Introduction:
Complications of device closure of ASD are well known and device position has been implicated in the incidence of heart block. We suggest preclosure ASD electrophysiology may also predispose patients to permanent forms of heart block.
Method:
A retrospective analysis was performed on patients who underwent catheterization for closure of ASD or PFO between March’02 and October’08. Pre and post procedure electrocardiograms were reviewed.
Results:
16.5 % (41/248) had preexisting prolonged PR interval (first degree block). 8 of these 41 (19.5%) still had first degree block at 12 months. Of the 207 with normal PR pre closure, 5 had first degree block at 12 months (2.4%).
ANOVA with post hoc Tamhane’ T2 was performed to test the change in PR, HR over time. No change in HR was seen (P=0.083). Compared to baseline, PR significantly shortened by 6 months post procedure (P<0.01) and more notably by 12 months (P<0.001).
2% (5/248) had atrial arrhythmia (not heart block) that completely resolved (2/248 required oral antiarrythmic therapy).
Conclusion:
A high incidence of prolonged PR interval was observed prior to ASD closure (16.5%); this has not been previously reported. After device closure, PR interval remained abnormal in a 19.5% of these patients at one year post implant. Denovo first degree block was seen in only 2.4% at one year. Preoperative right atrial enlargement with tricuspid annular enlargement may predispose patients to pericatheterization or post device heart block; heart block may not be entirely related to the device.