What type of triggers include muscle bundles in the superior vena cava (SVC) and the muscular structure of the coronary sinus (CS)?

Triggers that include muscle bundles in the superior vena cava (SVC) and the muscular structure of the coronary sinus (CS) are classified as non-PV triggers. Atrial fibrillation can originate from various ectopic foci, and while pulmonary veins (PVs) are well-known sources of ectopic activity, non-PV triggers can also play a significant role in initiating episodes of atrial fibrillation. Non-PV triggers often comprise structures that have intrinsic myocardial tissue capable of generating electrical impulses, which is characteristic of the SVC and CS areas. This understanding of non-PV triggers is particularly important in the context of catheter ablation procedures, where identification and isolation of these foci are key to successful treatment.

In contrast, triggers from pulmonary veins focus primarily on the ectopic foci located specifically within the veins themselves. Focal triggers refer to localized sources of electrical activity, which can include both PV and non-PV origins but generally denote a singular point of ectopic firing. Maintenance triggers are related to mechanisms that sustain atrial fibrillation once initiated, rather than initiating the arrhythmia itself. Understanding the distinction between these different types of triggers is crucial for developing effective management strategies for patients with atrial fibrillation.