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Verapamil in the treatment of atrial tachycardia with block
Insights
Verapamil effectively treats atrial tachycardia (A-T) with block, converting it to sinus rhythm in most patients. However, recurrence is common, suggesting A-T with block may involve atrioventricular nodal reentry.
Area of Science:
- Cardiology
- Electrophysiology
- Pharmacology
Background:
- Atrial tachycardia (A-T) with block frequently recurs after DC shock conversion.
- Current drug treatments for A-T with block are generally unsatisfactory, lacking a definitive drug of choice.
Purpose of the Study:
- To evaluate the efficacy of verapamil in treating atrial tachycardia (A-T) with block.
- To explore the potential mechanism of A-T with block based on verapamil's effects.
Main Methods:
- A study involving 14 patients diagnosed with atrial tachycardia (A-T) with block.
- Administration of verapamil to assess its effect on the arrhythmia and subsequent rhythm.
Main Results:
- Verapamil successfully converted A-T with block to sinus rhythm in 10 out of 14 patients.
- Recurrence of A-T with block was observed in 4 patients post-conversion.
- Optimal response to verapamil was noted in patients with minimal cardiac enlargement and shorter arrhythmia duration.
Conclusions:
- Verapamil demonstrates significant efficacy in managing atrial tachycardia (A-T) with block.
- The findings support the hypothesis that A-T with block may originate from atrioventricular (A-V) nodal reentry.
- Verapamil's mechanism likely involves prolonging the effective refractory period of the A-V node.
Abstract:
Atrial tachycardia (A-T) with block is easily converted as a rule to sinus rhythm by DC shock, but the recurrence rate is high. So far drug treatment of this arrhythmia has been unsatisfactory. There is no drug of choice in the treatment of A-T with block. We report on the effect of verapamil on this arrhythmia in 14 patients. Ten of them reverted to sinus rhythm, but A-T with block later recurred in 4. The best effect was found in patients with no or only minimal heart enlargement and in patients with short duration of the arrhythmia. The effect of verapamil on A-T with block may support the concept of this arrhythmia being due to atrioventricular (A-V) nodal reentry, as the main effect of verapamil is a prolongation of the effective refractory period of the A-V node.