Right ventricular (RV) failure remains a major concern in heart failure (HF) patients undergoing left ventricular assist device (LVAD) implantation. We aimed to measure the kinetic energy of blood in the RV outflow tract (KE-RVOT) – a new marker of RV global systolic function. We also aimed to assess the relationship of KE-RVOT to other echocardiographic parameters in all subjects and assess the relationship of KE-RVOT to hemodynamic parameters of RV performance in HF patients.
Fifty-one subjects were prospectively enrolled into 4 groups (healthy controls, NYHA Class II, NYHA Class IV, LVAD patients) as follows: 11 healthy controls, 32 HF patients (8 NYHA Class II and 24 Class IV), and 8 patients with preexisting LVADs. The 24 Class IV HF patients included 21 pre-LVAD and 3 pre-transplant patients. Echocardiographic parameters of RV function (TAPSE, St', Et', IVA, MPI) and RV outflow color-Doppler images were recorded in all patients. Invasive hemodynamic parameters of RV function were collected in all Class IV HF patients. KE-RVOT was derived from color-Doppler imaging using a vector flow mapping proprietary software. Kruskal-Wallis test was performed for comparison of KE-RVOT in each group. Correlation between KE-RVOT and echocardiographic/hemodynamic parameters was assessed by linear regression analysis. Receiver operating characteristic curves for the ability of KE-RVOT to predict early phase RV failure were generated.
KE-RVOT (median ± IQR) was higher in healthy controls (55.10 [39.70 to 76.43] mW/m) than in the Class II HF group (22.23 [15.41 to 35.58] mW/m,
KE-RVOT, a novel noninvasive measure of RV function, strongly correlates with well-established echocardiographic markers of RV performance. KE-RVOT is the energy generated by RV wall contraction. Therefore, KE-RVOT may reflect global RV function. The utility of KE-RVOT in prediction of RV failure post LVAD implantation requires further study.