Radiofrequency catheter ablation for the treatment of human type 1 atrial flutter.

Quantitative Sequential Coronary AngiographyI read with interest the recent article by Lichtlen and col- leagues.'I am a great proponent of the development of an international system for quantitative sequential coronary angiography, with a substantial degree of accuracy and repeatability.The clinical and research implications of such a method are vast.At the same time, I must point out to Dr Lichtlen and associates that human panel readings have been the accepted standard of reference for sequential arteriographic readings.Furthermore, the panel readings used in CLAS and in POSCH have been the only method to be documented in a randomized, controlled clinical trial as statistically valid surrogate end points for clinical events.2There is no documented basis for the authors' introductory statement in which they refer to quantitative coronary angiography as the approach that ". ..yields a higher accuracy when comparing the two angiograms years apart than subjective estimates based on score systems."