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A Battler

Publications and source records attributed to A Battler.

157 records · Page 9Linked to original sources
PubMed1979

Reproducibility of ejection fraction and ventricular volume by gated radionuclide angiography after myocardial infarction.

To validate the repeated use of radionuclide equilibrium angiography for determining left ventricular (LV) ejection fraction (EF) and end-diastolic and end-systolic volumes (EDV and ESV), 25 patients were studied on an hourly basis an average of 9.1 days after acute myocardial infarction. Data were processed with a semi-automatic computer program which develops an averaged-volume curve from an assigned LV region-of-interest. LV EDV and ESV were derived from a previously described method which correlates well with contrast angiography (r = 0.977, y = 0.0255x - 0.121). Comparison between initial and subsequent equilibrium EF and between initial and subsequent volumes showed excellent correlation. Excluding three anginal episodes, the EF variation between studies averaged 0.03 +/- 0.02.

Acute Disease↗
PubMed1979

Reproducibility of ejection-fraction determinations by equilibrium radionuclide angiography in response to supine bicycle exercise: concise communication.

Sixteen patients with stable, chronic coronary artery disease were studied twice within and average of 15 days to evaluate the reproducibility of ejection fraction (EF) determined by equilibrium radionuclide angiography (EQ) at rest, during supine bicycle exercise (ex), and in the recovery period (rec). Following injection of 20--25 mCi of Tc-99m-tagged human serum albumin, data were analyzed for 2-min periods at rest, during several stages of exercise (submax, max), and during recovery (rec1 = minutes 2 + 3, rec2 = minutes 9 + 10). Each patient reached similar (heart rate) X (blood pressure) products in the two studies: 21280 +/- 5200 compared with 20390 +/- 4140 mmHg/min. Mean EFs for the first and second studies were: at rest (53.0 +/- 10.8)%, 52.5 +/- 10.4)% (r = 0.95; submax ex (51.4 +/- 12.0)%, (52.1 +/- 12.8)%, (r = 0.91); max ex (50.6 +/- 12.6)%, (51.6 +/- 12.9)% (r = 0.97); rec1 (62.7 +/- 11.6)%, (62.4 +/- 12.2)% (r = 0.95); rec2 (55.5 %/- 10.8)%, (57.2 +/- 11.7)% (r = 0.91). In stable patients, the reproducibility of EF determined by EQ is excellent during rest, supine bicycle exercise, and recovery from exercise.

Adult↗
PubMed1979

[Diagnosis of coronary artery disease: value and limitations of non-invasive methods. (Ecg, thallium perfusion scintigraphy, radionuclide angiography) (author's transl)].

In order to compare the three non-invasive exercise tests Ecg, Thallium myocardial perfusion imaging and radionuclide angiography in the diagnosis of coronary artery disease, the results of these tests in a consecutive series of 30 patients and 14 controls were analyzed. In all 88 symptom-limited exercise tests a significantly higher double product (heart rate x systolic blood pressure, mm Hg/min) was reached on a treadmill test (for Ecg and Thallium scintigraphy) as compared to the supine bicycle ergometer exercise (for radionuclide angiography: 243.1 +/- 61.1 vs. 215.2 +/- 46.5 x 10(2) (p less than 0.01). Considering all 132 diagnostic tests the overall sensitivity for rest/exercise Ecg was 67%, for Thallium scans 77%, for both combined 83% and for the ejection fraction response to exercise determined by radionuclide angiography 97%. If only the exercise response was considered, the corresponding sensitivity values were 60% (Ecg), 47% (Thallium scans), 70% (both tests combined) and 97% (radionuclide angiography). The specificity for coronary artery disease was determined to be 79% for Ecg, 86% for Thallium scintigraphy, 64% for Ecg/Thallium scans and 71% for radionuclide angiography. The most common reason for a false-positive result in all tests was found to be the diagnosis of cardiomyopathy, whereas most false-negative results were seen in patients with single vessel right coronary artery disease. Based on these results, the clinical implications of the three non-invasive tests in the diagnosis of coronary artery disease are discussed.

Adult↗
PubMed1975

Coronary venous flow and O2 saturation during transitional phases between various cardiac rates.

The instantaneous and continuous interrelationship between coronary blood flow and coronary venous O2 saturation was determined during transient periods following abrupt rate change in the electrically paced canine heart. Through a catheter in the coronary sinus, O2 saturation was continuously monitored using a fibreoptics technique, and venous flow was measured with an electromagnetic flowmeter. Various patterns of change in flow and O2 saturation were observed depending both on the absolute values of the cardiac rates as well as on the relative difference between them during changes from one rate to another. Whereas elevation of coronary flow was monophasic when the magnitude of heart rate change was below 75 beats per minute, a drop in flow was observed preceeding its elevation when the difference was greater. At high rates further increase in rate caused either no alteration or led to a monophasic drop in flow during the transitional period. Changes in O2 saturation were observed only when heart rate difference exceeded 60 beats per minute. Between 60-90 beats per minute O2 saturation remained steady except during the transient rate elevation, ending in a lower steady state O2 saturation. The results indicate that both O2 saturation and coronary flow change with heart rate initially because of mechanical consequence of the increased rate on the myocardium, and later according to its new metabolic needs also manifested by changed O2 extraction.

Animals↗
PubMedDate not supplied

Characterization of regional left ventricular contraction by curvature difference analysis.

A method which characterizes the contraction of the left ventricle (LV) by changes in the LV endocardial contour curvatures is presented. A normalized curvature difference function (NCDF) is defined by the difference between the (normalized) curvature functions of end diastolic (ED) and end systolic (ES) contours. Unlike wall-motion based procedures, NCDF is independent of any reference system and of the method used for ED-ES shape alignment. Normal and pathological diagnosis criteria were first established based on right anterior oblique (RAO) projection ventriculograms of a study group which included 58 normal and 28 abnormal patients. Patients with an infarcted myocardial region differed from the characteristic NCDF pattern of normals and exhibited regionally defined irregularities. The diagnosis criteria were then applied to a total of 159 patients in two groups in two independent laboratories. One group (in Israel) included 49 cases (20 normals, 29 abnormals); the second (in France) included 108 cases (48 normals, 60 abnormals). These two groups yielded similar sensitivity (97% and 97%) and specificity (90% and 100%) in detection of abnormality of the ventricle. When tested against other quantitative wall motion techniques, the NCDF shwos a regional sensitivity of 95%, indicating that curvature difference analysis is a potential tool for the automatic and objective diagnosis of regional LV function abnormalities.

Heart↗
PubMedDate not supplied

Decreased thickening of normal myocardium with transient increased wall thickness during stress echocardiography with atrial pacing.

Stress echocardiography is used increasingly in the evaluation of coronary artery disease. The echocardiographic evaluation of ischemia is based on stress-induced changes in wall motion and wall thickening of the ischemic segments. Studies have demonstrated that left ventricular volumetric changes may induce changes in wall thickness. The aim of the study was to evaluate whether significant changes in ventricular volume, wall thickness, and wall thickening occur during stress echocardiography with atrial pacing. Seven German Landrace female pigs were studied 4 weeks after the induction of a small myocardial infarction. Echocardiographic measurements were conducted in noninfarcted segments on the short-axis view at baseline and during atrial pacing at 120, 150, and 180 beats/min. End-diastolic circumferential area decreased from 12.3 +/- 2.0 cm2 at baseline to 8.9 +/- 1.9 cm2 at 180 beats/min of atrial pacing (p < 0.01). Mean wall thickness (interventricular septal plus posterior wall thickness divided by 2) increased markedly and progressively from 6.7 +/- 0.6 mm at baseline to 9.8 +/- 1.0 mm at 180 beats/min (p < 0.01). The increase in wall thickness correlated inversely with end-diastolic area (r = -0.57; p < 0.01). Percent systolic thickening decreased from 38.9 +/- 12.0 at baseline to 14.9 +/- 7.4 at 180 beats/min of atrial pacing (p < 0.01). The decrease in percent wall thickening correlated with the increase in wall thickness (r = -0.71; p < 0.01). In conclusion, this study shows that a marked increase in wall thickness (pseudohypertrophy) and decrease in percent systolic thickening are observed during rapid atrial pacing in normal myocardium and do not indicate stress-induced left ventricular dysfunction.

Animals↗
PubMedDate not supplied

Quantitative myocardial ultrasonic integrated backscatter measurements during contrast injections.

We and others have shown that normal myocardium exhibits 4 to 5 dB diastolic-to-systolic cyclic variation (CV) of integrated backscatter. To investigate the effect of intramyocardial contrast on integrated backscatter, we injected 5% sonicated albumin, containing microbubbles in the range of 5 microns in diameter, into the left atrium in nine open-chest dogs. The dogs were anesthetized and placed in the right lateral decubitus position on a specially designed table with a cutout allowing ultrasound imaging from below. Ultrasonic data was obtained from the right precordium by use of a prototype M-mode integrated backscatter system implemented in a commercially available two-dimensional system. Usable data were obtained in eight of nine dogs. Integrated backscatter increased up to 13 dB after contrast injections. There was a significantly decreased CV of integrated backscatter during myocardial contrast in all eight dogs. The mean level of CV of integrated backscatter for the eight dogs decreased from 4.7 dB (530 beats analyzed) without contrast to 2.8 dB during contrast (436 beats analyzed). There was a trend to greater CV at higher levels of contrast. Septal excursion, as measured by M-mode echocardiography simultaneously with integrated backscatter by the same ultrasound beam, was similar with and without contrast (mean 8.2 vs 8.3 mm). Thus left atrium contrast injection produces quantitatively measurable integrated backscatter effects. Cyclic variation of integrated backscatter decreases with contrast. However, at higher contrast levels the decrease tends to be smaller. These effects should be considered during quantitative tissue characterization and myocardial contrast studies.

Albumins↗
PubMedDate not supplied

QRS prolongation measured by a new computerized method: a sensitive marker for detecting exercise-induced ischemia.

This study compared thallium stress testing and exercise changes in QRS duration using a computerized 'optic scanner' in three groups. Group 1 consisted of 108 subjects with positive exercise ECG tests by ST-T segment criteria and with proven coronary artery disease. Group 2 included 19 subjects with nondiagnostic exercise ECG ST-T changes and with proven coronary artery disease. Group 3 was formed by 38 healthy controls. Group 1: Mean increase in exercise QRS width of 12.4 +/- 14 ms. Group 3: Mean decrease in exercise QRS width of 4.9 +/- 9.3 ms (p < 0.0001). Group 2: Mean QRS prolongation of 7.8 +/- 9.2 ms, which was significantly different from the controls (p < 0.0001) but not from group 1. When compared to thallium stress testing, exercise QRS prolongation had a sensitivity of 93%, specificity of 71%, relative risk of 5, and positive predictive value of 86%. QRS duration measurement can improve the diagnostic accuracy of the exercise ECG stress test.

Adult↗