Related Experiment Videos
Fascicular conduction disturbances and ischemic heart disease: adverse prognosis despite coronary revascularization
Insights
Certain fascicular conduction disturbances after bypass surgery increase mortality risk. Left bundle branch block and intraventricular conduction defects are particularly dangerous, indicating a need for closer patient monitoring post-surgery.
Area of Science:
- Cardiology
- Cardiac Electrophysiology
Background:
- Fascicular conduction disturbances in ischemic heart disease correlate with higher mortality.
- Post-myocardial revascularization outcomes for these disturbances require further investigation.
Purpose of the Study:
- To assess the mortality associated with specific fascicular conduction disturbances following coronary artery bypass grafting (CABG).
- To identify high-risk patient subgroups with these conduction defects post-CABG.
Main Methods:
- Prospective study of 227 patients undergoing bypass surgery.
- Analysis of pre- and post-operative fascicular conduction disturbances.
- Follow-up for cardiac mortality over 66 +/- 14 months.
- Comparison of risk factors between survivors and non-survivors with specific conduction defects.
Main Results:
- Overall mortality was low in patients without conduction disturbances (4%).
- Right bundle branch block and left hemifascicular block showed no significant increase in mortality.
- Left bundle branch block or intraventricular conduction defects were associated with significantly higher cardiac mortality (38%, p < 0.05).
- High-risk factors for mortality included advanced age, Class IV angina, prior myocardial infarction, reduced ejection fraction, three-vessel disease, and left ventricular aneurysm.
Conclusions:
- Specific fascicular conduction disturbances, notably left bundle branch block and intraventricular conduction defects, portend a poor prognosis after bypass surgery.
- These findings highlight the importance of identifying and closely monitoring high-risk patients with these specific conduction abnormalities post-CABG.
Abstract:
In patients with ischemic heart disease, fascicular conduction disturbances are associated with increased mortality. This study reveals that increased mortality also exists for certain types of fascicular conduction disturbances after myocardial revascularization. In 227 consecutive patients undergoing bypass surgery, 24 had preoperative and an additional 52 developed at surgery a fascicular conduction disturbance. At 66 +/- 14 months of follow-up, 6 (4%) of 148 control patients without pre- or postoperative fascicular conduction disturbances had died from cardiac causes. Although right bundle branch block and left hemifascicular block were the most common form of fascicular conduction disturbance, only 1 of 55 of these patients died (p = NS). Mortality rates were much higher for patients with left bundle branch block or an intraventricular conduction defect; 8 (38%) of 21 died from cardiac causes (p less than 0.05). A high risk subgroup was identified by comparing 14 consecutive patients with left bundle branch block or an intraventricular conduction defect who survived more than 1 year postoperatively with 21 consecutive patients with these same conduction defects who died within 1 year of surgery. The following variables were significantly (p less than 0.05) different (survivors versus nonsurvivors): age (58 +/- 7 versus 65 +/- 9 years); class IV angina (2 of 14 versus 16 of 21), prior myocardial infarction (9 of 14 versus 21 of 21), left ventricular ejection fraction (53 +/- 18 versus 41 +/- 15%), three vessel disease (9 of 14 versus 20 of 21) and left ventricular aneurysm (2 of 14 versus 13 of 21).(ABSTRACT TRUNCATED AT 250 WORDS)