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Cold pressor test in detection of coronary heart-disease and cardiomyopathy using technetium-99m gated blood-pool imaging.

50 normotensive subjects (22 controls with no cardiac disease, 24 patients with coronary heart-disease, and 4 with early cardiomyopathy) were investigated with gated cardiac blood-pool scintigraphy before and during cold pressor stimulation. The controls had no change or a significant rise (p less than 0.005) in left ventricular ejection fraction and preserved normal myocardial-wall motion, whereas patients with coronary-artery disease or cardiomyopathy had a significant fall (p less than 0.001) in left ventricular ejection fraction and many developed abnormal regional wall motion despite the absence of angina pectoris. Cold pressor gated cardiac blood-pool studies were more sensitive than single-lead exercise electrocardiography (p = 0.03) in the detection of patients with severe coronary-artery disease without previous myocardial infarction.

Adolescent

Clinical assessment of left ventricular regional contraction patterns and ejection fraction by high-resolution gated scintigraphy.

An improved, noninvasive, radionuclidic, gated blood-pool imaging technique has been developed for clinical analysis of regional contraction abnormalities of the left ventricle and determination of ejection fraction. The principal innovations include high-resolution collimation, higher information density, improved method for dynamic aortic-mitral-diaphragmatic border delineation, accurate selection of the endsystolic gating interval through the use of the phonocardiogram, and accurate end-diastole by on-line gating immediately following the electrocardiographic QRS. The results of scintigraphic studies were compared with selective radiopaque cineangiographic findings in 27 patients with cardiac disease; excellent correlations of ejection fractions (r = 0.93) and abnormal contraction patterns (17/17 patients) were demonstrated. In addition, the clinical usefulness in evaluating ventricular performance was demonstrated in 79 patients with acute and chronic coronary artery disease. This radionuclidic technique allowed assessment of reversibility of segmental dyssynergy by the response to nitroglycerin in 20 patients. These findings demonstrate the validity of this improved radionuclidic technique in the atraumatic quantification of ventricular function and suggest its usefulness in a variety of clinical conditions.

Acute Disease

Multiple-gated acquisition cardiac blood-pool isotope imaging. Evaluation of left ventricular function correlated with contrast angiography.

Thirty-one patients were assessed by the multiple-gated acquisition cardiac blood-pool isotope-imaging technique using radiolabeled albumin within 24 hours of biplane contrast ventriculography. Data from the imaging method were analyzed by a semiautomatic technique with computer-generated edge detection and background subtraction. An excellent correlation was observed between ejection fractions determined with multiple-gated isotope imaging and those obtained by biplane contrast ventriculography (r = 0.93), and the same was true for average ejection rates (r = 0.80). For assessment of wall motion with this imaging technique, the anterior and the left anterior oblique left ventricular views were divided into nine segments, and a score was assigned to each segment based on the degree of wall motion. The cumulative anterior and left anterior oblique scores correlated well with the score from biplane contrast ventriculography (r = 0.90), and in 94% of segments in the left anterior oblique projection the assessment with multiple-gated isotope imaging was the same as or varied by only one class from the assessment by biplane contrast ventriculography. The multiple-gated acquisition cardiac blood-pool isotope-imaging technique is thus a valuable noninvasive method for assessing left ventricular function as measured by ejection fraction, ejection rates, and wall motion.

Adult

Radionuclide computed tomography of the body using routine radiopharmaceuticals. II. Clinical applications.

A whole-body computed tomography system for single-photon emitters was used to investigate the clinical utility of this imaging modality. We have explored its application in brain, lung, liver, kidney, cardiac, bone, and gallium imaging in over 200 patients. Brain images demonstrated better lesion contrast than that in standard scintiphotos. Images of the lung and liver showed radionuclide distribution that was not readily apparent in standard scintiphotos. Moderate or strongly positive pyrophosphate myocardial images demonstrate the potential for infarct quantitation. ECG-gated cardiac blood-pool images in cross section, displayed in cine formate, permit evaluation of segmental motion of the free and septal walls of both ventricles. These results suggest significant clinical potential for this imaging modality using standard radiopharmaceuticals, but some increase in system sensitivity will likely be necessary to realize the full benefit of the technique.

Abdomen

[Left ventricular function assessed by multigated blood pool single photon emission computed tomography with 99mTc].

To evaluate the usefulness of gated blood pool single photon emission computed tomography with 99mTc (gated SPECT) for assessing left ventricular function, we performed gated SPECT in 2 normal subjects and 18 patients including 13 with ischemic heart disease, 3 with hypertrophic cardiomyopathy and 2 with dilated cardiomyopathy. Left ventricular end-diastolic volume (LVEDV), left ventricular ejection fraction (LVEF) and regional wall motion obtained by gated SPECT were compared with the results of contrast left ventriculography (contrast LVG), echocardiography and planar multigated blood pool imaging (planar blood pool). After the patients' red blood cells were labelled with 30 mCi (1,110 MBq) 99mTc in vivo, gated SPECT was performed in each of 32 projections through a 360 degree arc for each of the cardiac cycle divided into 16. From these images, the left ventricular vertical long-axis image, the horizontal long-axis and short-axis images were reconstructed. To calculate LVEDV, we used serial short-axis images which were composed of the left ventricle. To define left ventricular and left atrial borders, we used amplitude images and cinematic displays of the vertical long-axis image. The level of the optimal cut for delineating the left ventricular border was determined from the volume-cut-level-graph at each background activity, which was constructed by a phantom study. Left ventricular wall motion by gated SPECT was compared with the results of contrast LVG according to segmental analysis. LVEDV obtained by gated SPECT showed an excellent linear correlation with LVEDV calculated by echocardiography (r = 0.98, p < 0.01) and by contrast LVG (r = 0.89, p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

[Myocardial perfusion and left ventricular function during exercise evaluated by 201Tl myocardial scintigraphy and 99mTc radionuclide ventriculography in patients treated with PTCA].

To evaluate the effects of percutaneous transluminal coronary angioplasty (PTCA), we investigated myocardial ischemia and left ventricular function during exercise before and after successful PTCA in 30 patients. We used extent and severity scores of 201thallium (201Tl) exercise myocardial scintigraphy to assess myocardial ischemia and determined global and regional left ventricular ejection fraction (EF and REF) of 99mTc-RBC exercise radionuclide ventriculography to assess left ventricular function. The extent and severity scores of stress images were significantly less after PTCA than before PTCA. The scores of the redistribution images were unchanged before and after PTCA. Global EF during exercise was significantly higher after PTCA than before PTCA. There was no difference in resting global EF between before and after PTCA. Myocardial ischemia induced by exercise was semi-quantitatively analyzed as transient perfusion defect with severity score. Severity score was significantly less after PTCA than before PTCA. delta EF, which was obtained by subtraction of resting global EF from exercise one, was significantly higher after PTCA than before PTCA. However, the degree of improvement in myocardial ischemia and left ventricular function varied from patient to patient. In 17 patients with one-vessel left anterior descending artery disease, delta REF, which was determined by subtracting resting regional EF from exercise one, was significantly higher in septal and apical segments after PTCA than before PTCA. Myocardial ischemia and left ventricular function under exercise were alleviated by PTCA. However, the degree of improvement varied from patient to patient and it might have been affected by various factors including coronary dissection, edema, thrombus, restenosis, spasm, side branch stenosis or occlusion, distal thrombus, and myocardial hibernation.

Aged

Assessment of left ventricular dysfunction in acromegalic patients using radionuclide ventriculography parameters.

The left ventricular function of 14 acromegalic patients was investigated using radionuclide ventriculography. After labeling the red blood cells with 750-1,000 MBq 99mTc-pertechnetate, ECG-triggered left anterior oblique images were recorded. Fourier analysis was then performed on the time-activity curve of the left ventricle. The ejection fraction (EF), peak ejection rate, time to peak ejection (TPE), time to end-systole (TES), peak filling rate (PFR), time to peak filling (TPF), 1/3 EF, 1/3 filling fraction (FF), TPE/T, TPF/T and TES/T values (T: time interval for one heart beat) were calculated for each patient. Five patients (35.7%) had clinical cardiovascular symptoms. A decreased EF was observed in 28.5% of the patients. In comparison to the control group, the EF (53.5 +/- 5.5 vs. 60.8 +/- 5% p less than 0.009), 1/3 EF (14.45 +/- 3 vs. 20 +/- 4%, p less than 0.001), 1/3 FF (28.5 +/- 10.6 vs. 41 +/- 11%, p less than 0.02), TPE (158 +/- 33 vs. 132 +/- 35 ms, p less than 0.01), TPE/T (20.2 +/- 5 vs. 16 +/- 3.7, p less than 0.01) and PFR (2.4 +/- 0.5 vs. 2.9 +/- 0.4 EDC/s, p less than 0.005) were significantly different. It was found that TPE was prolonged and the early ejection function was decreased. Diastolic dysfunction was found in 5 (35.7%) patients; 21.4% of the patients had decreased PFR values although they had no cardiac symptom, hypertension and/or cardiomegaly. Scintigraphic parameters did not correlate with the presence of hypertension, cardiomegaly or cardiovascular symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)

Acromegaly

Effects of regional systolic asynchrony on left ventricular global diastolic function in patients with coronary artery disease.

Patients with coronary artery disease often have impaired left ventricular diastolic filling despite normal global systolic function. The influence of regional systolic asynchrony on diastolic function was assessed by radionuclide angiography in 60 patients with coronary artery disease and normal ejection fraction at rest: group 1 (n = 30) with normal wall motion at rest and group 2 (n = 30) with abnormal wall motion. Data were compared with those obtained from 19 normal volunteers. Age, heart rate, ejection fraction and echocardiographic end-diastolic dimension did not differ among the three groups. Peak filling rate in group 1 and group 2 was similar (2.5 +/- 0.5 and 2.3 +/- 0.6 end-diastolic counts/s, respectively) and significantly lower than that in the normal subjects (2.8 +/- 0.7 end-diastolic counts/s; p less than 0.01 vs. group 2, p less than 0.05 vs group 1). Time to peak filling rate was prolonged in group 2 (184 +/- 27 ms) compared with that in normal subjects (162 +/- 19 ms; p less than 0.01) and group 1 (172 +/- 15 ms; p less than 0.05). Left ventricular end-diastolic pressure was significantly higher in group 2 than in group 1 (14 +/- 7 vs. 10 +/- 5 mm Hg, respectively; p less than 0.05). Asynchrony was assessed by sector analysis of the radionuclide left ventricular region of interest. Diastolic asynchrony was similar in the two patient groups (30 +/- 23 ms in group 2, 26 +/- 16 ms in group 1) and was higher in both groups than in the normal subjects (16 +/- 8 ms; p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance

Assessment of left ventricular volumes by magnetic resonance in comparison with radionuclide angiography, contrast angiography and echocardiography.

The present study shows that for assessment of LVEF, MRI and the standard methods seem to provide information of similar value. For absolute volume measurements, MRI and RNA are superior to single plane angiography and 2 DE using the modified Simpson-rule. The time consuming transversal MRI method does not seem to be superior to the oblique multislice method, when apical aneurysms can be ruled out. MRI thus seems to be an accurate method for determination of LV stroke volume as well as for determination of LVEF and hence for diastolic and systolic volumes. MRI, however, depends of a good image quality, which is crucial especially in dilated ventricles containing stagnant or slowly moving blood.

Adult

The acute effects of intravenous nisoldipine on left ventricular function within 24 h after acute myocardial infarction.

Nisoldipine is a calcium antagonist with potent coronary vasodilating effects in patients with chronic stable angina pectoris. We studied the acute effects of nisoldipine in six patients within 24 h (mean 14 +/- 4 h) after the onset of myocardial infarction. Nisoldipine was administered as a 4.5 micrograms kg-1 intravenous bolus over 3 min followed by intravenous infusion of 0.2 microgram kg-1 min-1 during 60 min. Radionuclide angiography, cardiac output and intra-arterial blood pressure measurements were performed before and during nisoldipine. Left ventricular ejection fraction increased from 48.3 +/- 10.3% to 55.3 +/- 11.8% (P = 0.034) during nisoldipine infusion. Regional wall motion score changed during nisoldipine infusion from 3.3 +/- 2.5 to 1.8 +/- 2.6 (P = 0.027). Cardiac output increased from 5.5 +/- 1.0 to 7.3 +/- 1.3 l min-1 (P = 0.0001). Heart rate increased from 78 +/- 12 to 88 +/- 11 beats.min-1 (P = 0.004). Mean arterial blood pressure decreased from 91.7 +/- 20.2 to 78.7 +/- 13.1 mmHg (P = 0.038). The rate-pressure product did not change significantly during nisoldipine infusion. It is concluded that nisoldipine improves global and regional left ventricular function in patients with acute myocardial infarction within the first 24 h. Our findings suggest that this effect is achieved without increasing myocardial oxygen demand.

Adult

Diagnostic reliability of radionuclide ventriculography in detecting left ventricular hypertrophy. Echocardiographic and ECG correlations.

Left ventricular hypertrophy (LVH) is frequently present in patients referred for radionuclide ventriculography (RVG) for evaluation of left ventricular function. During interpretation of these studies, the nuclear medicine physician may have the subjective impression that increased septal thickening is present because of the abnormally prominent separation of the right and left ventricular blood pools. To examine the diagnostic reliability of this finding, we retrospectively reviewed the RVG studies of 43 consecutive patients and correlated the finding of subjectively increased septal thickness with established echocardiographic (ECHO) criteria and commonly used electrocardiographic (ECG) indices of LVH. Using standard ECHO measurements of septal thickness as a gold standard, RVG interpretation of septal thickening demonstrated a sensitivity of 0.69, specificity of 0.70, and accuracy of 0.70. When compared with standard ECG criteria for LVH, RVG performed quite favorably in the diagnosis of LVH confirmed by ECHO left ventricular mass index. We conclude that scintigraphic evidence of LVH should be reported when RVG studies are interpreted.

Adult

Scintigraphic evaluation of left ventricular function and correlation with autonomic cardiac neuropathy in diabetic patients.

Left ventricular function of 20 diabetic patients was investigated at rest and during hand-grip test using radionuclide ventriculography. The aim of the study was to discuss the correlation of cardiac function with autonomic cardiac neuropathy (ACN) in diabetic subjects. ACN was tested using heart rate response to valsalva maneuver, standing up, deep breathing; blood pressure response to standing up, sustained hand-grip, and additionally corrected QT (QTc) measurements. Plasma glucose regulation was screened with fructosamine levels. Ejection fraction (EF), peak ejection (PER) and filling rates (PFR), times to peak ejection (TPE) and filling (TPF), time to endsystole (TES), TES/T, TPE/T, TPF/T, 1/3 PER, 1/3 PFR, 1/3 EF, 1/3 FF (filling fraction) we calculated. Thirteen patients had ACN. Six patients (30%) had a low EF at rest. As a response to hand-grip, 14 patients (70%) showed a decrease in EF (9 ACN). PFR was low in 10 patients (50%) at rest and in 12 (60%) during hand-grip. The mean rest PER value of ACN+ patients (4.4 +/- 1.3) was significantly higher than that of controls (2.9 +/- 0.5) and patients without ACN (3.4 +/- 0.4; p < 0.05) as well as the mean 1/3 PER value (1.7 +/- 0.5 vs. 1.3 +/- 0.5; p < 0.05). Fourteen patients (70%) had a fall in PER 10 ACN) as a response to hand-grip. The mean TES/T value of patients with ACN (0.44 +/- 0.05) was significantly higher than of those without ACN (0.38 +/- 0.05; p < 0.05). In conclusion, diastolic dysfunction was detected frequently at rest. Systolic parameters were markedly impaired as a response to hand-grip in patients with ACN. Sympathetic overactivity was noted in ACN+ group at rest. Our results indicated that the patients with diabetes and ACN have subclinical left ventricular diastolic dysfunction and symphatic overactivity.

Adult

Prognostic value of thallium-201 exercise scintigraphy in low-risk patients after Q-wave myocardial infarction: comparison with exercise testing and catheterization.

In a prospective study of 100 consecutive patients discharged after a Q-wave myocardial infarction, the value of reversible ischemia on thallium-201 scintigraphy to assess the risk of cardiac events (death or reinfarction) during 4 years was compared with variables from exercise testing and cardiac catheterization. Patients with markedly impaired left ventricular function [ejection fraction (EF) < or = 0.30] were excluded. During follow-up there were 20 cardiac events (10 cardiac deaths and 10 reinfarctions). Thallium-201 scintigraphy was significantly better than all exercise test variables and better than an EF < 0.40, with good sensitivity and specificity (75 and 51%, respectively). Exercise-induced reversible ischemia on scintigraphy yielded the same information as the presence of multivessel disease. Exercise test variables were of limited value to assess prognosis. Thus, thallium-201 scintigraphy can be used as the only tool to predict future cardiac events in low-risk patients after a Q-wave myocardial infarction.

Adult

[Assessment of prognosis of old myocardial infarction].

In an attempt to predict high risk myocardial infarction, we studied 201 patients with Q wave infarction with dipyridamole-loading thallium-201 myocardial perfusion scintigraphy (D-MPS), left ventriculography, coronary angiography and treadmill exercise testing. The results of these tests were related to the use of initial PTCA or CABG, and the occurrence of cardiac deaths and nonfatal cardiac events during a mean follow-up period of 39 months. Three high risk parameters were identified by D-MPS; partial redistribution, diffuse slow washout, and extensive fixed defects. The patients were categorized into 3 groups according to the numbers of high risk parameters: group A (n = 50), patients with 2 or more high risk parameters; group B (n = 95), patients with one high risk parameter; group C (n = 56), patients without a high risk parameter. The prevalence of 3-, 2-, and one- or insignificant vessel disease was 72, 20 and 8% in group A, 15, 16, and 69% in group B, and 5, 13 and 82% in group C, respectively. Initial PTCA or CABG was performed in 42% of the patients in group A, 5% of the patients in group B, and 2% of the patients in group C. Among medically-treated patients, cardiac deaths occurred in 31% in group A, 4% in group B, and in none in group C. Nonfatal cardiac events occurred in 24, 12, and 4%, respectively. Coronary angiography revealed 3-vessel disease in 53 patients, 2-vessel disease in 32, and one-vessel disease or insignificant lesions in 116 patients. Initial PTCA or CABG was performed in 45% of the patients with 3-vessel disease, 6% of those with 2-vessel disease and 1% of those with one-vessel disease. Among medically-treated patients, cardiac deaths occurred in 31% with 3-vessel disease, 7% with 2-vessel disease, and in 2% with one-vessel disease. Nonfatal cardiac events occurred in 17, 10, and 3%, respectively.

Adult

[The diagnostic potentials of pirfotekh in cardiovascular diseases].

The authors examined 98 patients with different cardiovascular diseases and 20 practically healthy subjects and established that complex use of pirphotech with 99mTc-pertechnetate gives an objective information on circulatory disorders in the myocardium. Radionuclide ventriculography in the static variant should be carried out early for obtaining adequate information on the state of cardiodynamics.

Adult