An evaluation of postoperative P-wave variables after cardiothoracic surgery.

Postoperative atrial fibrillation is common after cardiac surgery. Prediction of which patients will develop postoperative atrial fibrillation would be clinically useful. Increased P-wave duration, suggesting atrial conduction delay and measured from preoperative electrocardiograms, predicts postoperative atrial fibrillation. However, postoperative P-wave duration has not been evaluated after cardiac surgery. In this study, we evaluated postoperative P-wave variables (maximum P-wave duration and P-wave dispersion) over 5 days in cardiac surgery patients receiving amiodarone, pacing or no atrial fibrillation prophylaxis. P-wave variables gradually shortened as time passed from surgery. Amiodarone did not shorten P-wave measurements throughout therapy, while pacing shortened P-waves in the immediate postoperative period; however, shortening was not sustained. P-waves did not differ between those who did and did not develop atrial fibrillation with amiodarone or pacing. Our findings suggest that atrial conduction delay resulting from cardiothoracic surgery tends to resolve over time and may not play a critical role in the etiology of postoperative atrial fibrillation.

Hemodynamic and electrocardiographic effects of short-term Ginkgo biloba.

OBJECTIVE: To evaluate the immediate and short-term hemodynamic and electrocardiographic effects of Ginkgo biloba (ginkgo). METHODS: Healthy volunteers were randomized to receive ginkgo 120 mg or placebo twice daily for 7 days in this prospective, double blind trial. After at least a 7-day washout period, subjects were crossed over to an additional 7 days of alternate therapy. Blood pressure, heart rate, and 12-lead electrocardiograms were evaluated immediately before (baseline), and at 1, 3, and 5 hours after observed ingestion of study drug on days 1 and 7 of therapy. Electrocardiographic parameters (P wave and QRS complex duration; PR, QT, and QTc intervals) were measured in lead II by a blinded investigator. RESULTS: Ginkgo had no effect on any of the evaluated electrocardiographic parameters at any time point on days 1 or 7. Additionally, no changes in heart rate or systolic and diastolic blood pressure were found between the groups at any time point on any evaluative day. CONCLUSIONS: Commonly used doses of Ginkgo biloba do not have any immediate or short-term effects on blood pressure, heart rate, or electrocardiographic variables in young, healthy volunteers.