Left ventricular filling characteristics in pulmonary hypertension: a new mode of ventricular interaction

Abstract

Objective-To examine the effects of pulmonary hypertension on left ventricular diastolic function and to relate the findings to possible mechanisms of interdependence between the right and left sides of the heart in ventricular disease.Design-A retrospective and prospective analysis of echocardiographic and Doppler studies.Setting-A tertiary referral centre for both cardiac and pulmonary disease.Patients-29 patients with pulmonary hypertension (12 primary pulmonary hypertension, 10 pulmonary fibrosis, five atrial septal defect (ASD), and two scleroderma) were compared with a control group of 10 patients with an enlarged right ventricle but normal pulmonary artery pressure (six ASD, one after ASD closure, one ASD and pulmonary valvotomy, one tricuspid valve endocarditis and repair, and one pulmonary fibrosis). None Conclusions-Prolonged decline of right ventricular tension, the direct result of severe pulmonary hypertension, may appear as prolonged tricuspid regurgitation. It persists until after mitral valve opening on the left side of the heart, where events during isovolumic relaxation are disorganised, and subsequent filling is impaired. These effects are likely to be mediated through the interventricular septum, and this right-left ventricular asynchrony may represent a hitherto unrecognised mode of ventricular interaction.The right and left ventricles cannot be considered independently of one another, and there is evidence of interaction in isolated perfused hearts,' whole animals,2 3 4 and humans.56 Experimental studies and animal models of acute and chronic right ventricular pressure overload have shown that the shape of both ventricles is altered as a result of leftward displacement of the interventricular septum. Also, some echocardiographic studies have shown that patients with right ventricular pressure or volume overload often have impaired left ventricular diastolic function that has been related to the geometrical distortion of the left ventricle.789The aim of this study was to show the abnormalities of left ventricular diastolic function present in a group of patients with right ventricular pressure overload secondary to severe pulmonary hypertension, and to compare these with a control group of patients with right ventricular dilatation but normal pulmonary artery pressures. In this way we hoped to study the possibility of right ventricular disease affecting left ventricular diastolic function, and in particular to separate any direct effects of pulmonary hyper-16

Prevalence and Prognostic Value of Left Ventricular Diastolic Dysfunction in Idiopathic and Heritable Pulmonary Arterial Hypertension

“…Several authors have previously noted the high prevalence of LV diastolic dysfunction in patients with PAH. [1][2][3]14 However, most of these studies included patients with chronic thromboembolic disease or a heterogenous group of patients with PAH. In our cohort, which consisted of carefully selected patients with hemodynamic criteria for PAH, 9 we observed that nine out of 10 patients had impaired LV relaxation (grade I diastolic dysfunction) by echocardiographic criteria, with redistribution of the LV fi lling from early to late diastole.…”

“…pressure gradient, 15,16 leading to decrease in LV compliance. 1,2,14,[17][18][19] Other causes include an increase in RV tension that leads to prolonged RV myocardial shortening with abnormal relaxation of the interventricular septum that impairs RV systole and LV diastole, 1,20 decrease in LV torsion, 21 delay in early diastolic LV untwisting, 22 reduction in the preload, 4,5,21 diastolic asynchrony in the anterior-lateral or apical regions, 23,24 and intrinsic disease of the left ventricle. [25][26][27] In our study, as well as others, 2,14 septal displacement (measured as eccentricity index) was predominantly observed in systole and early diastole, possible decreasing LV compliance and explaining impaired LV relaxation.…”

“…[1][2][3] Little is known, however, about its association with severity of disease and outcomes in patients with idiopathic or heritable PAH, since most of the studies were done on subjects with chronic thromboembolic disease or included a heterogeneous group of patients with PAH.…”

“…Impaired LV relaxation in PAH is commonly attributed to decreased LV compliance as a result of right-to-left interventricular septal displacement 1,2 or reduced LV preload. 4,5 Studies comparing echocardiographic with hemodynamic data have noted an association between the degree of PAH and the presence of LV diastolic dysfunction, 3,6,7 but limited information exists about the prognostic value of param eters that measure LV diastolic function.…”

Indexes of diastolic RV function: load dependence and changes after chronic RV pressure overload in lambs

“…Impaired diastolic function may precede systolic ventricular dysfunction (13,14), and it influences the performance of the contralateral ventricle via ventricular interdependence (23,34,39). The gold standard for determination of right ventricular (RV) [and left ventricular (LV)] diastolic function is still considered to be cardiac catheterization with simultaneous high-fidelity pressure and volume measurements (32).…”