[Myocardial adrenergic derangement due to myocardial ischemia: decreased myocardial uptake of I-123 metaiodobenzylguanidine after PTCA in a patient with effort angina]

Regional denervation of adrenergic nerves has been clinically demonstrated in patients with myocardial infarction using I-123 metaiodobenzylguanidine (MIBG) scintigraphy. However, it is not clarified whether adrenergic denervation can be induced by prolonged myocardial ischemia as well as by myocardial infarction. This case with effort angina had 99% stenosis of right coronary artery and showed perfusion defects at inferior myocardial regions in the exercise thallium-201 study. However, inferior wall motion estimated by echocardiography and left ventriculography was normal indicating the absence of myocardial infarction. After percutaneous transluminal coronary angioplasty for the stenosis, I-123 metaiodobenzylguanidine (MIBG) and thallium-201 (Tl-201) myocardial scintigraphies were done to estimate the therapeutic effect of PTCA. Although the Tl-201 study during exercise showed normal findings indicating the success of PTCA, marked defects was detected at inferior myocardial regions in the I-123 MIBG studies just after and 4 hours after an intravenous injection of I-123 MIBG. These results suggest that adrenergic derangement may be induced by prolonged myocardial ischemia and may persist for periods even though myocardial perfusion is normalized.

[Gallium-67 myocardial imaging for the detection of adriamycin cardiomyopathy]

To detect Adriamycin cardiomyopathy, radionuclide myocardial imagings with Tl-201, Tc-99m pyrophosphate, I-123 metaiodobenzylguanidine and Ga-67 were performed in a 49 year-old-woman receiving Adriamycin (a total dose of 230 mg/m2) for the treatment of breast cancer. This patient demonstrated symptoms of congestive heart failure 2 months after the last intravenous administration. At the period of performing the radionuclide studies, echocardiographic LV ejection fraction (EF) was 22%. Despite severe deterioration of cardiac function, Tl-201 SPECT demonstrated no defect and Tc-99m pyrophosphate (PYP) SPECT demonstrated no positive finding. I-123 metaiodobenzylguanidine (MIBG) scintigraphy demonstrated no regional defect. However, I-123 MIBG washout rate during 4 hours was markedly enhanced, probably reflecting abnormalities of norepinephrine kinetics due to the progression of heart failure. Compared to these pharmaceuticals, Ga-67 was diffusely accumulated in the heart. Then, 5 months after the first study, when LV EF improved to 30% and congestive symptoms disappeared probably owing to beta-blockade therapy, myocardial accumulation of Ga-67 markedly reduced. It has been reported that Ga-67 accumulates in malignant tumor cells and leukocytes. Since, in Adriamycin cardiomyopathy, myocardial accumulation of leukocytes with myocardial fibrotic changes have been histologically demonstrated, the results of Ga-67 scintigraphy may reflect the accumulation of leukocytes. Thus, this case indicates that Ga-67 scintigraphy is advantageous for detecting Adriamycin cardiomyopathy and may be more useful than Tl-201 and Tc-99m PYP scintigraphies.

Coronary angiographic features within 48 hours from onset of non-Q wave myocardial infarction with R wave regression and no ST segment depression

The clinical features of acute non-Q wave myocardial infarction (NQMI) with R wave regression and no ST segment depression are distinct from those of acute Q wave myocardial infarction (QMI). NQMI patients showed ST segment elevation at admission, and significantly earlier regression of the ST segment elevation and appearance of coronary T waves were observed compared to QMI patients. In addition to the significantly lower level of mean peak serum creatine kinase activity and the significantly lower incidence of pump failure during the acute phase, the incidences of in-hospital mortality and multivessel disease were significantly lower in the NQMI patients. With respect to acute-phase coronary angiographic features within 48 h after the onset, the rate of spontaneous opening of infarct-related vessels was significantly higher in the NQMI patients. Thirteen of the 19 NQMI patients responded to urokinase infusion. These facts suggest that transient, intermittent or incomplete obstruction may favor this type of NQMI over QMI, and that thrombus might be an important factor in the pathogenesis of this type of NQMI.

Humoral immune responses in experimental gingivitis in rats

Serum IgG, IgM, and IgA antibody levels to extracts of rat dental plaque and five oral bacteria (Haemophilus actinomycetemcomitans Y-4, Bacteroides gingivalis 381, Bact. intermedius ATCC 25261, Capnocytophaga sp. M-12, Eikenella corrodens ODU) were determined by ELISA. In addition, the presence of rat dental plaque and oral bacterial components in the inflamed gingival tissue was studied using immunofluorescence techniques. Serum and gingival tissue samples were obtained from ODU plaque-susceptible and plaque-resistant rats. In several susceptible rats, IgG, IgM, and IgA antibodies against dental plaque and oral bacteria were detected. There was a correlation between the levels of IgG antibody to dental plaque and pocket probing depth, but not between pocket probing depth and the levels of IgM and IgA. Furthermore, components of rat dental plaque and oral bacteria were detected in the inflamed gingival tissue.

[Noninvasive diagnosis of cardiac involvement by technetium-99m-pyrophosphate (Tc-99m PYP) myocardial scintigraphy in 2 cases of familial amyloid polyneuropathy and 1 case of secondary amyloidosis]

To validate the significance of technetium-99m-pyrophosphate (Tc-99m PYP) myocardial scintigraphy in diagnosing cardiac amyloidosis, 2 patients with familial amyloid polyneuropathy (FAP) and 1 patient with amyloidosis secondary to chronic rheumatic arthritis were studied. All three patients had echocardiographic abnormalities, which were increased wall thickness of the interventricular septum and the left ventricular posterior wall, and granular sparkling appearance in the septum. In 2 patients with FAP, abnormal myocardial uptake of Tc-99m PYP was diffusely detected in Tc-99m PYP SPECT. In the remaining 1 patient with secondary amyloidosis, however, Tc-99m PYP SPECT showed no abnormality, although we had confirmed the presence of myocardial amyloid deposits (type AA amyloid protein) with high amount in the histological examination. Thus, these results indicate that Tc-99m PYP scintigraphy may have a limitation in detecting cardiac involvement in secondary amyloidosis although it is useful in FAP.

[Radial long-axis tomography: a new reconstructing algorithm for thallium-201 myocardial SPECT]

The long-axis (L-A) tomograms of the heart in thallium-201 SPECT have been conventionally reconstructed as those parallel to the midventricular vertical or horizontal L-A plane. We developed a new algorithm for reconstructing the rotated L-A tomograms around the L-A to longitudinally observe thallium-201 myocardial distribution and to provide an optimal view of the cardiac apex. After determining the orientation of the L-A and reconstructing the short-axis (S-A) tomograms using standard techniques, the coordinates of the S-A planes were transformed to the polar coordinates whose origin is located at the position of the L-A in each plane. Then, "radial L-A tomograms", i.e. midventricular L-A planes oriented at the angle of every 6 degrees to the midventricular horizontal L-A plane, were reconstructed. Also, we developed a new technique for analyzing thallium-201 distribution of the L-A tomograms. For the basal 2/3 regions, two profiles which consist of the pixels with maximum count on the upper and lower myocardial portions of the lines (spaced at 1 pitch) vertically to the L-A were computed. For the remaining apical 1/3 regions, the semi-circumferential maximum-count profile from the values of 30 radii spaced at 6 degrees interval were computed. Based on these profiles, a 2D polar representation was then generated. From the study using a cardiac phantom with an apical small infarction, the usefulness of this new tomographic method for the detection of apical myocardial ischemia was demonstrated. The application to the exercise/redistribution studies in patients with effort angina indicated that radial long-axis tomography provides precise information about the longitudinal extent of perfusion defects, particularly in the apical regions.

E-series prostaglandins activate cAMP-mediated potassium currents in follicle-enclosed Xenopus oocyte

Receptor-mediated responses to prostaglandins E1 and E2 are shown by electrophysiological methods in follicle-enclosed oocytes of Xenopus laevis. In voltage-clamped oocytes, prostaglandins E1 and E2 elicited an outward hyperpolarizing current. This outward membrane current was caused by an increase in K+ conductance. The prostaglandin-induced current was augmented by adenylate cyclase activator, forskolin, and by phosphodiesterase inhibitor, theophylline, indicating that adenosine 3', 5'-cyclic monophosphate (cAMP) is involved in activating the K+ current. The prostaglandin responses were either abolished or greatly reduced by removing follicular cells with collagenase, suggesting that prostaglandin receptors reside in the follicular cells.

[Regional left ventricular diastolic function in hypertrophic cardiomyopathy: application of "sector analysis" to ECG forward and reverse gated radionuclide ventriculography]

To estimate regional left ventricular (LV) diastolic filling patterns in hypertrophic cardiomyopathy (HCM), a computer-assisted method by applying "sector analysis" to ECG forward and reverse gated radionuclide ventriculography was developed. Fourteen patients with HCM (four with localized septal hypertrophy, seven with apical hypertrophy and three with septal and apical hypertrophy according to echocardiography) were observed at rest. After establishing serial 20 msec imaged frames, the LV region of interest was subdivided into eight sectors radiating from the geometric center. A time-activity curve was generated for each sector and was fitted by third-order harmonics of the Fourier series. From each fitted curve, the regional peak filling rate (rPFR) and the time of rPFR (rTPFR) in the forward gating method and regional atrial contribution to filling (rAC/FV) in the reverse gating method were calculated. The coefficient of variance of rTPFR was used as an index of LV diastolic asynchrony. In HCM, a prominent delay of rTPFR was observed in the hypertrophied regions. The coefficient of variance of rTPFR correlated inversely with global LVPFR (r = -0.62, p less than 0.05), indicating that diastolic asynchrony is one of the determinants of the LV early filling rate. Regional AC/FV was augmented in the hypertrophied regions, indicating the important role of atrial systolic LV filling for slowed early filling. Thus, this new method provides valuable information concerning regional diastolic LV wall mechanics in HCM.

[Estimation of myocardial viability in left ventricular regions with akinetic wall motion by postextrasystolic potentiation using list-mode radionuclide ventriculography in an interesting case with silent ischemia and with premature ventricular complexes (quadrigeminy)]

For determining an indication of percutaneous transluminal angioplasty (PTCA), a 73-year-old-man with silent ischemia and with ventricular premature complexes (quadrigeminy) were performed cardiac nuclear studies. This case had 99% stenosis in LCX (#11) and 90% stenosis in RCA (#1), and demonstrated akinetic wall motion in left ventricular (LV) inferior and posterior regions. Exercise-redistribution Tl-201 studies indicated myocardial viability in a portion of the inferior wall but not in the posterior wall. To estimate the potential contractile function in the regions with akinesis, from the list-mode data of radionuclide ventriculography, those of postsinus beats and postextrasystolic beats were separately selected and were analyzed for investigating LV wall motion and LV ejection fraction (EF). With the post-extrasystolic potentiation, LVEF increased from 36% to 45% and the systolic wall motion was augmented in the inferior wall but not in the posterior wall. From these findings we recognized the existence of myocardial viability in a portion of the inferior wall. After PTCA for the RCA lesion, improvements of the myocardial Tl-201 distribution and LV wall motion in the inferior wall were definitely observed and hence LVEF increased by 16% to contribute to an increase in exercise performance. Thus, this case indicates that the postextrasystolic potentiation is useful for determining an indication of PTCA in patients with LV asynergy, demonstrating the myocardial viability and the potential LV function.

Immediate and long-term prognoses of acute myocardial infarction: analysis of determinants of prognosis

In order to investigate the immediate and long-term prognoses of acute myocardial infarction, we followed up 790 consecutive patients who were admitted to the Sakurabashi Watanabe Hospital within 24 hours after the onset of infarction from January 1975 to December 1984 and evaluated early mortality, cumulative survival rate after discharge, cause of death and occurrence of recurrent myocardial infarction during follow-up. Early mortality (within 30 days after the onset) in all patients was 17.6% and declined serially in the most recent five years. Pump failure was the most common cause of death, followed by cardiac rupture and arrhythmias. Age, gender (female), presence of a previous infarct and anterior infarction were important contributing factors to the immediate prognosis. One hundred and thirty-five of the 651 patients who survived one month after the onset of infarct died during the follow-up period (mean follow-up interval: 41.0 +/- 29.9 (SD) months). Cumulative survival rates calculated by the life-table method at one and 5 years after the onset were 91.0% and 76.0%, respectively, and the average annual mortality in the first 5 years was 4.8%. Age and reinfarction were the important determining factors of long-term prognosis. Recurrent myocardial infarction, pump failure and sudden cardiac death were common causes of late death. One hundred and two reinfarctions in 93 patients occurred during the follow-up period. Thirty-two of 93 patients (34.4%) died due to fatal reinfarction. These results indicate that the immediate prognosis of acute myocardial infarction has improved serially, but the long-term prognosis is still poor.(ABSTRACT TRUNCATED AT 250 WORDS)