Pulmonary endarterectomy normalizes interventricular dyssynchrony and right ventricular systolic wall stress
- PDF / 322,903 Bytes
- 9 Pages / 595.28 x 793.7 pts Page_size
- 57 Downloads / 177 Views
RESEARCH
Open Access
Pulmonary endarterectomy normalizes interventricular dyssynchrony and right ventricular systolic wall stress Gert-Jan Mauritz1, Anton Vonk-Noordegraaf1, Taco Kind1, Sulaiman Surie4, Jaap J Kloek5, Paul Bresser6, Nabil Saouti1, Joachim Bosboom1, Nico Westerhof1,3 and J Tim Marcus2*
Abstract Background: Interventricular mechanical dyssynchrony is a characteristic of pulmonary hypertension. We studied the role of right ventricular (RV) wall stress in the recovery of interventricular dyssynchrony, after pulmonary endarterectomy (PEA) in chronic thromboembolic pulmonary hypertension (CTEPH). Methods: In 13 consecutive patients with CTEPH, before and 6 months after pulmonary endarterectomy, cardiovascular magnetic resonance myocardial tagging was applied. For the left ventricular (LV) and RV free walls, the time to peak (Tpeak) of circumferential shortening (strain) was calculated. Pulmonary Artery Pressure (PAP) was measured by right heart catheterization within 48 hours of PEA. Then the RV free wall systolic wall stress was calculated by the Laplace law. Results: After PEA, the left to right free wall delay (L-R delay) in Tpeak strain decreased from 97 ± 49 ms to -4 ± 51 ms (P < 0.001), which was not different from normal reference values of -35 ± 10 ms (P = 0.18). The RV wall stress decreased significantly from 15.2 ± 6.4 kPa to 5.7 ± 3.4 kPa (P < 0.001), which was not different from normal reference values of 5.3 ± 1.39 kPa (P = 0.78). The reduction of L-R delay in Tpeak was more strongly associated with the reduction in RV wall stress (r = 0.69,P = 0.007) than with the reduction in systolic PAP (r = 0.53, P = 0.07). The reduction of L-R delay in Tpeak was not associated with estimates of the reduction in RV radius (r = 0.37,P = 0.21) or increase in RV systolic wall thickness (r = 0.19,P = 0.53). Conclusion: After PEA for CTEPH, the RV and LV peak strains are resynchronized. The reduction in systolic RV wall stress plays a key role in this resynchronization. Keywords: Chronic Thrombo-Embolic Pulmonary Hypertension, Pulmonary Endarterectomy, interventricular mechanical asynchrony, myocardial strain, wall stress
Background Interventricular mechanical dyssynchrony is a characteristic of right ventricular (RV) pressure overload [1-3]. It occurs at the end of RV myocardial shortening, when the RV free wall continues shortening while the left ventricular (LV) wall is already in its early diastolic phase [4-7]. Consequently, the ventricular septum bows to the left, and the RV shortens without ejection thereby making the RV very inefficient [8], and in addition impairing * Correspondence: [email protected] 2 Department of Physics and Medical Technology, University of Amsterdam, Amsterdam, The Netherlands Full list of author information is available at the end of the article
early LV filling [9,10]. The underlying mechanism of this prolonged RV contraction duration is unknown. In an isolated Langendorf-perfused heart, Handoko et al [11] created a L-R dyssynchrony in peak pressure by increasing RV pre
Data Loading...
