Coronary Sinus Ablation Is a Key Player Substrate in Recurrence of Persistent Atrial Fibrillation

Abstract

Atrial fibrillation (AF) is the most frequent atrial arrhythmia. During the last few decades, owing to numerous advancements in the field of electrophysiology, we reached satisfactory outcomes for paroxysmal AF with the help of ablation procedures. But the most challenging type is still persistent AF. The recurrence rate of AF in patients with persistent AF is very high, which shows the inadequacy of pulmonary vein isolation (PVI). Over the last few decades, we have been trying to gain insight into AF mechanisms, and have come to the conclusion that there must be some triggers and substrates other than pulmonary veins. According to many studies, PVI alone is not enough to deal with persistent AF. The purpose of our review is to summarize updates and to clarify the role of coronary sinus (CS) in AF induction and propagation. This review will provide updated knowledge on developmental, histological, and macroscopic anatomical aspects of CS with its role as arrhythmogenic substrate. This review will also inform readers about application of CS in other electrophysiological procedures.

Coronary sinus diverticulum: Importance, function, and treatment

“…In addition to the largest cardiac venous structure, it is an interatrial connection. 6 However, unlike the veins, it has myocardial tissue that is the remnant of left atrial muscles. 7 Although CS has been regarded as a venous structure for a long time, but recently its crucial role was clarified in the pathophysiology of atrial tachyarrhythmia.…”

“…Additional reentry mechanism, probably by the involvement of CS, was proposed. 6 Muscular sleeve, which is around the proximal 25-50 mm of the CS length, connects the two atria. 11 Arrhythmia most likely emerges from these connections.…”

“…19 CS anomalies are, but not limited to, enlarge-ment, absence, atresia of right ostium, and hypoplasia. 6 These anomalies may affect cardiac hemodynamics, which leads to clinical manifestations and requires prompt diagnosis and treatment. However, some others are clinically occult without any obvious symptoms.…”

“…43 Ablation of the CS eliminated focal tachyarrhythmia with CS origin. 6 As CS has anatomic and electrophysiological relationship with atria, origin of multifocal tachyarrhythmia from either atria could be determined. If myocardial part of the CS is the origin, high-frequency higher amplitude component indicates a near-field potential.…”

Gigantic arteriovenous fistula between left coronary cusp and coronary sinus draining into the right atrium

“…CAF are reported to range in size from 2 to 5 mm [3]. They are generally asymptomatic but occasionally cause severe symptoms, including dyspnea, chest pain and palpitations, depending on the severity of the shunt [1][2][3]. They may be treated medically, surgically or by transcatheter closure [3,4].…”