title: Screening for sinus node dysfunction by analysis of short-term sinus cycle variations on the surface electrocardiogram.
abstract: A new noninvasive screening method for diagnosing sinus node dysfunction (SND) was evaluated. Sinus cycle variations from 1-minute electrocardiograms (ECG) were described by two variables: the variation range around the mean cycle length (percentage) and the maximal change between any two consecutive cycles (milliseconds). SND was diagnosed when both variables were increased. Part 1: Validation of this method against Holter and sinus node recovery time assessment in 69 patients with proven or possible sick sinus syndrome (SSS). Part 2: Application of the method to 60 patients with clinically significant cardiovascular and pulmonary disorders (group 3), but without any pretest suspicion of SND. Part 1: Sinus cycle variations and sinus node recovery times were abnormal in similar proportions, 55% and 63%, respectively. The sensitivities in proven SSS were 72% and 71%, respectively. Sinus node function was concordantly classified in 80% of 64 patients undergoing both tests. When sinus cycle variations were abnormal the probability of a prolonged recovery time was 89%. Part 2: Asymptomatic SND was found in 12% of patients in group 3. Thus, analysis of short-term beat-to-beat variations in the surface ECG has a sensitivity of approximately 70% and a specificity of 100% for diagnosing SND.
authors.affiliation: Department of Cardiology, Karolinska Hospital, Karolinska Institute.
authors.forename: L
authors.initials: L
authors.lastname: Bergfeldt
authors.forename: M
authors.initials: M
authors.lastname: Rosenqvist
authors.forename: H
authors.initials: H
authors.lastname: Vallin
authors.forename: R
authors.initials: R
authors.lastname: Nordlander
authors.forename: H
authors.initials: H
authors.lastname: Aström
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001146:Arrhythmia, Sinus / Q000175:diagnosis / Q000188:drug therapy / Q000503:physiopathology; D016001:Confidence Intervals; D004562:Electrocardiography / Q000187:drug effects / Q000295:instrumentation / Q000379:methods* / Q000706:statistics & numerical data; D015716:Electrocardiography, Ambulatory; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D010507:Periodicity; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D012849:Sinoatrial Node / Q000187:drug effects / Q000503:physiopathology*; D013997:Time Factors