Haruo Tomoda

Plasma endothelin-1 in acute myocardial infarction with heart failure

Endothelin-1 is a potent vasoconstricting substance that may aggravate circulatory dysfunction in acute myocardial infarction. In 59 patients with acute myocardial infarction peripheral venous blood was sampled, and endothelin-1 was measured by radioimmunoassay. Hemodynamic measurements were performed with a flow-directed thermodilution catheter in 16 patients. Plasma endothelin-1 levels in Killips classes were as follows: group I (no heart failure, n = 25), 1.97 +/- 0.69 pg/ml; group II (heart failure, n = 16), 2.74 +/- 1.02 pg/ml; group III (pulmonary edema, n = 13), 4.54 +/- 1.17 pg/ml; and group IV (cardiogenic shock, n = 5), 8.91 +/- 3.16 pg/ml (normal control group, n = 12: 1.51 +/- 0.39 pg/ml). There were significant correlations between the plasma endothelin-1 level and mean right atrial pressure (r = 0.554; p < 0.05), mean pulmonary artery pressure (r = 0.589; p < 0.02), and cardiac index (r = -0.534; p < 0.05). There were closer correlations between plasma endothelin-1 level and mean pulmonary artery wedge pressure (r = 0.678; p < 0.005) and total pulmonary vascular resistance (r = 0.831; p < 0.001). These results indicate that endothelin-1 is elevated in accordance with cardiac and pulmonary circulatory distress in patients with acute myocardial infarction, which may further aggravate circulatory dysfunction.

Evaluation of pericardial effusion with computed tomography.

Evaluation of pericardial effusion was attempted with computed tomography in 11 patients. The volume and distribution of pericardial fluid were assessed with satisfactory resolution and the nature of the fluid was estimated by the difference in x-ray transparency (CT numbers). The volume of pericardial fluid calculated by tomographic methods ranged from 25 ml. to 585 ml. and agreed well with the surgically drained fluid volume. The CT numbers of the pericardial effusion due to renal or heart failure, acute viral pericarditis, hypothyroidism, and hemopericardium were +12 to +13, +20, +28 to +30, and +26 to +40, respectively. Therefore the volume and gross nature of the pericardial fluid could be estimated noninvasively with computed tomography.

Evaluation of intracardiac thrombus with computed tomography

Left atrial (LA) and left ventricular (LV) thrombus was evaluated by computed tomography in 56 patients. The patients were divided into 2 groups: Group I, 28 patients with mitral valve disease, and Group II, 28 patients with myocardial infarction. Computed tomography and 2-dimensional echocardiography were performed in all the patients studied. Cineangiocardiography was performed in all Group I and in 13 Group II patients. Open heart surgery or autopsy was performed in all Group I and 4 Group II patients. The sensitivity in detecting LA thrombus was 100% with computed tomography, 70% with angiocardiography, and 60% with 2-dimensional echocardiography. The specificity in detecting LA thrombus was 91% with computed tomography, 86% with 2-dimensional echocardiography, and 88% with angiocardiography. Thrombi located at the LA appendage were associated with great difficulties in detection by other methods, but were well delineated with computed tomography. LV thrombus was also visualized by computed tomography with similar or greater accuracy than other diagnostic methods, although the sensitivity and specificity were not ascertained because surgery or autopsy was performed in only a minority of Group II patients. Therefore, as far as the detection of intracardiac thrombus is concerned, computed tomography has the advantage of offering uniform slices of the heart in an attempt to detect thrombi in unknown areas of cardiac chambers, including the LA appendage or LV apex, without being disturbed by the surrounding cardiac and noncardiac structures. Thus, computed tomography has excellent accuracy in the detection of intracardiac thrombus.

Regional sympathetic denervation detected by iodine 123 metaiodobenzylguanidine in non-Q-wave myocardial infarction and unstable angina.

Previous studies have revealed that the sympathetic nervous system is more vulnerable to ischemia than the myocardium itself. Thus our study was undertaken to detect denervated myocardium in non-Q-wave myocardial infarction (MI) and unstable angina with iodine 123 metaiodobenzylguanidine (123I-MIBG), which can delineate myocardial sympathetic innervation. Eight patients with non-Q-wave MI and 12 with unstable angina were studied. Sequential 123I-MIBG and thallium-201 chloride (201TlCl) imaging and single-photon emission computed tomography (SPECT) were performed at rest 24 +/- 12 days after the last ischemic attack. Myocardial perfusion defect was not detected by 201TlCl in 4 of 8 patients with non-Q-wave MI, whereas 123I-MIBG SPECT imaging revealed defects corresponding to myocardial ischemic areas predicted by coronary angiography in all 8 patients. 123I-MIBG imaging revealed defects in 7 of 12 patients with unstable angina corresponding to coronary angiographic findings, whereas no myocardial perfusion defect was detected by 201TlCl imaging in any of them. In conclusion, 123I-MIBG SPECT is a sensitive method for detecting myocardium exposed to transient ischemia that cannot be detected by 201TlCl imaging.

Atrial natriuretic peptide in acute myocardial infarction.

Abstract Plasma atrial natriuretic peptide (ANP) has been reported to be elevated in heart failure induced by various cardiovascular diseases.1 A close correlation has been found between atrial pressure and plasma ANP levels in patients with chronic cardiovascular diseases.2,3 Although the plasma ANP level in various hemodynamic states in patients with acute myocardial infarction (AMI) is of great interest, there have been no reports on this subject. This report evaluates the relation between plasma ANP and hemodynamic measurements in patients with AMI.

Evaluation of left atrial thrombus with computed tomography

Left atrial thrombi were evaluated with computed tomography in 23 patients with mitral valvular diseases. In three of the patients, left atrial thrombi were delineated with computed tomography and were confirmed by cardiac surgery or autopsy. The minimum size of the thrombi detected tomographically was 3.5 gm. There were no false-positive or false-negative results with computed tomography in 13 patients who subsequently underwent cardiac surgery. Computed tomography is essentially noninvasive and appears to be one of the best methods to evaluate left atrial thrombus.

Possible prevention of postangioplasty restenosis by ascorbic acid

In this preliminary study to assess the possibility of using ascorbic acid to prevent post-percutaneous transluminal coronary angiography (PTCA) restenosis, the incidence of restenosis was significantly less in 50 patients receiving 500 mg/day of oral ascorbic acid than in 51 control patients. Thus, ascorbic acid, a potent natural antioxidant, appeared to be possibly effective in attenuating post-PTCA restenosis.

Effect of oxymetholone on left ventricular dimensions in heart failure secondary to idiopathic dilated cardiomyopathy or to mitral or aortic regurgitation

This study suggests that the short-term administration of a small dosage of anabolic steroids may have a beneficial effect on the deteriorated myocardium, although long-standing exposure to a larger dosage of anabolic steroids may induce myocardial and systemic complications.

Comparison of protective effects of preinfarction angina pectoris in acute myocardial infarction treated by thrombolysis versus by primary coronary angioplasty with stenting

The protective effects of preinfarction angina were evaluated in acute myocardial infarction (AMI) treated by primary percutaneous transluminal coronary angioplasty (PTCA) and stenting. We studied 613 patients with AMI. Group 1 (n = 306) was treated by conventional medical therapies and coronary thrombolysis and group 2 (n = 307) was treated by primary PTCA supported by stenting. Each group was subdivided into those with and without preinfarction angina within 24 hours before the onset of AMI. There was no significant difference in clinical characteristics between the subgroups of groups 1 and 2. In group 1, there were differences between patients with preinfarction angina (n = 84) and those without (n = 222) in in-hospital mortality (11% vs 18%), pump failure (Killip classes 3 and 4) (11% vs 21%, p <0.05), left ventricular ejection fraction at discharge (52 +/- 13% vs 48 +/- 14%, p <0.05), and peak creatine kinase (2,106 +/- 1,637 vs 2,764 +/- 2,154 U/L, p <0.02). In group 2, however, there was no significant difference between those with preinfarction angina (n = 82) and those without (n = 225) in mortality (6% vs 6%), pump failure (12% vs 12%), left ventricular ejection fraction (50 +/- 13% vs 50 +/- 13%) and peak creatine kinase (3,285 +/- 2,306 vs 3,291 +/- 2,262 U/L). Multivariate analysis indicated that preinfarction angina was an independent determinant of in-hospital death and pump failure in group 1, but not in group 2. We conclude that the protective effects of preinfarction angina in AMI are not evident in those treated by primary PTCA and stenting, possibly because of the overwhelming protective effects of complete coronary revascularization provided by primary PTCA and stenting.

Evaluation of left ventricular thrombus with computed tomography

Abstract In 21 patients with myocardial infarction left ventricular thrombi were evaluated with a third generation computed tomographic system. In three patients, thrombus was delineated with computed tomography and confirmed with the conventional echocardiographic and angiographic methods. In one patient the thrombus was not detected with two dimensional echocardiography. This experience indicates that identification of left ventricular thrombus with computed tomography is possible.