CHARACTERISTICS OF VENTRICULAR PREMATURE CONTRACTIONS AND THEIR CLINICAL COURSE

One hundred patients with frequent (>1,000 beats/day) ventricular prem ature contractions (VPCs) were followed for 4 years. All of the patien ts, except those with non-cardiac death (n=8), were classified into 3 groups based on their outcome. Group A consisted of 29 patients with i diopathic VPCs who survived the study period. Group B consisted of 49 patients with underlying diseases who survived the study period. Group C consisted of 14 patients who suffered cardiac death. There was no s ignificant difference in the daily number of VPCs. However, groups B a nd C had more patients with Lown grade 4a or 4b VPCs than group A. The mean coupling interval was significantly longer in group C than in gr oup A, and the standard deviation of the coupling interval was signifi cantly larger in group C than in group A. Forty patients underwent ser ial Holter monitorings to assess changes in the number of VPCs. VPCs s pontaneously decreased in 13 patients, while the other 27 patients con tinued to have frequent VPCs. Most of these 13 patients were classifie d as Lown grade 2. The results suggest that in patients with frequent VPCs, longer and more varied coupling intervals may predict a poor pro gnosis, and Lown grade 2 may predict a spontaneous regression.