What is the clinical evidence from this study?

Study design: Case-Control. Population: Pulmonary Hypertension (n=88). Intervention: Right ventricular pressure overload vs. Healthy subjects. Primary outcome: Right ventricular lateral wall longitudinal strain (p=<0.001).

What does this research mean for the field?

Right ventricular pressure overload in pulmonary hypertension significantly reduces right ventricular lateral wall longitudinal strain and alters left ventricular geometry, resulting in impaired left ventricular torsion. Novelty: ClaimNovelty.INCREMENTAL. Consensus alignment: ConsensusAlignment.NEUTRAL.

January 5, 2010Open Access

Ventricular Geometry, Strain, and Rotational Mechanics in Pulmonary Hypertension

Q: What are the key findings of this study?

Right ventricular pressure overload in pulmonary hypertension reduced RV lateral wall longitudinal strain compared to healthy controls (-15.9% vs -25.5%, P<0.001) and impaired LV torsion.

Q: What does this research mean for the field?

Right ventricular pressure overload in pulmonary hypertension significantly reduces right ventricular lateral wall longitudinal strain and alters left ventricular geometry, resulting in impaired left ventricular torsion. Novelty: ClaimNovelty.INCREMENTAL. Consensus alignment: ConsensusAlignment.NEUTRAL.

Key Result

Right ventricular pressure overload in pulmonary hypertension reduced RV lateral wall longitudinal strain compared to healthy controls (-15.9% vs -25.5%, P<0.001) and impaired LV torsion.

Study Design

Type

Case-Control (n=88)

Structured PICO

Does pulmonary hypertension alter right and left ventricular geometry, strain, and rotational mechanics compared to healthy controls?

Population

44 patients with evidence of pulmonary hypertension (estimated pulmonary artery systolic pressure, 71+/-23 mm Hg), age 46+/-12 years, 82% women, excluding intrinsic LV diseases, and 44 age- and gender-matched healthy subjects.

Comparator

44 age- and gender-matched healthy subjects

Outcome

Ventricular geometry, strain (longitudinal and circumferential), and rotational mechanics (torsion, untwisting rates)surrogate

Chronic right ventricular pressure overload in pulmonary hypertension directly impairs RV longitudinal systolic deformation and further alters LV geometry and torsion.

Main Result

Absolute Event Rate: -15.9% vs -25.5%

p-value: p=<0.001

Abstract

BACKGROUND: We tested the hypothesis that right ventricular (RV) pressure overload affects RV function and further influences left ventricular (LV) geometry, which adversely affects LV twist mechanics and segmental function. METHODS AND RESULTS: Echocardiographic images were prospectively acquired in 44 patients (age, 46+/-12 years; 82% women) with evidence of pulmonary hypertension (estimated pulmonary artery systolic pressure, 71+/-23 mm Hg) and in 44 age- and gender-matched healthy subjects. Patients with intrinsic LV diseases were excluded. RV lateral wall longitudinal strain (LS) and interventricular septal (IVS) LS were reduced in the pulmonary hypertension group compared with control subjects (-15.9+/-7.6% versus -25.5+/-6.1%, P<0.001; and -17.3+/-4.4% versus -20.2+/-3.9%, P=0.002, respectively), whereas LV lateral wall LS was preserved. RV lateral wall LS and IVS LS, but not LV lateral wall LS, correlated with pulmonary artery systolic pressure (r=0.56, P<0.01; r=0.32, P<0.01) and LV eccentricity index (r=0.57, P<0.01; r=0.57, P<0.01). IVS and LV lateral wall circumferential strain (CS) were both reduced in the pulmonary hypertension group. Although IVS CS and LV lateral wall CS correlated with pulmonary artery systolic pressure and LV eccentricity index, after adjustment of CS for LV eccentricity index, differences between groups persisted for IVS CS (P<0.01) but not LV lateral wall CS (P=0.09). LV torsion was decreased in patients with pulmonary hypertension compared with control subjects (9.6+/-4.9 degrees versus 14.7+/-4.9 degrees , P<0.001). LV torsion inversely correlated with pulmonary artery systolic pressure (r=-0.39, P<0.01) and LV eccentricity index (r=-0.3, P<0.01). LV untwisting rates were similar in both groups (P=0.7). CONCLUSIONS: Chronic RV pressure overload directly affects RV longitudinal systolic deformation. RV pressure overload further influences IVS and LV geometry, which impairs LV torsion and segmental LS and CS, more for the IVS than for the free wall of the LV.