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Biomedical subjects

R Kusukawa

Publications and source records attributed to R Kusukawa.

At least 37 records · Page 2Linked to original sources
PubMed1991

Absence of atrial contraction and exercise in patients with isolated atrial fibrillation.

The aim of the study was to assess the effect of absence of atrial contraction during exercise. During the incremental ergometer exercise tests, heart rate, oxygen uptake, and oxygen pulse in patients with isolated atrial fibrillation were compared with those in control subjects at rest, at the exercise level of gas exchange anaerobic threshold, and at peak exercise. The study population consisted of 51 subjects aged 40 years or more: 12 patients with isolated atrial fibrillation and 39 control subjects with normal sinus rhythm. Heart rate in control subjects was lower than that in patients with isolated atrial fibrillation, at rest, anaerobic threshold, and peak exercise (74 +/- 12 vs 85 +/- 8 beats/min at rest, 108 +/- 16 vs 134 +/- 18 beats/min at anaerobic threshold, and 151 +/- 16 vs 173 +/- 22 beats/min at peak exercise, all p less than 0.01). During exercise, oxygen uptake in patients with isolated atrial fibrillation was not significantly different from that in control subjects. Oxygen pulse in patients with isolated atrial fibrillation was lower than that in control subjects during exercise (6.45 +/- 2.04 vs 7.84 +/- 1.63 ml/beat at anaerobic threshold, 7.79 +/- 2.28 vs 9.16 +/- 1.79 ml/beat at peak exercise, both p less than 0.05). In patients with isolated atrial fibrillation, the oxygen pulse might be reduced due to the lack of atrial contraction during exercise. However, the oxygen uptake that represents the exercise capacity would be preserved with the increase in heart rate.

Adult↗
PubMed1991

[A case of polyangiitis overlap syndrome].

A 25 year old man was admitted to our hospital on June 1, 1989 because of general fatigue and pleural effusion. He had noticed purpuras and nodules on his bilateral lower legs in July 1988. He was admitted to Nihon University Hospital and was diagnosed as allergic granulomatous angiitis. Methylprednisolone was administered. In March, 1989, a nodular shadow was detected in his lung CT films. From the findings of TBLB a granulomatous lesion was suspected. However, his clinical course was rather stable so he was discharged from the hospital. Two months later, he was suffered from fever and general fatigue. On his chest X ray film pleural effusion was detected in the lower part of his left lung. The nodular shadow was increasing gradually. Laboratory findings on his admission showed leukocytosis, thrombocytosis, elevated CRP and a high titer of RA factor. He was diagnosed as hypersensitivity angiitis in a broad sense based on his biopsy findings of the skin lesion. Furthermore, the diagnosis of an early stage of Wegener's granulomatosis (WG) or limited type of WG was also made from the clinical course of his lung lesion. The combination therapy with cyclophosphamide and methylprednisolone was started. It was so effective that the nodule of his left lung was almost disappeared. It seems that this case is one of the polyangiitis overlap syndrome proposed by Fauci.

Adult↗
PubMed1991

[Assessment of atherosclerotic lesions and distensibility of the thoracic aorta in familial hypercholesterolemia by biplane transesophageal echocardiography].

Atherosclerosis involving the thoracic aorta frequently occurs in patients with familial hypercholesterolemia (FH). In this study, we employed two-dimensional (2-D) transesophageal echocardiography (TEE: 5 MHz) to assess atherosclerotic lesions of the thoracic aorta in 9 patients with FH (47.8 +/- 10.3 yrs) and 11 age-matched normal control subjects. Biplane TEE probe (i.e., transverse or sagittal scan transducer) was used to permit direct imaging of the distal half of the ascending aorta. The atherosclerotic lesions were classified based on the severity of the aortic wall sclerosis as intimal thickening (I.), atheromatous plaque, (II.) and calcification (III.). In all of the patients with FH, atherosclerotic lesions of grade I. or greater were observed particularly in the aortic arch and descending aorta, while, lesions more severe than grade I. in the thoracic aorta were not observed in any of the control subjects. In 6 FH patients (67%), atherosclerotic lesions more severe than grade II. were frequently observed, which were more frequent in the aortic arch and descending aorta than in the ascending aorta.

Adult↗
PubMed1991

[Estimation of atherosclerotic lesions in the thoracic aorta by transesophageal echocardiography].

The thoracic aorta is one of the portions frequently involved with atherosclerotic lesions. We estimated atherosclerotic lesions in the thoracic aorta in consecutive 137 patients (59 +/- 10 years old) using transesophageal echocardiography. The study population consisted of 60 with coronary artery disease (CAD), 36 with hypertension (HT), 28 with hypercholesterolemia (HC, total cholesterol greater than or equal to 230 mg/dl), eight with dissecting aneurysm, nine with true aneurysm and two with aortitis syndrome. We used a single transverse scan-plane probe with ultrasound frequency of 5 MHz. We could obtain satisfactory echograms of whole thoracic aorta except upper portion of the ascending aorta. We defined atherosclerotic lesions as an increased echo-density of the intima, protruded plaque, ulceration or aneurysm. Atherosclerotic lesions were observed in 71 of 137 patients (52%). High incidence of the atherosclerotic lesions was seen in patients with HT (72%), HC (57%) and CAD (57%), whereas incidence of atherosclerotic lesions was low (15%) in patients without HT, HC, CAD or aortic aneurysm. Atherosclerotic lesions were observed more frequently in patients aged greater than or equal to 60 years (69% vs 34%, p less than 0.001). In patients with HT or HC, atherosclerotic lesions were frequently observed even in patients younger than 60 years old (HT: 58%, HC: 53%). We concluded that HT, HC and aging were important risk factors for the atherosclerotic process in the thoracic aorta, and transesophageal echocardiography was a useful approach for the detailed estimation of atherosclerotic lesions in the thoracic aorta.

Adolescent↗
PubMed1991

[Reliability of the exercise ECG in detecting silent ischemia in patients with prior myocardial infarction].

To assess the reliability of the exercise ECG in detecting silent ischemia, ECG results were compared with those of stress-redistribution thallium-201 single-photon emission computed tomography (SPECT) in 116 patients with prior myocardial infarction and in 20 normal subjects used as a control. The LV was divided into 20 segmental images, which were scored blindly on a 5-point scale. The redistribution score was defined as thallium defect score of exercise subtracted by that of redistribution image and was used as a measure of amount of ischemic but viable myocardium. The upper limit of normal redistribution score (= 4.32) was defined as mean +2 standard deviations derived from 20 normal subjects. Of 116 patients, 47 had the redistribution score above the normal range. Twenty-five (53%) of the 47 patients showed positive ECG response. Fourteen (20%) of the 69 patients, who had the normal redistribution score, showed positive ECG response. Thus, the ECG response had a sensitivity of 53% and a specificity of 80% in detecting transient ischemia. Furthermore, the 116 patients were subdivided into 4 groups according to the presence or absence of chest pain and ECG change during exercise. Fourteen patients showed both chest pain and ECG change and all these patients had the redistribution score above the normal range. Twenty-five patients showed ECG change without chest pain and 11 (44%) of the 25 patients had the abnormal redistribution. Three (43%) of 7 patients who showed chest pain without ECG change had the abnormal redistribution score. Of 70 patients who had neither chest pain nor ECG change, 19 (27%) had the redistribution score above the normal range. Thus, limitations exist in detecting silent ischemia by ECG in patients with a prior myocardial infarction, because the ECG response to the exercise test may have a low degree of sensitivity and a high degree of false positive and false negative results in detecting silent ischemia.

Aged↗
PubMed1990

Diagnosis and quantitative evaluation of secundum-type atrial septal defect by transesophageal Doppler echocardiography.

Transesophageal echocardiography (horizontal sector scan) was performed in 11 patients with secundum atrial septal defect (ASD). In all 11 patients, transesophageal echocardiography presented the definite visualization of the defect and a clear laminar shunt flow that showed its 2 peaks in late systole and late diastole. We estimated the size of ASD and a shunt volume across the defect by using transesophageal echocardiography. The defect size determined by transesophageal echocardiography was correlated with the surgical measurement (horizontal width, r = 0.92, p less than 0.001; vertical length, r = 0.85, p less than 0.01). A significant high correlation was shown between the shunt volume measured by transesophageal echocardiography and that by Fick's method (r = 0.87, p less than 0.01). There was no significant correlation between the pulmonary to systemic flow volume (ratio) and the mean shunt flow velocity across ASD, although a high linear correlation was observed between the pulmonary to systemic flow ratio and the defect size in horizontal direction (r = 0.82, p less than 0.01). Transesophageal echocardiography used for diagnosis and quantitative evaluation of ASD could be performed easily and satisfactorily within 10 minutes. Thus, transesophageal echocardiography is a useful method in evaluation of the defect size and the shunt flow volume of ASD. The mean shunt flow velocity was not a reliable index for estimating the shunt flow volume. The defect size might be a valuable determinant of left-to-right shunt volume in ASD.

Adolescent↗
PubMed1990

Coronary artery spasm during cardiac angiography.

Unexpected occurrence of coronary artery spasm is sometimes observed during cardiac catheterization. We report here two cases of coronary artery spasm with hypotension and urticaria subsequent to administration of contrast material. The etiology of coronary artery spasm is discussed.

Angiocardiography↗
PubMed1990

Effects of the partial beta 1-adrenergic agonist, xamoterol, on hemodynamics and regional myocardial function during acute coronary occlusion in dogs.

Xamoterol is a partial beta 1-adrenergic agonist that has combined beta 1-stimulating and beta 1-blocking actions. We studied the effects of xamoterol on hemodynamics and regional left ventricular (LV) function after circumflex coronary artery occlusion in eight anesthetized dogs. Left ventricular systolic wall thickening (%WT: sonomicrometry) was measured in nonischemic, marginal, and ischemic zones. Xamoterol (350 micrograms/kg i.v.) increased the maximum LV pressure (dP/dt) by 62% and aortic flow (AOF) by 52% and decreased LV end-diastolic pressure (EDP) but did not change heart rate (HR) and peak LV pressure (LVP). Xamoterol increased %WT in nonischemic (23.6 +/- 2.3 to 35.1 +/- 2.6%, p less than 0.05) and marginal (5.0 +/- 0.6 to 12.0 +/- 1.5%, p less than 0.05), but not in the ischemic region [-5.7 +/- 0.7 to -2.7 +/- 0.3%, not significant (NS)]. The beta 1-blocking action of xamoterol was evaluated. Xamoterol significantly attenuated the increase in HR and maximum dP/dt caused by isoproterenol (0.1 microgram/kg/min). %WT in each region was maintained at the level caused by xamoterol after isoproterenol. Thus, xamoterol improved cardiac function, yet prevented excessive stimulation by catecholamine in the presence of acute myocardial ischemia.

Acute Disease↗
PubMed1990

Oral verapamil effects on global and regional left ventricular diastolic filling in hypertrophic cardiomyopathy.

To assess the effects of oral verapamil therapy on global and regional left ventricular (LV) diastolic filling of hypertrophic cardiomyopathy (HCM), we studied 9 patients with HCM by radionuclide ventriculography and M-mode echocardiography before and after 2 weeks of oral verapamil therapy (240 mg/day). LV regional function was assessed by subdividing the LV region of interest into 4 regions from which global, septal, apical and lateral time-activity curves and their first-derivative curves were derived. Diastolic asynchrony during early diastole was measured as the sum of the absolute values (total delta t) of the time differences (delta t) from peak filling rate in the global left ventricle to that in each of the 3 regions. Verapamil did not alter LV systolic function globally and regionally. Global LV peak filling rate improved after verapamil therapy from 1.92 +/- 0.59 to 2.35 +/- 0.63 end-diastolic counts/s (p less than 0.02) without altering regional peak filling rates significantly. Global and regional times to peak filling rate showed a shortening or no change despite a tendency to increase in the diastolic time after verapamil therapy. The total delta t decreased from 93 +/- 61 to 41 +/- 23 ms after verapamil (p less than 0.05), indicating more synchronous LV diastolic filling after verapamil. There was a negative correlation between the global peak filling rate and the total delta t (r = -0.54, p less than 0.05, n = 18), suggesting that the global peak filling rate may improve after verapamil therapy in association with the decrease in the asynchronous LV diastolic filling.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1990

Effects of dialysis on left ventricular diastolic filling in patients with chronic renal failure--assessment with radionuclide ventriculography.

To examine the effects of dialysis on left ventricular (LV) filling, gated radionuclide ventriculography was conducted in 15 patients with renal failure before and after dialysis. The LV regional function was assessed by subdividing the LV region of interest into 4 regions from which global and regional time-activity curves and their first-derivative curves were obtained. Early diastolic asynchrony was measured as the sum of the absolute values (total delta t) of the time differences (delta t) between the global peak LV filling rate (PFR) and that for each of the other 3 regions. Dialysis produced an increase in the peak LV ejection rate (PER), heart rate, total delta t and total delta t/diastolic time. It caused a delay or tendency to delay in the time to PFR without significant changes in the PFR either globally or regionally, and the PFR/PER ratio decreased both globally and regionally. These alterations indicated a failure of improvement of the global and regional LV filling, with more asynchronous filling occurring after dialysis despite the increases in PER and heart rate, both of which are expected to increase PFR and shorten the time to PFR. There was a negative correlation between the change in total delta t/diastolic time and the change in the PFR/PER ratio (r = -0.62, p less than 0.01), with a greater increase in asynchrony occurring with the relative greater reduction in the relative global PFR compared with the global PER after dialysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Increased dependence on slow filling for left ventricular diastolic filling in patients with coronary artery disease and a depressed systolic function--assessment with radionuclide ventriculography.

Contributions of rapid filling, slow filling and atrial systole to the left ventricular (LV) filling volume were analyzed with the use of radionuclide ventriculography at rest, both globally and regionally, in 34 patients with isolated disease of the left anterior descending coronary artery. The patients included 17 with a normal ejection fraction (EF greater than or equal to 50%; group 1) and 17 with a depressed EF (less than 50%; group 2), and the data were compared with those obtained from 13 normal subjects. A computer program subdivided the LV image into 4 regions, and time-activity curves were constructed globally and regionally by reverse-gating from the R wave. In both groups the contribution of rapid filling to the LV filling volume was decreased significantly in the affected septal and apical regions, and in the global left ventricle compared with that in normal subjects. In group 1, the contribution of atrial systole showed an increase in these affected regions and in the global left ventricle. In contrast, in group 2, the atrial contribution was not increased globally or regionally as much as was expected. However, the contribution of slow filling was either increased significantly or tended to increase in the affected regions and in the global left ventricle. There were negative correlations between the contribution of rapid filling and that of slow filling in the global left ventricle (r = -0.73, p less than 0.001) and in each of the septal, apical and lateral regions (r greater than or equal to -0.60, p less than 0.001), which suggested that the contribution of slow filling as well as of atrial systole undergoes an increase as rapid filling is impaired. Thus, in patients with coronary artery disease, the left ventricle relies on slow filling as well as atrial systole to affect diastolic LV filling in the affected regions and in the global left ventricle in the presence of LV systolic dysfunction.

Adult↗
PubMed1990

Global and regional diastolic filling dynamics in compensated dilated cardiomyopathy.

To assess the left ventricular (LV) global and regional (anterior, apical, inferior) diastolic filling dynamics in compensated dilated cardiomyopathy (DCM), we measured left ventricular pressure and instantaneous volume from angiography in 7 normal controls (CTL) and 6 DCM patients with sinus rhythm. Global and regional peak filling rate (PER), time constant of LV pressure decline (T; Weiss's method) and LV chamber stiffness (k; Gaasch's method) were calculated. In DCM, left ventricular end-diastolic volume (ml/m2) was larger than in CTL (137 +/- 29 vs. 74 +/- 6, p less than 0.001), and stroke index (ml/m2) was not different from CTL (46 +/- 14 vs. 46 +/- 8, NS), indicating a compensated state of LV. Mitral valve opening pressure (mmHg) tended to increase in DCM compared with CTL (12 +/- 6 vs. 8 +/- 4). Global PFR (ml/sec/m2) (CTL = 216 +/- 47 vs. DCM = 201 +/- 36) and k (CTL = 0.044 +/- 0.023 vs. DCM = 0.029 +/- 0.016) were not different between 2 groups. However, T (msec) was markedly prolonged in DCM compared with CTL (61 +/- 10 vs. 35 +/- 5, p less than 0.001). In CTL, regional PFR (1/sec) showed almost the same values in each region, but in DCM, apical region showed higher PFR than in other regions. Thus, early diastolic filling might play an important role in maintaining the total transmitral flow in DCM despite severe impairment of LV relaxation. This compensation could be related mainly to accelerated regional lengthening of the LV apical region.

Adaptation, Physiological↗
PubMed1990

[Effects of anteroseptal myocardial infarction on systolic and diastolic filling function of the right ventricle].

To assess the effects of wall motion abnormalities of the anterior left ventricle and interventricular septum on right ventricular (RV) systolic and diastolic filling function, multiple-gated radionuclide angiography was performed at rest in 53 patients with previous anteroseptal myocardial infarction and 14 normal subjects. There were 26 patients with left ventricular ejection fraction (LVEF) greater than or equal to 45% (group 1) and 27 with LVEF less than 45% (group 2). Six measurements were obtained simultaneously in both ventricles: 1) EF, 2) peak ejection rate, 3) duration of systole, 4) peak filling rate, 5) time to the peak filling rate, and 6) ratio of the peak filling rate to the peak ejection rate. The mean RV ejection fraction and the peak ejection rate in groups 1 and 2 were similar to those in the normal subjects. The ratio of the peak RV filling rate to the peak RV ejection rate, a sensitive indicator of diastolic filling function, decreased significantly in group 1 (0.61 +/- 0.15, p less than 0.02) and group 2 (0.59 +/- 0.15, p less than 0.02) as compared with that in the normal subjects (0.74 +/- 0.14). This indicates an impairment of early diastolic RV filling compared with RV systolic function. Thus, RV systolic function appears to be normally maintained even when anteroseptal wall motion is severely impaired; however, even in the presence of mild anteroseptal wall motion abnormality, RV filling may be impaired without reduced RV systolic function.

Aged↗
PubMed1990

[A case report of right ventricular infarction clearly detected by transesophageal echocardiography].

We reported a case of a 70 year-old woman who suffered from right ventricular infarction with cardiogenic shock, detected clearly by transesophageal echocardiography. On admission, her pulse rate was 31 bpm and her blood pressure was unobtainable. Conscious level was III-1-2 and she was cold and clammy. The ECG showed complete AV block with junctional escape rhythm at a rate of 31 bpm which required temporary pacing and ST elevation in leads II, III, a VF, V4R, V3R, V1. An echocardiogram showed akinesis of RV free wall and paradoxical septal motion. Transesophageal echocardiography was performed safely on the 5th hospital day and detected RV wall motion abnormality clearly. A Swan-Ganz catheter was inserted. Mean PCW was 12 mmHg. PA pressure was 19/11 mmHg. Mean RA pressure was 13 mmHg. Cardiac index was 1.33 l/min/m2. SvO2 was 54%. Volume loading, administration of dopamine, dobutamine and nitroprusside were started. Cardiac index increased to 1.88 l/min/m2, and SvO2 increased to 59%. On the 4th hospital day, mean RA pressure increased to 29 mmHg and PA pressure increased to 47/31 mmHg acutely. Endotracheal intubation was done and PEEP 6 cmH2O was used and mean RA pressure and PA pressure decreased. On the 6th hospital day, cardiac index increased 4.08 l/min/m2. Cardiac catheterization done two months after acute myocardial infarction showed 75% stenosis of the proximal right coronary artery.

Aged↗
PubMed1990

[Age-related modification of regional left ventricular filling in normal subjects].

Age-related reduction in global left ventricular filling has been reported. To assess how regional left ventricular filling is modified by aging, radionuclide ventriculography was conducted in 48 normal subjects aged 15 to 73 years. Left ventricular regional filling was assessed by dividing left ventricular region of interest into 4 quadrants, from which global (GLB), septal (SEP), apical (Ax) and lateral (LAT) time-activity curves and first-derivative curves were derived. Indexes of left ventricular systolic function at rest did not vary with age, but early diastolic filling significantly declined with age: peak filling rate normalized to end-diastolic volume (EDV/S), peak filling rate normalized to stroke volume (SV/s) and peak filling rate/peak ejection rate decreased (r = -0.42; p less than 0.01, r = -0.48; p less than 0.001, r = -0.47; p less than 0.001), time to peak filling rate increased (r = 0.41; p less than 0.01) with aging. Early diastolic asynchrony was measured as the sum of the absolute values of the time differences from global peak filling rate to that in each of three quadrants (delta TPFR). delta TPFR increased with age (r = 0.37; p less than 0.01). Moreover, delta TPFR correlated with global peak filling rate (EDV/s), peak filling rate (SV/s) and peak filling rate/peak ejection rate (r = -0.40; p less than 0.01, r = -0.45; p less than 0.01, r = -0.51; p less than 0.001). Time to peak filling rate of the lateral region was the shortest (163 +/- 38 ms), followed by the global (179 +/- 36 ms), apical (184 +/- 38 ms) and finally the septal region (195 +/- 35 ms). This suggested that physiologic asynchrony with regard to the sequence of regional filling exists in resting condition in normal subjects. Time to peak filling rate in the septal and apical regions increased with age (r = 0.29; p less than 0.05, r = 0.30; p less than 0.05), but that in the lateral region did not correlate with age (r = 0.11). These regional differences correlated with increase in delta TPFR. Thus, aging alter left ventricular diastolic function, with reduced rate related to increased asynchronous early diastolic filling due to prolongation of time to peak filling rate in the septal and apical regions.

Adolescent↗
PubMed1990

[Clinical applications of transesophageal echocardiography].

Standard transthoracic ultrasound examination of the heart has provided increasingly better images since it was clinically introduced approximately 25 years ago. Although two-dimensional echocardiography is an established tool in clinical cardiology, the image qualities of conventional transthoracic approaches are sometimes unsatisfactory for various reasons, such as obesity, chronic obstructive lung disease, and changes with age in the chest wall. In these patients, transesophageal echocardiography can provide important diagnostic information because chest wall interference and intrathoracic attenuation are eliminated. Furthermore, the close vicinity of the heart and thoracic aorta to the transducer allows the use of higher frequency, near-focused focused transducer, which produces better resolution and improved signal to noise ratio. In this brief review, We discuss the diagnostic possibilities and clinical advantages of transesophageal echocardiography based on its application in more than 1,500 awake patients since 1977 in our department.

Aortic Dissection↗