Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Radionuclide Angiography”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5Linked to original sources

Prognostic value of exercise radionuclide angiography in a population-based cohort of patients with known or suspected coronary artery disease.

Five hundred thirty-six residents of Olmsted County, Minnesota, who underwent supine rest and exercise radionuclide angiography because of known or suspected coronary artery disease, were followed for a median of 46 months to determine the prognostic value of exercise radionuclide angiography in a community population who generally did not undergo coronary angiography. There were 71 persons who experienced a new cardiac event (the initial events were cardiac death and nonfatal myocardial infarction in 26 and 45 persons, respectively). A proportional-hazards model identified 4 independent predictors of cardiac events: exercise ejection fraction (p < 0.001), exercise heart rate (p < 0.001), and age (p = 0.04). Four-year infarct-free survival was 98% for the 152 patients with a peak exercise heart rate at or above the median (122 beats/min) and an exercise ejection fraction at or above the median (0.58). In the 150 patients with a peak exercise heart rate < 122 beats/min and an exercise ejection fraction < 0.58, 4-year infarct-free survival was 68%. When this population-based cohort was compared with a referral case series previously reported from our institution, these population-based patients were significantly more likely to be men, to have typical angina, to have higher exercise heart rates and exercise ejection fractions, and were less likely to be receiving beta-receptor antagonist therapy. At each level of exercise ejection fraction, the population-based patients had a slightly but insignificantly greater risk than referral patients for subsequent cardiac events. These population-based data provide strong evidence of the prognostic value of exercise radionuclide angiography in community practice.

Age Factors↗

Risk stratification of single or double vessel coronary artery disease and impaired left ventricular function using exercise radionuclide angiography.

Patients with 3-vessel coronary artery disease (CAD) and normal left ventricular (LV) function have a worse prognosis if they manifest ischemia during exercise testing. The present study determines if exercise radionuclide angiography can aid in the risk stratification of patients with 1- or 2-vessel CAD and impaired LV function (ejection fraction less than 50%). Sixty-five consecutive patients with these findings were followed for a median duration of 24 months (range 12 to 49). Eleven of the 65 patients (17%) had severely ischemic exercise radionuclide angiograms, defined as: a decrease in ejection fraction with exercise; greater than or equal to 1.0 mm of ST-segment depression; and peak exercise workload less than or equal to 600 kg-m/min. During follow-up 11 patients had initial significant cardiac events: 4 cardiac deaths, 1 cardiac arrest, 4 myocardial infarctions and 2 bypass or angioplasty procedures for unstable angina greater than or equal to 3 months after the exercise study. Four of 11 patients (36%) with severely ischemic exercise radionuclide angiograms had events, compared to 7 of 54 patients (13%) without ischemic radionuclide angiograms. Event-free survival at 18 months was 73% for patients with severe exercise ischemia versus 92% for those without ischemia (p less than 0.05). Univariate analysis showed that severe ischemia on radionuclide angiography was the only variable of several tested that significantly predicted future cardiac events (chi-square = 8.16, p less than 0.005). Among patients with 1- or 2-vessel CAD and impaired resting LV function, severe ischemia on exercise radionuclide angiography identifies a subgroup at high risk for future cardiac events.

Coronary Disease↗

Detection of radiation cardiomyopathy by gated radionuclide angiography.

Twenty-one asymptomatic adults underwent rest and exercise gated radionuclide angiography seven to 20 years after having received mediastinal radiation (2,000 to 7,600 rads) for Hodgkin's disease. None of these patients received cytotoxic chemotherapy. Twelve patients (57 percent) had abnormal left (less than 53 percent at rest and/or greater than 5 percent decrease at peak exercise) and/or right (less than 27 percent at rest and/or greater than 5 percent decrease at peak exercise) ventricular ejection fractions. Previous reports have described myocardial fibrosis occurring late after therapeutic mediastinal radiation; however, the incidence of this occurrence based on clinical follow-up has been low. Rest and exercise radionuclide angiography is a sensitive method for assessing systolic ventricular function and reveals a high prevalence of cardiomyopathy that can be linked to previous radiotherapy.

Adult↗

[Diagnosis of pericardial effusion by echocardiography and radionuclide angiography (author's transl)].

Echocardiography and radionuclide angiography are presently the two first choices non-invasive methods for the diagnosis of pericardial effusion. To evaluate the sensitivity and specificity of these methods, a prospective study of 43 consecutive patients was undertaken. Confirmation by tap or autopsy was obtained in 10 cases; for the remainers, strict clinical signs were requested. The results of both methods were classified in a quantitative manner. Our data confirms the greater sensitivity and specificity of echocardiography compared with radionuclide angiocardiography, when small amounts of effusion are present. However, the correlation between the two methods is satisfactory when a greater amount of fluid is present.

Adult↗

Left ventricular volumes by gated equilibrium radionuclide angiography: a new method.

To compare radionuclide end-diastolic (EDV) and end-systolic (ESV) volumes with angiographic volume, we studied 52 patients with equilibrium radionuclide angiography using 99mTc-human serum albumin within 48 hours of contrast angiography. Each RR interval was divided into 20--28 equally timed frames and a time-activity curve generated. End-diastolic counts were taken at the early peak of the curve and end-systolic counts at its nadir. Counts were divided by the total number of processed heart beats and normalized for: 1) dose per body surface area; 2) plasma volume; and 3) counts/ml of plasma. A cardiac phantom was developed and serial volumes were studied using a normalization factor. Radionuclide values were expressed as dimensionless units and compared with either biplane angiographic volumes (in the patient studies) or known phantom volumes. Good correlations were obtained with methods 1 and 2 in 35 patients (r greater than 0.84), but the best correlation was obtained in 17 patients when normalization for counts/ml of plasma was used (r = 0.98; y = 0.255 x -0.121). The standard error of the estimate (SEE) was +/- 11.5 ml for EDV and +/- 7.3 ml for ESV. The phantom study also showed an excellent correlation (r = 0.99), with a SEE of +/- 6.5 ml. We conclude that a radionuclide method independent of geometric assumptions can be used to estimate left ventricular volume in man.

Adult↗

Hemodynamic correlates of right ventricular ejection fraction measured with gated radionuclide angiography.

Right ventricular function was studied in 60 patients with equilibrium gated radionuclide angiography. The mean (+/- standard deviation) right ventricular ejection fraction in 20 normal subjects was 53 +/- 6 percent, a value in agreement with previous data from both radionuclide and contrast angiographic studies. This value was similar (55 +/- 7 percent) in 11 patients with coronary artery disease but normal left ventricular function. Radionuclide measurements of right ventricular ejection fraction were correlated with right heart hemodynamics. There was a significant negative linear correlation between right ventricular ejection fraction and mean pulmonary arterial pressure (r = -0.82) and between right ventricular ejection fraction and right ventricular end-diastolic pressure (4 = -0.67). Furthermore, patients with elevated right ventricular end-diastolic pressure and mean pulmonary arterial pressure had a more severely depressed ejection fraction than did those with an elevated mean pulmonary arterial pressure alone. Thus, an abnormal value for right ventricular ejection fraction by gated radionuclide angiography in the absence of primary right ventricular volume overload suggests abnormal right heart pressures, whereas a normal value excludes severe pulmonary arterial hypertension or an elevated right ventricular end-diastolic pressure.

Adult↗

Postoperative evaluation of the Fontan procedure by radionuclide angiography.

Seven patients were evaluated by radionuclide angiography (RNA) following Fontan-like procedures for complex cyanotic congenital defects. Both first-pass and ECG gated equilibrium angiography were performed in each. Residual right-to-left shunts, right atrial (RA) outflow and pulmonary arterial obstruction, and left ventricular dysfunction were demonstrated by these techniques. In addition, RA ejection fraction (RAEF) by gated equilibrium scan was measured in each patient. Relatively low RAEF was seen in conjunction with residual obstruction to pulmonary flow. RNA is useful in the postoperative evaluation of patients after Fontan procedures.

Adolescent↗

Noninvasive quantitation of valvular regurgitation by gated equilibrium radionuclide angiography.

R-wave synchronous equilbrium radionuclide angiography (RNA) is a noninvasive method that provides time-activity curve count information proportional to ventricular volumes and is used for relative volume comparisons within the left or right ventricle to derive the ejection fraction. Comparison of the ventricular count output between both ventricles may permit quantitation of the relative amount of valvular regurgitation, i.e., the regurgitant fraction. We performed resting gated RNA in 30 consecutive patients undergoing cardiac catheterization and quantitative contrast ventriculography for aortic or mitral valvular regurgitation. RNA regurgitant fraction correlated well with cardiac catheterization regurgitant fraction (r = 0.85). In 11 patients imaged before and 1-4 months after successful valve replacement, the regurgitant fraction declined from 0.68 +/- 0.11 to -0.09 +/- 0.13 (p < 0.001). In 20 control patients without valvular regurgitation, the calculated regurgitant fraction did not exceed 0.20. We conclude that valvular regurgitation may be accurately detected, quantitative and followed serially after therapeutic intervention using gated RNA.

Aortic Valve Insufficiency↗

Noninvasive quantitation of right-ventricular volume overload in adults by gated equilibrium radionuclide angiography.

R-wave-synchronized equilibrium radionuclide angiography (RNA) is a noninvasive method whose time-activity curves provide count information that is proportional to ventricular volume. We have performed resting gated RNA in nine consecutive adult patients undergoing cardiac catheterization for evaluation of left-to-right shunting. Pulmonary/systemic flow ratios (Qp/Qs) calculated from RNA correlated well with Qp/Qs defined by oximetry (r = 0.87, y = 0.85x + 0.11, sy . x = 0.46). In five patients imaged before, and within 1 mo after, successful surgical repair, RNA Qp/Qs declined from a mean (+/- s.d.) of 2.9 +/- 1.0 to 1.1 +/- 0.2. Right/left ventricular end-diastolic volume ratios declined from 3.1 +/- 1.3 to 1.7 +/- 0.2. Although left-ventricular ejection fraction did not change, right-ventricular ejection fraction declined in these patients. Imaging in nine patients with right-ventricular dysfunction, but without shunt or regurgitation, yielded a mean Qp/Qs of 0.94 +/- 0.27. We conclude that Qp/Qs, right-ventricular ejection fraction, and relative ventricular enlargement may be accurately quantitated and followed serially after therapeutic intervention using gated RNA.

Adult↗

Criteria for the accurate interpretation of changes in left ventricular ejection fraction and cardiac volumes as assessed by rest and exercise gated radionuclide angiography.

Although serial left ventricular ejection fraction and volumetric measurements using gated radionuclide angiography are commonly used to evaluate clinical changes and therapeutic outcomes in individual patients, criteria are not available for accurately interpreting whether a change in any of these hemodynamic measurements is clinically meaningful. Accordingly, the magnitude of inherent variability among sequential measurements of hemodynamic variables assessed by gated radionuclide angiography was investigated in a double-blind placebo-controlled fashion in 39 patients during two placebo periods separated by 6 weeks. All patients analyzed had remained clinically stable during the study period. Although the mean values for all hemodynamic variables between the two placebo periods were minimally changed, the differences in individual patients were striking. Criteria were developed to allow meaningful interpretation of changes in hemodynamic variables by estimating the likelihood that an observed change is due to variability alone. On the basis of this analysis of placebo radionuclide angiographic data, variation due to chance alone is unlikely to account for all variability if a change observed between the two rest gated studies in a patient is greater than or equal to 7% units for left ventricular ejection fraction, greater than or equal to 45 ml/m2 for end-diastolic volume index, greater than or equal to 35 ml/m2 for end-systolic volume index, greater than or equal to 20 ml/m2 for stroke volume index and greater than or equal to 1.25 liters/min per m2 for cardiac index. An observed 4% unit change in left ventricular ejection fraction (increase or decrease) after a medical intervention in an individual patient occurs by random variation greater than 25% of the time.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Volume↗

Evaluation of left ventricular function after acute myocardial infarction. Two-dimensional echocardiography versus radionuclide angiography. Study of 50 patients.

Two-dimensional echocardiography and gated blood radionuclide angiography was performed in 50 patients (mean age 51.3 years; 48 men and 2 women) after acute myocardial infarction, before discharge from the hospital. The aim of this study was to compare the wall motion score, determined by two-dimensional echocardiography (2DE), with the ejection fraction obtained by radionuclide angiography (RNA). The correlation between the results obtained by 2DE and RNA was good (r = 0.75; p less than 0.0001). We conclude that 2DE is a powerful diagnostic tool for the evaluation of left ventricular function.

Adult↗

Radionuclide angiography in the evaluation of iliofemoral venous patency.

Radionuclide angiography (RNA), was compared to contrast phlebography (CP) for evaluation of iliofemoral venous patency. Twenty-three patients that six months earlier had been treated for iliofemoral venous thrombosis were investigated. The reproducibility of RNA was good as the interindividual and intraindividual variation was 80-85% and 90-95% respectively. The sensitivity of RNA was 91% in the iliac and 65% in the femoral segment. The specificity was 78% in the iliac and 74% in the femoral segment. The advantages as compared to CP are: easy performance, easy to repeat, no adverse reactions and visualization of the whole venous system. The disadvantages are: e.g. difficulties in interpretation in bilateral disease or abnormal anatomy. RNA is recommended as a screening method for suspected iliac venous obstruction and for follow-up of venous patency after iliofemoral venous thrombosis.

Adolescent↗

Prognostic value of exercise radionuclide angiography in low risk acute myocardial infarction survivors.

Patients with an uneventful course during hospital stay, which represent from 30 to 50% of all myocardial infarction survivors, still have an incidence of new coronary events up to 7% during the first year of follow-up. To assess the value of radionuclide angiography in predicting new coronary events in this low risk population, 93 patients without evidence of left ventricular failure or recurrent postinfarction angina underwent rest and exercise radionuclide angiography and treadmill exercise testing before hospital discharge. During follow-up (16 +/- 5 months, range 12 to 32) 14 patients developed new coronary events: two patients died, four had a new myocardial infarction and the remaining eight had unstable angina. There were no differences regarding clinical variables, the results of the exercise test and the resting ejection fraction, between patients with or without new coronary events; however, patients without events during follow-up exercised longer during both exercise treadmill test and exercise radionuclide angiography. Resting end-diastolic and end-systolic volume indexes were higher in patients presenting coronary events (122 +/- 50 vs 92 +/- 32 ml.m-2, P < 0.05, 69 +/- 47 vs 47 +/- 26 ml.m-2, P < 0.05). These patients also had a higher incidence of wall motion abnormalities in more than one area (64 vs 28%, P < 0.02). During exercise, ejection fraction increased significantly in patients with an uneventful outcome (49 +/- 13 to 56 +/- 14%, P < 0.01), while it did not change in their counterparts (46 +/- 14 to 45 +/- 14%, NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

Predischarge exercise radionuclide angiography in predicting multivessel coronary artery disease and subsequent cardiac events after thrombolytic therapy for acute myocardial infarction.

The value of exercise testing in postinfarction patients receiving thrombolytic therapy has not been established. Ninety-four patients treated acutely with thrombolytic therapy without angioplasty who underwent exercise radionuclide angiography and coronary angiography before hospital discharge were studied. Thirty patients underwent early revascularization, often for multivessel disease. During a median follow-up period of 3.5 years, only 5 patients had "hard" events (cardiac death, cardiac arrest, or myocardial infarction) and 5 other patients underwent late (> 90 days) revascularization. The results of radionuclide angiography did not predict multivessel disease. Peak exercise ejection fraction was the only significant (p = 0.003) independent predictor of events. Among the 65 patients with a peak exercise ejection fraction > or = 40%, the 3-year hard and "combined" event-free survival were 98% and 91%, respectively. Among the 29 patients with a peak exercise ejection fraction < 40%, the 3-year hard and combined event-free survival were 74% and 69%, respectively. Postinfarction patients treated with thrombolytic therapy, who often underwent early revascularization, had an excellent prognosis through 3.5 years of follow-up. Although exercise radionuclide angiography had little value for identifying multivessel disease, a reduced peak exercise ejection fraction was associated with subsequent events.

Aged↗

Radionuclide angiography as a confirmatory test for brain death: a review of 229 studies in 219 patients.

BACKGROUND: Radionuclide angiography (RA) has been used for many years to confirm the clinical diagnosis of brain death, but quantitative data regarding the technique are unavailable. METHODS: We conducted a retrospective review of 229 RA procedures done in 219 patients. RESULTS: Of 206 patients who had interpretable studies and met clinical criteria for brain death (profound coma, absent brain stem reflexes, and apnea), including 10 patients who had repeated studies, 203 (98.5% sensitivity) had positive studies, and 6 (2.9%) had negative studies. Of nine patients who had interpretable studies and did not meet the clinical criteria for brain death, five (56% specificity) had positive studies and four (44%) had negative studies. CONCLUSIONS: Radionuclide angiography is a sensitive confirmatory test of brain death. The study does not evaluate the posterior fossa circulation, and an occasional patient may have residual brain stem function. The examination is most reliable when the patient is in a deep coma, has no brain stem reflexes, and has failed a formal apnea test.

Adolescent↗

Diagnostic value of technetium-99m radionuclide angiography for detecting thrombosis in left atrial appendage.

In mitral valve disease, it is important to know whether thrombi are present in the left atrium when deciding upon a course of treatment. The left atrial thrombus usually locates in the left atrial appendage. In most cases of mitral valve disease, the left atrial appendage is clearly demonstrated by radionuclide angiography using 99mTc-labeled red blood cells and it can be speculated that the cases in which left atrial appendage are not demonstrated by RNA have left atrial thrombi. On the basis of this hypothesis, the diagnostic accuracy of radionuclide angiography to detect left atrial thrombi was evaluated retrospectively in 60 patients with mitral valve disease who had undergone surgery. The sensitivity of first-pass and equilibrium radionuclide angiography to detect left atrial thrombi was 83% and 67%, the specificity 79% and 54%, and the accuracy 80% and 57%, respectively. Although there were two false-negative cases in which the left atrial thrombi did not locate in the appendage and 10 false-positive cases in which left atrial appendages were not dilated, the negative predictive value was so high that a clearly demonstrated left atrial appendage can be translated into the absence of left atrial thrombi.

Adult↗

Supine exercise electrocardiography compared with exercise radionuclide angiography in noninvasive identification of severe coronary artery disease.

STUDY OBJECTIVE: To determine the incremental value of exercise radionuclide angiography for identification of severe coronary artery disease. DESIGN: Retrospective analysis comparing logistic regression models. SETTING: A tertiary care referral center. PATIENTS: Three hundred and ninety-one consecutive patients who had normal resting electrocardiograms (ECGs) and no digoxin therapy within the previous week. MEASUREMENTS AND MAIN RESULTS: The exercise ECG model, consisting of magnitude of ST depression, exercise heart rate, and patient gender, was highly predictive of three vessel or left main coronary artery disease (chi 2 = 100, P less than 0.0001). The model correctly classified 60% of the study group which included 56 patients with and 179 without severe disease. The addition of radionuclide angiographic variables improved the predictive power of the model (chi 2 = 124, P less than 0.0001). However, the exercise radionuclide angiographic variables increased the number of patients who were correctly classified by only 11 and the percentage by 3% (to a total of 63% of the study group). CONCLUSIONS: The modest additional advantage provided by exercise radionuclide angiography for identification of three vessel or left main coronary artery disease in patients with normal resting ECGs would not appear to justify its routine use for this purpose. Before this conclusion is used as a guide for clinical practice, our results should be prospectively confirmed in a separate sample of patients in another institution.

Coronary Angiography↗