Indications for the use of pacing pulmonary artery catheters in cardiac surgery.

Several varieties of pulmonary artery catheters (PACs) with pacing capabilities are now available. Although specific recommendations for prophylactic perioperative placement of pacemakers have been offered previously, the authors believe that those recommendations warrant further examination, taking into consideration the availability of new pacing modalities. Toward this end, the use of pacing PACs in cardiac surgical patients was prospectively examined. In 600 consecutive adult patients with PACs placed prior to cardiopulmonary bypass (CPB), the cardiac anesthesiologist recorded if a pacing PAC was placed, the indications for placing it, and whether the catheter was used to pace. If a pacing PAC was not chosen, the anesthesiologist indicated whether cardiac pacing was needed prior to CPB. In all patients, the presence and specifics of the following five possible indications were documented: sinus node dysfunction/bradydysrhythmias, atrioventricular heart block, fascicular or bundle branch block, cardiac reoperation, and/or valvular heart disease. PACs with pacing capability were placed in 180 of the 600 patients (30.0%) and were used in 34 of these 180 patients (18.8%). In 4 of 420 patients (0.95%) without pacing PACs, cardiac pacing was needed prior to CPB. The following preoperative diagnoses were significant predictors (P less than .05) for the use or need for pacing catheters: sinus node dysfunction/bradydysrhythmias, a history of transient complete atrioventricular block, aortic stenosis, aortic insufficiency, and reoperation. The majority of adult patients undergoing cardiac surgery do not require the use of a pacing PAC prior to CPB.(ABSTRACT TRUNCATED AT 250 WORDS)

Left atrial V waves following mitral valve replacement are not specific for significant mitral regurgitation.

Left atrial or pulmonary capillary wedge pressure V waves are used immediately after mitral valve replacement to evaluate valve competence. However, their correlation with hemodynamically significant regurgitation has not been established. Transesophageal echocardiography (TEE) was used to prospectively examine whether left atrial V waves represented significant mitral regurgitation in 11 patients undergoing mitral valve replacement. Left atrial pressure V waves were measured in the immediate postcardiopulmonary bypass period by direct cannulation of the right superior pulmonary vein and recorded on a paper chart recorder. In each patient, three evaluations of mitral regurgitation by Doppler TEE were made at 15-minute intervals. In 22 of 33 evaluations, left atrial V waves with peak V wave height more than 5 mm Hg above the mean left atrial pressure were present. However, only in 3 of these periods did transesophageal echocardiography show evidence of more than trace mitral regurgitation by pulsed Doppler and color flow mapping. As indicators of mild-to-severe mitral regurgitation diagnosed by TEE, left atrial V waves had a specificity for the three evaluation periods of 40%, 30%, and 40%. Left atrial V waves with peak height greater than 5 mm Hg above mean left atrial pressure frequently appear following mitral valve replacement, but these V waves are nonspecific signs of mitral regurgitation.