Non-invasive estimation of pulmonary vascular

resistanceCongenital heart disease

TWO VARIABLES

• TRV

• RVOT VTI

TWO FORMULAS

• TRV/TVIRVOT × 10 + 0.16(Abbas E et al)

• PVRDoppler (WU) = 37.96 × (TRV/ VTIRVOT)−0.131(Arindam P et al)

PERSPECTIVE

• PVR is a critical and essential parameter during the assessment and selection of modality of treatment in patients with congenital heart disease accompanied by pulmonary arterial hypertension

• Better decide anatomy and physiology both by ECHO

• Choose a non-invasive strategy if sensitive/specificity is comparable to Invasive catheterization

ECHOCARDIOGRAPHIC EVALUATION

• Tricuspid regurgitation velocity (TRV)

• Velocity time integral of the right-ventricular outflow tract (VTIRVOT).

USEFUL FOR CHD WITHOUT PULMONARY OUTFLOW TRACT OBSTRUCTION

• VSD

• ASD

• PDA

• AP WINDOW

• ASD+VSD

• ASD+VSD+PDA

FORMULA

ECHOCARDIOGRAGHY CARDIC CATHETERISATION

PVRDoppler (WU) = 37.96 × (TRV/ VTIRVOT)−0.131

AGREEMENT :CATH VS. ECHO

• Linear regression plot for pulmonary vascular resistance at atheterization (PVRcath) versus (TRV)/( VTIRVOT) ratio (r = 0.896, 95% confidence interval [CI] 0.816 to 0.9423, P < 0.001)

PVR OF 8 WU

TRV/VTIRVOT value of 0.17

sensitivity of 79.17%

specificity of 95%

Area under the ROC= 0. 0.923[ 95% CI 0.801 to 0.982]

PVR OF 6 WU

TRV/VTIRVOT value of 0.14

Sensitivity of 96.67%

specificity of 92.86%

Area under the ROC = 0.963,95%[ CI 0.858 to 0.997]

BLAND-ALTMAN ANALYSIS

• Very good the limits of agreement between PVRDoppler and PVRcath at a PVR around 6

ARINDAM PANDE ET.AL: NON-INVASIVE ESTIMATION OF PULMONARY VASCULAR RESISTANCE IN PATIENTS OF PULMONARY HYPERTENSION IN CONGENITAL HEART DISEASE WITH UNOBSTRUCTED PULMONARY FLOW . ANN OF PAED CARD: 2014 ; VOLUME : 7( 2 ): 92-97

PVRDoppler (WU) = 37.96 × (TRV/ VTIRVOT)−0.131

The TRV/VTIRVOT ratio correlated well with PVR measured at catheterization (PVRcath) (r = 0.896, 95% confidence interval [CI] 0.816 to 0.9423, P < 0.001). Using the Bland-Altman analysis, PVR measurements derived from Doppler data showedsatisfactory limits of agreement with catheterization estimated PVR. For a PVR of 6 Wood units (WU), a TRV/VTIRVOT value of 0.14 provided a sensitivity of 96.67% anda specificity of 92.86% (area under the curve 0.963, 95% confidence interval 0.858 to 0.997) and for PVR of 8 WU a RV/VTIRVOT value of 0.17 provided a sensitivity of 79.17% and a specificity of 95% (area under the curve 0. 0.923, 95% confidence interval

0.801 to 0.982).

ABBAS AE, FRANEY LM, MARWICK T, MAEDER MT, KAYE DM,VLAHOS AP, ET AL. NONINVASIVE ASSESSMENT OF PULMONARYVASCULAR RESISTANCE BY DOPPLER ECHOCARDIOGRAPHY. J AMSOC ECHOCARDIOGR 2013;26:1170-7

• TRV/TVIRVOT is a reliable method to identify patients with elevated PVR. In patients with TRV/TVIRVOT > 0.275, PVR is likely > 6 WU, and PVRecho2 derived from TRV(2)/TVIRVOT provides an improved noninvasive estimate of PVR compared with PVRecho

• PVR ≤6 WU : a good estimate of invasively derived PVR.PVR >6:This formula is less accurate

•TRV/TVIRVOT × 10 + 0.16

TAKE HOME

• Doppler-derived ratio of TRV/VTIRVOT is a simple, non-invasive index, which can be used to estimate PVR

RADIATION FROM YOUR CELL PHONE AFFECTS MIGRATORY BIRDS