title: Disopyramide: a promising new approach to the medical treatment of the hypercyanotic spell complicating tetralogy of Fallot.
abstract: Under continuous ECG and oxygen saturation (SpO2) monitoring, the following measurements were taken by Doppler echocardiography in 6 consecutive patients with tetralogy of Fallot (TF) before and after intravenous administration of disopyramide (2mg/kg): left ventricular shortening fraction (LVSF); peak velocities in the right ventricular outflow tract (RVOT); diastolic and systolic internal diameters of the right ventricular outflow tract (dRVOT, sRVOT); and systolic blood pressure. SpO2 increased (p<0.01) from 78 to 98 (89 +/- 7, mean +/- standard deviation)% to 86-99 (94 +/- 5)%. LVSF decreased (p<0.05) from 0.34-0.56 (0.42 +/- 0.08) to 0.22-0.54 (0.33 +/- 0.13). The systolic blood pressure fell slightly (p<0.05) from 68-92 (79 +/- 8) to 64-92 (71 +/- 11)mmHg. The sRVOT increased (p<0.05) from 2.1-4.8 (2.7 +/- 1.5)mm to 3.0-8.1 (4.9 +/- 2.4)mm, while RVOT peak velocity decreased (p<0.05) from 2.20-4.88 (3.70 +/- 0.97)m/sec to 2.05-4.07 (2.92 +/- 0.72)m/sec. Disopyramide alleviates hypoxia in patients of TF through its negative inotropic action on right ventricular outflow obstruction.
authors.affiliation: Department of Pediatrics, Sapporo Medical University School of Medicine, Japan. tomitah@sapmed.ac.jp
authors.forename: H
authors.initials: H
authors.lastname: Tomita
authors.forename: S
authors.initials: S
authors.lastname: Fuse
authors.forename: K
authors.initials: K
authors.lastname: Hatakeyama
authors.forename: M
authors.initials: M
authors.lastname: Suzuki
authors.forename: S
authors.initials: S
authors.lastname: Chiba
mesh_terms: D001783:Blood Flow Velocity / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D002675:Child, Preschool; D003490:Cyanosis / Q000188:drug therapy* / Q000209:etiology* / Q000503:physiopathology; D004206:Disopyramide / Q000627:therapeutic use*; D015150:Echocardiography, Doppler; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging; D006801:Humans; D007223:Infant; D008297:Male; D013771:Tetralogy of Fallot / Q000150:complications* / Q000000981:diagnostic imaging / Q000503:physiopathology; D016276:Ventricular Function / Q000187:drug effects*
chemical_list: D004206:Disopyramide