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D S Berman

Publications and source records attributed to D S Berman.

At least 145 records · Page 8Linked to original sources
PubMed1989

Exercise thallium-201 scintigraphy and prognosis in typical angina pectoris and negative exercise electrocardiography.

Patients with a history of typical angina but negative exercise electrocardiography represent a subgroup with an intermediate likelihood of having coronary artery disease and future cardiac events. A retrospective study of the prognostic utility of stress-redistribution thallium-201 scintigraphy was performed in 190 such patients. A second group of 203 patients with typical angina and a positive exercise electrocardiogram were analyzed for comparative scintigraphic purposes. The cardiac event rate for the 144 negative exercise electrocardiogram patients with normal thallium results was 5 vs 15% in the 46 patients with abnormal thallium results (p = 0.01). These patients were further stratified into high (14 to 18%), intermediate (9%) and low (less than 2%) risk groups for future cardiac events based on combining the thallium results with the percentage of maximal predicted heart rate achieved. A multivariate analysis revealed that an abnormal thallium result was the only significant correlate of future cardiac events. Mechanisms responsible for the discordant finding of a negative exercise electrocardiogram in patients with typical angina include (1) false-positive angina symptomatology in low prevalence coronary artery disease groups in whom the thallium test is negative, and (2) "electrocardiographically silent" ischemia in patients in whom the thallium test is positive. These findings reveal that thallium stress-redistribution scintigraphy can be used to stratify 1-year prognosis in this subgroup of patients with typical angina and negative exercise electrocardiograms.

Angina Pectoris↗
PubMed1989

Radionuclide imaging of myocardial perfusion and viability in assessment of acute myocardial infarction.

Technical advances in radionuclide imaging have important implications for the management of patients with acute myocardial infarction. Single-photon emission computerized tomography with thallium 201 (TI-201) offers greater accuracy than planar imaging in detecting, localizing and sizing myocardial perfusion defects. Use of single-photon emission computerized tomography with TI-201 should allow for a more accurate assessment of prognosis after myocardial infarction. A new radiopharmaceutical, technetium 99-m methoxyisobutyl isonitrile, provides a number of advantages over TI-201, including higher quality images, lack of redistribution, and the ability to assess first-pass ventricular function. Applications of TI-201 and technetium 99-m methoxyisobutyl isonitrile include assessment of arterial patency and myocardial salvage immediately after thrombolytic therapy, detection of resting ischemia after thrombolytic therapy, targeting of subsets of patients for further intervention, and predischarge assessment to predict the future course of patients after an acute myocardial infarction.

Coronary Circulation↗
PubMed1989

Exercise-induced ischemia in the streptokinase-reperfused myocardium: relationship to extent of salvaged myocardium and degree of residual coronary stenosis.

To assess the functional significance of residual stenosis at the site of the thrombolysed infarct-related coronary artery, 37 patients underwent exercise radionuclide ventriculography or stress-redistribution thallium-201 scintigraphy at an average of 7 weeks following streptokinase therapy during evolving myocardial infarction. The size of the initially jeopardized myocardium and the salvaged myocardium were quantitated on thallium-201 studies obtained immediately before and 10 days after streptokinase infusion. Exercise-induced ischemia (defined by reversible thallium-201 perfusion defects or stress-induced deterioration of regional wall motion) in the reperfused myocardium was absent in 46% of patients and was present in different degrees in the remaining 54%. A significantly lower proportion of patients, however, showed exercise-induced chest pain and/or ST segment depression (10% and 20%, respectively). By stepwise multiple logistic regression analysis, the quantitatively determined size of the salvaged myocardium (398 units versus 65 units, p less than 0.01) and the ratio of the salvaged myocardium/extent of initially jeopardized myocardium (70% versus 28%, p less than 0.01) were both independent predictors of stress-induced ischemia, whereas the extent of initially jeopardized myocardium (585 units versus 407 units, p = NS), incidence of greater than or equal to 99% coronary stenosis (37% versus 46%, p = NS), and ischemic time (160 versus 196 minutes, p = NS) did not provide additional predictive information. We conclude that exercise-induced ischemia, which is frequently present in the streptokinase-reperfused myocardium, cannot be detected accurately by exercise-induced chest pain or ST segment depression, nor can it be predicted by the severity of residual coronary stenosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Responses of left and right ventricular ejection fractions to aerobic and anaerobic phases of upright and supine exercise in normal subjects.

The effects of aerobic and anaerobic exercise on ventricular performance were studied in 13 normal subjects who underwent simultaneous pulmonary gas exchange evaluation and exercise radionuclide ventriculography in the supine and upright postures. Right and left ventricular ejection fraction was measured serially at 2-minute intervals during exercise. The anaerobic threshold occurred at 74% and 80% of maximum heart rate, respectively, during upright and supine exercise. Left and right ventricular ejection fractions rose from rest to the anaerobic threshold (p less than 0.01, p less than 0.01, respectively) and there was a further increase between the anaerobic threshold and maximum exercise (p less than 0.01, p less than 0.01, respectively). The rate of rise of ejection fraction beyond the anaerobic threshold was slightly blunted compared with the rise prior to attaining the anaerobic threshold. There was no significant difference in ventricular performance between supine and upright exercise. The data demonstrate that ventricular performance increases steadily during exercise and is not limited by the conversion of aerobic to anaerobic metabolism.

Adult↗
PubMed1989

Comparison of technetium 99m methoxy isobutyl isonitrile and thallium 201 for evaluation of coronary artery disease by planar and tomographic methods.

To compare stress/rest technetium 99m methoxy isobutyl isonitrile (Tc-MIBI) with stress redistribution thallium 201(T1-201) myocardial perfusion imaging, 36 patients were studied by single photon emission computerized tomography (SPECT) and planar methods. For SPECT, overall sensitivities for identification of patients with coronary artery disease were 93% (14/15) by Tc-MIBI and 80% (12/15) by TI-201 (p = NS). For planar methods, overall sensitivities were 73% (11/15) by both TI-201 and Tc-MIBI. Overall specificity was 75% (3/4 patients with normal coronary arteries) for both tracers with SPECT and Tc-MIBI by planar imaging and was 50% for planar TI-201 (p = NS). The normalcy rates for overall identification of coronary artery disease were determined in 17 patients with a low likelihood of disease. For SPECT, normalcy rates were 100% by Tc-MIBI and 77% by TI-201 (p = NS). For planar, they were 94% by Tc-MIBI and 88% by TI-201 (p = NS). Vessel sensitivities in the 35 stenosed coronary arteries (greater than or equal to 50% stenosis) for SPECT were 87% by Tc-MIBI and 77% by TI-201 (p = NS). For planar, the vessel sensitivities were 60% by Tc-MIBI and 54% by TI-201 (p = NS). For both tracers, the SPECT vessel sensitivities were significantly higher (p less than 0.005) than planar vessel sensitivities. The vessel specificities in 22 coronary vessels with less than 50% stenosis were 86% by SPECT Tc-MIBI and TI-201, 80% by planar Tc-MIBI and 73% by planar TI-201 (p = NS, SPECT vs planar, Tc-MIBI vs TI-201). Regarding myocardial segmental agreement, for the presence of stress defects the agreement was 91% for the 720 SPECT segments and 95% for the 540 planar segments. For severity of stress defects based on semiquantitative visual scoring, the exact agreement was 87% for SPECT and 80% for planar. For the pattern of reversibility in myocardial segments with stress defects, the agreement was 97% for SPECT and 91% for planar. This study demonstrated that Tc-MIBI and TI-201 correlate well on both planar and SPECT images with respect to the identification of patients with coronary artery disease, identification of disease in individual coronary arteries, the presence and severity of perfusion defects, and the assessment of defect reversibility. Furthermore, SPECT Tc-MIBI was shown to be superior to planar Tc-MIBI for the identification of individual diseased vessels.

Adult↗
PubMed1989

Quantification of left ventricular myocardial mass in humans by nuclear magnetic resonance imaging.

The ability of NMRI to assess LV mass was studied in 20 normal males. By means of a 1.5 Tesla GE superconducting magnet and a standard spin-echo pulse sequence, multiple gated short-axis and axial slices of the entire left ventricle were obtained. LV mass was determined by Simpson's rule with the use of a previous experimentally validated method. The weight of the LV apex (subject to partial volume effect in the short-axis images) was derived from axial slices and that of the remaining left ventricle from short-axis slices. The weight of each slice was calculated by multiplying the planimetered surface area of the LV myocardium by slice thickness and by myocardial specific gravity (1.05). Mean +/- standard deviation of LV mass and LV mass index were 146 +/- 23.1 gm (range 92.3 to 190.4 gm) and 78.4 +/- 7.8 gm/m2 (range 57.7 to 89.4 gm/m2), respectively. Interobserver agreement as assessed by ICC was high for determining 161 individual slice masses (ICC = 0.99) and for total LV mass (ICC = 0.97). Intraobserver agreement for total LV mass was also high (ICC = 0.96). NMRI-determined LV mass correlated with body surface area: LV mass = 55 + 108 body surface area, r = 0.83; with body weight: LV mass = 26 + 0.77 body weight, r = 0.82; and with body height: LV mass = 262 +/- 5.9 body height, r = 0.75. Normal limits were developed for these relationships. NMRI-determined LV mass as related to body weight was in agreement with normal limits derived from autopsy literature data.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Technetium-99m hexakis 2-methoxyisobutyl isonitrile: human biodistribution, dosimetry, safety, and preliminary comparison to thallium-201 for myocardial perfusion imaging.

The biodistribution, dosimetry, and safety of a new myocardial imaging agent, 99mTc-hexakis-2-methoxyisobutyl isonitrile (HEXAMIBI), was evaluated in 17 normal volunteers at rest and exercise (Phase I studies). Technetium-99m HEXAMIBI clears rapidly from the blood with good myocardial uptake and favorable myocardial-to-background ratios for myocardial imaging. Dosimetry allows for administration of up to 30 mCi (1, 110 Bq) of [99mTc]HEXAMIBI. The myocardial images were of good quality and appeared less granular with sharper myocardial walls compared to 201T1 images. The clinical efficacy of [99mTc]HEXAMIBI planar stress and rest imaging was evaluated in a multicenter Phase II clinical trial involving 38 patients. Of 36 patients with significant coronary artery disease, 35 patients (97%) had abnormal 201T1 stress images, and 32 (89%) had abnormal [99mTc]HEXAMIBI stress images (P = N.S.). Technetium-99m HEXAMIBI images correlated in 31/35 patients (86%) who had either scar or ischemia on 201T1 images. By segmental myocardial analysis, exact concordance was obtained in 463/570 myocardial segments (81%). This multicenter Phase I and II study indicates that planar [99mTc]HEXAMIBI stress imaging is safe and compares well with 201T1 stress imaging for detection of coronary artery disease.

Adult↗
PubMed1989

"Upward creep" of the heart: a frequent source of false-positive reversible defects during thallium-201 stress-redistribution SPECT.

A new cause of artifactual 201Tl defects on single photon emission computed tomography (SPECT) termed "upward creep" of the heart is described. In 102 consecutive patients undergoing 201Tl SPECT, 30 (29%) demonstrated upward creep defined by an upward movement of the heart of greater than or equal to 2 pixels during acquisition. In 45 consecutive patients with a less than 5% likelihood of coronary artery disease, 17 (38%) had upward creep. Of these nine had reversible 201Tl defects localized to the inferior and basal inferoseptal walls, while none of the 28 without upward creep had defects. The 17 low likelihood patients with upward creep had longer exercise duration and higher peak heart rate than those without upward creep. In five additional low likelihood patients with upward creep in whom imaging was immediately repeated, the upward creep pattern disappeared on the repeated images. After we changed our test protocol to begin imaging 15 min postexercise, only five (14%) of 36 low likelihood patients tested demonstrated upward creep. Upward creep is probably related to a transient increase in mean total lung volume early following exhaustive exercise, resulting in a mean lower position of the diaphragm (and thus the heart) at the beginning of imaging. The frequency of this source of false-positive 201Tl studies can be reduced by delaying SPECT acquisition until 15 min postexercise.

Adult↗
PubMed1988

Mental stress and the induction of silent myocardial ischemia in patients with coronary artery disease.

To assess the causal relation between acute mental stress and myocardial ischemia, we evaluated cardiac function in selected patients during a series of mental tasks (arithmetic, the Stroop color--word task, simulated public speaking, and reading) and compared the responses with those induced by exercise. Thirty-nine patients with coronary artery disease and 12 controls were studied by radionuclide ventriculography. Of the patients with coronary artery disease, 23 (59 percent) had wall-motion abnormalities during periods of mental stress and 14 (36 percent) had a fall in ejection fraction of more than 5 percentage points. Ischemia induced by mental stress was symptomatically "silent" in 19 of the 23 patients with wall-motion abnormalities (83 percent) and occurred at lower heart rates than exercise-induced ischemia (P less than 0.05). In contrast, we observed comparable elevations in arterial pressure during ischemia induced by mental stress and ischemia induced by exercise. A personally relevant, emotionally arousing speaking task induced more frequent and greater regional wall-motion abnormalities than did less specific cognitive tasks causing mental stress (P less than 0.05). The magnitude of cardiac dysfunction induced by the speaking task was similar to that induced by exercise. Personally relevant mental stress may be an important precipitant of myocardial ischemia--often silent--in patients with coronary artery disease. Further examination of the pathophysiologic mechanisms responsible for myocardial ischemia induced by mental stress could have important implications for the treatment of transient myocardial ischemia.

Adult↗
PubMed1988

Late reversibility of tomographic myocardial thallium-201 defects: an accurate marker of myocardial viability.

Twenty-one patients were studied who underwent thallium-201 stress-redistribution single photon emission computed tomography (SPECT) both before and after coronary artery bypass grafting (n = 15) or transluminal coronary angioplasty (n = 6). All patients underwent thallium imaging 15 min, 4 h and late (18 to 72 h) after stress as part of the preintervention thallium-201 scintigram. In a total of 201 tomographic myocardial segments with definite post-stress thallium-201 perfusion defects in which the relevant coronary arteries were subsequently successfully reperfused, the 4 h redistribution images did not predict the postintervention scintigraphic improvement: 67 (85%) of the 79 4 h reversible as well as 88 (72%) of the 122 4 h nonreversible segments improved (p = NS). The 18 to 72 h late redistribution images effectively subcategorized the 4 h nonreversible segments with respect to postintervention scintigraphic improvement: 70 (95%) of the 74 late reversible segments improved after intervention, whereas only 18 (37%) of the 48 late nonreversible segments improved (p less than 0.0001). The frequency of late reversible defects and the frequency of postrevascularization improvement of late nonreversible defects are probably overestimated by this study because of referral biases. The cardiac counts and target to background ratios from late redistribution studies resulted in satisfactory cardiac images for visual interpretation. For optimal assessment of the extent of viable myocardium by thallium-201 scintigraphic studies, late redistribution imaging should be performed when nonreversible defects are observed on 4 h redistribution images.

Aged↗
PubMed1988

Patient motion in thallium-201 myocardial SPECT imaging. An easily identified frequent source of artifactual defect.

Because Tl-201 SPECT requires that patients remain in an awkward position for a prolonged time, patient motion is a potentially serious source of artifactual defects on tomographic reconstructions. Thus, a simple method was developed for detection and correction of motion from SPECT images using a Co-57 point source placed on the lower anterior chest, an area remaining in the camera's field of view throughout imaging. In the absence of motion, this point source inscribes a straight line on planar summation of the 32 projections over 180 degrees. Movement is detected by deviation from this line. The number of pixels of motion is used to shift images so that the resultant images of the point source are linear. The method of motion detection and correction was tested in 48 consecutive patients undergoing Tl-201 SPECT. The corrected and uncorrected images were reconstructed and long and short axis tomographic cuts were quantitatively analyzed using circumferential profiles of maximal counts with comparison to the lower limits of normal. Motion was detected in eight of 48 patients (17%). The amount of motion was 2 pixels in three patients and 1 pixel in five patients. Quantitative defect extent was less after correction in seven of eight patients, with a mean decrease of 71% in patients with 2 pixel motion and 44% in patients with 1 pixel motion. This corresponded with a definite reduction in the size of the tomographic defect by visual analysis, and closer resemblance to quantitatively analyzed planar images performed either before or after tomography in the same patient.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Incremental prognostic power of clinical history, exercise electrocardiography and myocardial perfusion scintigraphy in suspected coronary artery disease.

The incremental ability of a clinical history, exercise electrocardiography (ECG) and myocardial perfusion scintigraphy to identify coronary events in the year after testing was assessed in 1,659 patients with symptoms suggestive of coronary artery disease (CAD), 74 of whom suffered a coronary event in the year after testing. Prognostic power was quantified in terms of the area under receiver operating characteristic curves derived from logistic regression. In 1,451 patients with normal rest ECG findings, a clinical history alone provided the most prognostic power (area = 72%). This improved significantly (by 5%) only when both tests were analyzed. In contrast, clinical history had significantly less prognostic power in the 208 patients with abnormal rest ECG findings (area = 58%), but each test then provided a significant incremental improvement in these patients (by 14% for each). A strategic model was thereby developed for prognostic assessment that recognizes the incremental power of these tests in specific patient groups as well as their overall accuracy and monetary cost. This strategy stratified individual patient risk for subsequent coronary events over a full order of magnitude (from 2 to 22%) at a 64% reduction in the cost of testing compared to performing both stress tests in all patients.

Aged↗