The Large Right Heart Is Associated with the Prolongation of the Procedure Time of Leadless Pacemaker Implantation

Round 1

Reviewer 1 Report

I would like to complement the authors about the interesting idea of studying the relationship between baseline structural heart abnormalities and the difficulties in implanting the leadless pacemaker.

The manuscript is well written especially the introduction, methods, and results. 

The discussion had some grammar issues. I think the part between lines 131 to 136 need to be rephrased.

Line 134: please clarify what do you mean by longer procedure time is associated with reduced quality of life?

The number of patients is very small to draw a conclusion as the authors indicated in line 168. I suggest softening the language of the conclusion to indicate the limited size of the sample and suggest larger number of patients evaluation.

It will be helpful to include other factors that might played a role in difficulty of MICRA implantation. I suggest evaluating for tricuspid valve regurgitation and pulmonary HTN in these patients.

The author indicated the total procedure time. Is there a way to break down the different parts of the procedure durations? Sometimes vascular access can be lengthy and problematic in MICRA implantation, and it is not related to deployment issues. I think, if the data is available, it will be a good contribution.  

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

Well written paper. It would be important to know the operator's degree of skill performing the procedure eg > x years in practice etc. Is this an academic institution? If so , how do you know a trainee wasn't the cause of the longer procedure time. This should be explained. 

The measurements in the 'right heart parameters and procedure times' section should be describe which echo society guidelines were followed to obtain the measurements. 

The readers are left wondering if imaging other than fluoroscopy was used during the procedure, eg surface echo or ICE or TEE, to help guide the catheter position.  Please explain what the role of this could be and how it may improve procedural time. 

Although procedural time was long, the authors don't really elaborate on what downside that has other than radiation exposure. This should be explained in further detail. There are obviously several benefits to a leadless pacemaker, and just because the duration is longer, doesn't necessarioly mean to abort the procedure. Where is the data that supports that a prolonged procedure time is associated with a poor or worse outcome. 

Please explain or show in a graph how many of the prolonged procedure time implants were successful vs not in the end. 

On page 8 there is mention of Table4. I do not see a Table 4. 

 

 

 

 

Author Response

Please see the attachment.

Author Response File: Author Response.docx