Left Ventricular Myocardial Function in Children With Pulmonary Hypertension

Abstract

Background Through ventricular interdependence, pulmonary hypertension (PH) induces left ventricular (LV) dysfunction. We hypothesized that LV strain/strain rate, surrogate measures of myocardial contractility, are reduced in pediatric PH and relate to invasive hemodynamics, right ventricular (RV) strain, and functional measures of PH. Methods and Results At two institutions, echocardiography was prospectively performed in 54 pediatric PH patients during cardiac catheterization, and in 54 matched controls. PH patients had reduced LV global longitudinal strain (LS) (-18.8 [-17.3 - -20.4]% vs. -20.2 [-19.0 - -20.9]%, P=0.0046) predominantly due to reduced basal (-12.9 [-10.8 - -16.3]% vs. -17.9 [-14.5 - -20.7]%, P<0.0001) and mid (-17.5 [-15.5 - -19.0]% vs. -21.1 [-19.1 - -23.0]%, P<0.0001) septal strain. Basal global circumferential strain (CS) was reduced (-18.7 [-15.7 - -22.1]% vs. -20.6 [-19.0 - -22.5]%, P=0.0098), as were septal and free-wall segments. Mid CS was reduced within the free-wall. Strain rates were reduced in similar patterns. “Basal septum” LS, the combined average LS of basal and mid interventricular septal segments, correlated strongly with degree of PH (r=0.66, P<0.0001), pulmonary vascular resistance (r=0.60, P<0.0001), and RV free-wall LS (r=0.64, P<0.0001). Brain natriuretic peptide levels correlated moderately with septal LS (r=0.48, P=0.0038). PH functional class correlated moderately with LV free-wall LS (r=-0.48, P=0.0051). The septum, shared between ventricles and affected by septal shift, was the most affected LV region in PH. Conclusions Pediatric PH patients demonstrate reduced LV strain/strain rate, predominantly within the septum, with relationships to invasive hemodynamics, RV strain, and functional PH measures.

Reference Ranges of Left Ventricular Strain Measures by Two-Dimensional Speckle-Tracking Echocardiography in Children: A Systematic Review and Meta-Analysis

“…70,71 In total, 43 datasets of strain measures from 63 manuscripts of strain measures with 2325 children were considered eligible for assessment in the meta-analysis (Figure 2). 7-49 Forty out of 43 authors (93%) responded and provided either the raw strain data and/or filled in the missing information on study quality and potential sources of variability. The remaining three data sets (7%) from the authors that did not respond via electronic mail were included with the available information provided in their respective manuscripts.…”

“…Forty-one datasets with 2084 patients were eligible for the meta-analysis of GLS or LS ; 7-24,26-34,36-49 26 datasets with 1506 patients were eligible for the meta-analysis of GCS or CS , 7,9,11,12,14-20,23,25,26,28-31,33,34,41-44,46,48 and 15 datasets with 1092 patients were eligible for the meta-analysis of GRS or RS. 11,15,16,19,20,23,25,26,28,29,33,41-43,46 The patient characteristics of the included studies are listed in Table 1.…”

“…All the studies used a deformation imaging acquisition and post-processing protocol. Reproducibility analysis was performed in 32/43 7-10,14-21,23-27,33,35-46,48,49 datasets and referenced in 4/43. 11,30,31,47 …”

Left Ventricular Diastolic Dysfunction in Pediatric Pulmonary Hypertension

“…18 Nevertheless, over-reliance on a single echocardiographic variable and false estimation of RV systolic pressure because of poor CW-Doppler envelopes or severe tricuspid regurgitation can limit the value of the methodology for non-PH experts. 18 More novel, potentially prognostic echocardiographic variables to assess RV/LV geometry/ function and RVP or PAP in pediatric PH include RA size 19,20 ; tricuspid annular plane systolic excursion 21 ; RV outflow tract velocity time integral; trivial tricuspid/RVOT velocity time integral ratio 22 ; pulmonary regurgitation velocity; RV size 20 ; LV size, LV end-systolic eccentricity index, end-systolic and end-diastolic RV/LV ratio 23 ; RV stroke work 24 ; LV strain and strain rate 25 ; RV systolic/diastolic duration ratio 26 ; and pulmonary artery acceleration time (Koestenberger M, MD, unpublished data, 2016). A combination of the above variables can help the clinician avoid some of the pitfalls of the echocardiographic examination at initial diagnosis and serial…”

“…A deformation imaging (speckle tracking) study on the identical cohort of pediatric PH patients had identified decreased systolic LV strain/strain rate, predominantly within the septum, with relationships to invasive hemodynamics, RV strain, and functional PH measures. 25 In the current study, 27 the authors aimed to study the impact of pulmonary hemodynamics and ventricular interdependence on LV diastolic function in pediatric PH. By doing so, they directed their focus beyond RV systolic dysfunction that is known to determine clinical outcome but often is a late finding, particularly in younger patients, and even in those with advanced PAH.…”