A Noninvasive, Hand-Held Device for Assessing Left Ventricular End-Diastolic

Pressure Based on Finger Photoplethysmography and the

Valsalva Maneuver

Panagis Galiatsatos, MDJohns Hopkins Bayview Medical Center

February 2nd 2013

No Disclosures

Outline

• 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 ManeuverPhase 1: Initial blood pressure increasePhase 2: Maintaining the strain – decrease in pressurePhase 3: Release of the strain – short decrease of arterial pressurePhase 4: Distinct overshoot of pressure“Sinusoidal Response”

Background Information

Valsalva ManeuverBedside technique with sphygmomanometry

Issue1. No standardization of technique2. 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, battery-powered device that inputs finger PPG and expiratory pressure signals during the Valsalva maneuver, guides subject performance and calculates PAR automatically.

Mouthpiece / pressure transducer

Photoplethysmography (PPG) probe

User-friendly display

A

A B

B

C

C

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

CharacteristicsAll Patients

(N=14)+ SD

Age 53 + 8.5

Female 7 (50%)

BMI (kg/m2) 33.1 + 7.6

Co-MorbiditiesHypertension (n)Hemodialysis (n)

Diabetes mellitus (n)Coronary Artery Disease (n)

7 (50%)2 (14%)4 (29%)8 (57%)

MedicationsCalcium 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%)

PAR > 0.72 was 78% sensitive and 100% specific in identifying LVEDP > 15 mmHg.

Conclusions

• This study represents initial testing of a hand-held, 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