Right ventricular end-diastolic stiffness heralds right ventricular failure in monocrotaline-induced pulmonary hypertension
Recent studies suggest right ventricular (RV) stiffness is important in pulmonary hypertension (PH) prognosis. Smaller stroke volume (SV) variation after a certain RV end-diastolic pressure (EDP) respiratory variation as assessed by spectral transfer function (STF) may identify RV stiffness. Our aim was to evaluate RV stiffness in monocrotaline (MCT)-induced PH progression and to validate STF gain between EDP and SV as marker of stiffness. Seven-week-old male Wistar rats randomly injected with 60 mg/kg MCT or vehicle were divided into three groups (n = 12 each) according to cardiac index (CI): controls (Ctrl), preserved CI (MCT pCI), and reduced CI (MCT rCI). All underwent RV pressure-volume (PV) evaluation 24–34 days after MCT, under halogenate anesthesia and constant positive-pressure ventilation. End-diastolic stiffness (βi), end-systolic elastance (Eesi), arterial elastance for indexed volumes (Eai), and preload recruitable stroke work (PRSW) were obtained and beat-to-beat fluctuations during ventilation assessed by STF. Eai was the strongest determinant of CI, alongside βi but not PRSW. MCT rCI showed impaired ventricular-vascular coupling (VVC) and higher βi, along with low end-diastolic pressure (EDP) and stroke volume index (SVi) STF gain, denoting impaired preload reserve. On multivariate analysis βi and not Eesi correlated with EDP-SVi STF gain (P < 0.001). Receiver-operating characteristics (ROC) curve analysis of EDP-SVi STF gain showe...
Source: AJP: Heart and Circulatory Physiology - Category: Cardiology Authors: Alaa, M., Abdellatif, M., Tavares-Silva, M., Oliveira-Pinto, J., Lopes, L., Leite, S., Leite-Moreira, A. F., Lourenco, A. P. Tags: Integrative Cardiovascular Physiology and Pathophysiology Source Type: research
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