Computer-enhanced digital angiography: correlation of clinical assessment of left ventricular ejection fraction and regional wall motion.

We compared computer-enhanced digital angiography (CEDA) following pulmonary injection of 20 ml Renografin-76 (5 ml/sec) to conventional directly injected left ventriculography (LV) in 13 patients undergoing routine diagnostic catheterization. Left ventricular ejection fraction (LVEF) was determined by planimetry from end-diastolic and end-systolic images by two independent angiographers. The correlation coefficient for LVEF (CEDA vs. LV) was r = 0.75 (p less than 0.005) for observer 1 and r = 0.85 (p less than 0.0005) for observer 2. The interobserver variability for LVEF was very low, resulting in a high correlation coefficient (r = 0.91, p less than 0.0005). Three angiographers independently reviewed both the conventional and CEDA images in a random order for assessment of anterior, apical, and inferior regional wall motion, using a 6-point subjective grading system (198 determinations). The interobserver correlation for subjective assessment of regional wall motion by both LV and CEDA was poor (49% for LV and 59% for CEDA, p = NS). These poor correlations were not improved by excluding any region or angiographer from the analysis. The agreement of regional motion assessments between the two techniques was only 40%. To improve reproducibility of wall motion interpretation, an automated analysis program was developed. First the range of normal contraction was defined from pooled literature data. The movement of any segment of the left ventricular wall could then be determined in millimeters and referenced to the normal range. This method eliminated interobserver variability. In the absence of an acceptable standard of segmental wall motion to which this measurement can be compared, the accuracy of this objective format could not be determined. We conclude that CEDA images allow accurate determination of ejection fraction and that the large interobserver variability of subjective regional wall motion analysis can be overcome by employing more objective formats.

Improved assessment of inferior segmental wall motion by the addition of a 70-degree left anterior oblique view in multiple gated equilibrium scintigraphy.

Conventional anterior and 45-degree left anterior oblique (LAO) views are limited in the evaluation of inferior segmental wall motion by multiple gated equilibrium cardiac blood pool scintigraphy. This study evaluated the addition of a 70-degree LAO view by comparing scintigraphic and contrast ventriculography in 25 patients, of whom 17 demonstrated abnormal inferior wall motion. Abnormal inferior wall motion was correctly identified in only 10 of 17 patients in the anterior view, but in 16 of 17 patients in the 70-degree LAO view. The number of assessable inferior segments was improved from 58% in the anterior view to 98% in the 70-degree LAO view. When the inferior segments could be visualized in the anterior view, inferior wall motion was accurately assessed. The addition of the 70-degree LAO view aids in the multiple gated equilibrium scintigraphic detection of inferior wall motion abnormalities with a minor loss in specificity.

Application of conditional probability analysis to the clinical diagnosis of coronary artery disease.

Analysis of multiple noninvasive tests offers the promise of more accurate diagnosis of coronary artery disease, but discordant test responses can occur frequently and, when observed, result in diagnostic uncertainty. Accordingly, 43 patients undergoing diagnostic coronary angiography were evaluated by noninvasive testing and the results subjected to analysis using Bayes' theorem of conditional probability. The procedures used included electrocardiographic stress testing for detection of exercise-induced ST segment depression, cardiokymographic stress testing for detection of exercise-induced precordial dyskinesis, myocardial perfusion scintigraphy for detection of exercise-induced relative regional hypoperfusion, and cardiac fluoroscopy for detection of coronary artery calcification. The probability for coronary artery disease was estimated by Bayes' theorem from each patient's age, sex, and symptom classification, and from the observed test responses. This analysis revealed a significant linear correlation between the predicted probability for coronary artery disease and the observed prevalence of angiographic disease over the entire range of probability from 0 to 100% (P less than 0.001 by linear regression). The 12 patients without angiographic disease had a mean posttest likelihood of only 7.0 +/- 2.6% despite the fact that 13 of the 60 historical and test responses were falsely "positive." In contrast, the mean posttest likelihood was 94.1 +/- 2.8% in the 31 patients with angiographic coronary artery disease, although 45 of the 155 historical and test responses were falsely "negative." In 8 of the 12 normal patients, the final posttest likelihood was under 10% and in 26 of the 31 coronary artery disease patients, it was over 90%. These estimates also correlated well with the pooled clinical judgment of five experienced cardiologists (P less than 0.001 by linear regression). The observed change in probability for disease for each of the 15 different test combinations correlated with their information content predicted according to Shannon's theorem (P less than 0.001 by linear regression). These results support the use of probability analysis in the clinical diagnosis of coronary artery disease and provide a formal basis for comparing the relative diagnostic effectiveness and cost-effectiveness of different test combinations.

[Cardiokymography: noninvasive assessment of the regional myocardial wall motion in the detection of coronary artery disease (author's transl)]. / Cardiokymographie: Nichtinvasive Beurteilung der regionalen myokardialen Wandbewegung zur Erkennung der koronaren Herzkrankheit.

Cardiokymography is a technique to assess myocardial wall motion by means of an electromagnetic field induced over the left precordium. The normal cardiokymogram (CKG) is characterized predominantly by systolic inward movement. An abnormal contraction pattern--either at rest or provoked by a stress test--reveals a different tracing with decreased or absent systolic inward motion and/or systolic outward motion (bulging). In 50 patients with suspected coronary artery disease (CAD) the CKG was recorded before and after treadmill exercise test and the results compared to coronary angiography. Out of 33 patients with angiographically documented CAD (more than 50% luminal narrowing) 25 showed an abnormal CKG after exercise. There was one false positive postexercise CKG in the group of 17 patients without angiographically documented CAD. The CKG allows the qualitative assessment of regional myocardial wall motion, which is a sensitive and specific marker of ischemia. In conjunction with an ECG-stress test the CKG helps to detect the evolving ischemic abnormalities of myocardial contraction. The CKG represents a marker of ischemia independent of the ECG and helps to improve the diagnostic accuracy of stress testing for detection of CAD. The stress CKG is especially advantageous in those cases in which the interpretation of the stress ECG is difficult or even not possible. Its simple and inexpensive technique makes it a useful adjunct to the stress ECG in the diagnosis of CAD.