Related Experiment Videos
Septal Q wave in exercise testing: evaluation by single-photon emission computed tomography
Insights
Exercise-induced changes in septal Q waves, particularly regression, indicate significant left anterior descending coronary artery (LAD) stenosis and septal perfusion defects. This finding aids in diagnosing coronary artery disease (CAD).
Area of Science:
- Cardiology
- Nuclear Cardiology
- Diagnostic Imaging
Background:
- Septal Q waves in lead V5 can change with exercise.
- Coronary artery disease (CAD) diagnosis often involves assessing myocardial perfusion.
- Left anterior descending (LAD) coronary artery disease is a common and significant finding.
Purpose of the Study:
- To evaluate the relationship between exercise-induced changes in septal Q waves and myocardial perfusion defects.
- To determine if septal Q wave alterations can predict LAD coronary artery disease.
Main Methods:
- Single-photon emission computed tomography (SPECT) was used to assess myocardial perfusion.
- Patients were categorized into groups based on septal Q wave changes during exercise (regression, progression/no change, or none).
- Septal perfusion defects were quantified as a percentage of the total septum.
Main Results:
- Patients with Q wave regression during exercise (Group A) showed a high prevalence (94%) of septal perfusion defects and LAD stenosis.
- Patients with no Q wave changes (Group B) had a low prevalence of septal perfusion defects (10%).
- Patients with no Q waves at rest or exercise (Group C) with LAD lesions showed a high rate of septal perfusion defects (91%).
- The area of septal perfusion defects was significantly larger in Group A and Group C compared to Group B.
Conclusions:
- Exercise-induced regression of septal Q waves in lead V5 is a strong indicator of LAD stenosis and associated septal perfusion defects.
- SPECT imaging can effectively identify perfusion abnormalities correlating with Q wave changes.
- These findings suggest that septal Q wave dynamics during exercise are valuable in diagnosing significant coronary artery disease, particularly involving the LAD territory.
Abstract:
Changes of septal Q waves in lead V5 by exercise were evaluated with single-photon emission computed tomography. Coronary artery disease was present in 66 patients, 48 of whom had left anterior descending coronary artery (LAD) involvement. Forty-one subjects had normal coronary arteries. All patients under investigation were classified into 3 groups: group A (18 patients)--regression of Q amplitude during exercise; group B (48 patients)--progression or no change of Q wave or a new Q wave during exercise; and group C (41 patients)--no Q waves at rest and during exercise. Perfusion defects of the septum were calculated 3-dimensionally and expressed as a percent of the total septum. Seventeen patients (94%) in group A showed septal perfusion defects by exercise and all of them had LAD stenosis. Forty-three patients (90%) in group B showed no septal perfusion defects, but the others with perfusion defects had LAD stenosis. In group C, 23 of 41 patients (56%) had an LAD lesion, of whom 91% showed septal perfusion defects; none of the remaining 18 patients without LAD stenosis showed perfusion defects. The area of septal perfusion defects during exercise was larger in group A (62 +/- 19%) and in group C (52 +/- 19%) than in group B (23 +/- 9%) (groups A vs B, p less than 0.001; groups C vs B, p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)