[Malignant ventricular hyperkinetic arrhythmias. Classificational criteria: review of Lown's classification. Polycentric study].

Although Lown grading system of ventricular premature complexes (VPCs) has important conceptual shortcomings and has shown severe limitations in either cross-sectional or longitudinal studies, this classification is still the most well-known and used method to characterize the arrhythmologic ventricular pattern of the individual patient. We have looked at a modification of VPCs Lown grading scheme to correct the defects and to make the use of the classification more accurate. Our proposal is based on maintenance of 5 classes--similar to those of Lown original classification--to which we have assigned a score from 0 to 60. We have also introduced many sub-classes, each with a definite score, to better characterize the type of arrhythmic event. The sum of the score of the highest class and the score of every subclass furnishes the final score. This score is a direct index of the importance of the ventricular arrhythmias and seems to be useful for statistical evaluation of the anti-arrhythmic therapy and for follow-up studies, as confirmed by preliminary clinical results obtained through the use of this new VPCs classification.