Ιπποκράτειες μέρες καρδιολογίας Θεσσαλονίκη, 9-10 Μαρτίου 2018 Φωτεινή Α. Λαζαρίδου Επιμελήτρια Α Γενικό Νοσοκομείο Αγιος Παύλος, Θεσσαλονίκη
RV shape Triangular shape in frontal plane crescent shape in the transversal plane
Anatomically RV is separated into (i) the inflow tract comprising the tricuspid valve, chordae tendineae, and papillary muscles; (ii) the outflow tract with smooth walls; and (iii) the muscular trabeculated apex.
Myofibers of RV vs LV superficial layer are arranged circumferentially and turn obliquely toward the cardiac apex and continue into the superficial myofibers of the L V the deep muscle fibers of the RV are longitudinally alligned obliquely oriented myofibers superficially, longitudinally oriented myofibers in the subendocardium, The continuity between the muscle fibers of the RV and LV functionally binds the 2 ventricles together and represents the anatomic basis of RV free-wall traction caused by LV contraction. This continuity also contributes, along with the IVS, to ventricular interdependence mainly circular fibers in between This arrangement contributes to the more complex movement of the LV which contains torsion, translation, rotation, and also thickening. Arch Cardiovasc Imaging. 2015 November; 3(4):e35717. Circulation. 2008;117:1436-1448.
The muscle mass of the RV is about one-sixth that of the LV. The RV pumps the same stroke volume as does the LV, but with about 25% of the stroke work due to the low resistance of the pulmonary vasculature. Longitudinal shortening is a greater and more important contributor to RV stroke volume than is circumferential shortening. The RV is linked to the LV in several ways: by a shared wall (via the septum), by reciprocally encircling epicardial fibers, by sharing the pericardial space, and by the attachment of RV free wall to the anterior and posterior septum. Arch Cardiovasc Imaging. 2015 November; 3(4):e35717.
RV function RV function is dependent on preload and afterload. It provides the same stroke volume as the LV with decreased contractility, likely due to the decreased afterload it faces from the pulmonary vasculature. In response to volume overload, the RV elongates and produces septal flattening in diastole. In response to pressure overload, chronic or acute, the RV produces a flattened septum in systole. Even in normal conditions, the RV can change in morphology. In elite athletes, the right ventricular end-diastolic volume is increased compared with the LV enddiastolic volume, and a bulge is noted on the RV free wall. the LV substantially contributes to RV performance due to the presence of shared fibre bundles, attachment to the interventricular septum (IVS), and pressure transmission through the IVS. Clinical Cardiology. 2017;40:542 548.
RV contraction The RV contracts by 3 separate tools: A. contraction of the longitudinal myofibers, which shortens the long axis and pulls the tricuspid annulus toward the apex; B. inward movement of the RV free wall, which creates a bellows effect C.traction on the free wall at the points of attachment secondary to LV contraction/ bulging of the IVS into the RV during the LV contraction and stretching the free wall of the RV over the septum https://aneskey.com/cardiac-anatomy-and-physiology-2/ Circulation, 2008; 117: 1436 1448. Arch Cardiovasc Imaging. 2015 November; 3(4):e35717.
Difficulties in RV assessment RV does not have a symmetrical, well-defined shape and does not lend itself to simplified formulas. the position of the RV directly behind the sternum can impair adequate visualization of all segments of the RV. visualization of the RV inflow-outflow tract is difficult to perform on echocardiograms. there are no clear landmarks to address standardization of views. Different angulations can result in very different measurements. Clinical Cardiology. 2017;40:542 548.
Standard RV views by echo anterior & inferior RV walls, RV inflow tract two leaflets RV anterior wall prox part of RVOT basal part of RV anterior wall, RVOT, two leaflets, pulmonary valve PA RV crescent shape, eccentricity index, IVS septum motion; RV inferior wall; inflow and apical RV, RV lateral wall, interventricular septum, and s/p leaflets Kardiologia Polska 2016; 74, 6: 307 322
Qualitative assessment Eccentricity index >1 at end diastole is highly suggestive for RV volume overload, and at end systole or during the whole cardiac cycle for RV pressure overload Visual assessment of the RV size may be performed from the apical 4C view : the area of normal RV should not exceed two-thirds of the LV (aprox). Evaluation of the RV walls structure and motion (aneurysm, hypo/a-kinesia) Surkova, 2016
Quantative assessment RV outflow tract (RVOT) distal diameter is the most reproducible. The lack of precise anatomic landmarks to define the RV standard views may lead to an under- or overestimation of RV size. True RV-focused four-chamber image : LV apex at the centre of the scanning sector, while displaying the largest basal RV diameter and thus avoiding foreshortening J Am Soc Echocardiogr, 2015; 28:1 39.e14. Surkova, 2016
RV focused view Avoid underestimation Rotate the transducer until the maximal plane is obtained Avoid overestimation Ensure that the RV is not foreshortened and that the LVOT is not opened up (avoid the apical 5-chamber view) J. Am. Soc. Echocardiogr. 23 (7) (2010) 685 713. J. Am. Soc. Echocardiogr. 28 (1) (2015) 1 39.
RVOT size The PSAX distal RVOT diameter, just proximal to the pulmonary annulus, is the most reproducible and should be generally used J. Am. Soc. Echocardiogr. 23 (7) (2010) 685 713. J. Am. Soc. Echocardiogr. 28 (1) (2015) 1 39.
RV wall thickness RV wall thickness important in pts with RV pressure overload, biventricular hypertrophic cardiomyopathies, and storage diseases. It is recommended to use the zoomed image of the RV free wall
Transoesophageal echo Some segments of the RV, such as the RVOT contributing up to 25 30% of the RV volume, could be overlooked when using standard transthoracic 2DE (TTE) Transesophageal echocardiography (TEE) with the midesophageal inflow outflow view can evaluate RVOT. TEE is essential in the peri- and intraoperative settings and allows continuous monitoring of right heart function during noncardiac surgery In addition to standard TEE views, five additional deep transgastric views have been suggested to provide additional information on the RV inflow tract, free wall, outflow tract and the right-sided valves. International Journal of Cardiology 214 (2016) 54 69
3D echo modes of a 3D data set of the right ventricle (RV) obtained from the RV-focused apical four-chamber view using full-volume multi-beat acquisition A. Volume rendering demonstrating the RV anatomy; B. Multi (twelve)-slice mode including three longitudinal (0, 60, and 120 ) and nine transversal equidistant tomographic views C. Semiautomatic identification of the RV endocardial surface D. Surface rendered 3D model of the RV
3D echo 3DE tends to underestimate RV volumes compared CMR Overall, women have smaller 3D echocardiographic RV volumes, despite indexing to BSA, and higher EFs. Also, older age is associated with smaller volumes (expected decrements of 5 ml/decade for EDV and 3 ml/decade for ESV) and higher EF (an expected increment of 1% per decade) Kardiologia Polska 2016; 74, 6: 307 322; J Am Soc Echocardiogr, 2015; 28:1 39.e14.
RV function The assessment of RVEF using 2DE is no longer recommended due to its inaccuracy a number of surrogate echocardiographic parameters :RV fractional area change, tricuspid annular plane systolic excursion, peak S wave velocity of the lateral tricuspid annulus by tissue Doppler imaging [TDI], and RV myocardial performance index) have been proposed for clinical use. J Am Soc Echocardiogr, 2015; 28:1 39.e14
2D evaluation TAPSE, RVFAC, and right ventricular ejection fraction (RVEF) can change with a change in load without any true change in myocardial contractility and therefore do not reflect innate myocardial function. RIMP can be falsely low in conditions associated with elevated RA pressures, which will shorten the IVRT. Clinical Cardiology. 2017;40:542 548. J Am Soc Echocardiogr 2015;28:1-39.
RV diastolic function During acute RV pressure overload, RV diastolic function is not affected Chronic RV pressure overload impacts RV diastolic function, resulting in prolonged diastolic relaxation time and increased RV diastolic stiffness The assessment of RV diastolic function includes the evaluation of the RV inflow by pulsed wave Doppler sampling at the tips of the tricuspid valve leaflets; measuring the TDI velocities of the tricuspid annulus at RV free wall; evaluation of right atrial, inferior vena cava, and hepatic vein size and function Rudski et al JASE 2010 Circulation, 2005; 112: I212 I128
RV pressures Rudski et al JASE 2010
RV mechanics RV longitudinal strain Being extremely load dependent, RVEF is a partial indicator of the RV systolic function RV long strain : either TDI or 2DSTE techniques. The correlation between Doppler-derived and 2DSTE-derived RV longitudinal strain appears to be moderate abnormality threshold for the RV free-wall longitudinal strain : 20% The term global RV longitudinal strain is commonly used for average values calculated from three segments of the RV free wall and three segments of the IVS from apical fourchamber view, even though the contribution of other walls and RVOT is neglected relatively low repeatability of regional RV strainrepresents a relative weakness of both echocardiographic techniques limiting their routine use for an individual patient follow-up of segmental function
RV dyssynchrony a cutoff value of 18 ms was introduced as a criterion for RV dyssynchrony J Am Coll Cardiol Cardiovasc Imaging, 2015; 8: 642 652.
RV tissue characterisation RV freewall strain may be an accurate echocardiographic marker of the extent of RV myocardial fibrosis correlating with patients functional capacity (end stage HF pts) JACC Cardiovasc. Imaging 8 (5) (2015) 514 522.
RV shape RV regional curvature The apical free wall becomes more pointed (black arrows at apex), and the body free wall flattens, as do the RVOT and RVIT (see arrows at respective positions). There was no change in septal curvature during the transition from end-diastole to endsystole. Addetia et al ; JASE 2017
Addetia et al ; JASE 2017 Surkova et al; International Journal of Cardiology 214 (2016) RV shape- 3DE RV regional curvature Conclusions: This study established normal three-dimensional echocardiographic values for RV rci, which are needed to further study RV diastolic dysfunction and remodeling with disease. in patients With pressure overload the RV exhibits differences in regional curvature: the RVOT is more round, both body and apical portions of the septum are more convex bulging into the LV with a more flattened apical free wall.
RV pre LVAD
Over the last two decades RV performance has been demonstrated to be an important independent predictor of morbidity and mortality in patients with congenital heart disease, heart failure, pulmonary hypertension, dilated cardiomyopathy, coronary artery disease, left ventricular (LV) dysfunction, respiratory distress syndrome, sepsis, heart transplant, implanted LV assist devices, and even in the population free of cardiovascular diseases. Circulation, 2008; 117: 1717 1731. J Card Fail, 2014; 20: 343 349.
CMR is the reference standard method Echocardiography is the most frequently utilized imaging modality for the assessment of RV size and systolic function. Multimodality comparison studies between CMR, CCT, and 3D echocardiography have demonstrated a high correlation between 3D echo, CCT and RV volume measurements in CMR as the reference method. CCT volumetric measurements have shown slight (4%) overestimation and 3D echocardiographic measurements have revealed small underestimation Arch Cardiovasc Imaging. 2015; 3(4):e35717.
Journal of the American Society of Echocardiography January 2015
3D RV evaluation J Am Soc Echocardiogr. 2015;28:1 39
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