CLINICAL IMPLICATIONS OF PLEOMORPHIC VENTRICULAR TACHYCARDIAS ON ORALSOTALOL THERAPY

In 90 consecutive patients with coronary artery disease and sustained monomorphic ventricular tachycardia, who were treated with oral sotalo l and underwent programmed stimulation to determine drug effectiveness , the influence of sotalol on induced ventricular tachycardia morpholo gy was retrospectively examined. In 54 patients (60%) sotalol rendered the tachycardia non-inducible. However; contrary to drug-testing with class I antiarrhythmic agents, induction of multiple morphologies at baseline study did not predict failure of subsequent drug-testing with sotalol. In the remaining 36 patients (40%), in whom sotalol did not modify inducibility, 21 patients (ie. a total of 23%) manifested at le ast one new morphology during electropharmacological testing on sotalo l. This effect was independent of rite degree of left ventricular dysf unction, infarct location and numbers of morphologies at baseline, but corresponded with drug-induced changes in refractoriness. This observ ation may be related to a proarrhythmic effect of sotalol. Slowing of ventricular tachycardia rate and changes in morphology may have implic ations in patients receiving implantable cardioverter-defibrillators o r those undergoing ablative procedures.