Extensive asymptomatic pulmonary air embolism during CRT-implantation.

This report presents a case of pulmonary air embolism during implantation of a cardiac resynchronisation therapy system. For left ventricular pacing the thinnest available coronary sinus lead was used in association with a standard subclavian vein introducer sheath. It is hypothesised that the difference of size between the small lead diameter and the subclavian vein introducer sheath may have predisposed to air entry into the venous system.