title: Inter-institutional variation of systolic time intervals in normal subjects.
abstract: The study was designed to evaluate inter-institutional variability in systolic time interval (STI) measurement. STI records were obtained from 8 institutions in Czechoslovakia. Altogether 262 normal subjects of both sexes were evaluated. The conclusions of three independent investigators were compared for inter-observer variability assessment. No significant differences were found among the participating centres for electromechanical systole, left ventricular ejection time and pre-ejection time dependence on heart rate and for ratio preejection time-left ventricular ejection time. The regression equations obtained for these indicators were suggested as a national standard for normal subjects.
mesh_terms: D000328:Adult; D003604:Czechoslovakia; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D012016:Reference Values; D012044:Regression Analysis; D013318:Stroke Volume; D013599:Systole