Limiting left-sided catheter dwelling time using 3-D NavX to mark and reaccess the left atrium via prior transseptal puncture site.

Introduction: Ablations requiring transseptal access to the left heart place patients at increased risk for stroke, bleeding, and post-procedural cognitive dysfunction and other complications. Diminishing left atrial catheter dwelling time may decrease these risks. 3-D NavX can be used to facilitate reaccess of transseptal puncture sites to allow catheter removal from the left atrium immediately after ablation, with reaccess through the prior transseptal site if required.

MS/MS of protonated polyproline peptides: the influence of N-terminal protonation on dissociation.

A unique collision-induced dissociation pattern was observed for protonated polyproline peptides of length n in which y(n-2) and/or y(n-4) ions were formed in much higher abundance than any other product ions. Cleavage occurs only at every other amide bond, such that product ions are formed only from the losses of even numbers of proline residues. Exclusive losses of even numbers of proline residues were not observed from sodiated peptides.