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Anti-arrhythmic agents in ischemic heart disease: supraventricular arrhythmias, digitalis toxicity and chronic stable
Insights
Digoxin effectively manages chronic atrial fibrillation and heart failure ectopic beats. For rapid rate control in arrhythmias, verapamil infusion is preferred, but caution is advised with digitalis toxicity.
Area of Science:
- Cardiology
- Pharmacology
Background:
- Digoxin is a key treatment for chronic atrial fibrillation and heart failure-related ectopic beats.
- Rapid ventricular rate control in arrhythmias like atrial fibrillation requires specific pharmacological interventions.
Purpose of the Study:
- To outline the appropriate use of various antiarrhythmic agents.
- To differentiate treatment strategies based on specific arrhythmias and patient conditions, including digitalis toxicity.
Main Methods:
- Review of current pharmacological approaches for managing cardiac arrhythmias.
- Discussion of drug choices for chronic management versus acute rate control.
- Consideration of specific scenarios like digitalis toxicity and contraindications.
Main Results:
- Verapamil infusion is the primary choice for rapid ventricular rate control in atrial fibrillation, flutter, and paroxysmal atrial tachycardia.
- In digitalis toxicity, lignocaine or phenytoin are indicated for ventricular arrhythmias and A-V block, respectively.
- Beta-blockade is beneficial for anxiety-associated ectopic beats, angina, or hypertension, with contraindications including heart failure or asthma.
Conclusions:
- Drug selection for arrhythmias depends on the specific condition, urgency, and patient's overall health status.
- Careful consideration of potential drug interactions and contraindications, such as digitalis toxicity and beta-blockade limitations, is crucial for effective treatment.
Abstract:
Digoxin remains a very useful agent for chronic atrial fibrillation or for the ectopic beats associated with heart failure. But when rapid control of the ventricular rate is required to arrhythmias such as atrial fibrillation, atrial flutter, or paroxysmal atrial tachycardia, a slow infusion of verapamil is the agent of choice. In general, verapamil may be added to digoxin or given intravenously while a digoxin effect is awaited, unless there is digitalis toxicity. In digitalis toxicity, lignocaine remains the agent of choice for ventricular arrhythmias, and is given in the same doses as for acute myocardial infarction; phenytoin is used for digitalis-arrhythmias with A-V block. Verapamil may be infused very cautiously for digitalis-induced supraventricular tachyarrhythmias. The use of oral agents such as quinidine, disopyramide and mexilitene for chronic prophylaxis of ventricular ectopic beats is of doubtful effectiveness, unless the ectopic activity is symptomatic. Serious ventricular arrhythmias may be induced by quinidine and disopyramide. Beta-blockade is especially useful for ectopic beats associated with anxiety, or when arrhythmias are associated with angina of effort or hypertension. As always, major contraindications to the use of beta-blockade include cardiomegaly, heart failure or asthma.