Abstract 14261: A Noninvasive Handheld Device Detects Changes in Left Heart Filling Pressure After Hemodialysis
Background: A hand-held device has been developed for assessing left heart filling pressure noninvasively. The device analyzes a finger photoplethysmography (PPG) waveform during a standardized Valsalva maneuver. We have previously shown using finger PPG a correlation between left ventricular end-diastolic pressure and Pulse Amplitude Ratio (PAR), which is the ratio of pulse amplitude at end-Valsalva to pulse amplitude at baseline. The objective of this study was to determine if PAR is sensitive enough to detect changes in left heart filling pressure that accompany fluid removal in hemodialysis.
Methods: We tested 27 subjects (21 M, 6F), ages 25-75 years, with end-stage renal disease, before and after a hemodialysis session. Each subject performed a Valsalva maneuver with an effort of 20 mmHg for 10 seconds, guided by the device display. Finger PPG was recorded continuously before and during the maneuver. PAR was calculated automatically. The subject was asked to repeat the measurement sequence up to 6 times.
Results: Duration of hemodialysis ranged from 180 to 330 minutes (access sites: AV-fistulas of the arm predominantly, some tunneled catheters). The number of expiratory efforts obtained from each subject was 3.6 ± 0.9. Weight decreased from 99.7 ± 36.9 kg to 97.0 ± 36.0 kg (p<0.0003) with an average fluid removal of 3.07 ± 1.08 liters. Correspondingly, PAR decreased from 0.74 ± 0.24 to 0.62 ± 0.23 (p=0.003, Figure). Furthermore, the change in PAR was correlated with baseline PAR (r^2 =0.23, p = 0.01).
Conclusion: An index of left heart filling pressure obtained noninvasively using finger photoplethysmography during the Valsalva maneuver is sensitive enough to detect reductions in filling pressure after fluid removal with hemodialysis. A hand-held device has been developed that guides the user and calculates PAR automatically. Further studies are warranted to determine the clinical utility of PAR derived from finger PPG in various disease states.
- © 2013 by American Heart Association, Inc.