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Usefulness of a third Holter lead for detection of myocardial ischemia
G A Lanza1, M Mascellanti, M Placentino
1Istituto di Cardiologia, Universitá Cattolica del S. Cuore, Roma.
Insights
Adding a third chest lead to ambulatory electrocardiograms (ECG) improves myocardial ischemia detection in coronary artery disease patients. This enhanced ECG monitoring captures more ischemic episodes than standard two-lead systems.
Area of Science:
- Cardiology
- Medical Diagnostics
- Exercise Physiology
Background:
- Ambulatory electrocardiographic (ECG) monitoring is crucial for detecting transient myocardial ischemia in coronary artery disease (CAD).
- Two-lead monitoring may miss a significant number of ischemic events, limiting diagnostic accuracy.
Purpose of the Study:
- To evaluate the added diagnostic value of a third bipolar chest lead in ambulatory ECG monitoring.
- To compare the sensitivity of 2-lead versus 3-lead ambulatory ECG for detecting myocardial ischemia during exercise testing.
Main Methods:
- Simultaneous 12-lead ECG and 3-channel ambulatory ECG were recorded during exercise testing.
- 223 patients with suspected or confirmed coronary artery disease were enrolled.
- Ambulatory ECG leads included CM5, CM3, and an inferior lead (Y-modified or CMf).
Main Results:
- 96% of patients with diagnostic ST-segment depression on standard ECG also showed changes on ambulatory ECG.
- Lead CM5 demonstrated the highest sensitivity (89%) for ischemia detection.
- Adding CM3 and an inferior lead increased sensitivity to 91% and 94%, respectively; all 3 leads achieved 96% sensitivity.
Conclusions:
- A third ambulatory ECG lead, particularly an inferior lead combined with CM5, significantly enhances the detection of myocardial ischemia.
- The combination of 3 ambulatory leads offers a marginal improvement over the best 2-lead combination but improves detection of specific ischemia types.
- Enhanced ambulatory ECG monitoring is valuable for comprehensive ischemia assessment in CAD patients.
Abstract:
Two-channel ambulatory electrocardiographic (ECG) monitoring is a useful method for detecting transient myocardial ischemia in patients with coronary artery disease. However, the monitoring of only 2 leads may fail to detect a significant number of ischemic episodes. In this study, the additional diagnostic value of a third bipolar chest lead was evaluated by recording a simultaneous 12-lead electrocardiogram and a 3-channel ambulatory electrocardiogram during exercise testing in 223 patients (aged 63 +/- 10 years) with proved or suspected coronary disease. Leads CM5, CM3, and an inferior lead (Y-modified or CMf) were monitored on the ambulatory electrocardiogram. Diagnostic ST-segment depression on the standard electrocardiogram was detected in 98 patients (44%), 94 (96%) of whom also had diagnostic ST-segment changes on the ambulatory electrocardiogram. Two additional patients had ST-segment depression only on the ambulatory electrocardiogram (both in lead CM5). Maximal ST-segment depression and duration of ischemia detected on standard and ambulatory ECG leads were similar in the 94 patients in whom ST-segment changes were detected on both types of ECG monitoring. CM5 was the single lead with the highest sensitivity (89%) in detecting myocardial ischemia. The addition of CM3 to CM5 increased sensitivity to 91%, and the addition of an inferior lead to CM5 increased sensitivity to 94%, particularly improving the detection of isolated inferior myocardial ischemia. The combination of all 3 ambulatory ECG leads had a sensitivity of 96%, an improvement of only 2% compared with the best combination of 2 leads (i.e., CM5 +/- inferior lead).(ABSTRACT TRUNCATED AT 250 WORDS)