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C P Miranda

Publications and source records attributed to C P Miranda.

6 recordsLinked to original sources
PubMed1993

Comparison of computer ST criteria for diagnosis of severe coronary artery disease.

To determine which computer ST criteria are superior for predicting patterns and severity of coronary artery disease during exercise testing, 230 male veterans were studied who had both coronary angiography and a treadmill exercise test. Significant (p < or = 0.05) differences in computer-scored ST criteria were observed among patients with progressively increasing disease severity. Three-vessel/left main disease produced responses significantly different from 1- and 2-vessel disease or those with < 70% occlusion. Discriminant function analysis revealed that horizontal or downsloping ST depression measured at the J junction during exercise or recovery, or both, was the most powerful predictor of severe disease. With use of a cut point of 0.075 mV ST depression, horizontal or downsloping ST depression alone yielded a sensitivity of 50% (95% confidence interval = 35 to 65%) and specificity of 71% for prediction of severe disease; the only additional variable that added significantly to the prediction was exercise capacity, which improved sensitivity to 57% (95% confidence interval = 41 to 72%) with no change in specificity. Measurements of ST amplitude at the J junction and at 60 ms after the J point without slope considered and other scores, including the Treadmill Exercise Score, ST Integral, and ST/heart rate index, had a lower but comparable predictive accuracy when compared with horizontal or downsloping ST depression. Prediction of coronary artery disease severity can be achieved using computerized electrocardiographic measurements obtained during exercise testing. The most powerful marker for severe coronary artery disease is the amount of horizontal or downsloping ST-segment depression during exercise or recovery, or both, a measurement that stimulates the traditional visual approach.

Adrenergic beta-Antagonists↗
PubMed1992

Usefulness of exercise-induced ST-segment depression in the inferior leads during exercise testing as a marker for coronary artery disease.

Multiple lead systems are shown to have a higher sensitivity than that of single leads for detecting coronary artery disease (CAD) during exercise testing, but the value of ST-segment depression isolated to the inferior leads is questionable. To ascertain the diagnostic accuracy of inferior limb lead II compared with that of precordial lead V5, a retrospective analysis of 173 men was performed (108 in a training population and 65 in a validation cohort). All patients had a standard exercise test and underwent diagnostic coronary angiography within 15 days of the exercise test (range 1 to 65). Sixty-three patients had greater than or equal to 1 coronary stenoses greater than or equal to 70%, or left main lesion greater than or equal to 50%, whereas 45 patients in the training population did not. Exclusion criteria were female sex, left ventricular hypertrophy, left bundle branch block or resting ST-segment depression on the baseline electrocardiogram, previous myocardial infarction or revascularization procedures, and any significant valvular or congenital heart disease. Lead V5 had a better combination of sensitivity (65%) and specificity (84%) (chi-square = 24.11; p less than 0.001) than that of lead II (sensitivity 71%, specificity 44%) (chi-square = 2.25; p = 0.13) at a single cut point, and this improved specificity was substantial (95% confidence interval for observed difference 22 to 58%). Receiver-operating characteristic curve analysis also revealed that lead V5 (area = 0.759) was markedly superior to lead II (area = 0.582) over multiple cut points (z = 3.032; 2p = 0.002).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Comparison of silent and symptomatic ischemia during exercise testing in men.

OBJECTIVE: To compare angina and ST-segment depression during exercise testing, as markers for coronary artery disease. DESIGN: Retrospective analysis of exercise test responses and cardiac catheterization results. SETTING: A U.S. Veterans Affairs medical center. PATIENTS: Four hundred and sixteen men who were referred for the evaluation of symptoms, postmyocardial infarction testing, or both. Two hundred patients had no clinical or electrocardiographic evidence of previous myocardial infarction, whereas 216 were survivors of a previous myocardial infarction. INTERVENTIONS: All patients did a standard exercise test and had diagnostic coronary angiography with ventriculography within an average of 32 days (range, 0 to 90 days) of their exercise test. RESULTS: Two hundred patients without a previous myocardial infarction were divided into four groups: the no ischemia group had 80 patients; the angina pectoris only group had 23 patients; the silent ischemia group had 40 patients; and the ST-segment depression and angina pectoris group had 57 patients. In patients without a previous myocardial infarction, exercise-induced ST-segment depression was a better marker than exercise-induced angina for the presence of any coronary artery disease (P less than 0.005). Patients with symptomatic exercise-induced ischemia had a higher prevalence of severe coronary artery disease than did those with only silent ischemia (30% compared with 20%; 95% CI, - 7.3% to 27.0%; P = 0.005). For the 216 survivors of a myocardial infarction, divided into the same four groups, ST-segment depression again was a better marker for the presence of severe coronary artery disease compared with angina alone (P = 0.08). The prevalence rates of severe coronary artery disease in the no ischemia plus myocardial infarction group, the angina pectoris only plus myocardial infarction group, the silent ischemia plus myocardial infarction group, and the ST-segment depression and angina pectoris plus myocardial infarction group were 10%, 9%, 23%, and 32%, respectively (P less than 0.01). CONCLUSIONS: Exercise-induced ST-segment depression is a better marker for coronary artery disease than is exercise-induced angina. Symptomatic ischemia during the exercise test is a better marker for severe coronary artery disease than is silent ischemia.

Angina Pectoris↗
PubMed1991

Correlation between resting ST segment depression, exercise testing, coronary angiography, and long-term prognosis.

Resting ST segment depression has been identified as a marker for adverse cardiac events in patients with and without known coronary artery disease. To correlate this with exercise testing, coronary angiography, and how it impacts on long-term prognosis, a retrospective study was performed on 476 patients, of whom 223 had no clinical or electrocardiographic evidence of prior myocardial infarction while 253 were survivors of an infarction. All patients performed a standard exercise test and underwent diagnostic coronary angiography within an average of 32 days of their exercise test (range 0 to 90 days). Exclusions were women, those with left bundle branch block, left ventricular hypertrophy, use of digoxin, previous revascularization procedures, or significant valvular or congenital heart disease. Long-term follow-up was carried out for an average of 45 months (+/- 17). Of the patients without prior infarction, 23 (10%) had persistent resting ST segment depression, and of those with a prior history of infarction, 37 (15%) also had resting ST segment depression. Patients with resting ST segment depression and no prior myocardial infarction had a higher prevalence of severe coronary disease (three-vessel and/or left main) (30%) than those without resting ST segment depression (16%) (95% confidence interval [CI] for observed difference -5.0% to 33.9%, p = 0.12). The criterion of greater than or equal to 2 mm of additional exercise-induced ST segment depression was a particularly useful marker in these patients for the diagnosis of any coronary disease (likelihood ratio 3.35, 95% CI 0.56 to 19.93, p = 0.06). Patients with resting ST segment depression and a prior myocardial infarction had a 2.5 times higher prevalence of severe coronary artery disease compared with patients without resting ST segment depression (43% versus 17% prevalence, respectively, 95% CI for observed difference 9.38% to 42.8%, p less than 0.001) and also had larger left ventricles postinfarction (left ventricular end-diastolic volume index 102 ml/m2 compared with 96 ml/m2, p less than 0.001).(ABSTRACT TRUNCATED AT 400 WORDS)

Coronary Angiography↗
PubMed1991

Post-myocardial infarction exercise testing. Non-Q wave versus Q wave correlation with coronary angiography and long-term prognosis.

BACKGROUND: The presence or absence of baseline diagnostic Q waves has been believed to compromise the accuracy of standard exercise electrocardiography in identifying severe coronary artery disease (three-vessel and/or left main disease); therefore, a retrospective analysis was performed using a personal computer data base of exercise test responses and cardiac catheterization results to evaluate this premise, and follow-up was performed to observe how Q waves and/or severe coronary disease impacted on survival. METHODS AND RESULTS: Two hundred fifty-three male patients who had survived a myocardial infarction were studied. Patients on digitalis, those with left bundle branch block or left ventricular hypertrophy on their baseline electrocardiogram, those with previous revascularization procedures, and those with significant valvular or congenital heart disease were excluded. All patients performed either a low-level predischarge or a sign/symptom limited exercise test and underwent diagnostic coronary angiography within 32 days of each test (range, 0-90 days). Long-term follow-up on patients was performed for an average of 45 months (+/- 17 months). Group NQMI comprised 103 post-myocardial infarction patients lacking Q waves at the time of exercise testing and group QMI comprised 150 patients who developed Q waves with their myocardial infarction. The cut points of greater than or equal to 1 mm (chi 2 = 14.39, p less than 0.001) and greater than or equal to 2 mm (chi 2 = 26.11, p less than 0.001) of exercise-induced ST segment depression were reliable markers of severe coronary disease in Q wave infarct survivors. This was also true for non-Q wave infarct survivors as greater than or equal to 1 mm (chi 2 = 6.02, p = 0.01) and greater than or equal to 2 mm (chi 2 = 4.37, p = 0.04) of ST segment depression were reliable markers of severe coronary disease. Receiver operating characteristic curve analysis revealed that exercise-induced ST segment depression had discriminating power for the identification of severe coronary artery disease in both the Q wave myocardial infarction patients (area = 0.735, z = 4.47, p less than 0.001) and the non-Q wave infarct patients (area = 0.700, z = 3.20, p less than 0.001). After 4.4 years of cumulative follow-up, patients with severe coronary disease had an infarct-free survival rate of 72% (95%, CI, 50.0-86.0%), whereas those without severe disease had an 86% (95% CI, 76.5-91.5%) infarct-free survival rate (Cox chi 2 = 4.00, p = 0.045). Non-Q wave patients had an infarct-free survival rate of 81% (95% CI, 66.0-89.5%), whereas those with Q waves had an infarct-free survival rate of 85% (95% CI, 73.9-91.3%) (Cox chi 2 = 0.0005, p = NS). CONCLUSIONS: The presence or absence of diagnostic Q waves has no significant effect on the ability of the exercise electrocardiogram to identify severe coronary artery disease in survivors of myocardial infarction. Long-term infarct-free survival of patients with myocardial infarction is more related to the presence of severe coronary disease rather than if they suffered a non-Q wave or Q wave infarction.

Coronary Angiography↗