Preserved Left Ventricular Contractile Reserve in Patients with Right Ventricular Pressure/Volume Overload Assessed by Combined Stress Echocardiography with Strain Analysis

Objectives: Right ventricular (RV) pressure/volume overload usually results in RV dysfunction but may also affect left ventricular (LV) function because of ventricular interaction. The aim of this study was to assess the effect of chronic RV load on LV myocardial mechanics and contractile reserve by combining stress echocardiography with strain analysis.

Methods: Thirty-one patients (mean age: 20.4 ± 8.6 years, 59% female) with chronic pulmonary regurgitation (PR; 52% mild, 26% moderate, and 22% severe) and 50 healthy controls of similar age and gender were prospectively recruited. Overall, 14 of 31 patients had an additional pressure load defined as Doppler echocardiographically estimated pressure gradient across the pulmonary valve of ≥15 mm Hg. Furthermore, electrical dyssynchrony was assessed by 12-lead electrocardiograms and measurement of QRS duration. Echo-loops were acquired at rest, low stress, submaximal stress, and during recovery according to a standardized protocol. Optimal image quality for offline strain analysis was pursued. Global longitudinal strain (GLS) and strain rate (SR) from apical four-/two-/three-chamber views were analyzed using vendor-independent software.

Result: While the mean GLS was significantly lower at rest (−18.4 ± 3.0 vs. −20.6 ± 1.6%; p < 0.001) and at low stress (−20.4 ± 3.1 vs. −22.6 ± 1.6%; p < 0.001) in patients with RV load compared with controls, GLS almost equalized for both groups at submaximal stress level (−23.0 vs. −23.7; p = 0.59). Further analysis of potential influencing factors revealed no significant impact of an additional pressure gradient across the pulmonary valve or electrical dyssynchrony (using the median of QRS duration [116 ms] as cut-off value) on LV mechanics during physical stress.

Conclusion: Patients with RV pressure/volume overload have abnormal LV myocardial mechanics, as demonstrated by combined stress echocardiography with strain analysis indicating that RV dysfunction adversely affects LV function, probably by mechanical coupling of the ventricles. The most striking changes were noted at rest and during low stress, whereas at submaximal stress level, no significant difference compared with healthy controls was detected, reflecting a preserved LV contractile reserve. The clinical significance and potential prognostic implications of these observations remain to be determined.

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Artikel online veröffentlicht:
21. Februar 2021