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Atrioventricular conduction abnormalities in patients undergoing isolated aortic or mitral valve replacement
Insights
Complete heart block during aortic valve replacement is common but not predictable. Transient heart block does not indicate late recurrence, making prophylactic pacemakers unnecessary.
Area of Science:
- Cardiology
- Cardiac Surgery
Background:
- Cardiac conduction defects are frequent in patients with aortic valve disease.
- Calcium deposits in the aortic valve may correlate with spontaneous complete heart block.
- Predictive factors for complete heart block during valve replacement are unknown.
Purpose of the Study:
- To identify predictive factors for complete heart block during isolated aortic or mitral valve replacement.
- To assess the incidence and predictors of transient and late heart block in these patients.
Main Methods:
- Prospective evaluation of 102 patients undergoing isolated aortic valve replacement.
- Comparison with 100 patients undergoing isolated mitral valve replacement.
- Follow-up for over four years to assess late heart block incidence.
Main Results:
- Transient complete heart block occurred in 17.6% of aortic and 13% of mitral valve replacement patients.
- No predictive factors were identified for the occurrence of transient complete heart block.
- Late heart block incidence was very low during the follow-up period.
Conclusions:
- Temporary pacing capability is essential during valve replacement surgery.
- Transient atrioventricular (AV) block in the perioperative period does not predict late AV block recurrence.
- Prophylactic pacemaker implantation is not indicated for transient block during valve replacement.
Abstract:
Cardiac conduction defects are common in patients with aortic valve disease. Several studies have suggested that the spontaneous occurrence of complete heart block in these patients is related to the extent of calcium deposits in the aortic valve and adjacent structures. No studies have been done to relate the occurrence of complete heart block at the time of valve replacement to predictive factors. We evaluated 102 consecutive patients undergoing isolated aortic valve replacement and 100 patients undergoing isolated mitral valve replacement. Although transient complete heart block was relatively common in each group (17.6% and 13%, respectively), we were not able to identify any factors predictive of its occurrence. There was a very low incidence of late heart block in a follow-up period of over four years. Thus, the capability for temporary pacing is mandatory in patients undergoing valve replacement. However, transient complete AV block during the perioperative period does not predict late recurrence of AV block and, therefore, prophylactic pacemaker or electrode implantation during or following transient block appears unnecessary.