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Updated: May 4, 2026
Optocardiography and Electrophysiology Studies of Ex Vivo Langendorff-perfused Hearts
Published on: November 7, 2019
Coronary sinus-ventricular accessory connections producing posteroseptal and left posterior accessory pathways:
Yingxian Sun1, Mauricio Arruda, Kenichiro Otomo
1Cardiac Arrhythmia Research Institute and Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City 73104, USA.
Insights
Posteroseptal and left posterior accessory pathways (CSAPs) often originate from the coronary sinus myocardial coat (CSMC) extending into cardiac veins. Most patients with these pathways have a normal-appearing coronary sinus on angiography.
Area of Science:
- Cardiology
- Electrophysiology
- Cardiac Anatomy
Background:
- The coronary sinus (CS) possesses a myocardial coat (CSMC) with connections to both atria.
- Accessory pathways (APs) may arise from CSMC extensions along cardiac veins to the ventricle.
Purpose of the Study:
- To define coronary sinus accessory pathways (CSAPs) using CS angiography and mapping.
- To determine the incidence of CSAPs and their relationship to CS anatomy.
Main Methods:
- Defined CSAP by accessory pathway potential or earliest activation in the middle cardiac vein (MCV) or posterior coronary vein (PCV).
- Utilized CS angiography and electrophysiological mapping in 480 patients undergoing ablation.
Main Results:
- Identified CSAPs in 171 of 480 patients.
- Coronary sinus diverticulum or enlargement was found in 30% of patients; 70% had normal CS anatomy.
- CSMC extension potentials were recorded in 100% of patients with normal CS anatomy, occurring between atrial and accessory pathway potentials.
Conclusions:
- CSAPs result from connections between CSMC extensions along the MCV or PCV and the ventricle.
- The coronary sinus appears angiographically normal in the majority of patients with CSAPs.
Background:
The coronary sinus (CS) has a myocardial coat (CSMC) with extensive connections to the left and right atria. We postulated that some posteroseptal and left posterior accessory pathways (CSAPs) result from connections between a cuff of CSMC extending along the middle cardiac vein (MCV) or posterior coronary vein (PCV) and the ventricle. The purpose of the present study was to use CS angiography and mapping to define and determine the incidence of CSAPs and determine the relationship to CS anatomy.
Methods And Results:
CSAP was defined by accessory pathway (AP) potential or earliest activation in the MCV or PCV and late activation at anular endocardial sites. A CSAP was identified in 171 of 480 patients undergoing ablation of a posteroseptal or left posterior AP. CS angiography revealed a CS diverticulum in 36 (21%) and fusiform or bulbous enlargement of the small cardiac vein, MCV, or CS in 15 (9%) patients. The remaining 120 (70%) patients had an angiographically normal CS. A CSMC extension potential (CSE), like an AP potential, was recorded in the MCV in 98 (82%), in the PCV in 13 (11%), in both the MCV and PCV in 6 (5%), and in the CS in 3 (2%) of 120 patients. CSMC potentials were recorded between the timing of atrial and CSE potentials.
Conclusions:
CSAPs result from a connection between a CSMC extension (along the MCV or PCV) and the ventricle. The CS is angiographically normal in most patients.
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