Fig. 1From: The usefulness of proximal anchor balloon technique during implantation of a cardiac resynchronization therapy device in a patient with complex coronary venous anatomy: a case reportTwelve-lead ECG (25Â mm/s) showing sinus rhythm and left bundle branch block with a QRS duration of 160Â ms before cardiac resynchronization therapy (Pre) and marked narrowing of the QRS (110Â ms) upon implantation of a cardiac resynchronization therapy (Post)Back to article page