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Biomedical subjects

F Takatsu

Publications and source records attributed to F Takatsu.

At least 37 records · Page 2Linked to original sources

Comparative study of QRST values from body surface potential mapping, 12-lead ECGs, VCGs in detecting inferior myocardial infarction, and evaluating the severity of left ventricular wall motion abnormalities in simulated left bundle branch block.

The authors compared the ability of QRST time-integral values (QRST values) from body surface potential maps (BSPM), 12-lead electrocardiograms (ECGs), and Frank lead vectorcardiograms (VCGs) in diagnosing a prior inferior myocardial infarction (MI) in simulated left bundle branch block (LBBB). The study included 32 patients whose digitized ECGs were recorded simultaneously for BSPM, ECGs, and VCGs during normal sinus rhythm and during right ventricular pacing simulating LBBB (18 with and 14 without an inferior MI). QRST values were calculated in each lead point of ECGs. Data on 608 normal subjects were used as controls; mean +/- 2 SD was regarded as the normal range. The following parameters were derived: sigma DM, sigma DE, sigma DV, the sum of the differences between the normal mean QRST value, and the QRST value of a given patient in leads where the QRST value was less than the normal range ("-2 SD area") in BSPM, ECGs, and VCGs (Y lead). The correlation coefficients for sigma DM, sigma DE, and sigma DV between the two activation sequences were highly significant. Sensitivity and specificity were as follows: 89% and 93% for sigma DM > 100 mV.ms, 89% and 93% for sigma DE > 50 mV.ms, and 56% and 100% for sigma DV > 10 mV.ms, respectively. Although sigma DM, sigma DE, and sigma DV were significantly (P < .01) correlated with the asynergy index calculated from left ventriculograms, sigma DM showed the best correlation. QRST values from BSPM, ECGs, and VCGs provide information that is useful in detecting an inferior MI and in estimating the severity of left ventricular wall motion abnormalities in the setting of LBBB. Of the three parameters, BSPM showed the best correlation with the severity of left ventricular wall motion abnormalities.

Aged↗

The presence of small q waves and decreased precordial r waves indicates a small amount of fibrosis of the anterior myocardial wall.

Biopsy specimens were obtained from the anterior wall of the left ventricle during aortocoronary bypass surgery in 79 patients with critical narrowing or occlusion of the left anterior descending artery. The percent of fibrous replacement on histological analysis was calculated using the point-count method and compared with electrocardiographic findings in the precordial leads. In specimens from 19 patients with abnormal Q waves, the percent of fibrosis ranged between 38% and 100% (mean, 61 +/- 17%). Fifteen patients had small q waves or decreased r waves, and the percent of fibrosis in these patients ranged between 20% and 45% (mean, 38 +/- 10%). Specimens from 45 patients with normal QRS complexes had between 3% and 27% (mean, 11 +/- 5%) fibrosis of the entire thickness of the anterior wall. Thus, small q waves or decreased r wave amplitude in the precordial leads indicates a lesser degree of myocardial loss than the presence of abnormal Q waves.

Coronary Angiography↗

Correlation between various parameters derived from body surface maps and ejection fraction in patients with anterior myocardial infarction.

To determine the best map parameter to predict cardiac function, various map parameters were correlated with the left ventricular ejection fraction (EF) in patients with a previous (between 3 months and 1 year) anterior myocardial infarction, but without overt congestive heart failure or ventricular dyssynergy. From 300 consecutive patients with a previous myocardial infarction, 82 patients with only an anterior infarction and who underwent cardiac catheterization and body surface mapping were selected for this study. The maps from 100 healthy subjects were used as normal controls. Body surface maps using 87 unipolar electrodes were recorded and various parameters were derived from the Q map, the QRS departure maps, the QRS isointegral (IQRS) map, and the QRST isointegral (IQRST) maps. They were compared with the angiographically determined EF. The EF was correlated with nQ (r = -0.72), four parameters derived from the QRS departure map (r ranged from -0.73 to -0.79), two parameters derived from the IQRS map (r = -0.90 and -0.86), and two parameters derived from the IQRST map (r = -0.84 and -0.85). Some parameters derived from body surface maps were found to have a very high correlation with the EF in patients who had a previous anterior myocardial infarction.

Electrocardiography↗

The ability of QRST isointegral maps to detect myocardial infarction in the presence of simulated left bundle branch block.

The clinical value of QRST isointegral maps (I-maps) for the detection of myocardial infarction (MI) in the presence of left bundle branch block (LBBB) was investigated. We recorded I-maps during sinus rhythm and right ventricular (RV) pacing, which simulated LBBB, in 62 patients with MI (42 patients had at least one akinetic segment and the remaining 20 patients had only hypokinesis or normal contraction) and 26 patients without MI. An abnormal decrease in the QRST value of the I-map was assessed by the difference map (D-map), which indicated a '-2SD area', where the QRST integral value was less than the lower limit of the normal range (mean -2SD) calculated from 608 normal individuals. The I-maps recorded during the two activation sequences were similar to each other in patients with and without MI (r = 0.87 and 0.92, respectively). The '-2SD area' was located over the left anterior chest in patients with an anterior MI and over the lower torso in patients with an inferior MI during each activation sequence. We were able to diagnose MI during simulated LBBB with a sensitivity of 84%, a specificity of 81% and a diagnostic accuracy of 83% when we used the criterion that MI is present if the sum of QRST integral values below the normal range (sigma DM) exceeds 100 mV.ms. We were able to diagnose an akinesis with a sensitivity of 81%, a specificity of 85% and a diagnostic accuracy of 83% when we used the criterion that akinesis is present if sigma DM exceeds 500 mV.ms during simulated LBBB.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Cigarette smoking is a major risk factor for coronary spasm.

BACKGROUND: Although there have been many studies on the risk factors for coronary artery disease, the etiology of coronary artery spasm has not yet been determined. METHODS AND RESULTS: After diagnosis by coronary arteriography, various risk factors were compared between two groups of subjects using logistic regression analysis. The vasospasm group included 175 patients with angiographically determined coronary artery spasm but no coronary artery narrowing exceeding 25% of the luminal diameter. The control group comprised 176 subjects with completely normal coronary arteries and a negative response to ergonovine maleate. The adjusted odds ratio and 95% confidence interval for smoking as a risk factor for vasospasm was 2.41 and 1.53-3.82, respectively (p < 0.05). The adjusted odds ratios for total cholesterol, low density lipoprotein, high density lipoprotein, triglycerides, diabetes mellitus, and body mass index, calculated by multivariate logistic regression analysis, were not statistically nonsignificant. CONCLUSIONS: Smoking appears to be a major risk factor for vasospastic angina without significant coronary narrowing. The other risk factors for coronary artery disease may not contribute to coronary vasospasm.

Adult↗

Effects of simulated left bundle branch block on QRST time-integral values of 12-lead electrocardiograms in patients with and without prior anterior wall myocardial infarction.

The effects of right ventricular pacing, which simulated left bundle branch block (BBB), on QRST time-integral values of 12-lead electrocardiograms (ECGs) were examined, and the clinical usefulness of QRST values for estimating the severity of left ventricular wall motion abnormalities due to a prior anterior wall myocardial infarction (MI) in the setting of left BBB were evaluated. Digitized ECGs were recorded during normal sinus rhythm and simulated left BBB in 38 patients (24 with and 14 without prior anterior wall MI). QRST values were calculated in each lead point of 12-lead ECGs. Data from 608 normal subjects were used as control values; the mean +/- 2 SD of these values was regarded as the normal range. The parameter sigma DE was defined as the sum of the differences between the normal mean QRST value and the QRST values of a given patient in leads where the QRST value was less than the normal range. The correlation coefficient of sigma DE for the 2 activation sequences was highly significant. Although small but significant changes were seen in QRST values in leads I, II, III, aVR, aVF and V1 during simulated left BBB, left precordial leads showed no significant changes in QRST values. A criterion of sigma DE > 40 mV.ms for detecting an anterior wall MI showed a sensitivity of 88%, a specificity of 93%, and a diagnostic accuracy of 89%. The sigma DE was significantly (p < 0.001) correlated with the asynergy index calculated from left ventriculograms.(ABSTRACT TRUNCATED AT 250 WORDS)

Bundle-Branch Block↗

Long-term study of recurrent vasospastic angina using coronary angiograms during ergonovine provocation tests.

Chronologic changes of coronary spasm were examined by repeated ergonovine provocation tests during angiography. A total of 322 patients who had variant angina without severe atherosclerosis demonstrated a positive response to the first test. Ninety of these patients had recurrent variant anginal symptoms after an angina-free period of 38 +/- 12 months (mean +/- SD). Of these 90 patients, 76 (84%) had symptoms or electrocardiographic (ECG) findings similar to those of the first test. The initial 9 of these 76 patients underwent a second provocation test and showed coronary responses analogous to those on the first test. Of the 90 patients, 14 (16%) had different symptoms or ECG findings from those elicited at the first episode. All 14 patients again had a positive response to a second ergonovine test and the following angiographic changes were observed in the three major vessels between the two tests. Of the 21 vessels that had spasm on the first test, eight vessels (19%) did not have spasm on the second test. Of the 21 vessels that did not demonstrate spasm on the first test, 10 (24%) demonstrated spasm on the second test. In the present study it is concluded that the majority of patients with recurrent angina seemed to have consistency in the location of coronary spasm, while in some patients the fluctuation of coronary spasm was confirmed by two ergonovine provocation tests.

Adult↗

Relationship of QRST isointegral maps during simulated left bundle branch block to impairment of left ventricular function due to myocardial infarction.

The clinical usefulness of QRST isointegral maps for assessing left ventricular (LV) dysfunction due to myocardial infarction (MI) in patients with MI in the setting of simulated left bundle branch block (LBBB) was investigated. Isointegral maps were recorded during sinus rhythm and right ventricular pacing, which simulated LBBB, in 62 patients with MI and 26 patients without MI. An abnormal decrease in the QRST value in the isointegral map was assessed by the difference map that indicated a "-2 SD area" where the QRST integral value was less than the normal range (mean - 2 SD) calculated from 608 normal individuals. The isointegral maps during the two activation sequences were similar in patients with and without MI (r = 0.87 and 0.92, respectively). The sum of QRST integral values less than the normal range (sigma DM) during simulated LBBB correlated significantly with the asynergy index, derived from left ventriculographic data (r = 0.81, p < 0.01). LV dysfunction (asynergy index > or = 2) was diagnosed in simulated LBBB with a sensitivity of 81%, specificity of 77%, and diagnostic accuracy of 80% when the criterion that LV dysfunction is present if the number of lead points in the -2 SD area exceeds 4, and a sensitivity of 71%, specificity of 81%, and diagnostic accuracy of 74% if sigma DM exceeds 200 mVms was used. The findings demonstrate that isointegral maps may be useful in assessing LV dysfunction due to MI in patients with MI and LBBB in addition to detecting the presence and site of MI in these patients.

Adult↗

Long-term changes of infarct-related lesions. Comparison of angiograms in recent and remote phases.

Coronary angiograms recorded in the recent phase of an acute myocardial infarction in 73 patients were compared with those taken in the remote phase at least 12 months from the onset of the infarction. The infarct-related lesions of 23 patients (32%) showed a regression of 20% or more. Analysis of recent-phase angiograms proved that any one of several features (long-segment narrowing, intraluminal thrombus, flap-like structure or atheromatous ulceration) was present more frequently in the lesions showing a marked regression (18/23, 78%) than in the lesions without regression (15/40, 38%) (p less than 0.01). Thus, the narrowings of infarct-related lesions seen on the recent-phase angiograms regress frequently. The possibility of regression can be predicted from the angiographic features.

Coronary Angiography↗

Clinical significance of residual collaterals immediately after successful coronary angioplasty.

The clinical significance of collaterals visible on angiography immediately after successful percutaneous transluminal coronary angioplasty (PTCA) was analyzed in 221 patients who underwent successful PTCA for coronary arteries receiving collaterals. Filling of the collaterals was classified as good; filling the entire epicardial segment of the stenosed site, fair; partially filling the epicardial segments distal to the stenosed site, and faint; visible but not filling the epicardial segments of the diseased vessel. Fifteen of 41 good collaterals remained good or fair on angiography immediately after PTCA. Among the 114 fair collaterals, 26 remained fair and 20 of 66 faint collaterals remained visible on the angiogram immediately after PTCA. There was no relationship between the degree of residual stenosis after PTCA and the degree of residual collaterals. Repeat coronary angiography was obtained in 156 patients. There was no correlation between the presence, absence or degree of collaterals observed on angiography immediately after successful PTCA and the rate of restenosis. Thus, collaterals to the vessels dilated by PTCA often remain on the angiogram immediately after PTCA and are dependent primarily on their degree before dilation. They do not indicate inadequate dilation or predict restenosis.

Aged↗

Randomized trial of a selective inhibitor of thromboxane A2 synthetase, (E)-7-phenyl-7-(3-pyridyl)-6-heptenoic acid (CV-4151), for prevention of restenosis after coronary angioplasty.

A selective inhibitor of thromboxane A2 synthetase, CV-4151, has the unique property of increasing prostacyclin synthesis in addition to its anti-platelet aggregating effect. Prostacyclin inhibits the growth of smooth muscle cells which is considered to be an underlying mechanism of restenosis occurring after successful coronary angioplasty. A prospective randomized trial was conducted to determine whether CV-4151 could prevent restenosis. Administration was begun greater than or equal to 2 days before angioplasty, and continued until the follow-up study performed between 3 and 6 months after angioplasty. Follow-up angiography was performed in 58 patients (81 segments) taking the active drug and in 27 patients (35 segments) taking the placebo. The incidence of angiographic restenosis was 38.3% in the former group and 31.4% in the latter group. Thus, CV-4151 did not significantly reduce the incidence of restenosis, perhaps due to endothelial denudation after angioplasty preventing an increase of the subendothelial local prostacyclin level.

Angioplasty, Balloon, Coronary↗

Intercoronary and intracoronary communications in four cases of vasospastic angina.

Persistent intercoronary and intracoronary communications were observed on cineangiograms in four patients having vasospastic angina without significant coronary narrowings. On provocation of coronary spasm using ergonovine maleate, these communications seemed to protect myocardium from ischemia, at least partially.

Angina Pectoris, Variant↗

Vectorcardiographic criteria for diagnosis of high lateral infarction--supplement for Chou's criteria.

The concept of high lateral myocardial infarction (HLMI) has not been clearly defined, so criteria for its vectorcardiographic (VCG) diagnosis have had no firm basis. However, we have reported that HLMI, expressed as abnormal Q waves in lead aVL on the electrocardiogram, corresponds to necrosis of the area usually supplied by the diagonal branches of the left anterior descending coronary artery. Here, we evaluated conventional VCG criteria for the diagnosis of HLMI on the basis of angiographic findings, and selected the criteria of Chou as typical. The frontal plane VCG was analyzed in 46 patients with HLMI on angiograms; other subjects were 233 healthy controls and 194 patients with left ventricular hypertrophy. Chou's criteria had good specificity, but sensitivity was unsatisfactory (32/46, or 70%). Accordingly, we examined various parameters of the QRS and T loops and found that the addition of four new criteria to Chou's improved sensitivity (46/46, or 100%) without impairment of specificity. The additional criteria are; 1) initial counterclockwise rotation of the QRS loop, 2) the ratio of the maximal QRS magnitude to the maximal T magnitude less than 4.5, 3) direction of the maximal T between +60 degrees and +180 degrees, 4) the QRS-T angle between 40 degrees and 135 degrees, all in the frontal plane.

Adult↗

Relationship between abnormal Q waves in lead aVL and angiographic findings--a study to redefine "high lateral" infarction.

To re-evaluate the concept of "high lateral" myocardial infarction, angiographic findings were analysed in 29 patients with remote infarction and abnormal Q waves in lead I or aVL but no abnormal Q waves in other leads and no prominent R wave in lead V1. All patients except one showed asynergy in the anterior segment on right anterior oblique left ventriculogram. Asynergies in other segments were, if present, mild or small. Critical narrowing was present in the diagonal branches or in their "parent" arteries (that is, the left anterior descending artery or left main trunk) in 28 patients but in the circumflex artery in only 3 patients. Thus, the traditional concept that a "high lateral" infarction is myocardial necrosis of the basal aspect of the left ventricle, receiving its blood supply from the circumflex artery, needs correction. "High lateral infarction" corresponds to necrosis of the area between the obtuse margin and the interventricular groove ordinarily supplied by the diagonal branches of the left anterior descending artery. Such infarctions are expressed by asynergy of the anterior segment rather than the posterior segment.

Coronary Angiography↗

A case with spasm of a saphenous vein graft.

A 54-year-old man developed angina pectoris 18 months after a successful aortocoronary bypass graft. The angiogram demonstrated patent grafts and no significant changes in the native coronary vessels. However, ergonovine maleate provoked spasm in a saphenous vein graft.

Coronary Angiography↗