Abstract
Atrial fibrillation (AF) and flutter (AFI) occur frequently after aortocoronary bypass grafting. To identify patients at highest risk, we observed 99 patients undergoing aortocoronary bypass surgery. P wave duration was measured on a three-channel ECG. An intra-atrial conduction defect (IACD), defined by conventional criteria as a single standard lead P wave greater than 110 msec, was present in 42 patients. We also identified IACDs by measuring the total P wave duration (TPWD) from the simultaneous three-channel recording of the standard leads (IACD-TPWD). Sustained AF-AFI, less than one hour, occurred in 29/99 patients. Of the 29 patients with AF-AF1, 24 had IACD-TPWD. The mean total P wave duration of patients with and without AF-AFI was 126 msec and 116 msec, respectively (P less than .001). The mean P wave duration measured conventionally (ECG lead 2) was 114 msec in the patients with AF/-AFI and 110 msec in patients without AF/-AFI. An isoelectric interval (IEI), derived by subtracting the ECG lead 2 P wave duration from the total P wave duration measured from three simultaneous limb leads, for patients without AF-AFI was 5.9 msec vs 12.4 msec for patients with AF-AFI (P less than 0.001). Of the patients with IACD-TPWD, 24/64 (38 percent) had AF-AFIRM; of the patients without IACD-TPWD, 5/35 (14 percent) had AF-AFI (P less than .05). The mean ages, number of bypass grafts, preoperative propranolol dose and prevalence of digoxin use presence of IACD-TPWD is a sensitive but non-specific predictor of AF-AFI after bypass surgery, and a prolonged IEI enhances the specificity.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call