This study aimed to assess the relationship between different LA strain components and PCWP as well as to the relationship with other established methods. We studied 144 symptomatic patients, age 63 +/- 14 years, 54 males, using conventional transthoracic echocardiography protocols, including LA and LV myocardial deformation from speckle tracking technique investigations along with simultaneous right heart catheterization (RHC) using established techniques. From RHC, pulmonary artery pressure (PAP), and pulmonary capillary wedge pressure (PCWP) were measured and pulmonary vascular resistance (PVR) calculated. LA strain rate during atrial contraction (LASRa) was the strongest correlate with PCWP (r(2) = - 0.40, p < 0.001), over and above both LASR during LV systole (LASRs) and LA longitudinal strain during ventricular systole (LASs) (r(2) = 0.21 and 0.19, respectively, p < 0.001 for both). The correlation between LASRa and PCWP was stronger in patients with post-capillary PH compared to pre-capillary PH (r(2) = 0.21 vs. r(2) = 0.02, respectively). The strongest relationship between LASRa and PCWP was in patients with enlarged LA volume > 34 ml/m(2) (r(2) = 0.60, p < 0.001). In all patients LASRa < = 0.9 1/s was 88% accurate in predicting LA pressure > 15 mmHg which was superior to recently proposed uni- and multi-variable models. LASR during atrial contraction is the strongest predictor of PCWP, particularly in patients with post-capillary PH and with dilated LA cavity. Furthermore, it proved superior to recently proposed uni- and multi-variable based algorithms. Its close relationship with LV strain rate counterpart reflects important left heart chamber interaction in patients with raised LA pressure.