Abstract 16039: Sustained Biventricular Pacing May Improve Cardiac Index, Blood Pressure and Cerebral Blood Flow in Infants with Electrical Dyssynchrony after Surgery for Congenital Heart Disease
Background: Cardiac index (CI) decreases in the initial post-operative period after congenital heart disease (CHD) surgery, exposing infants to adverse hemodynamics. Electrical dyssynchrony, manifest by prolonged QRS duration (QRSd) may be an important factor. We hypothesized that continuous, simultaneous left and right ventricular pacing (BiVp) after CHD surgery improves cardiac index and hemodynamics in the early post-operative period.
Methods: We prospectively recruited infants with biventricular CHD < 4 mo of age undergoing surgery on cardiopulmonary bypass. Infants were randomized, regardless of QRS duration, to receive standard of care or standard of care + BiVp for 48 post-operative hours or until extubation if sooner. Infants randomized to BiVp received atrial, right ventricular and left ventricular leads. Continuous BiVp (atrial tracking) was initiated upon return to ICU. Hemodynamics were assessed at least every 3 hours for the 1st 24 hours and at least every 6 hours thereafter up to 48 hours. CI was measured by Fick using mass spectroscopy for oxygen consumption. Near infrared spectroscopy was used to measure cerebral saturation. Primary outcome was change in CI over the 1st 48 post-operative hours.
Results: 42 infants (21Cntrl, 21 Bivp; 3.8±0.9 kg, 50% transposition of the great arteries) were randomized. Infants with prolonged baseline QRS (>98th centile) experienced decreased CI, which was prevented by BiVp. Controls with normal QRS durations for age had consistent improvement in CI in the 1st 48 hrs, while those with prolonged QRS durations showed delayed CI recovery. BiVp tended to improve CI recovery (+0.118 (0.374) ml/min/m2, p=NS), blood pressure (BIVP +8 (3) mmHg, p=0.01) and cerebral blood flow in infants with wide QRS (Fig), but did not improve CI in infants with narrow QRS.
Discussion: Continuous BiVp may be useful to improve CI, blood pressure and cerebral flow in infants with electrical dyssynchrony after CHD surgery.
- © 2012 by American Heart Association, Inc.