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[Changes in the high-amplification electrocardiogram after myocardial revascularization. Comparison between coronary
A Richard1, S Rami, D Deschamps
1Service de cardiologie, clinique Ste Clothilde, Réunion.
Insights
Signal-averaged electrocardiogram (SA-ECG) analysis showed significant improvements in myocardial revascularisation patients after coronary bypass surgery (CBS). These findings suggest CBS favorably modifies the arrhythmogenic substrate compared to percutaneous transluminal coronary angioplasty (PTCA).
Area of Science:
- Cardiology
- Electrophysiology
- Cardiac Surgery
Background:
- Myocardial revascularisation aims to improve outcomes in patients with coronary artery disease.
- Signal-averaged electrocardiogram (SA-ECG) assesses electrical substrate and predicts arrhythmias.
- The impact of different revascularisation strategies on SA-ECG parameters requires further investigation.
Purpose of the Study:
- To compare the effects of coronary bypass surgery (CBS) versus percutaneous transluminal coronary angioplasty (PTCA) on SA-ECG parameters.
- To evaluate modifications in the arrhythmogenic substrate following myocardial revascularisation.
Main Methods:
- Signal-averaged electrocardiogram (SA-ECG) was performed on 148 patients before and after myocardial revascularisation (CBS n=64, PTCA n=84).
- SA-ECG was assessed at baseline, 7 days (D7), and 120 days (D120) post-procedure.
- Key SA-ECG criteria analyzed included QRS duration, 'Under 40' (U40), and 'Last 40' (L40) for late potentials (LP).
Main Results:
- No significant baseline SA-ECG differences were observed between CBS and PTCA groups.
- CBS significantly modified SA-ECG criteria: QRS duration (p < 0.05) and U40 (p < 0.01).
- PTCA did not produce significant changes in SA-ECG parameters; however, CBS patients with pre-existing late potentials showed significant improvements in U40 and L40 values.
Conclusions:
- Coronary bypass surgery (CBS) leads to favorable modifications in the arrhythmogenic substrate, as indicated by SA-ECG changes.
- Percutaneous transluminal coronary angioplasty (PTCA) did not demonstrate similar favorable effects on the SA-ECG parameters.
- These findings support the hypothesis that CBS favorably impacts the electrical substrate post-myocardial revascularisation.
Abstract:
The signal-averaged electrocardiogram (SA-ECG) was studied in 148 patients undergoing myocardial revascularisation either by coronary bypass surgery (CBS) (64 cases) or transluminal angioplasty (PTCA) (84 cases). The investigation was performed before the procedure, at day 7 (D7) and after 3 months (D120). No difference was observed in the SA-ECG between the two groups before revascularisation. The CBS population was older, more symptomatic and had more severe lesions than the PTCA population. One hundred and thirty-nine patients were followed up until the end of the study protocol (CBS = 63; PTCA = 76). Two criteria of the SA-ECG were significantly modified after CBS: QRS duration (p < 0.05) and Under 40 (p < 0.01). No significant changes were observed after PTCA. In the patients with late potentials (LP) before revascularisation, the mean value of these criteria (Under 40 and Last 40) were significantly modified after CBS (U40 = 54.3 +/- 16 to 35.4 +/- 15; p < 0.01) (L40 = 11.9 +/- 4.7 to 26.1 +/- 24.3; p < 0.01). No changes in these criteria were observed after PTCA. The value of negativation of the criteria of LP for patients with two criteria of positivity was 71.1% after CBS compared with 25% after PTCA (not significant). These observations support the hypothesis of a favourable modification of the arrhythmogenic substrate after myocardial revascularisation, especially by CBS.