Application of the Vacuum-Assisted Closure device (VAC) to open sternal wounds has negative hemodynamic effects. We hypothesized that the interposition of a muscle flap attenuates these negative hemodynamic effects. After institutional approval, monitoring lines were placed in anesthetized, ventilated pigs. Through a median sternotomy, sonometric crystals were strategically positioned around the left ventricle. A rectus flap was rotated over the mediastinal wound, and the VAC was placed over the flap. After baseline measurements, a vacuum of 125 mmHg [Group (GP) 1, n = 5] or 50 mmHg (GP2, n = 6) was initiated. Hemodynamics were recorded every 15 min for 1.5 h, and 15 min after cessation of the vacuum therapy. GP3 (n = 6) underwent intermittent VAC cycling (on 5 min/off 2 min). Significance determined by t test. While non-flapped animals had significant detriment in both left ventricular filling volume and cardiac output, flapped animals had insignificant depression of both parameters. Application of muscle flaps to sternal wounds prior to VAC therapy significantly attenuates the negative hemodynamic effects seen when the VAC is used alone.