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Usefulness of esophageal pill electrode atrial pacing with quantitative two-dimensional echocardiography for
R V Matthews1, R J Haskell, L E Ginzton
1Heart Institute, Hospital of the Good Samaritan, Los Angeles, California 90017.
Insights
Esophageal pill electrode atrial pacing offers a non-exercise method for diagnosing coronary artery disease (CAD). This technique, combined with echocardiography, effectively detects CAD by analyzing changes in ejection fraction and pressure-volume ratio.
Area of Science:
- Cardiology
- Medical Devices
- Diagnostic Imaging
Background:
- Noninvasive diagnosis of coronary artery disease (CAD) is challenging in patients unable to perform exercise stress tests.
- Traditional exercise stress tests may not be suitable for all patients.
Purpose of the Study:
- To evaluate esophageal pill electrode atrial pacing as a non-exercise myocardial stress method for diagnosing CAD.
- To assess the utility of quantitative 2-dimensional echocardiography in conjunction with pacing.
Main Methods:
- Esophageal pill electrode atrial pacing was employed as a non-exercise stressor in 26 patients.
- Changes in ejection fraction and pressure-volume ratio were quantitatively analyzed using 2-dimensional echocardiography.
- Results were compared with treadmill exercise tests and coronary arteriography.
Main Results:
- Successful pacing was achieved in 85% of patients, yielding comparable rate-pressure products to treadmill exercise.
- Patients with CAD showed a significant decrease in ejection fraction (-8%) with pacing, unlike those without CAD (3%).
- The pressure-volume ratio increased in patients without CAD (3.8 mm Hg/min/m2) but remained unchanged in those with CAD (0.3 mm Hg/min/m2).
Conclusions:
- Esophageal pill electrode atrial pacing is a feasible and effective non-exercise method for myocardial stress.
- This technique, coupled with echocardiography, demonstrates significant potential for noninvasive CAD detection.
- The method shows comparable predictive accuracy to treadmill exercise testing for identifying CAD.
Abstract:
Noninvasive diagnosis of coronary artery disease (CAD) is difficult in patients who are unable to exercise. In this study esophageal pill electrode atrial pacing was used as a myocardial stress not requiring exercise, and changes in ejection fraction and pressure volume ratio during pacing with 2-dimensional echocardiography were quantitatively analyzed. All patients had completed a Bruce protocol treadmill exercise test and had undergone coronary arteriography. Of 26 patients, 22 were successfully paced (85%). Comparable rate-pressure products were obtained for treadmill exercise (23,500 +/- 5,900 mm Hg/min) and pacing (24,100 +/- 4,400 mm Hg/min; difference not significant). Of the 22 patients completing the study 8 had normal coronary arteries (group I) and 14 had CAD (group II). The change in ejection fraction with pacing in group I patients was not significant (3 +/- 8%). In group II ejection fraction decreased with pacing (-8 +/- 13%; p = 0.025). The pressure/volume ratio increased in group I with pacing (3.8 +/- 1.8 mm Hg/min/m2; p = 0.05) and was unchanged in group II (0.3 +/- 1.8 mm Hg/min/m2; difference not significant). Using an ejection fraction decrease with pacing or a failure to increase pressure/volume ratio with pacing as criterion for the presence of CAD, similar predictive accuracies were obtained when compared to treadmill exercise testing. Esophageal pill electrode atrial pacing with quantitative 2-dimensional echocardiography may be a useful noninvasive, nonexercise method to detect CAD.