Related Experiment Videos
Ventricular arrhythmia following successful myocardial revascularization: incidence, predictors and prevention
T K Kaul1, B L Fields, L S Riggins
1Department of Cardiac Surgery, Baptist Medical Center, Birmingham, AL, USA.
Insights
Sudden cardiac death risk persists after coronary artery bypass grafting (CABG). Routine electrophysiologic (EP) evaluation is recommended for patients with poor left ventricular function to manage ventricular arrhythmia (VT/VF) risk.
Area of Science:
- Cardiology
- Cardiac Surgery
- Electrophysiology
Background:
- Coronary artery bypass grafting (CABG) is a common procedure for myocardial revascularization.
- Sudden cardiac death (SCD) due to ventricular arrhythmia (VT/VF) remains a concern post-CABG.
- Identifying risk factors and effective prophylactic strategies is crucial for patient outcomes.
Purpose of the Study:
- To estimate the risk of SCD from VT/VF after CABG.
- To identify predictors of these post-CABG cardiac events.
- To evaluate the long-term benefits of prophylactic regimens for managing VT/VF.
Main Methods:
- Analysis of 8642 patients undergoing isolated, first-time CABG (1980-1995).
- Utilized a standard hazard function model for statistical analysis.
- Examined prophylactic regimen efficacy in 350 high-risk patients (LVEF ≤ 30%), comparing EP-guided vs. empirical antiarrhythmic medication.
Main Results:
- Early hazard phase (up to 3 months post-CABG) linked to low LVEF and prior VT/VF episodes.
- A low-risk constant phase followed, merging into a slow-rising late phase after 6 years.
- EP-guided prophylaxis significantly reduced SCD risk in high-risk patients (P=0.03).
Conclusions:
- The risk of VT/VF persists even after successful CABG surgery.
- Routine electrophysiologic (EP) evaluation is recommended pre- and post-CABG for patients with impaired left ventricular function.
- Sequential EP evaluation aids in detecting drug resistance and progression of VT/VF.
Objectives:
We estimated the risk of sudden cardiac death (SCD), from a spontaneous episode of ventricular arrhythmia (VT/VF), after a successful surgical myocardial revascularization (coronary artery bypass grafting; CABG) procedure. Predictors of these events were identified, and long term benefits of the prophylactic regimes, that were used to control these events, were evaluated.
Methods:
We selected 8642 consecutive patients, who had undergone an isolated and first time CABG procedure, between 1/3/1980 and 1/3/1995. A standard hazard function model (1) was used for statistical analysis. Efficacy of the prophylactic regimes, was examined in a group of 350 high risk patients, with a preoperative left ventricular ejection fraction 30% or less, who were recently operated since 1/1/1988. Electrophysiologic (EP) guided prophylaxis was used in 92 (26%) patients, who had survived a documented episode of SCD, and remaining 258 patients were maintained on antiarrhythmic medication on an empirical basis. A sequential EP evaluation was performed, when indicated.
Results:
During an early phase of hazard, which mainly lasted for up to 3 months after CABG, incremental risk factors were preoperative LVEF 30% or less (P = 0.0007) and preoperative episodes of VT/VF (P = 0.04). This phase was followed by a constant phase with a low risk of the events, which merged into a slowly rising late phase after 6 years. EP guided prophylaxis, reduced the risk of SCD in high risk patients (P = 0.03). A sequential EP evaluation, helped to detect the problems of drug resistance and a cross over from non-sustained to sustained runs of VT/VF.
Conclusions:
Despite a successful CABG surgery, risk of VT/VF persists. A routine EP evaluation before and after a CABG procedure is recommended in all patients with a poor left ventricular function.