The Cox maze III procedure has equivalent operative risk and long-term efficacy in patients undergoing both lone operations and concomitant procedures. The Cox maze III procedure remains the standard against which alternative procedures for atrial fibrillation must be judged.

Bipolar radiofrequency ablation can be used to replace the surgical incisions of the Cox maze procedure. This energy source did not result in pulmonary vein stenosis. The modification of the Cox maze III procedure to use bipolar radiofrequency ablation simplified and shortened this procedure without sacrificing short-term efficacy.

No abstract

Bipolar radiofrequency energy can produce permanent transmural linear lesions on the beating heart. Online measurement of tissue conductance reliably predicted lesion transmurality. This new technology may enable surgeons to perform a curative minimally invasive operation for atrial fibrillation on the beating heart.

Radial artery patency is sensitive to both target location and proximal target stenosis. Selective use of the radial artery to targets of the left anterior descending and circumflex distributions remains encouraging. Radial artery grafts to targets of the right coronary artery or those with moderate stenosis appear to be at particularly high risk of failure.

The purpose of this study was to investigate the relationship between right atrial (RA) reservoir and conduit function and to determine how hemodynamic changes influence this relationship and its impact on cardiac output. In 11 open-chest sheep, RA reservoir and conduit function were quantified as RA inflow with the tricuspid valve closed versus open, respectively. Conduit function was separated into early (before A wave) and late (after A wave) components. The effects of inotropic stimulation, partial pulmonary artery occlusion, and pericardiotomy were tested. At baseline with the pericardium intact, reservoir function accounted for 0.56 (SD 0.13) of RA inflow, early conduit for 0.29 (SD 0.07), and late conduit (during RA contraction) for 0.16 (SD 0.11). Inotropic stimulation decreased conduit function and increased reservoir function, but these effects did not reach statistical significance. With partial pulmonary artery occlusion, early conduit function fell to 0.20 (SD 0.11) (P Ͻ 0.04), and the conduit-to-reservoir ratio decreased by 41% (P Ͻ 0.03). Similarly, after pericardiotomy, early conduit function fell to 0.14 (SD 0.09) (P Ͻ 0.004), reservoir function increased to 0.72 (SD 0.08) (P Ͻ 0.04), and, consequently, the early conduit-to-reservoir ratio decreased by 63% (P Ͻ 0.006). Cardiac output was inversely related to the conduit-to-reservoir ratio (r ϭ 0.39, P Ͻ 0.001). This study demonstrated that the right atrium adjusts its ability to act more as a reservoir than a conduit in a dynamic manner. The RA conduit-to-reservoir ratio was directly related to the right ventricular pressure-RA pressure gradient at the time of maximum RA volume, with increased ventricular pressures favoring conduit function, but it was inversely related to cardiac output, with an increase in the reservoir contribution favoring improved cardiac output. right atrial function; conductance catheter; right ventricular afterload; inotropic stimulation; pulmonary artery occlusion THE RIGHT ATRIUM is a dynamic structure whose role is to assist filling of the right ventricle. Ideally, the right atrium should transfer a high volume of blood rapidly to the ventricle at low pressure to prevent peripheral edema and hepatic congestion. The three components of atrial function are 1) reservoir function, storing blood when the tricuspid valve is closed and releasing stored blood when it opens; 2) conduit function, passive blood transfer directly from the coronary and systemic veins to the right ventricle when the tricuspid valve is open; and 3) booster pump function, atrial contraction in late diastole to complete ventricular filling (10,13,31). Previous studies have demonstrated that pathologically altered left atrial conduit-to-reservoir function is an important determinant of left heart function and can profoundly affect cardiac performance (2, 4, 14 -17, 30, 33, 34, 38), but studies examining right atrial (RA) reservoir and conduit function are limited.The mechanics of the right atrium are complex (5,8,24,26). In 1628, William Harvey was the...

The Cox maze III procedure has a low operative mortality and excellent long-term efficacy in patients with ischemic heart disease. These data suggest a more widespread use of this procedure in these patients.

No abstract