Cardiac magnetic resonance (CMR)-determined right ventricular (RV) strain is associated with RV-arterial uncoupling and RV end-diastolic stiffness, according to study results published in JACC: Cardiovascular Imaging.1 This may be a promising noninvasive alternative to current invasive methods for assessing RV-arterial coupling and end-diastolic stiffness in patients with pulmonary hypertension (PH) with chronic RV overload.
PH is associated with progressive afterload-induced RV remodeling that eventually results in RV dilatation and clinical right heart failure.2 CMR is the standard imaging technique for measuring RV function,3 but the pathophysiologic and clinical value of CMR-derived RV strain relative to invasive pressure-volume loop-derived measurements in PH remains to be defined. Thus, the researchers sought to assess the association between CMR RV strain with invasively measured pressure-volume loop-derived RV contractility, stiffness, and afterload parameters and RV-arterial coupling in 38 patients with PH.1
They found that diastolic stiffness significantly correlates with strain in the chronic pressure-overloaded RV in PH. In addition, RV strain mirrors RV-arterial uncoupling and its assessment also provides information on the adaptation of RV inotropic function to afterload, the associated alteration in lusitropic function, and adaptive vs maladaptive remodeling.
The investigators concluded that, “our findings help to close the knowledge gap regarding the physiology of RV strain in chronic pressure overload, which was recently set as a research target by the American Thoracic Society.”1,3
However, “Additional conductance catheterization studies (using multiple-beat as well as single-beat approaches) will be needed to confirm the relationship of RV strain with RV maladaptation in larger patient populations with PH, and to evaluate further the effect of RV maladaptation on radial vs longitudinal strain,” they noted.
- Tello K, Dalmer A, Vanderpool R, et al. Cardiac magnetic resonance imaging-based right ventricular strain analysis for assessment of coupling and diastolic function in pulmonary hypertension [published online March 13, 2019]. JACC: Cardiovasc Imaging. doi:10.1016/j.jcmg.2018.12.032
- Vonk Noordegraaf A, Westerhof BE, Westerhof N. The relationship between the right ventricle and its load in pulmonary hypertension. J Am Coll Cardiol. 2017;69:236-243.
- Lahm T, Douglas IS, Archer SL, et al. Assessment of right ventricular function in the research setting: Knowledge gaps and pathways forward. An official American Thoracic Society research statement. Am J Respir Crit Care Med. 2018;198:e15-e43.