The link between left atrial mechanics and the pulmonary circulatory-right ventricular uncouplings in acute decompensated heart failure

Abstract

Abstract Background The worsening of right ventricular (RV) function and its uncoupling to pulmonary circulation (Pc) represents a turning point in terms of clinical outcome in heart failure (HF) patients. Relate to this In this context, the deterioration of Left Atrial (LA) function, which physiologically act as a watershed between the LV and the right heart cavities, favors the development of pulmonary venous congestion and vascular remodeling, triggering congestion. This is most apparent in the setting of Acute Decompensated Heart Failure (ADHF), where LA dysfunction unmask pulmonary capillary hypertension. The link between the acute changes in LA dynamics and the adaptive/maladaptive hemodynamic RV-to-Pc coupling is not defined in the acute decompensated (AD) HF. Purpose To investigate, in a cohort of ADHF patients, the association between the degree of RV-to-Pc uncoupling, assessed by the ratio between tricuspid annular plane systolic excursion (TAPSE) to pulmonary artery systolic pressure (PASP), and LA mechanics, evaluated with Speckle Tracking Echocardiography (STE). Methods Eighty-five ADHF patients (mean age 75.6±10.4 years, 59% males) were prospectively enrolled within 24 hours from admission to the Emergency Department. In the acute phase all patients underwent cardiac echocardiography and laboratory blood testing. Patients were then stratified in tertiles according to TAPSE/PASP ratio (group I: <0.4 mm/mmHg; group II: 0.4 to 0.6 mm/mmHg and group III: >0.6 mm/mmHg) correlating the degree of RV-to-Pc with LA mechanics. LA function was evaluated analyzing LA strain at peak relaxation and STE analysis was performed offline. Results At baseline, patients exhibited a high prevalence of RV dysfunction, increased PASP and an impairment in terms of RV coupling to PC (average TAPSE/PASP at admission: 0.44±0.18 mm/mmHg). When stratified in tertiles according to TAPSE/PASP ratio (group I: <0.4 mm/mmHg; group II: 0.4 to 0.6 mm/mmHg and group III: >0.6 mm/mmHg), exhibited an exponential direct relationship between LA-Strain values at admission, with levels increasing progressively with the increment of the ratio (Figure 1). A linear correlation between the degree of RV-to-Pc uncoupling and a more severely depressed LA functioning was noticed (r=0.4, CI 95% 0.21–0.57; p<0.001) (Figure 2). Conclusions In ADHF, there is a strong association between RV to Pc uncoupling and echo-derived measures of LA mechanics. These data underscore the importance to detect and treating the LA mechanical properties to blunt the negative repercussions on the right heart ultimately impacting on the clinical evolution. Funding Acknowledgement Type of funding sources: None.