title: Changes in cardiac output determined by continuous-wave Doppler echocardiography during propafenone or mexiletine drug testing.
abstract: Antiarrhythmic drugs may induce congestive heart failure in patients with malignant ventricular arrhythmias and depressed left ventricular (LV) function. Whether Doppler echocardiography can detect drug-induced depression in LV function was assessed. Continuous-wave Doppler measurements of ascending aortic blood flow velocity were obtained in 16 patients while not receiving antiarrhythmic drugs on 2 consecutive days to assess day-to-day variability, as well as while receiving maximally tolerated oral doses of mexiletine (11 patients) and propafenone (9 patients). While receiving propafenone, a drug with moderate negative inotropic activity, peak flow velocity declined by 9 +/- 8% (p less than 0.05), the flow velocity integral (termed stroke distance, representing stroke volume) declined by 8 +/- 11% (p less than 0.10), the rate-corrected stroke distance declined by 9 +/- 8% (p less than 0.02) and the minute distance, representing cardiac output, declined by 10 +/- 12% (p less than 0.05). In contrast, while receiving mexiletine, a drug with minimal negative inotropic activity, none of these parameters changed significantly. Five of 9 patients (56%) treated with propafenone showed a decline in rate-corrected stroke distance exceeding the 95% confidence limit of day-to-day variability, which was +/- 13 percent. Two of these 5 patients developed clinical signs of congestive heart failure. Continuous-wave Doppler echocardiography can detect antiarrhythmic drug-induced LV dysfunction and may be used to anticipate the development of significant clinically overt congestive heart failure.
authors.affiliation: Department of Nutrition, Harvard School of Public Health, Boston, Massachusetts 02115.
authors.forename: H
authors.initials: H
authors.lastname: Lange
authors.forename: S
authors.initials: S
authors.lastname: Lampert
authors.forename: M S
authors.initials: MS
authors.lastname: Sutton
authors.forename: B
authors.initials: B
authors.lastname: Lown
mesh_terms: D002302:Cardiac Output / Q000187:drug effects*; D003864:Depression, Chemical; D015150:Echocardiography, Doppler; D005260:Female; D006333:Heart Failure / Q000139:chemically induced; D006801:Humans; D008297:Male; D008801:Mexiletine / Q000627:therapeutic use / Q000633:toxicity*; D008875:Middle Aged; D011405:Propafenone / Q000627:therapeutic use / Q000633:toxicity*; D013318:Stroke Volume / Q000187:drug effects; D013610:Tachycardia / Q000188:drug therapy
chemical_list: D008801:Mexiletine; D011405:Propafenone