Pericardiocentesis is not routinely recommended in most patients with pericardial effusion (PE), except for patients with cardiac tamponade. However, the long-term follow-up results in patients with clinically not significant PE are few.

Sixty-five consecutive patients (mean age:57 yrs, 26 males) out of 87 patients with PE, who were clinically not serious, were studied prospectively once in every two month for mean 6 months (2-12 months) without any specific treatment. The amount of PE was measured at the enddiastole period of parasternal long axis view and apical four chamber view.

The incidence of insignificant PE in our echocardiographic laboratory is 3.4% (n=87 from 2461). The maximal accumulation site of PE was posterior (n=51, 79%). The next is anterior (n=11, 17%) and right ventricular side (3, 5%). The amount of PE is less (0.37±0.17cm vs 0.64±0.54cm, p=0.018) in localized PE (n=24, 37%) than that of diffuse form (n=41, 63%), which spreads to more than 2 chambers. The presumptive etiologies of PE were unknown (n=41), heart failure (n=5), myocardial infarction (n=6), viral (n=3), and others (n=10). The amount of PE was decreased from 0.54±0.46 cm to 0.30±0.26 cm, 0.23±0.24 cm, and 0.21±0.23 cm 2, 4, and 6 months after intial evaluation, respectively, without any complication.

The patients with PE, not combining >KERN=<with cardiac tamponade, can be followed by regular echocardiographic examination without any specific treatment.