The relation of left ventricular (LV) diastolic filling with the clinical outcome in patients with idiopathic dilated cardiomyopathy (IDC) was examined. LV diastolic filling was assessed by Doppler echocardiography in 57 patients with IDC at the time that the diagnosis was established by angiocardiography. Patients were followed for 29 +/- 16 months. Fifteen patients died: 12 due to progressive congestive heart failure and 3 suddenly. Four other patients underwent cardiac transplantation because of progressive heart failure (1-year survival 86%). Patients who died of congestive heart failure or underwent cardiac transplantation had a steep increase and decrease in the early filling phase as compared with survivors; the peak early Doppler velocity was higher (0.84 +/- 0.16 vs 0.65 +/- 0.21 m/s; p < 0.005), and the deceleration time of the early velocity peak was shorter (117 +/- 26 vs 188 +/- 62 ms; p < 0.001) than in survivors. Surviving patients and those who died suddenly showed similar patterns of LV filling. Deceleration time and peak early Doppler velocity were the strongest predictors of survival as compared with systolic function and clinical status in a Cox proportional-hazards analysis. Patients with a shortened deceleration time (< or = 140 ms) had a significantly reduced 2-year survival rate of 52% (confidence interval 34 to 71%) as compared with those with a longer deceleration time (94%; confidence interval 89 to 98%) (p < 0.001). Evidence was presented for a relation between LV filling and survival in patients with IDC.