A left lateral wall accessory-pathway tachycardia displays which coronary sinus activation pattern during tachycardia?

A left lateral wall accessory-pathway tachycardia displays which coronary sinus activation pattern during tachycardia?

• A. Distal CS to Proximal CS to His to HRA
• B. Proximal CS to Distal CS to His to HRA
• C. His to Proximal CS to Distal CS to HRA
• D. HRA to His to Distal CS to Proximal CS

Answer: (A)

In left lateral accessory-pathway tachycardia, the retrograde impulse travels from the ventricle back to the atrium via the left lateral pathway anchored on the left atrial lateral wall near the coronary sinus. Because the distal coronary sinus overlies that left-lateral insertion, the earliest atrial activation during tachycardia is recorded at the distal CS. From there, activation spreads proximally along the coronary sinus as the left atrium is activated, then reaches the region near the His bundle and finally the high right atrium. This distal-to-proximal CS activation, followed by His and then HRA, is the expected pattern for a left lateral pathway tachycardia.

In left lateral accessory-pathway tachycardia, the retrograde impulse travels from the ventricle back to the atrium via the left lateral pathway anchored on the left atrial lateral wall near the coronary sinus. Because the distal coronary sinus overlies that left-lateral insertion, the earliest atrial activation during tachycardia is recorded at the distal CS. From there, activation spreads proximally along the coronary sinus as the left atrium is activated, then reaches the region near the His bundle and finally the high right atrium. This distal-to-proximal CS activation, followed by His and then HRA, is the expected pattern for a left lateral pathway tachycardia.