Abstract 4897: Right Ventricular Diastolic Dysfunction in Upper-normal and Mildly Hypertensives: A Tissue Doppler Imaging Study
Background: Systemic hypertension is known to affect the right ventricle in addition to its wide-ranging effects on left ventricular structure and function. Whether upper-normal increments in systemic blood pressure (BP), sampled by ABPM, exert any effect on right ventricular function is, however, unknown at this point.
Methods: Left (LV) and right ventricular (RV) diastolic longitudinal function were assessed by pulsed-wave TDI sampled at mitral (early:EmMIT and late:AmMIT) and tricuspid (EmTRIC and AmTRIC) annular level in a group of 98 (37F/61M, age: 46 ± 14yrs) otherwise normal subjects with office BP values ranging from the optimal (< 120/80 mmHg) to the mild hypertensive (140–160/90–100 mmHg) range. RV free wall (FWT) and interventricular septum thickness (IVST), LV ejection fraction (EF), TRIC annulus plane systolic excursion (TAPSE, an index of RV systolic function), LV mass index (MI, g/m2.7) were evaluated by standard methods. The sample was stratified by ascending 24-hr systolic(S) BP tertiles (cutoffs:117 and 130 mmHg, I:110 ± 7/68 ± 7, II:125 ± 4/77 ± 7, III:139 ± 7/87 ± 8 mmHg) and analyzed accordingly.
Results: EmTRIC decreased significantly at each increasing 24-hr SBP stratum (I:15.9 ± 2.8, II:12. ± 3.1, III:10.9 ± 3.6 cm/sec, I vs II p < 0.01, II vs III p < 0.01) in parallel with consensual reductions in EmMIT (I:11.1 ± 2.8, II:8.7 ± 2.9, III:8.3 ± 2.6 cm/sec, I vs II & III p < 0.001). RVFWT (I:3.5 ± 0.6, II:4.0 ± 1.1, III:3.6 ± 0.9 mm, NS) and LVMI (I:38.6 ± 8.3, II: 41.3 ± 6.6, III: 43.0 ± 9.1 g/m2.7, NS) did not change in contrast to the graded, BP-related thickeness of IVS (I: 7.9 ± 1.1, II: 9.3 ± 1.25, III: 10.3 ± 1.34 mm, I vs II: p = 0.001, II vs III: p = 0.001). Intra-individually (n = 98), EmTRIC associated with 24-hr SBP (r =−0.52, p < 0.001), IVST (r = −0.63, p < 0.001) and EmMIT (r = 0.41, p < 0.001) but only the two latter (IVST: t = 5.5, p < 0.0001; EmMIT: t = 2.8, p = 0.006) were independent predictors of EmTRIC when entered in a multiple regression model.
Conclusions: Systemic BP increments still within the normal range associate with echocardiographic evidence of RV diastolic longitudinal dysfunction. Interventricular septum thickening appears to be the main determinant of that behavior, possibly as an expression on interventricular dependence.