title: The systolic to diastolic duration ratio in children with heart failure secondary to restrictive cardiomyopathy.
abstract: Systole (S) and diastole (D) are fundamental to cardiac function, yet their durations are not routinely evaluated. We defined the S/D duration ratio in 11 children with restrictive cardiomyopathy (CM) and 31 control subjects, using tricuspid regurgitant flow duration. We correlated S/D ratio, S duration, and D duration with heart rate and compared groups. Heart rates of control subjects and patients with restrictive CM were similar (P = .995). The S/D ratio was higher in patients with restrictive CM than in control subjects (1.6 +/- 0.81 vs 0.8 +/- 0.19, P < .001) as a result of shortened D (0.43 +/- 0.13 vs 0.56 +/- 0.06, P < .01) and prolonged S (0.58 +/- 0.12 vs 0.44 +/- 0.06, P < .01). The S/D ratio was highly correlated to heart rate in restrictive CM (r = 0.95, P < .0001). The high S/D ratio found in restrictive CM, found also in dilated CM, suggests that this index is generic to heart failure rather than to a specific disease. The S/D ratio is easily measured using Doppler flow, enhancing echocardiographic assessment of D function in children.
authors.affiliation: Division of Pediatric Cardiology, Department of Pediatrics, Lucille Packard Children's Hospital and Stanford University, Stanford, California, USA.
authors.forename: Mark K
authors.initials: MK
authors.lastname: Friedberg
authors.forename: Norman H
authors.initials: NH
authors.lastname: Silverman
mesh_terms: D002313:Cardiomyopathy, Restrictive / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D003971:Diastole; D015150:Echocardiography, Doppler / Q000379:methods*; D005260:Female; D006333:Heart Failure / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008297:Male; D012189:Retrospective Studies; D013599:Systole