Cardiovascular abnormalities are common in patients with ADPKD. Several studies demonstrated a specific bi-ventricular diastolic dysfunction in young normotensive ADPKD patients. The diastolic untwisting motion of the left ventricular (LV) along its longitudinal axis is emerging as an important, sensitive parameter of LV diastolic function. Recently developed two-dimensional speckle tracking echocardiography has been validated as a reproducible, non-invasive technique to quantify LV twist mechanics throughout the whole cardiac cycle.
In this pre-specified, matched-cohort study we explored in 35 ADPKD patients with normal renal function or mild to moderate renal insufficiency from the ALADIN study and in 35-matched controls (no ADPKD), the correlates of LV untwisting rate in this population. Speckle tracking echocardiography analysis was performed on 3 consecutive cardiac cycles. Rotation (degrees) and rotation rate (degrees/sec) profiles in basal and apical short-axis planes were measured. Instantaneous LV twist and twist rate were calculated by subtracting basal rotation from apical rotation and basal rotation rate from apical rotation rate, respectively, at corresponding time points in the cardiac cycle. LV untwisting rate was calculated as the early diastolic negative peak on LV twist rate curve.
As compared to control, ADPKD patients exhibited similar higher LV mass index (p=0.026) left atrium volume (p=0.04) and ratio between mitral early diastolic wave (E) and mitral annulus early diastolic wave (Ea) (p=0.03) and lower global systolic longitudinal strain (p=0.04), peak LV twist (p=0.02) and untwisting rate (p<0.001). At multivariate analysis, LV mass index (B= 0.56, p= 0.045), diastolic BP (B= 1.6, p= 0.033) and LV twist (B=-1.1, p=0.014) resulted significantly associated to untwisting rate. A significant correlation was found between untwisting rate and E/Ea(r=52,P= 0.002).
The present data throw light on the mechanisms of LV diastolic dysfunction in ADPKD patients with preserved renal function and, for the first time, demonstrate a specific subclinical systolic impairment.
