Search PubMed⌕ Search

Biomedical subjects

M Ohyanagi

Publications and source records attributed to M Ohyanagi.

At least 55 records · Page 3Linked to original sources
PubMed1991

[Diagnostic utility of 111In-antimyosin Fab scintigraphy in acute myocardial infarction: comparison with 201Tl and 99mTc-pyrophosphate myocardial scintigraphy].

To assess the diagnostic accuracy, extent, and characteristics of 111In-antimyosin Fab scintigraphy (In-AM) in acute myocardial infarction (AMI), we studied In-AM in 17 patients with AMI and compared with In-AM, 99mTc-PYP and 201Tl scintigraphy. Intensity of In-AM uptake was classified into 3 grades. Fourteen of 17 patients (82%) showed positive uptake of In-AM. The locations of infarct area diagnosed by In-AM were in accordance with those by electrocardiography. There was a good correlation between the extent score of In-AM planar and that of SPECT (r = 0.72), In-AM SPECT and Tl SPECT (r = 0.79), In-AM planar and PYP planar (r = 0.92), In-AM SPECT and PYP SPECT (r = 0.76), respectively (p less than 0.01). Thus, In-AM is a useful method for diagnosis of AMI.

Adult↗
PubMed1991

[Exercise tolerance in patients after successful percutaneous transluminal coronary angioplasty].

In 32 patients with successful percutaneous transluminal coronary angioplasty (PTCA), we performed treadmill exercise tests (TMET) before and about one month after PTCA to assess the correlation between the improvement in coronary artery lesions and exercise tolerance. Either the Bruce protocol (B: n = 12) or the modified Bruce protocol (MB: n = 20) was used; with the latter being applied to patients whose cardiac function seemed depressed. In 15 patients, oxygen consumption (VO2) was measured by analyzing the expired gases, 13 patients underwent exercise thallium-201 myocardial perfusion scintigraphy before and after PTCA, whose results were compared with those of TMET. In both B and MB protocols, the treadmill walking time was significantly prolonged after PTCA, compared to that before PTCA (B: 7.4 +/- 1.3 vs 9.5 +/- 1.9, MB: 11.4 +/- 3.5 vs 12.7 +/- 3.5 min). Heart rates (HR) and rate pressure products (RPP) were significantly increased after PTCA in both protocols (HR B: 139 +/- 18 vs 154 +/- 17, MB: 121 +/- 20 vs 137 +/- 19 bpm, RPP B: 26,500 +/- 5,600 vs 30,300 +/- 6,700, MB: 19,400 +/- 6,200 vs 22,700 +/- 6,600 mmHg.bpm), however, systolic blood pressure did not change significantly after PTCA in either protocol. While there was a significant improvement in VO2 after PTCA (21.6 +/- 6.3 vs 25.7 +/- 4.2 ml/kg/min), the O2-pulse remained unchanged. Thallium-201 myocardial scintigraphy revealed improvement of myocardial perfusion in 8 of the 13 cases examined.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Positive indium-111 leukocyte imaging in post myocardial infarction syndrome.

The diagnosis of post myocardial infarction syndrome (PMIS) is sometimes difficult because of the absence of a specific test. We report a 68-year-old man with PMIS who had a persistent accumulation of indium-111 oxine labeled leukocytes in the infarcted myocardium for 1 month. The uptake of leukocytes preceded the appearance of the main symptoms and disappeared with the clinical improvement after the therapy with steroids. Leukocyte imaging has a potential as a useful tool for early diagnosis, evaluation of therapy and assessing the mechanism of PMIS.

Aged↗
PubMed1990

[111In-antimyosin scintigraphy on acute myocardial infarction].

Indium-111 antimyosin (InAM) scintigraphy was performed in 17 patients with acute myocardial infarction (on 15 +/- 6 days from the onset). The degree of myocardial uptake was classified into 3 groups. They were ranged from low intensity as in bone marrow to high intensity as in liver. All of 17 cases showed positive myocardial uptake including low intensity. The locations of infarction judged by InAM were in agreement with those by electrocardiography, coronary angiography (CAG), and 99mTc-pyrophosphate scintigraphy (PYP, performed on 5 +/- 2 days from the onset). In 5 cases, the uptake of InAM showed doughnuts or diffuse pattern which was occasionally observed on PYP. These cases showed myocardial uptake of 4th degree of Parkey's classification with doughnuts-like pattern on PYP, and showed involvement of left anterior descending artery on CAG. In some cases, the extent of myocardial uptake on InAM did not agree with those on PYP.

Aged↗
PubMed1989

Intracellular distribution of cardiac beta-adrenoceptors in SHR and WKY.

To compare the intracellular distribution of beta-adrenoceptors in isolated myocytes of SHR with that of age-matched WKY and to examine changes in the distribution with aging, we measured the number of cell surface and total beta-adrenoceptors in 6-(young groups) and 37-week old (old groups) SHR and WKY. The number of surface beta-adrenoceptors was significantly lower in 6-week old SHR compared with that in age-matched WKY. But there was no difference in the number of total beta-adrenoceptors between the two groups. The number of surface beta-adrenoceptors in old groups was significantly reduced compared with that in the young groups, in both SHR and WKY. However, the number of total beta-adrenoceptors in the old groups did not show any difference from that in the young groups. Isoproterenol-stimulated c-AMP formation in 6-week old SHR was significantly lower than that of WKY of the same age. Isoproterenol-stimulated c-AMP formation in the old groups was significantly reduced than that of the young groups in both SHR and WKY. These results suggested that (1) there may be a difference in the intracellular distribution of cardiac beta-adrenoceptors between 6-week old SHR and WKY, (2) the intracellular distribution of cardiac beta-adrenoceptors may be changed with aging, and (3) intracellular distribution might be related to the difference in c-AMP formation to beta-agonist.

Adenylyl Cyclases↗
PubMed1989

[Indication for coronary revascularization in patients without redistribution on 201Tl myocardial scintigraphy].

To determine the indication for coronary revascularization (A-C bypass and PTCA), we performed thallium(Tl)-201 scintigraphy and contrast left ventriculography (LVG) in 25 cases who had A-C bypass surgery and 22 cases who had PTCA. The Tl uptake in the delayed image (Tl score = normal: 3, mild hypoperfusion: 2, severe hypoperfusion: 1, defect: 0), the presence of redistribution, and regional wall motion by LVG (LVG score = normal: 3, reduced: 2, none: 1, dyskinesis: 0), were compared with each other before and after revascularization. Sensitivity, specificity and accuracy of myocardial viability as evaluated by each index were; the presence of redistribution; 96%, 35%, and 60%; Tl score much greater than 2; 83%, 33%, and 66%; Tl score much greater than 1; 81%, 75%, and 81%; LVG score much greater than 2; 80%, 29%, and 63%; and LVG score much greater than 1; 79%, 33%, and 74%; respectively. It was difficult to evaluate the myocardial viability only by the presence of redistribution. However, any case with redistribution was a prime candidate for coronary revascularization. The Tl score much greater than 1 was the most reliable indication using the individual index. Although the diagnostic accuracies of the Tl and LVG scores were superior to the presence of redistribution, there was no individual index of myocardial viability common to all cases. If there were clinical necessity and angiographic indication, coronary revascularization could be tried in all cases except those whose Tl and LVG scores were both 0. In conclusion, myocardial viability can be evaluated scintigraphically only by the delayed image and by the presence of redistribution. As a conventional indication for coronary revascularization, the Tl score is relatively useful for predicting improvement after revascularization.

Aged↗
PubMed1989

[Ischemic heart disease evaluated by exercise stress thallium-201 myocardial scintigraphy: a comparison of SPECT and bull's eye display].

T1-201 stress myocardial scintigraphy was performed in 35 cases of ischemic heart disease (angina pectoris and myocardial infarction) to assess the accuracy of SPECT and bull's eye display in the quantitative diagnosis of coronary artery lesions. We evaluated the sites of ischemic heart disease using the following methods: 1. SPECT (visual): visual evaluation by myocardial SPECT images. 2. SPECT +bull's eye (visual): visual evaluation by stress, delayed and washout images of bull's eye display. 3. bull's eye (quantitative): quantitative evaluation by the washout rate and % uptake. The diagnostic accuracy of method 2 was higher than that of method 1 in all coronary arterial vessels; LAD (74% vs 80%), LCX (60% vs 63%) and RCA (57% vs 60%). The diagnostic accuracy of method 3 was approximately equal to that of method 2. The diagnostic accuracy of method 2 was higher than of method 1 in patients with three-vessel disease (43% vs 67%), while there was no such difference in patients with both single and two-vessel disease. Moreover, the diagnostic accuracy of method 3 was approximately equal to that of method 2 in patients with three-vessel disease. In some cases the redistribution was recognized only by using washout images or by calculating the washout rate as a quantitative evaluation. In conclusion, the bull's eye display improved the diagnostic accuracy of T1-201 scintigraphy, but the quantitative analysis did not further improve the accuracy. However, there were some possibilities of evaluating the redistribution in some cases by using quantitative analysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1989

[Factors influencing exercise tolerance in patients with myocardial infarction as elucidated by Tl-201 myocardial scintigraphy].

Measurements of O2 consumption during treadmill exercise tests and Tl-201 myocardial scintigraphy were performed in 17 cases of myocardial infarction to elucidate O2 consumption at an anaerobic threshold ATVO2 as an adequate index of exercise tolerance, and the scintigraphic indices influencing the exercise tolerance. ATVO2 was obtained using the method of Wasserman and Davisand corrected by body weight. The scintigraphic indices such as the location, extent (residual myocardium), and severity (% uptake) of myocardial infarction were obtained from SPECT and bull's eye displays on Tl-201 myocardial scintigraphy. ATVO2 was correlated with theoretical VO2max as obtained by the predicted maximal heart rate (r = 0.56, p less than 0.01) and with left ventricular ejection fraction as obtained by radionuclide left ventriculography (r = 0.59, p less than 0.01). There was no significant difference between ATVO2 in cases of anterior wall infarction and those of inferior (and/or lateral wall) infarction. There was no significant correlation between % uptake and ATVO2. However, the residual myocardium showed a significant correlation with ATVO2 (r = 0.61, p less than 0.01). In conclusion, 1) ATVO2 is an adequate index of exercise tolerance and reflects cardiac function. 2) The extent of the residual myocardium is most strongly influenced by ATVO2 among the indices of myocardial damage as obtained by Tl-201 myocardial scintigraphy.

Adaptation, Physiological↗
PubMed1988

Beta-adrenergic receptors in ischemic and nonischemic canine myocardium: relation to ventricular fibrillation and effects of pretreatment with propranolol and hexamethonium.

To explore possible roles of the sympathetic nervous system (especially the beta-adrenergic receptor and cAMP system) in the pathogenesis of ventricular fibrillation (VF), the authors examined changes in the number of myocardial beta-adrenergic receptors and the cAMP level in animals showing VF after experimental induction of myocardial ischemia. In animals that developed VF approximately 15 min after coronary ligation, the ischemic myocardium had a significantly larger number of beta-adrenergic receptors (90 +/- 8 fmol/mg protein) and a significantly higher level of cAMP (1.4 +/- 0.17 nmol/g weight) compared with the nonischemic area where the number of beta-receptors was 68 +/- 7 fmol/mg protein and the cAMP level was 0.80 +/- 0.20 nmol/g weight. In animals in which VF was electrically induced 20 min after coronary ligation, no elevation was recorded in the ischemic area in terms of the number of beta-adrenergic receptors (49 +/- 6 fmol/mg protein) and the level of cAMP (0.79 +/- 0.06 nmol/g weight). When animals were pretreated with a beta-blocker or a ganglion blocker, coronary ligation did not result in VF. In the ischemic area of these animals, no significant change was noted in the number of beta-adrenergic receptors (54 +/- 7 fmol/mg protein for animals pretreated with a beta-blocker, 56 +/- 3 fmol/mg protein for animals pretreated with a ganglion blocker). These results suggest that there is a strong correlation between the pathogenesis of VF (observed about 15 min after coronary ligation) and the increase of the number of beta-adrenergic receptors and cAMP levels.

Animals↗
PubMed1988

[Indications for coronary revascularization and the postoperative evaluations using Tl-201 exercise myocardial scintigraphy and a bull's eye display].

Tl-201 exercise myocardial scintigraphy and quantitative analysis using bull's eye display were performed in 31 cases (18 bypass cases, 13 PTCA cases) to determine the indications for coronary artery bypass surgery and PTCA, and to evaluate postoperative improvement. Regions of interest (ROI) corresponding to each revascularized area were created on a bull's eye display. Then the washout rates (WR) and % uptakes were expressed as percentages. Improvement was judged to have occurred if the revascularized coronary artery was patent and both the WR and % uptake returned to the normal range as determined from the examinations of 20 normal cases. The results were as follows: 1. The preoperative mean WR of the improved areas (30 vessels) was 19 +- 15%, while that of the unimproved areas (15 vessels) was 35 +- 7%. We assumed that the area was suitable for revascularization when the preoperative WR was less than 25% which was in the lower limit of the normal range. Then, 18 vessels were judged to be suitable for surgery, and subsequent postoperative improvement was obtained in the 17 areas. 2. In 32 scintigraphically-improved areas, 30 vessels were angiographically patent, while five vessels were obliterated angiographically in 13 scintigraphically-unimproved areas (diagnostic validity was 76% of all 45 vessels). 3. The exercise tolerance increased significantly (p less than 0.01) from 8.7 +- 2.0 min to 11.6 +- 2.5 min in the improved cases in which all the revascularized areas were improved after revascularization. There was no change of the exercise tolerance (before: 9.4 +- 3.4 min, after: 9.4 +- 2.5 min) in the unimproved cases in which all the revascularized areas were unimproved. 4. Quantitative analysis was useful for objective evaluation, because the visual evaluations did not always agree with the quantitative evaluation. We concluded that the area with the preoperative WR less than the normal range is suitable for revascularization. As the scintigraphic evaluation was in accord with improved exercise tolerance and with patency as observed by coronary angiography, our method seems useful for postoperative follow-up.

Angioplasty, Balloon↗
PubMed1988

[Clinical significance of precordial ST segment depression during acute inferior myocardial infarction].

To investigate the mechanisms and clinical significance of precordial (V1-V4) ST segment depression during acute inferior myocardial infarction, stress thallium-201 scintigrams and coronary angiograms were obtained within four to eight weeks after the onset of myocardial infarction in 37 patients experiencing their first acute inferior myocardial infarction. Among 18 patients with precordial ST depression (group 1), 11 with concomitant disease of the left anterior descending artery (LAD) had positive results on exercise test, whereas in seven patients without LAD lesion, only two had positive exercise test (p less than 0.01). In 19 patients without precordial ST depression (group 2), 11 had severe stenosis in the LAD. However, among these 11 patients, only two had positive exercise tests. Patients with precordial ST depression demonstrated a higher frequency of positive exercise tests than those without it (p less than 0.01). On stress thallium-201 scintigraphy, a perfusion defect involving the inferior wall was present in all patients, but additional anterior wall ischemia was present in only five of the 18 patients in group 1. These five patients had chest pain on exercise tests and a severe stenosis greater than 90% in the LAD. There was no significant difference in the frequency of additional posterolateral wall infarction between groups 1 and 2. In 18 patients in group 1, sigma ST (total degrees of ST segment depression in leads V1, V2, V3, and V4 in the acute stage) was significantly greater in 11 patients with LAD lesion than in seven without (p less than 0.05), and sigma ST greater than five mm was observed in 12 of 13 patients who had additional anterior wall ischemia and posterolateral wall infarction on stress thallium-201 scintigraphy (p less than 0.05). Myocardial revascularization, such as aortocoronary bypass surgery or percutaneous transluminal coronary angioplasty (PTCA), was performed in six of the 18 patients in group 1 in the chronic stage, but in only one of the 19 patients in group 2. Thus, in patients with initial acute inferior myocardial infarction, those with precordial ST depression seemed to be a high-risk group. It was suggested that, during the early stage of myocardial infarction, this abnormality on electrocardiograms is related to the summation of effects of anterior wall ischemia and posterolateral wall infarction. Furthermore, the sigma ST evaluation is useful in differentiating a mirror image of inferior wall infarction from anterior wall ischemia and posterolateral wall infarction as the mechanism of precordial ST depression.

Angiography↗
PubMed1988

Radionuclear measurement of peripheral hemodynamics in selection of vasodilators for treatment of heart failure.

In order to select the optimal vasodilator for the treatment of patients with congestive heart failure (CHF), the acute effects of three vasodilators (isosorbide dinitrate (ISDN) 5 mg, nifedipine 10 mg, and prazosin 1 mg) on peripheral capacitance and resistance vessels (CV and RV) were evaluated by a newly devised radionuclear technique (Study 1). Thirty-six patients with chronic CHF were divided into Group A (ejection fraction (EF) greater than or equal to 35%, n = 20, mean EF: 47.2 +/- 6.5%) and B (EF less than 35%, n = 16, mean EF: 24.8 +/- 7.1%). ISDN produced the strongest CV dilatation (25% in both groups). Nifedipine reduced RV tone in Groups A and B (14% and 27%, respectively), and CV tone in Group A (6%). Prazosin had the most prominent effects on both vessels in Group B. From these results, it appeared: (a) ISDN is indicated for the cases with increased CV tone, (b) nifedipine is suitable for those with increased RV tone, (c) in cases of increased tone in both vessels, nifedipine (when EF greater than or equal to 35%) or prazosin (when EF less than 35%) is optimal. To evaluate the validity of this assignment, 49 subjects with CHF were divided into Group 1 (n = 16, increased CV tone), Group 2 (n = 17, increased RV tone), and Group 3 (n = 16, increased CV and RV tone) in Study 2. In Group 1, the changes of all indexes were not significantly different between the subjects treated with optimal drug based on the assignment (subgroup P) and those with a non-optimal drug (subgroup N) after 2 wk of therapy. In Group 2, however, improvements of RV tone, EF, and exercise duration in subgroup P were greater than those in subgroup N (31 versus 10%, 21 versus 0%, 41 versus 14%, respectively). In Group 3, the results were the same as in Group 2 (34 versus 19%, 24 versus 8%, 26 versus 9%). These findings suggested that the selection of the optimal vasodilator based on peripheral hemodynamic evaluation with a newly devised radionuclear technique permits more effective treatment of chronic CHF.

Aged↗
PubMed1987

[Infarct size determined by emission computed tomography using 99mTc-PYP: effect of coronary thrombolysis].

Emission computed tomography with 99mTc-PYP was used to estimate infarct size in 38 patients with documented acute myocardial infarction. In the present study, the effect of thrombolysis with Urokinase on infarct size and on left ventricular function was assessed. Fourteen patients with acute myocardial infarction who underwent intracoronary thrombolysis within six hours after the onset of symptoms, and 24 patients who underwent conventional therapy were the subjects of this study. Infarct size was measured by drawing a region of interest around the myocardial pyrophosphate uptake for each tomographic slice. The boundary was then defined as 65% of the maximal count within the region of interest as determined by phantom volume studies. The total number of voxels was obtained by adding those in all slices and multiplying the sum by the voxel volume (0.205 ml per one voxel) to determine the infarct volume. Measurement of the 99mTc-PYP uptake on the tomographic image revealed an average infarct size of 100.1 +/- 36.0 ml (ranged 45 to 198). The calculated infarct volume correlated significantly with sigma CPK (p less than 0.01) and with left ventricular ejection fraction (p less than 0.01), but not with the peak CPK. In patients with acute inferior myocardial infarction, the mean infarct volume was 78.4 +/- 29.1 ml in the coronary thrombolysis group, and 105.1 +/- 33.7 ml in the conventional bypass graft treatment group (p less than 0.05). We concluded that successful intracoronary thrombolysis may reduce infarct size. ECT imaging with 99mTc-PYP to determine infarct size may be clinically applicable in patients with acute myocardial infarction.

Adult↗
PubMed1987

[Right ventricular ejection and regional wall motion evaluated by cardiac blood pool emission computed tomography].

Calculating right ventricular (RV) ejection fraction (EF) is difficult because of geometrical problems such as irregular trabeculations, a separate infundibulum, and variations in the right ventricular shape. We performed 99mTc ECG-(dual)gated cardiac blood pool emission computed tomography (ECT) in 10 patients with ischemic heart disease, three patients with dilated cardiomyopathy (DCM), and eight normal subjects as controls, and RVEF and % shortening of the RV were calculated to evaluate right ventricular function. Methods were as follows: 1) RVEF: The region of interest (ROI) of the RV was determined on reconstructed short-axial images, and then the RV counts in the ROI were summed from the apical slice to the RA-RV boundary slice. (Formula: see text) 2) % shortening of the RV: At the RV mid-portion, the contour from the short-axial image was obtained using the threshold method; the end-diastolic contour was superimposed on the end-systolic contour, and then shortenings in the RV free wall and septum respectively, were calculated. To evaluate reliability of RVEF obtained by this method, left ventricular ejection fraction (LVEF) calculated using the same method was compared with results obtained by the previously validated method: There were significant correlations with contrast cineangiography (r = 0.69) and the conventional multigated method (r = 0.90), respectively. Cases with decreased RVEF showed a variety of right ventricular abnormal findings, including positive uptake on 99mTc-PYP scintigraphy, occlusion of the right coronary artery, RV dilatation on echocardiography. The mean RV free wall shortening in the decreased RVEF group was lower than that of the normal group (p less than 0.01), whereas there was no significant difference in the decreased LVEF group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

[Comparison of two-dimensional echocardiography with 201T1-single photon emission computed tomography for evaluating the myocardial infarct zone].

The reliability of measuring the myocardial infarct zone by two-dimensional echocardiography (2 DE) was compared with that by regional myocardial blood flow as evaluated by single photon emission computed tomography (SPECT) in 47 patients with old myocardial infarction, with ventricular aneurysm (An group; n = 15), and without ventricular aneurysm (Non-An group; n = 32). Short-axis images of the left ventricle at the level of the mitral valve, the papillary muscles, and the apex were obtained both by 2DE and SPECT. The left ventricular wall was divided into 36 segments in 2DE and 40 segments in SPECT with reference points at the posterior end of the right side of the interventricular septum. The segments in which the radial shortening on 2DE and the 201Tl uptake index on SPECT were below one standard deviation from the means of 10 normal subjects were defined as those with abnormal wall motion and hypoperfused areas, respectively. The relationships between these findings were studied. The extent of apical movement was measured by left ventricular cineangiography in each case, and was compared between the An and Non-An groups. 1. Wall motion abnormalities on 2DE and hypoperfusion on SPECT showed a correspondence of 81% in the An group and 78% in the Non-An group at the level of the mitral valve, and 78% in the An group and 76% in the Non-An group at the papillary muscle level. However, a better correspondence was observed in the An group (84%) as compared to the Non-An group (64%) at the level of the apex. 2. Apical movement assessed by cineangiography showed more extensive changes in the Non-An group than in the An group (2.3 +/- 0.9 mm vs 4.1 +/- 1.7 mm in the RAO view, 2.4 +/- 1.9 mm vs 5.3 +/- 2.1 mm in the LAO view). From these observations, it was suspected that the cause of disparity between radial shortening and the 201Tl uptake index at the level of the apex is related to the cardiac movement of the apex toward the base during systole. 3. Since wall motion abnormalities demonstrated by radial shortening (2DE) and hypoperfusion indicated by the 201Tl uptake index (SPECT) generally corresponded well, 2DE was thought to be a useful method for evaluating myocardial infarct zone.

Aged↗
PubMed1986

[Left ventricular asynergy detected by cardiac blood pool emission computed tomography using the subtraction method].

To evaluate left ventricular regional wall motion, ECG dual-gated cardiac blood pool ECT was performed for 25 patients with ischemic heart disease, including 19 cases of myocardial infarction, five cases of angina pectoris, and one case of post A-C bypass surgery. There were six normal controls. Following SPECT obtained using 32 views (180 degrees), the vertical and horizontal long axes were reconstructed from transaxial images. Then, regional wall motion was evaluated from subtraction images; (end-diastolic)-(end-systolic) and (end-systolic)-(end-diastolic) images. SPECT images were compared with left ventriculography (LVG); vertical long-axial ECT images with segments 1-5 of LVG by the AHA classification, and horizontal ECT long-axial images with segments 6 and 7 of LVG, respectively. The subtraction images from ECG dual-gated cardiac blood pool ECT corresponded with left ventriculography in 79.4% of 175 segments in 25 patients with ischemic heart disease (sensitivity 92.6%, specificity 68.0%, and accuracy 79.4%). When wall motion was classified as normal, hypokinesis, akinesis, and aneurysmal, good agreement was observed between the two methods in 68% of these segments. The locations of asynergy as obtained by this method were closely in accord with those of perfusion defects by Tl-201 myocardial SPECT in 74.4% of segments. Left ventricular aneurysms were detected using subtraction image; (end-systolic)-(end-diastolic). We conclude that this subtraction method is useful for evaluating left ventricular asynergy.

Adult↗
PubMed1985

[Two-dimensional echo-Doppler technic for evaluating dissecting aneurysms using the paravertebral approach].

Cross-sectional echocardiography facilitates recognizing dissecting aortic aneurysms, but the diagnosis of abnormalities of the descending aorta in the retrocardiac portion is difficult. We prospectively designed to assess the usefulness of a new echocardiographic technique in defining the retrocardiac descending thoracic aorta in its long and short axes. Two patients with dissecting aneurysms involving the retrocardiac descending aorta were studied in the 90 degrees right lateral position using a Toshiba SSH-11A or SSH-40A cross-sectional echocardiographic apparatus. The transducer was positioned in the third or fourth intercostal space closely to the left of the thoracic vertebrae, and the ultrasonic beam was directed toward the retrocardiac descending aorta from the patient's back. The descending thoracic aorta was identified in its long axis as a straight tubular structure with parallel walls. The transducer was then rotated approximately 90 degrees, to visualize the descending aorta in its short axis as a circular structure. This "paravertebral approach" has not previously been reported. In both patients, the retrocardiac descending thoracic aorta was clearly visualized in its long and short axes, and the oscillating intimal flap was visualized within the descending aorta in the paravertebral approach. Pulsed Doppler echocardiography (PDE) using the long-axis paravertebral approach identified the flow in the false and true lumens of the descending thoracic aorta. Flow patterns including the peak flow velocity and the velocity profile obviously varied between the true and false lumens. The peak flow velocities in the former were extremely high compared to those in the latter. The former exhibited laminar profiles, but the latter showed some spectral broadening. By the same approach, the entrance tear was explored and the jet flow through the tear was detected in Case 1 by PDE, which had high flow velocity with wide spectral broadening and aliasing in systole and also had relatively low flow velocity with some spectral broadening in diastole. To our knowledge, there has been no previous report of detecting flow at the entrance tear by PDE. These cross-sectional echocardiographic studies suggest that the paravertebral approach may prove helpful in initially evaluating patients with symptoms or signs suggestive of acute dissecting aneurysms. However, comprehensive studies are necessary to define the sensitivity and specificity of these echocardiographic techniques in recognizing all types of dissecting aneurysms.

Aged↗