Noninvasive calibration of cardiac pressure transducers in patients with heart failure: an aid to implantable hemodynamic monitoring and therapeutic guidance.

BACKGROUND

Implantable cardiac pressure monitors require assurance of calibration. This study evaluated if airway pressure responses during Valsalva maneuver (VM) can be used for calibrating intracardiac pressure transducers.

METHODS AND RESULTS

Thirty-eight heart failure patients performed VMs while cardiac and airway pressures were recorded. Patients were designated as Lower (L) if baseline PCW was <20 mm Hg (n = 17); otherwise, they were categorized as Higher (H) (n = 21). VMs were repeated in 9 H patients after nitroglycerin. Procedural success was 92% and there were no complications. Differences between filling pressure and airway pressure (effective pressure) were eliminated during VM (RA(eff) = -0.9 +/- 1.3, RVED(eff) = 1.2 +/- 1.1, PCW(eff) = 2.1 +/- 2.8, and LVED(eff) = 0.9 +/- 1.6 mm Hg), and filling pressures were highly correlated with airway pressure r = 0.94. On average, group H had higher PCW(eff) and LVED(eff) than L patients by 1.8 and 2.5 mm Hg (P < or = .002), respectively, but after nitrates their responses were identical.

CONCLUSION

The relationships between cardiac filling pressure and airway pressure during the Valsalva maneuver are sufficiently reliable to be considered as a new, noninvasive method for establishing the calibration of cardiac pressure sensors in patients with heart failure.