Related Experiment Videos
The effect of myocardial surgical revascularization on left ventricular late potentials
L Can1, M Kayikçioğlu, H Halil
1Department of Cardiology, Ege University School of Medicine, Izmir, Turkey. can@bornova.ege.edu.tr
Insights
Complete surgical revascularization (CABG) eliminates ventricular late potentials (LP) by resolving myocardial ischemia. Persistent ischemia after CABG leads to persistent LPs, indicating a need for reevaluation for further interventions.
Area of Science:
- Cardiology
- Cardiac Electrophysiology
- Cardiovascular Surgery
Background:
- Ventricular late potentials (LP) are key indicators for ventricular tachyarrhythmias in ischemic heart disease.
- The impact of myocardial revascularization on LPs remains debated.
- This study investigates if complete myocardial surgical revascularization (CABG) alters the substrate for LPs.
Purpose of the Study:
- To determine if complete CABG, confirmed by myocardial perfusion scintigraphy, affects LP substrate.
- To assess the relationship between successful revascularization and changes in LPs.
- To evaluate the clinical implications of persistent LPs after CABG.
Main Methods:
- Prospective enrollment of patients undergoing elective CABG.
- Pre- and postoperative thallium-201 myocardial perfusion scintigraphy and signal-averaged ECG (SAECG).
- Serial SAECG recordings at baseline, 48-72 hours, and 3 months post-CABG; LP definition based on Gomes criteria.
Main Results:
- Successful revascularization in 23 patients, unsuccessful in 17.
- Significant decrease in LP incidence postoperatively in patients with improved myocardial perfusion (P < 0.05).
- No change in LP incidence in patients without improved perfusion.
Conclusions:
- Complete surgical revascularization eliminates LPs by resolving myocardial ischemia.
- Persistent ischemia post-CABG results in persistent LPs.
- Patients with persistent LPs may have unchanged ventricular arrhythmia risk and require reevaluation for reintervention.
Background:
The presence of ventricular late potentials (LP) is an important indicator for the development of ventricular tachyarrhythmias due to ischemic heart disease. The effect of myocardial revascularization on LP has remained controversial. The purpose of this study was to determine whether complete myocardial surgical revascularization (CABG) documented by myocardial perfusion scintigraphy might alter the substrate responsible for LP.
Methods:
Prospectively, enrolled patients undergoing elective CABG were evaluated with thallium-201 myocardial perfusion scintigraphy and signal- averaged ECG pre- and postoperatively. SAECG recordings were obtained serially: before, 48-72 hours and 3 months after CABG. LPS were defined as positive if SAECG met at least two of Gomes criteria. Scintigraphies were performed pre- and 3 months postoperatively for determination of the success of revascularization. Changes observed in SAECG recordings after CABG were compared between those with and without successful revascularization.
Results:
CABG resulted in successful revascularization in 23 patients and was unsuccessful in 17 (no change or deterioration of the perfusion defects). Preoperative SAECG values were not different between groups except for RMS values. The incidence of LP decreased significantly postoperatively in patients with improved myocardial perfusion, whereas there were no changes in patients who did not have postoperative perfusion improvement (McNemar test, P < 0.05).
Conclusions:
LPs disappear following the elimination of myocardial ischemia by complete surgical revascularization. Persistence of ischemia following CABG usually results in the persistence of late potentials. The incidence of ventricular arrhythmias is expected to be unchanged in these patients and they should be reevaluated for reinterventions.