Combination antiarrhythmic treatment among class Ia, Ib, and II agents for ventricular arrhythmias

Abstract

The possibility that a magnesium deficiency might be the underlying cause of vasospastic angina (VA) and the efficacy of Mg administration in its treatment were studied. Subjects included 15 patients with VA and 18 healthy subjects as the control group. The erythrocyte Mg content was measured by atomic absorption, and serum Mg was measured by conventional chemical assay. The efficacy of Mg administration was studied in seven patients with VA. The results were as follows: a) The mean erythrocyte Mg content was less in the group with frequent episodes of angina (1.59 +/- 0.11 mg/dl) than in the group without angina (2.11 +/- 0.38 mg/dl, p less than 0.01) and in the control group (2.22 +/- 0.29 mg/dl, p less than 0.01). There was no significant difference between the control group and patients of each group with respect to serum Mg. b) Coronary arterial spasm was induced by ergonovine maleate in seven patients and was completely inhibited by the administration of Mg sulfate (40-80 mEq, hourly) in six of these patients; in the remaining patient neither obvious ST change nor chest pain occurred. Thus, it was concluded that the measurement of erythrocyte Mg content is useful to determine how easily vasospasm might occur in VA and that the administration of Mg might be developed as a new therapy for spasm associated with a low erythrocyte Mg content.

Effectiveness and safety of mexiletine in patients at risk for (recurrent) ventricular arrhythmias: a systematic review

“…In 40 (18%) studies, worsening or not worsening of arrhythmias is actively mentioned. 27 , 31 , 34 , 38 , 39 , 41 , 50 , 54 , 55 , 57 , 58 , 60 , 62 , 64 , 68 , 75 , 76 , 85 , 87 , 90 , 106 , 118 , 128 , 129 , 138 , 141 , 151 , 154 , 161 , 164 , 166 , 174 , 175 , 183 , 201 , 207–209 , 213 , 218 In total, in this subset of 40 studies, in 137 of 2173 (6.3%) patients, the arrhythmia worsened after start of mexiletine.…”

Prevention of ventricular extrasystole by mexiletine in patients with normal QT intervals is associated with a reduction of transmural dispersion of repolarization

“…the mean value at RR ranging from 500 to 599 ms was calculated and assigned as the value at RR of 600 ms). Mexiletine was considered effective when it suppressed N75% of the total PVC in each patient [14].…”