Importance of End-Diastolic Rather than End-Systolic Right Atrial Size in Chronic Pulmonary Hypertension

Maximal systolic excursion of the tricuspid annulus is independent of right atrial size and function in chronic pulmonary hypertension

BACKGROUND

Even though the tricuspid annulus (TA) is anatomically and functionally related to right atrioventricular dependence and tricuspid annular plane systolic excursion (TAPSE) is a well-known measure of right ventricular (RV) systolic function, there is paucity of data regarding the potential impact that right atrial (RA) size and function have on TAPSE. Hence, we sought to determine whether RA volumetric and longitudinal measures affect TAPSE in patients with chronic pulmonary hypertension (cPH).

METHODS

In this retrospective study, echocardiographic data from 110 patients were reviewed and the studied population was divided into Group I consisting of 50 patients (50±11 years) without PH and Group II that included 60 patients (55±14 years) with cPH.

RESULTS

Even though RA areas, RA fractional area change, and maximal long-axis length measurements were abnormal in cPH patients, TA tissue Doppler imaging systolic velocity and RV fractional area change were the only useful variables in identifying patients with abnormal TAPSE (P<.0001 and P=.018, respectively). Additionally, TAPSE was independent of all RA measures, left ventricular ejection fraction, and age (P>.05).

CONCLUSIONS

Based on these results, TAPSE does not appear to be influenced by either RA size or function. Additional studies using strain echocardiography to interrogate RA mechanics might now be very useful to advance our understanding of TA motion in cPH patients given recent data showing that RA function accounts for a significantly greater proportion of total right heart function in patients with cPH than in normal subjects.

Echocardiographic Reference Values for Right Atrial Size in Children with and without Atrial Septal Defects or Pulmonary Hypertension

Right atrial (RA) size may become a very useful, easily obtainable, echocardiographic variable in patients with congenital heart disease (CHD) with right-heart dysfunction; however, according studies in children are lacking. We investigated growth-related changes of RA dimensions in healthy children. Moreover, we determined the predictive value of RA variables in both children with secundum atrial septal defect (ASD) and children with pulmonary hypertension (PH) secondary to CHD (PH-CHD). This is a prospective study in 516 healthy children, in 80 children with a secundum ASD (>7 mm superior-inferior dimension), and in 42 children with PH-CHD. We determined three RA variables, i.e., end-systolic major-axis length, end-systolic minor-axis length, and end-systolic area, stratified by age, body weight, length, and surface area. RA end-systolic length and area z scores were increased in children with ASD and PH-CHD when compared to those variables in the healthy control population. Using the Youden Index to determine the best cutoff scores in sex- and age-specific RA dimensions, we observed a sensitivity and specificity up to 94 and 91 %, respectively, in ASD children and 98 and 94 %, respectively, in PH-CHD children. We provide normal values (z scores -2 to +2) for RA size and area in a representative, large pediatric cohort. Enlarged RA variables with scores >+2 were predictive of secundum ASD and PH-CHD. Two-dimensional determination of RA size can identify enlarged RAs in the setting of high volume load (ASD) or pressure load (PH-CHD).