RT Journal A1 Kronhaus KD T1 DYsrhythmia vs arrhythmia JF JAMA JO JAMA YR 1979 FD January 5 VO 241 IS 1 SP 28 OP 28 DO 10.1001/jama.1979.03290270020009 UL http://dx.doi.org/10.1001/jama.1979.03290270020009 AB To the Editor.—  I commend Jules Constant, MD, for his efforts in trying to organize a more precise nomenclature for cardiology (240:868, 1978). However, I believe he excluded from the "Terms Wrongly Used" section the term "arrhythmia," which indicates an absence of rhythm but too often is applied to any variation from normal rhythm of the heartbeat. In contrast, the term "dysrhythmia" is not limited to irregularities of the heartbeat but also is applied to disturbances of rate and conduction.1 I hope this distinction will be applied.