Transcript A Noninvasive, Hand-Held Device for Assessing Left Ventricular

A Noninvasive, Hand-Held Device for
Assessing Left Ventricular End-Diastolic
Pressure Based on Finger
Photoplethysmography and the
Valsalva Maneuver
Panagis Galiatsatos, MD
Johns Hopkins Bayview Medical Center
February 2nd 2013
No Disclosures
Outline
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Background information
Objective of the study
Methods
Results
Conclusions
Future Direction
Background Information
• Knowledge of left ventricular filling pressure
useful in certain clinical settings.
• Non-invasive tools:
– Physical Exam
– Chest X-ray
– Daily weights
– Bloodwork (pro-BNP)
Background Information
Valsalva Maneuver
- Created by Antonio Maria Valsalva
- Effects on the cardiovascular system
Background Information
Valsalva Maneuver
Phase 1: Initial blood pressure increase
Phase 2: Maintaining the strain – decrease in
pressure
Phase 3: Release of the strain – short decrease
of arterial pressure
Phase 4: Distinct overshoot of pressure
“Sinusoidal Response”
Background Information
Valsalva Maneuver
Bedside technique with sphygmomanometry
Issue
1. No standardization of technique
2. Does not yield continuous measure
Background Information
“Finger photoplethysmography during the
Valsalva maneuver reflects left ventricular
filling pressure”
Silber HA et al. Am J Physiol Heart Circ Physiol 2012
Photoplethysmograph (PPG)
Pulse Amplitude Ratio (PAR)
Objective
Validate a new hand-held, batterypowered device that inputs finger PPG and
expiratory pressure signals during the
Valsalva maneuver, guides subject
performance and calculates PAR
automatically.
/ pressure
A Mouthpiece
transducer
B Photoplethysmography
(PPG) probe
C
A
C User-friendly display
B
Methods
Patients who were scheduled to undergo a
cardiac catheterization including the
measurement of LVEDP.
Expiratory pressure during Valsalva was
measured by having the subject place a tube in
their mouth that was connected to a pressure
transducer input into the device.
Methods
The subject was coached to keep the expiratory
effort at about 20 mmHg during a 10-second
Valsalva maneuver.
The output measure of the device is the ratio of
the amplitude of the PPG waveform near the
end of Valsalva to the amplitude at baseline
Methods
Results
All Patients
Characteristics
(N=14)
+ SD
Age
Female
BMI (kg/m2)
Co-Morbidities
53 + 8.5
7 (50%)
33.1 + 7.6
Hypertension (n)
Hemodialysis (n)
Diabetes mellitus (n)
Coronary Artery Disease (n)
7 (50%)
2 (14%)
4 (29%)
8 (57%)
Calcium channel blockers (n)
Beta blockers (n)
Thiazide diuretics (n)
ACE-I / ARB (n)
Loop diuretics (n)
1 (7%)
9 (64%)
1 (7%)
9 (64%)
1 (7%)
Medications
PAR > 0.72 was 78% sensitive and 100% specific in identifying
LVEDP > 15 mmHg.
Conclusions
• This study represents initial testing of a handheld, battery-powered device using finger PPG
during the Valsalva maneuver for assessing
left ventricular filling pressure noninvasively.
• The output measure of the device, Pulse
Amplitude Ratio (PAR), correlated well with
LVEDP obtained invasively by cardiac
catheterization.
Conclusions
• PAR > 0.72 was 78% sensitive and 100%
specific in identifying LVEDP > 15 mmHg, a
clinically meaningful cutoff value in heart
failure.
• Further testing is warranted to explore the
clinical utility of this device in heart failure
management and other settings.
Future Directions
• Use of the device to assess adequate fluid
removal from in-patient diuresis in heart
failure patients.
• PAR in the use of fluid removal in
hemodialysis.
Acknowledgements
• Harry Silber, MD, PhD
– Principal Investigator
• Jennifer Monti, MD, MPH
• Interventional Cardiologists
– David Bush, MD
– Jeffrey C. Trost, MD
– Peter Johnston, MD
• Colleen Christmas, MD
Questions