The purpose of the present study mainly aimed to evaluate whether thrombolysis and heparin anticoagulation for acute pulmonary thromboembolism (PTE) could improve the abnormal left ventricular diastolic filling induced by acute PTE. A total of 71 acute PTE patients (36 males and 35 females; age 64 ± 13 years, range 24 - 87 years) admitted to the emergency intensive care unit of Beijing Anzhen Hospital were consecutively recruited from January of 2006 to June of 2011. Fifty-one age-and gender-matched healthy controls (29 males and 22 females, age 61 ± 9 years, range 31 - 79 years) were also recruited from Health Center during the same period of time. PTE patients were classified into 2 treatment subgroups according to initial therapy, thrombolysis subgroup (n = 37) and direct anticoagulation subgroup with heparin (n = 34). Pre- and post-treatment, trans-thoracic Doppler echocardiography was used to assess left ventricular diameters and diastolic filling patterns. Trans-mitral flow velocities including early (E) and late atrial (A) filling velocities were measured, and E/A ratio was calculated reflecting the relative contribution of early and atrial filling. Compared with healthy controls, patients with acute PTE had significantly smaller left ventricular end-diastolic diameter (t = 3.629, P < 0.001), lower mitral E velocity and E/A ratio (t = 5.296, 6.510, both P < 0.001), and higher A velocity (t = 3.065, P < 0.01). After initial treatment including thrombolysis and direct anticoagulation with heparin for all patients with acute PTE, left ventricular end-diastolic diameter and end-systolic diameter were enlarged significantly (t = 5.284, 3.983, both P < 0.001), and mitral E velocity and E/A ratio were increased significantly (t = 3.452, 2.604, P < 0.05, respectively). Subgroup analysis revealed that, both thrombolytic therapy and anticoagulation with heparin could significantly enlarge left ventricular end-diastolic diameter (t = 4.145, 3.269, respectively) and end-systolic diameter (t = 4.145, 3.269, respectively, all P < 0.050), and increase mitral E velocity (t = 2.505, 2.492, P < 0.05, respectively). Compared with healthy controls, even after initial treatment with thrombolysis or heparin anticoagulation, PTE patients still showed lower mitral E velocity and E/A ratio (t = 2.615, 3.837, P < 0.05, respectively), and higher A velocity (t = 3.290, P < 0.01). The results strongly suggest that initial treatment for acute PTE with thrombolysis and heparin anticoagulation could improve the abnormal left ventricular diastolic filling induced by acute PTE.