The optimal timing for elective noncardiac surgery (NCS) after coronary stenting is uncertain. We identified 47 patients who underwent elective NCS within 90 days of coronary stent placement between January 1995 and December 2000. Twenty-seven patients had NCS within 3 weeks of coronary stenting. Six of the seven in whom thienopyridine antiplatelet therapy was discontinued died postoperatively in a manner suggestive of stent thrombosis. In contrast, only 1 of the 20 patients in whom the thienopyridine was continued through the NCS died. The frequency of perioperative hemorrhage was similar whether or not the antiplatelet agent was continued. Only 1 perioperative death occurred in the 20 patients with NCS more than 3 weeks following stenting.

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Cardiac resynchronization using biventricular (BiV) pacing systems has been introduced for the treatment of symptomatic heart failure in patients with bundle branch block or prolonged QRS duration. Recent controlled clinical trials 1,2 have concluded and the results indicate that the majority of carefully selected patients will experience clinical improvement. The Food and Drug Administration has recently approved BiV pacing systems for implantation in patients with NYHA class III-IV heart failure despite optimal medical therapy when the QRS duration is >130 ms. The BiV pacing system differs from the conventional permanent pacemaker by incorporating a third lead that is positioned on the epicardial surface of the left ventricle (LV) via the coronary venous system. Simultaneous stimulation of the right ventricle (RV) (via a conventional endocardial lead) and the LV accomplishes BiV pacing and "resynchronizes" ventricular activation. This nontraditional format of ventricular stimulation may present new challenges in the assessment of pacing function, and will necessitate a greater understanding of basic and complex features of BiV pacing and its effect on noninvasive modalities such as the electrocardiogram (ECG) and intracardiac recordings on the pacemaker programmers. Initial systems utilized a conventional pulse generator with a modified header where LV and RV signals and output were linked; systems with separate ports for the LV and RV are now available.Many variables, in addition to the basic lead configuration, can influence accurate assessment of BiV pacer function, including LV and RV lead position, consistency of capture, differences in impedance between the ventricular leads, conduction velocity and patterns, relative timing of stimulation between the ventricular channels, and fusion with intrinsic activation. New and unusual sensing problems can arise creating complications such as pacemaker-mediated tachycardia or inappropriate inhibition. Pacemaker programming also involves issues unrelated to combating bradycardia. This review will focus on performing a noninvasive assessment of the BiV pacing system using the 12-lead ECG and intracardiac electrograms, analyses of sensing and capture functions, and general programming recommendations. TWELVE-LEAD ECGThe ECG is the most readily available tool to ascertain whether BiV pacing has been successfully accomplished, and whether sensing or capture problems exist. The ECG can provide a permanent template of capture configurations (e.g., no pacing, RV, LV, BiV) for easy and reliable troubleshooting. Current BiV systems usually pace BiV via a unipolar LV lead as a common anode attached to the RV tip versus a ring or proximal shared electrode also on the RV lead. They may also pace in a unipolar 58

Atrial fibrillation (AF) is the most common complication of coronary artery bypass grafting (CABG), usually occurring on the second or third post-operative day. Post-operative AF is associated with prolonged hospital stay and increased costs. In several randomized trials, prophylactic oral beta-blocker reduced the incidence of post-operative AF. Theoretically, intravenous beta-blocker regimen with its rapid onset of action and ease of dose titration should be more efficacious than oral beta-blocker. We conducted an open-label randomized controlled pilot study, compared the efficacy of intravenous esmolol and an oral beta-blocker regimen for prevention of post-operative AF. Fifty patients at high-risk of developing post-operative AF (P wave duration >140 ms on signal averaged (SA) ECG) were randomized to either 24-hours of intravenous esmolol treatment post-CABG followed by oral beta-blocker or standard oral beta-blocker treatment. Seven (26%) out of 27 patients in the esmolol group and 6 (26%) out of 23 patients in the oral beta-blocker group developed post-operative AF (p = NS). The day of onset and duration of AF was similar between the two groups. In the esmolol group, 11 (41%) patients developed adverse effects, mostly hypotension, compared to only one patient (4%) in the oral beta-blocker group (p = 0.006). The result of this pilot study showed that intravenous esmolol compared to oral beta-blocker offers no advantage in preventing post-operative AF and is associated with increased adverse events. Thus, all patients without contraindication should receive oral beta-blocker before and after cardiac surgery to prevent post-operative AF.

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