Antiarrhythmic Therapy for Atrial Septal Defect in Adults: A Mini-Review

The small number of published articles concerning antiarrhythmic therapy against the background of ASD is noteworthy: in total, only 22 articles were published during the studied period of time. If we consider the number of publications on antiarrhythmic therapy for CHD in general, their number increases to 283, but still remains small.

At the same time, the overwhelming majority of papers were not included in this analysis due to the inconsistency of the request and purpose of the study on the fundamentally important points: publications often referred to pediatric patients or patients with other cardiovascular pathology. Also, a significant part of the authors note the low level of evidence of these works, because the approach to pharmacotherapy of arrhythmias in patients with CHD is highly individualized and rarely fits into the generally accepted algorithms of arrhythmia treatment [10].

It is known that the very fact of surgical correction of the malformation acts as a substrate for future arrhythmias and increases the risk of their occurrence, since scar tissue is formed in the area of surgical intervention, the conductivity of which differs from that of intact cardiomyocytes [11, 12, 13].

The choice of drugs for the treatment of arrhythmias on the background of ASD in adult patients is extremely limited and, alas, is often not characterized by high efficacy [14].

Amiodarone is one of the most studied drugs for the treatment of arrhythmias in CHD, in particular, ASD. It shows some of the best results within the rhythm control strategy, but its toxicity during long-term administration is a significant limitation in its use [10, 11, 14, 15]. Dronedarone may be a less toxic alternative to amiodarone, but its efficacy in associated CHD requires further study [16]. Another class III antiarrhythmic drug, dofetilide, has similar but even scarcer data [14].

The role of beta-blockers in the treatment of arrhythmias against CHD background is defined as positive, but as monotherapy the efficacy is insufficient [14, 17]. So, sotalol shows relatively good results comparable to amiodarone within the rhythm control strategy, but studies show shorter-term retention of sinus rhythm. [11, 14, 18]. Relating the difference in the number of side effects from long-term use of these drugs, the advantage of sotalol is undeniable [10, 18].

The efficacy of IC class antiarrhythmic drugs is currently insufficiently studied, which shows the importance of continuing studies of this group of drugs in the treatment of arrhythmias in the background of ASD and other ACHD. Flecainide and propafenone are contraindicated in structural heart disease, which limits their use in a large number of patients with ACHD. Nevertheless, there are data on the potential benefit of these drugs against the background of an implantable cardioverter-defibrillator [11, 14].

Non-dihydropyridine calcium channel antagonists in general can be recommended for the control of arrhythmias against the background of ASD, but it is necessary to evaluate the systemic ventricular function beforehand. If its dysfunction is detected, this group of drugs is inapplicable due to decreased myocardial contractility [14]. No works devoted separately to calcium channel blockers for arrhythmias management against the background of ASD have been published for the last 5 years.

But not only antiarrhythmic therapy itself can positively affect the course of arrhythmia. A team of authors from Canada and France published a paper in 2021, where the relationship between rhythm disturbances and heart failure on the background of CHD was established: in addition to the fact that arrhythmias themselves can lead to heart failure, as well as uncorrected heart failure leads to the development of arrhythmias due to structural (fibrosis, dilatation of chambers, myocardial hypertrophy, for example) and electrical remodeling effects. This fact shows the indirect influence of successful heart failure therapy on the course and drug control of arrhythmias, and, consequently, its greater effectiveness [14, 19].