Assessment of RV size, function, and pulmonary hypertension

1 Assessment of RV size , function, and pulmonary hypertensionSung-Ai Kim, MDDivision of Cardiology, HallymSacred Heart Hospital, HallymUniversity College of Medicine, Korea Anatomy of Right ventricle Crescent-like shape and a thin wall Wrapped around the LV Complex RV geometry in contrast to the symmetrical shape of LV KukulskiT, et al. Echocardiography 2000 McLureL, et al. Eur Respir J 2009 Anatomy of Right ventricle 3 distinct portions Smooth muscular Inflow (body) Trabecularapex Outflow(infundibulum) Work of Right ventricle RV vsLV 1/6 of the muscle mass 1/10 of the vascular resistance Same stroke volume of the stroke work d/t low resistance of pulmonary vasculatureWork of Right ventricle Inner longitudinal fiber (base-to-apex shortening) >> superficial circumferential fiber (inward movement)

2 Longitudinal shortening accounts for 80% of RV function in normal physiologic states CurrOpinCardiol2015, 30:292 300 RV linked to the LV By a shared septum By attachment of the RV free wall to the anterior & posterior septum By encircling epicardialfibers By sharing the pericardial spaceAssessment of RV size & function Because of the -complex geometry-poor RV endocardialdefinition-operator and acoustic window differences volumetric quantification is challenging limited data regarding the normal size rely on visual estimationComprehensive evaluation of the RVF/ 42 Idiopathic pulmonary HTNB efore After Assessment

3 Of RV size and Function1. RV dimension2. 2D Assessment of RV -RV area and FAC -2D volume and EF 3. 3D Assessment of RV -3D volume and EF 4. Non-volumetric Assessment of RV function RV dimension RV dilated in response to chronic volume and/or pressure overloadIdiopathic pulmonary HTNN ormalRV dimensionJASE 2002;15-633-9 Circulation. 2004;109:2401-2404RV dimension< 42mm< 27mm< 33mm the RV focused view RV dimensionRV dimensionRV dimensions are highly dependent on probe rotation by the user underestimation of RV width 2D Assessment of RVRV FAC (fractional area change):(end-diastolic area end-systolic area) x 100 / end-diastolic area Lower reference value < 35% ESEDRV FAC NassN et al.

4 AJC 1999;1:804-6RV FAC was found to be an independent predictor of heart failure, sudden death, stroke, and/or mortality in studies of patients after pulmonary embolism2D RV volume and EF approximation of RV geometry, pyramidal or ellipsoidal models underestimate RV volume and inferior to 3D2. Disk summation method determine a RV body volume underestimate d/t exclusion of the RVOT 2D estimation of RV EF is not recommended, because of the numerous geometric assumptions and heterogeneity of methods3D RV volume and EF 3D RV volume correlate well with MRI-derived RV volumesJ Am CollCardiol2007.

5 50:1668 76 Lower reference limit of 3D RV EF = 44%3D RV volume and EF Limited normative data (difference method, small numbers) Underestimate MRI-derived RV volumes Time consuming (disk summation method ) Fewer data in dilated or dysfunctional RVNon-volumetric Assessment of RV function Globalassessment -RV dp/dt Regionalassessment -TAPSE-TDI (S , MPI)-Doppler strain -2D strain RV dp/dt(mmHg)dp/dtis calculated by measuring the time required for theTR jet to increase in velocity from 1 to 2 m/s4 (2)2-4(1)2= 12mmHg time (s) RV dp/dt< 400mmHg/sis abnormal RV dp/dt(mmHg)TR dp/dt= 359 mmHg/s Simple technique with physiologic basis Limited data in both normal and pathologic conditions Load dependent Less accurate in severe TR (RA pressure )RV dp/dt(mmHg)TAPSE (tricuspid annular plane systolic excursion)

6 L = 16 mmTAPSE Represents longitudinal function Less dependent on image quality Rapid and reproducible Angle dependent Not valid in regional RV WMA No large scale validation Load dependent MPI (myocardial performationindex)MPI = IVRT + IVCT / ET Feasible in a majority of subjects w/o TR Reproducible Avoid geometric assumptions Unreliable in differing R-R intervals (A-fib) Load dependent Unreliable in RA pressure MPI TDI (S , color-coded) Pulsed (S )(abnormal < 10 cm/s)Color coded (insufficient data, wider CI) 2D strain 2D strain Relatively angle dependent Provide regional function as well as global function A lack of normative data Different algorithm in different platforms different normal ranges Summary of RV systolic function estimates*Lower/upper reference limit FAC < 35% TAPSE < 16 mmS < 10 cm/s Tissue MPI > RV EF < 44% Hemodynamic Assessment of RV and pulmonary pulmonary artery diastolic pressure PA pressure4.

7 pulmonary vascular resistance pulmonary artery pressureDetermined by the Amount of blood flow of the pulmonary circulation(cardiac output) Intrinsic properties of the vasculature (resistance, compliance, and impedance) LA pressure downstream of the pulmonary circuitNormal >>>>>>> pulmonary vascular remodeling >> RV failurePressure-volume loop Assessment of Systolic PAPSPAP = eRVSP= 4 (V)2+ RA pressure (w/o obstruction at the level of the RVOT or PV)Normal estimated SPAP < 35mmHg RA pressure estimation Systolic PAPSPAP with aging Circulation.

8 2009;119:2663-2670 The increased PAP was coupled with increases in pulse pressure and LV E/E age associated vascular stiffening and diastolic dysfunction contribute to changes in PAPP itfall in severe TREarly equalization of RV and RA pressures underestimate the RV-RA gradient PA diastolic pressure (PADP)PADP = 4 x (end-diastolic PR velocity)2+ RAP+Mean PA pressure = 1/3 (SPAP) + 2/3 (PADP)= 4 x (early-diastolic PR velocity)2+ RAPPVR ( pulmonary vascular resistance) PVR = (TR Vmax/ RVOT VTI) x 10 + J Am SocEchocardiogr2009.

9 22:814-9 TRRVOTS ignificant PH is defined as a PVR > 3 WU PVR ( pulmonary vascular resistance) pressure = flow x resistance Non-invasive PVR -not recommended for routine use In subjects with exaggerated SPAP by high SV SPAP by reduced SV (despite PVR)Summary (1) For Assessment of RV systolic function, FAC, TAPSE, S and MPIis recommended Combining more than one of the above measures more reliably distinguish normal from abnormal function, especially in patients with suspected RV dysfunctionSummary (2) Improvements in 3D echo will result in increased use and have the potential to help in the clinical Assessment of RV size and function Hemodynamic Assessment of pulmonary circulation (PAP, PVR) is crucial for better understanding of RV adaptation to PAH