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Biomedical subjects

C Kawai

Publications and source records attributed to C Kawai.

At least 307 records · Page 17Linked to original sources
PubMed1987

[Evaluation of coronary reperfusion for acute myocardial infarction by emission CT using technetium-99m pyrophosphate].

Twelve patients with acute transmural myocardial infarction (AMI) were treated with percutaneous transluminal coronary angioplasty (PTCA) following intracoronary thrombolysis using urokinase, and underwent technetium-99m stannous pyrophosphate (Tc-99m-PPi) imaging 9.2 +/- 2.1 hours after the onset of chest pain. The imaging was performed with emission computed tomography (ECT). Compared to planar imaging, this allowed more accurate detection of small myocardial infarcts and accurate measurements of infarcts irrespective of their location was also made. Early Tc-99m-PPi images were obtained to test the hypothesis that an early, abnormal Tc-99m-PPi image suggest successful reperfusion. The results were presented for two groups of patients: three with unsuccessful reperfusion (Group A) and nine with successful reperfusion (Group B). Eight of the nine patients with successful reperfusion had positive acute Tc-99m-PPi images. On the contrary, all the three patients for whom reperfusion failed had negative acute Tc-99m-PPi images. We also examined the feasibility of estimating infarct size using positive Tc-99m-PPi images in patients with successful reperfusion during the early phase of AMI. The Tc-99m-PPi uptake score (Tc-US) was used to measure infarct size in this study. Areas of increased Tc-99m-PPi uptake within myocardial infarcts were threshold at 60% of the peak activity. The Tc-US of each patient was obtained to sum the scores of all myocardial segments using a scoring system with a maximum score of 108. Using this method, Tc-US ranged from 2 to 39. The correlation of Tc-US with the peak serum creatine kinase level was significant (r = 0.91).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

[Exercise 13NH3-positron emission computed tomography (PET) versus exercise single photon emission computed tomography (SPECT)].

The value of exercise positron emission computed tomography (PET) was determined by comparing it with exercise T1-201 single photon emission computed tomography (SPECT) using graded ergometer exercise in 10 anginal patients with left anterior descending coronary (LAD) involvement (stenosis greater than or equal to 75%) with or without other coronary stenosis. The distribution of N-13 ammonia or T1-201 was determined and expressed as percent count ot the highest count on the circumferential profile curve (CPC) in the transaxial image. Two standard deviations below the mean counts of six normal hearts for PET and ten for SPECT were considered as the lower limit of normal, and these were determined separately during exercise and at rest. The ischemic areas per total myocardial areas (%C), the accuracy in diagnosing coronary involvement and the identification of coronary branch involvement were determined by CPC analysis in three corresponding slices. Regional analyses revealed that accuracy in diagnosing proximal left anterior descending artery (LAD) involvement was higher with PET (9/10) than with SPECT (7/10), but the difference was not statistically significant. The accuracy in diagnosing right coronary or circumflex artery stenosis was 9/10 with PET and 8/10 with SPECT (NS); the %C was significantly higher with PET than with SPECT during exercise (PET: mean +/- SD = 56 +/- 21%, SPECT: 35 +/- 21%, p less than .01) in spite of smaller double products (x10(3] (PET: 18.9 +/- 4.7, SPECT: 23.5 +/- 5.7, p less than .02). Thus, exercise PET was more reliable in evaluating regional ischemia and in semiquantifying the ischemic area in the myocardium.

Ammonia↗
PubMed1987

[Colored spatial mapping electrocardiography for detecting myocardial infarction].

Colored spatial mapping electrocardiography (ECG) was developed for practical use from Frank lead vectorcardiography using a microcomputer system (CERX-CQ3001). Compared to body surface electrocardiography this new device facilitated easy recording and analysis for display on eight-colored spatial mapping electrocardiography at points equivalent to those on a terrestrial globe at intervals of 20 degrees longitude and 10 degrees latitude. In this study, the extent and direction of the Q waves were easily recognized with the aid of a colored display and mapping electrocardiography. To quantitatively evaluate infarct size, the total Q wave area (sigma Aq) was calculated from the mapping electrocardiograms of 12 patients with anteroseptal myocardial infarction, and compared with thallium defect scores obtained by single photon emission CT (SPECT) and the left ventricular ejection fraction (EF). Defect scores were calculated using short-axis images. Sigma Aq was correlated with defect scores and EF (r = 0.83, 0.45, respectively). This new type of colored spatial mapping electrocardiography proved useful for detecting myocardial infarction and for evaluating infarct size.

Color↗
PubMed1987

[Hypertrophic cardiomyopathy: mode of death and pathological findings].

To ascertain relationships between modes of death and various pathological parameters in hypertrophic cardiomyopathy (HCM), quantitative analysis of the disarray, fibrosis, and size of myocytes was performed in 22 autopsied subjects with HCM. According to mode of death, the subjects were categorized as three groups; (1) a sudden death group (10 patients), (2) a heart failure group (7 patients) and (3) a control group (5 patients). The group consisted of patients with HCM who were over 55 years old and who died of other diseases (e.g., cancer 3) or from accidents. The hearts were fixed in 10% formalin and sectioned from the base to the apex at 1 cm intervals. A section with maximal septal hypertrophy was histologically examined. The histologic findings in the interventricular septum (VS) and the left ventricular free wall (FW) were quantitatively analyzed using an image analyzer (Olympus VIP-21). The extents of fibrosis and disarray were greater in the sudden death group (fibrosis: VS/FW = 16 + 3/11 + 5%, disarray: VS/FW = 58 + 18/32 + 17%) than in the control group (fibrosis: VS/FW = 7 + 2/6 + 4%; disarray: VS/FW = 24 + 7/8 + 6%), but there were no significant differences in the various parameters of hypertrophy (heart weight, wall thickness, degree of asymmetric septal hypertrophy and size of myocytes) between these two groups. The heart failure group consisted of four hearts with dilated LV cavities and two hearts with small LV cavities. The former showed extensive replacement fibrosis (VS/FW = 37 + 7/25 + 5%) and disarray of residual myocytes (VS/FW = 20 + 16/14 + 6%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1986

Vasodilator therapy with a new stable prostacyclin analog, OP-41483, for congestive heart failure due to coronary artery disease and comparison of hemodynamic effects and platelet aggregation with nitroprusside.

A new stable prostacyclin analog, OP-41483, was used in patients with severe congestive heart failure (CHF) due to coronary artery disease and compared with nitroprusside. During infusion of both drugs, mean brachial arterial pressure, total pulmonary resistance, pulmonary artery wedge pressure and systemic vascular resistance decreased significantly. Cardiac index and stroke index also increased significantly. Platelet aggregation did not change significantly during nitroprusside but decreased significantly with OP-41483 infusion. Thus, this analog may be useful for treatment of patients with CHF due to coronary artery disease.

Aged↗
PubMed1986

Detection and evaluation of tricuspid regurgitation using a real-time, two-dimensional, color-coded, Doppler flow imaging system: comparison with contrast two-dimensional echocardiography and right ventriculography.

To detect and evaluate regurgitant flow in tricuspid regurgitation (TR) with a newly developed, realtime, 2-dimensional (2-D), color-coded, Doppler flow imaging system (Doppler 2-D echo), 27 patients (18 with suspected TR and 9 normal subjects) were examined and the findings were compared with those obtained using contrast 2-D echocardiography (contrast 2-D echo) and right ventriculography. In 16 of 18 patients with suspected TR, Doppler 2-D echo easily visualized the color-coded regurgitant flow in the right atrium and estimated the severity of TR from the distance of the visible TR jet. On the basis of the QRS synchronized appearance of contrast in the inferior vena cava by the subxiphoid approach or of the negative contrast effect above the tricuspid valve just after the contrast entered the right ventricle with its subsequent back-and-forth movements across the tricuspid valve, Doppler 2-D echo was more sensitive and specific in detecting TR (100% and 100%) than contrast 2-D echo (75% and 82% in the subxiphoid view, 56% and 100% in the 4-chamber view) when the fast Fourier transformation frequency analysis was used as the standard of TR, and it was more sensitive in detecting TR (85%) than contrast 2-D echo (69% in the subxiphoid approach, 46% in the 4-chamber view) when right ventriculography was used as the standard of TR. Additionally, the severity of TR as shown by Doppler 2-D echo correlated fairly well with that shown by right ventriculography. Thus, Doppler 2-D echo is clinically useful for detecting and evaluating TR.

Adult↗
PubMed1986

Asynchronous filling in ischemic heart disease and hypertrophic cardiomyopathy.

A multigated blood-pool study was performed to assess regional and global emptying and filling in 16 patients with hypertrophic cardiomyopathy (HCM), 43 patients with ischemic heart disease (IHD), and 14 controls. The regional volume curve was fitted using second-order harmonics in the Fourier series, while the global left-ventricular volume curve was fitted using third-order harmonics. As asynchronous indices, the standard deviations (SD) in distribution histograms of time to end-systole (TES), time to peak ejection (TPE), and time to peak filling (TPF) were obtained in the left ventricle. In patients with IHD, the TPF-SD was higher (14.4 +/- 11.3 degrees) than the TES-SD (7.8 +/- 5.1 degrees) and TPE-SD (8.1 +/- 5.9 degrees), suggesting the presence of asynchronous filling. In patients with HCM, the TPF-SD was also higher (11.6 +/- 11.1 degrees) than the TES-SD (3.5 +/- 2.4 degrees) and TPE-SD (6.2 +/- 4.4 degrees). The phase delay was localized in the anteroseptal or apical region in all 5 HCM patients with abnormal wall motion, while it corresponded with the region of abnormal wall motion in the patients with IHD. The TPF-SD was inversely correlated with the left-ventricular ejection fraction (r = -0.46), peak filling rate (r = -0.50), and the ratio of peak filling rate to peak ejection rate (r = -0.52), suggesting that asynchronous filling is related to global diastolic disturbance. We conclude that asynchronous filling is often present in patients with IHD and HCM, and that our technique can be used to obtain a quantitative assessment of regional asynchronous emptying and filling in these diseases.

Adult↗