously. Doppler velocity time intervals were measured as follows: RV preejection period, acceleration time from the onset of the RV ejection flow velocity to the peak, and RV ejection time. Thirty patients had PA hypertension and 16 patients had a low cardiac index. The best correlation with PA pressure was achieved by the RV preejection period/acceleration time index (r = 0.89 vs mean pressure). Sensitivity and specificity for predicting PA hypertension were 93% and 97%, respectively. Acceleration time correlated best with the logarithm of PA mean pressure (r = 0.88). Patients were separated into 2 groups according to cardiac index. In those patients with a cardiac index of less than 2.5 liters/min/m2, both RV preejection period/acceleration time and acceleration time were significantly correlated with PA mean pressure (r = 0.87) and log (PA mean pressure) (r = -0.87), respectively. However, the slope of the regression line for acceleration time and log (PA mean pressure) was significantly steeper than that for patients with a cardiac index of greater than or equal to 2.5 liters/min/m2 (p less than 0.05), whereas the relation between RV preejection period/acceleration time and PA mean pressure in the 2 groups could not be differentiated statistically from each other. Other intervals and ratios were less quantitative because of late systolic turbulent flow and individual variability.(ABSTRACT TRUNCATED AT 250 WORDS)

Quantitative relationship between left ventricular function and serum cardiac myosin light chain I levels after coronary reperfusion in patients with acute myocardial infarction.

To estimate the extent of myocardial infarction after coronary artery reperfusion, serum levels of cardiac myosin light chain (LC) I and creatine kinase (CK) were determined serially in 49 patients with acute myocardial infarction. Intracoronary thrombolysis was successful in 25 patients (reperfusion group), and 24 patients were treated in a conventional manner (control group). The peak level of CK appeared significantly earlier in the reperfusion group (11.3 +/- 3.1 hr, mean +/- SD) than in the control group (21.6 +/- 7.2 hr). Cumulative release of CK was significantly related to angiographically determined left ventricular ejection fraction 1 month after the attack in both groups (r = -.50; -.45, respectively). However, the amount of cumulative release of CK in the reperfusion group was greater compared with that in those with the same left ventricular ejection fraction in the control group. Peak appearance time of LCI was almost equal in the two groups (3.8 +/- 1.4 vs 3.9 +/- 1.2 days). Peak levels of LCI were related to the left ventricular ejection fraction in the reperfusion group (r = -.63) and in the control group (r = -.74), and the slopes of their regression lines were similar. The cardiac index obtained on the day of onset in the two groups was related to peak levels of LCI but not to total release of CK. These results suggest that serum levels of LCI reflect the changes in left ventricular function after acute myocardial infarction, regardless of the presence of coronary reperfusion. Thus, serial determinations of LCI in serum facilitate noninvasive assessment of the effects of intracoronary thrombolysis on infarct size.

Right ventricular filling detected by pulsed Doppler echocardiography during the convalescent stage of inferior wall acute myocardial infarction

To evaluate right ventricular (RV) diastolic function in patients with inferior wall acute myocardial infarction (AMI), flow velocity patterns of the RV inflow tract were studied in patients with anterior AMI (n = 32), inferior AMI (n = 32) and angina pectoris without left ventricular asynergy (n = 10) using pulsed Doppler echocardiography. Doppler examinations were performed at least 4 weeks after the attack. Twenty-seven healthy persons served as control subjects. Three Doppler variables were measured at the RV inflow tract: the ratio of the late diastolic peak flow velocity due to atrial contraction to the rapid filling peak flow velocity in early diastole (A/E) and the acceleration time and deceleration time of the RV rapid filling wave. A/E in patients with inferior AMI (1.01 +/- 0.24, mean +/- standard deviation) was significantly greater than in those with anterior AMI (0.80 +/- 0.16, p less than 0.001) and angina pectoris (0.79 +/- 0.17, p less than 0.01) and in normal subjects (0.70 +/- 0.17, p less than 0.001). A/E in patients with inferior AMI correlated with the ratio of left ventricular to RV end-diastolic pressure (r = -0.60, p less than 0.05). A/E in inferior AMI with relatively high RV end-diastolic pressure (more than 8 mm Hg, n = 8) was significantly greater than that in those with normal pressure (8 mm Hg or less, n = 9). A/E in patients with proximal right coronary artery occlusion was significantly greater than that in those with distal occlusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Differences in response of myosin isozyme transition of ordinary and specialized myocardium to overload.

To investigate the response of myosin isozyme transition in specialized myocardium to cardiac overload, we examined immunohistochemically the distribution of myosin isozymes in sinus node cells of overloaded canine atria, using the monoclonal antibodies CMA19 and HMC14, which are specific for atrial myosin heavy chain (α-HC) and ventricular myosin heavy chain (β-HC), respectively. Overloading in canine right atria was induced by artificial tricuspid valve regurgitation and pulmonary stenosis. Right atrial mean pressure rose to 15-20 mm Hg (n = 4) 2 months after surgery. In the working myocardium, cardiac overload caused redistribution of myosin isozymes, α-HC to β-HC. Compared with the normal right atria, fewer myocytes were labeled with CMA19, but more were labeled with HMC14. However, the reactivity of sinus node cells with CMA19 and HMC14 was not changed between normal and overloaded right atria, indicating no redistribution of myosin heavy chain isozymes, α-HC to β-HC. These results suggest that isozymes in myosin heavy chains in the specialized myocardium are protected from overload effects by their firm cytoskeletal framework or other mechanisms.

Effect of recombinant human erythropoietin on cardiac function, peripheral circulatory function and life activity in patients with chronic hemodialysis.

慢性血液透析患者の運動耐容能, 左心機能および末梢循環機能におよぼすrecombinant human erythropoietin (rEPO) の影響を評価するとともに, 日常運動量の変化に関して検討した. 約3か月間のrEPO治療によって, ヘモグロビン濃度は7.9±0.8g/dlから10.5±1.1g/dlへ, ヘマトクリット値は24.2±2.3%から32.0±2.3%へと有意 (p<0.01) な上昇を示したが, 白血球数や血小板数は変化しなかった. このような腎性貧血の改善に伴い, functional aerobic impairment (FAI) は31.7±19.3%から11.6±18.9% (p<0.01) へ, PCIは16.7±20.4%から-4.2±12.3% (p<0.05) へと有意な低下を示したが, MAI (5.6±15.1% vs 5.2±6.7%) とHRI (8.3±8.7% vs 7.3±7.3%) は有意な変化を示さなかった. また, 透析間隔中の歩行数 (6,716±3,468歩vs 6,986±3,125歩) にも有意な変化を認めなかった. 以上の結果より, rEPO治療による腎性貧血の改善によって得られる運動耐容能の増加は, 主として末梢循環機能が改善するためと考えられた. しかし, このような運動耐容能の増加は直接日常運動量を変化させることはなく, 社会復帰の目的のためには, よりactiveな生活指導や積極的な運動療法の併用が必要であろうと考えられた.