Clinical Editor's Corner
A Relook at the Transseptal Puncture: Heparin Dosing and Other Top Tips



As we hear from our colleagues, I also asked them to share some their top tips and advice on TSP. I also want to point out several excellent reviews on TSP in the structural heart disease era in the references section.1-3
Zoltan Turi, New Jersey: Having had some unpleasant outcomes with regard to thrombus after transseptal, I tend to be on the aggressive side [re: anticoagulation]. I would have been more comfortable with an ACT in the low to mid 200s, but there’s not much evidence base, just bad experience.

My top tips for TSP: It’s very unusual for me to do TSP without echo guidance, even though that was how we did it for years. Intracardiac echocardiography (ICE) or transesophageal echocardiography (TEE) adds dramatically to the safety margin of the procedure. I would not do TSP while anticoagulated using angiographic landmarks only. In developing countries when neither is available, I usually puncture in the 90-degree lateral view, which allows fairly accurate placement and avoidance of pericardial entry if you are familiar with the x-ray landmarks (and you can stain the fossa with some dye before puncture for additional anatomic information — although I rarely do it, it’s typically quite benign). We used to breathe a sigh of relief once the LA pressure came up on the screen (yes, we always monitor pressure through the needle during TSP), but in 2017, getting across the fossa is not enough — most of the procedures we do in the LA require custom placement of the needle, and precise echo guidance is both essential and relatively simple. As to the ACT, we now compulsively check levels every 30 minutes; the EP folks check levels every 30 minutes and frequently use heparin drips to make sure they don’t let the ACT values fall too low. Finally, you still have to be extra careful to avoid air entering the LA.
Jeffrey Moses, New York: For keeping clots off diagnostic catheters, an ACT of 180-200s [is adequate]. For protracted therapeutic interventions, an ACT of 250s [is my choice].
Chet Rihal, Minnesota: This is a great question and one I get asked frequently. I err on the high side based on (bitter) experience. Most of the TSPs I do are for LA-based structural procedures and are performed with TEE guidance. 2000-4000u heparin is given after venous access to prevent thrombi on Mullins or other TS sheaths. Once in the LA, I like to use 200 u/kg of heparin (operating room-like doses) which keeps the ACT >350s for the duration of most procedures and is effective in preventing thrombi from building up in LA catheters, some of which sit in the LA for prolonged periods. The ACT can be reversed at the end of the procedure if needed. The way I look at it is the cost:benefit ratio. Development of an LA clot can be disastrous, whereas a high ACT for 1-2 hours is well tolerated. Once I went to high-dose heparin, I have not experienced any clots, something I learned from the surgeons.
Matthew Price, California: I agree with Chet. Given modern-day echo guidance, doing TSP while anticoagulated is not a big deal anymore. My approach is 70-100u unfractionated heparin after access in the groin and goal ACT around 300 seconds. If for some reason I am concerned about the transseptal technique, then I give half after venous access (e.g., 3000u) and then the rest after successful crossing. We check ACTs every 15-20 minutes.
My top TSP tips:
2) Don’t puncture if you don’t see the needle tenting the septum on echo. Don’t puncture if you don’t see the needle tenting the septum on echo. Don’t puncture if you don’t see the needle tenting the septum on echo. Repeat. [… I appreciate the emphasis on seeing the needle…]
3) If you are having trouble reaching the septum with the needle, put a little secondary bend proximal to the primary bend — sort of like shaping a coronary wire to get into a bifurcation side branch from a large main vessel.
Jonathan Tobis, California: I wait to give heparin until after I perform the transseptal. I recognize that this has not been studied formally and that the EP people give heparin before crossing the septum. But I am a creature of habit or primary education and I have seen no reason to change. I recognize that now that we do TEE guidance for the transseptals, the risk of puncturing the aorta or the transverse pericardial space is exceedingly unlikely. I measure ACT and keep it about 250s for the procedure.
My top TSP tips: I would emphasize that TEE helps to make the procedure safer and also makes the 3D anatomy more understandable compared to the early days, when fluoro guidance was all that we had. The operator needs to be meticulous, a common request for all interventions, but remember that you have a 3-foot long spear in your hands. Also, you are working in the left atrial side, so you have to be very careful about air embolism. There is also a learning curve of getting the feel of the TS catheter and introducer as it brushes along the curvature of the atrial septum from anterior to posterior, and to slide it down or up according to the optimal entry site.
Mort Kern, California: My top tips for TSP: Probably the most important consideration before TSP is ensuring the exclusion of LA thrombus (by TEE) even in chronically anticoagulated patients.
Should we do TSP with high INR? Since many operators use echo guidance for the TSP, some (especially the EP operators) feel comfortable doing TSP without holding coumadin. For some of us old-school operators, using angiographic landmarks only, it is recommended that the INR should be <1.6.



Training in TSP
Drs. Alkhouli, Rihal, and Holmes1 address appropriate training for TSP. Current training relies on performance of TSP on patients with supervision by an experienced operator. Approximately 30 TSPs are needed for a trainee to pass the steepest area of the learning curve.2 Use of virtual reality simulators can result in shorter training times and superior post-training performance.3 Partnering among different specialties involved in transseptal procedures (electrophysiology, structural heart disease, congenital heart disease) can afford trainees with an excellent opportunity to acquire the necessary TSP skills within the short span of their training programs.
The Bottom Line
TSP and subsequent LA-related interventions expose the patient to the risk of thrombotic events, namely stroke/TIA. Anticoagulation with intravenous heparin and meticulous attention to flushing sheaths (i.e., no thrombus and air bubbles) are critical. Many operators give 3000-5000u of heparin to achieve an ACT >250-300s when the transseptal system is introduced into the right heart and for interventions, many give another 5000u after the puncture has been completed, frequently checking the ACT to keep it above 300s.
I hope you’ve found this brief update of TSP helpful as we continue our advances in structural heart interventions.
References
- Alkhouli M, Rihal CS, Holmes DR Jr. Transseptal techniques for emerging structural heart interventions. JACC Cardiovasc Interv. 2016 Dec 26; 9(24): 2465-2480. doi: 10.1016/j.jcin.2016.10.035.
- Yao Y, Ding L, Chen W, et al. The training and learning process of transseptal puncture using a modified technique. Europace. 2013 Dec; 15(12): 1784-1790. doi: 10.1093/europace/eut078.
- De Ponti R, Marazzi R, Ghiringhelli S, et al. Superiority of simulator-based training compared with conventional training methodologies in the performance of transseptal catheterization. J Am Coll Cardiol. 2011 Jul 19; 58(4): 359-363. doi: 10.1016/j.jacc.2011.02.063.
- Ren JF, Marchlinski FE, Callans DJ, et al. Increased intensity of anticoagulation may reduce risk of thrombus during atrial fibrillation ablation procedures in patients with spontaneous echo contrast. J Cardiovasc Electrophysiol. 2005 May; 16(5): 474-477.
Disclosure: Dr. Kern is a consultant for Abiomed, Merit Medical, Abbott Vascular, Philips Volcano, ACIST Medical, Opsens Inc., and Heartflow Inc.