Impaired Left Ventricular Mechanics in Pulmonary Arterial Hypertension

Abstract

P ulmonary arterial hypertension (PAH) is characterized by pulmonary vascular remodeling, right heart failure, and reduced survival.1 Both symptoms and extent of right heart failure predict mortality. [2][3][4] Measures of RV filling pressure and systolic function have been shown to correlate with clinical disease progression and survival. 5-8 Clinical Perspective on p 755Right ventricular (RV) contraction is a complex process related to a variety of actions, the predominant being longitudinal motion because of the arrangement of ventricular myofibrils.9-12 RV systolic strain assessment by speckle-tracking echocardiography is an angle-independent sensitive measure of RV contraction shown to correlate with clinical symptoms and invasive hemodynamic measures and is predictive of disease progression and mortality. [13][14][15][16][17] PAH is a disease of the pulmonary circulation with resultant effects on the right heart. Conceptually, left heart anatomy and function should be normal in patients with PAH. However, the RV and left ventricle (LV) do not function in isolation, sharing a common pericardial sac and interventricular septum. 18 A delayed relaxation mitral inflow Doppler pattern on echocardiography (a feature seen in normal or low filling pressures and diastolic dysfunction) has been linked to severity of disease in PAH; however, it is unclear whether this Doppler pattern reflects impaired LV filling because of reduced RV output or intrinsic LV dysfunction. 19 We sought to define the clinical and prognostic significance of ventricular interdependence Background-Pulmonary arterial hypertension (PAH) is characterized by pulmonary vascular remodeling and right heart failure. The right (RV) and left ventricles (LV) do not function in isolation, sharing a common pericardial sac and interventricular septum. We sought to define the clinical and prognostic significance of ventricular interdependence in PAH and its association with LV filling patterns through speckle-tracking strain echocardiography. Methods and Results-Echocardiography was performed in 71 adults with a new diagnosis of PAH. To analyze LV and RV function separately, we measured peak systolic longitudinal and circumferential strain of the LV and RV. Survival was assessed >2 years. Patients had dilated right-sided chambers (right atrial volume index, 44±19 mL/m 2 ; RV end-diastolic area, 34±9 cm 2 ), and reduced RV function (RV fractional area change, 28±12%). Speckle-tracking echocardiography revealed significant reductions in RV free wall peak systolic strain (−15±3%). Despite normal LV size and normal conventional measures of LV systolic function (end-diastolic dimension, 42±6 mm; ejection fraction, 65±8%; cardiac index, 2.6±0.8 L/min per m 2 ), patients had reduced LV free wall systolic strain (−15±3%). Decreased LV free wall systolic strain was associated with a delayed relaxation mitral inflow Doppler pattern, P=0.0002. During 2-year follow-up, 19 patients (27%) died. LV strain was associated with increased mortality (unadjusted hazard ratio, 2...

Echocardiography in Pediatric Pulmonary Arterial Hypertension

“…Recently, a study on echocardiography in adults with PAH identified reduced systolic strain of the LV-free wall as a predictor of early mortality. 48 The observed correlation of echocardiography with both disease severity and outcome is supported by our finding, in a subgroup, that the echo variables were also associated with hemodynamic measures. The relationship of echocardiographic characterization of the RV with hemodynamics was recently further supported by Di Maria et al, 10 who showed TAPSE and RV-fractional-area-change to be associated with RV-stroke-work, which is a hemodynamic measure integrating information on RV performance and ventricular-vascular coupling.…”

Evaluation of right and left heart mechanics in patients with chronic thromboembolic pulmonary hypertension before and after pulmonary thromboendarterectomy

“…Postoperative improvement of myocardial function due to a prominent decrease in RV load and pressure may be evidence of that mechanism. Previous studies have shown that LV dysfunction is associated with increased mortality and morbidity in patients with PH [24]. In our study, we demonstrated that conventional LV dimensions significantly increased after PTE, although there was no change in LVEF.…”

Signs of Right Ventricular Deterioration in Clinically Stable Patients With Pulmonary Arterial Hypertension

“…Th is may be a result of reduced LV preload, but previous studies have also demonstrated by LV strain imaging that LV contractility and LV torsion are impaired in patients with PAH. 29,31 Furthermore, according to the LV pressure-volume relationship, an increased LVESV is associated with impaired LV contractility.…”