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The pacing stress test: a reexamination of the relation between coronary artery disease and pacing-induced
Insights
Atrial pacing demonstrates improved sensitivity and specificity for detecting coronary artery disease (CAD) compared to exercise stress testing, suggesting its potential as a reliable diagnostic tool. This method offers a valuable alternative for identifying myocardial ischemia.
Area of Science:
- Cardiology
- Diagnostic Imaging
- Clinical Medicine
Background:
- Electrocardiographic (ECG) changes during pacing-induced tachycardia have historically shown poor reliability for diagnosing coronary artery disease (CAD).
- Atrial pacing has not been widely adopted as an alternative to exercise stress testing due to perceived limitations.
Purpose of the Study:
- To investigate if technical modifications to atrial pacing can improve its diagnostic accuracy for CAD.
- To compare the sensitivity and specificity of atrial pacing versus standard exercise stress testing in detecting CAD.
Main Methods:
- 22 patients undergoing coronary cineangiography were subjected to both standard exercise stress testing and graded atrial pacing.
- A 12-lead ECG recorder was used for continuous monitoring during both tests.
- Pacing was terminated at 85% of maximal predicted heart rate or upon significant ischemic chest pain with diagnostic ECG changes.
Main Results:
- Atrial pacing correctly identified ischemia in 94% of patients with CAD, significantly higher than exercise testing (63%).
- There was a 90% concordance between exercise and atrial pacing tests in detecting ECG changes indicative of ischemia.
- Patients with CAD experienced chest pain during atrial pacing in 50% of cases, comparable to exercise testing (44%).
Conclusions:
- Optimized atrial pacing protocols show enhanced sensitivity and specificity for diagnosing CAD compared to traditional exercise stress tests.
- Atrial pacing, when technically refined, represents a promising and potentially more reliable diagnostic modality for coronary artery disease.
Abstract:
Electrocardiographic (ECG) changes during graded pacing-induced tachycardia have been considered unreliable as a test for the presence of coronary artery disease (CAD) because of poor sensitivity and specificity. As a result, atrial pacing has not been widely used as an alternative to exercise testing. However, the limited value of the pacing stress test may be related to technical aspects, such as the duration of pacing and ECG monitoring. To study this problem, 22 patients undergoing coronary cineangiography underwent standard exercise stress testing and graded tachycardia induced by atrial pacing. A 12-lead ECG recorder was used for both tests. Pacing tachycardia was terminated when 85% of maximal predicted heart rate had been achieved or when significant ischemic chest pain accompanied by diagnostic ECG changes occurred. The ECG was considered positive if at least 1 mm of horizontal or downsloping ST-segment depression was present. Six patients with normal or minimally diseased coronary arteries were compared to 16 patients with significant CAD. Of the patients without significant CAD, 5 (83%) had a negative electrocardiogram during both exercise and pacing. Of 16 patients with CAD, the electrocardiogram was positive for ischemia in 10 patients (63%) during exercise, in 15 (94%) during atrial pacing and in 12 (80%) after pacing. When the presence or absence of ECG changes was compared between the exercise and the pacing tests, there was a concordance of 90% (Fisher p less than 0.0015). Two patients without significant CAD (33%) had chest pain during both exercise and pacing. Among patients with CAD, 7 (44%) had chest pain during exercise and 8 (50%) had chest pain during atrial pacing.(ABSTRACT TRUNCATED AT 250 WORDS)