Abstract | OBJECTIVE: To assess the clinical criteria predicting the short and long-term efficacy of propafenone, an agent with class IC antiarrhythmic activity and a broad pharmacological profile. DESIGNS: Prospective study of propafenone at doses of 450 to 900 mg/day during a six week dose titration period (including a placebo phase with two separate 24 Holter recordings). Responders to treatment were followed for one year. PATIENTS: One hundred patients with frequent ventricular arrhythmias (greater than 30 extrasystoles/h) of Lown class III and IVA/B and without evidence of myocardial infarction within the past six months. ANALYSIS: Multivariate regression analysis of spontaneous arrhythmia variability and of different clinical variables to determine the short and long-term efficacy and safety of propafenone. MEASUREMENTS AND MAIN RESULTS:
Propafenone 450 mg/day was effective in 30/100 patients (30%), and at 600 mg/day another 14 responded. The efficacy of propafenone correlated with a low spontaneous arrhythmia variability and, as shown by multivariate analysis, with a lower patient age (p less than 0.05). When the dose was increased to 900 mg/day a further six (12%) patients responded. However, with increasing doses of propafenone, the one year probability of effective treatment decreased from 86% (450 mg/day) to 67% (600 mg/day) and to 44% (900 mg/day). After restudying the patients at three, six, and 12 months and after dose adjustment in 11/44 patients (25%), 31 patients (70%) remained responders. Loss of permanent antiarrhythmic efficacy was best predicted by the initial dose that achieved a response. No patient died suddenly or had arrhythmogenic effects during Holter monitoring. Side effects occurred in 36% of patients but these rarely limited long-term treatment. CONCLUSIONS: A younger age, low spontaneous arrhythmia variability, and particularly a low titration dose were the best predictors of the short and long term efficacy of propafenone. All other responders should have repeated Holter recordings during the first year of treatment.
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Authors | M Zehender, S Hohnloser, A Geibel, A Furtwängler, M Olschewski, T Meinertz, H Just |
Journal | British heart journal
(Br Heart J)
Vol. 67
Issue 6
Pg. 491-7
(Jun 1992)
ISSN: 0007-0769 [Print] England |
PMID | 1622701
(Publication Type: Clinical Trial, Journal Article)
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Chemical References |
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Topics |
- Adult
- Age Factors
- Aged
- Arrhythmias, Cardiac
(drug therapy, etiology)
- Coronary Disease
(complications)
- Drug Administration Schedule
- Electrocardiography, Ambulatory
- Female
- Humans
- Male
- Middle Aged
- Propafenone
(adverse effects, therapeutic use)
- Prospective Studies
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