Detection of sequential activation of left atrium and coronary sinus musculature in the general population

Abstract

BackgroundThe direction of impulse propagation across the coronary sinus (CS) musculature (CSM) is an important piece of the mechanistic puzzle underlying atrial tachyarrhythmias. We hypothesized that in the general population, the sequence of left atrial (LA) to CSM electrograms recorded in the CS reflects the direction of impulse propagation over the CSM.MethodsWe studied 19 patients with atrioventricular (AV) reentrant tachycardia (RT) utilizing a left-sided accessory pathway (AP) and 21 patients with typical counterclockwise atrial flutter (AFL). Conduction through the CSM during AVRT and AFL is from the left atrial (LA) to the right atrial (RA) and from the RA to LA direction, respectively. CS recordings of retrograde conduction over the AP and of AFL were analyzed in search of far-field, LA potentials.ResultsAmong 19 patients with AP, LA potentials were visible in 7 (37%), all in an LA → CSM activation sequence, while among the 21 patients with AFL, LA potentials were visible in 14 (67%), all in a CSM-LA activation sequence (P<0.0001). The prevalence of LA potentials was similar between both study groups (P=0.1119), and the overall prevalence was 53%.ConclusionsFar-field LA potentials are often recorded in the CS during sequential LA and CSM activation in the general population. The timing of LA potentials in CS recordings reflected the direction of conduction across the CSM.

Electrogram recording and analyzing techniques to optimize selection of target sites for ablation of cardiac arrhythmias

“…Similar in this respect are overlaying structures as present at the coronary sinus (CS). Atrial tissue overlays the CS, but is electrically isolated from the CS at most sites by adipose tissue . Recordings made from sites in the CS reveal deflections from atrial tissue and myocardium in the CS.…”

“…Atrial tissue overlays the CS, but is electrically isolated from the CS at most sites by adipose tissue. 14 Recordings made from sites in the CS reveal deflections from atrial tissue and myocardium in the CS. Distinguishing remote from local activity may be difficult in such overlaying structures because activation in the two tissues is very close together and both deflections can be sharp.…”

A cavotricuspid isthmus dependent flutter with an unexpected left atrial activation sequence: A case report

“…The left atrial activation has not been systematically evaluated but is re ected by the CS recordings. [9,10] Three patterns of the CS activation in CC and C atrial utter were described: proximal to distal, distal to proximal and a fused pattern. A typical atrial utter is normally associated with a proximal to distal CS activation.…”

Convergent Double Coronary Sinus Potentials During Atrial Tachycardia

“…Until recently, most clinical electrophysiologists believed that CS electrograms strictly reflect the LA activation. 2 Indeed, the CS constitutes the fifth chamber of the heart, and the recordings from catheters within the CS have near-field (NF) CS muscle signals. However, the recognition of far-field (FF) LA potentials distinct from the NF potentials of the CS muscle has increased after some detailed human anatomical and histopathological studies revealed a distinct spatial relationship and muscular connections between the CS muscularity and the LA myocardium.…”

“… 9 Although the local NF CS signal is usually used as a surrogate for the adjacent LA FF signals during mapping from the CS, 10 careful signal analysis and discrimination of the local NF CS from the FF-LA potentials might be necessary for some complex situations. 2 During ablation of left-sided atrioventricular re-entrant tachycardias, the separated DP of the atrial electrograms in the CS may suggest the connection of the MI inside the CS (epicardial connection) despite the conduction block in the LA (endocardial conduction block). 11 – 14 While the sharp potentials (NF components of the CS) demonstrate persistent conduction through the MI, the dull potentials of the FF component indicate the conduction block of the MI in the LA.…”