Cut to the Pace: Transcoronary Pacing

We have all been there: p-waves casually marching across the monitor. Giving the patient orders to “Cough! Cough!” It is a stressful scenario and as the technologists frantically unwrap transcutaneous pacing electrodes and another circulator grabs the venous sheath while a nurse is preparing atropine, this mayhem can be unnerving for even the most confident of cardiac teams. There is no luxury of time during hemodynamic decompensation. Additionally, the end result isn’t always without adverse consequences. Herein, we describe a technique that evolved in our lab cautiously and with somewhat wide-eyed apprehension.

It is not a new procedure; in fact, almost 27 years ago, we found limited use of transcoronary pacing (TCP) by Meier and Rutishauser.¹ The infrequent need for pacing during percutaneous coronary intervention (PCI) and cost to routinely place a prophylactic temporary pacing catheter was not only discouraged by SCA (the Society for Cardiac Angiography, now SCAI) starting in 1984^2-3, but was economically prohibitive. However, as the trend to perform PCI via the brachial or radial artery has increased, this shift presents even greater challenges in addressing bradycardia and asystole. Significant bradycardias are also more common in acute myocardial infarction⁴; furthermore, we see an even higher risk of bradyarrhythmias during the use of complex, catheter-based revascularization strategies like atherectomy, thrombectomy and various mechanical devices.  

Pacing the heart through the coronary artery is simple and quick. It is also more cost effective. Everything needed is already in place: a diagnostic or guiding catheter, and a wire. We remember discussing the option of TCP with one of our interventional cardiologists, Dr. Joseph Song (Whittier, Calif.) in the late 1990’s. This conversation took place during an era when it was more common to routinely place a venous sheath in the groin for prophylactic pacing or an extra port for fluids. Dr. Song read the study by Killeavy and Ferguson³, and after further research, decided TCP might be a worthwhile approach to pacing the heart. We decided to explore this unconventional method to see if we could achieve similar results to the study. Our initial attempt was excellent. It worked: two patients in a row! We became more comfortable with the technique and now only proactively place a venous sheath for patients where we want to have an extra port available for fluids.

How exactly does TCP work? Just like in the literature.⁵ Access the artery, have a guiding catheter in place, a wire distal in the culprit vessel, an alligator pacing wire, a battery-powered pulse generator, and a curved steel suture needle. Insert a needle in the skin just distal to your sheath and clamp the positive (red or anode) alligator clip (Figure 1). Then place the negative (black or cathode) clip on the coronary wire (outside the body) and plug it into the pacing generator. Remember the acronym ‘DAN’ (Distal Always Negative). Turn the pulse generator up to approximately 10 volts, impulse duration 25 mA, 60 or 70 pulses per minute, and pacing should begin. If the coronary wire is not distal enough, it may be necessary to manipulate the wire into an intramyocardial branch to capture and establish a lower threshold. Different coronary wires have been documented performing better for lower thresholds.⁶ Overall, hydrophilic wires are not as good in conduction as the conventional metal wires made of nitinol (NiTi), platinum (Pt), stainless, titanium and tungsten (w).

We recently treated a patient with two coronary stents who presented to the cath lab from the cardiac care unit with an acute stent thrombosis in the circumflex artery. The patient had the arterial sheath still sutured in the groin. We inserted a guide catheter into the ostium of the left coronary artery and quickly placed a guidewire down the distal circumflex through the thrombus. During our intervention, the patient suddenly developed bradycardia (Figure 2) with a very low systolic pressure and rate slowing by the second. While the team rushed for a venous sheath, temporary pacemaker and pacing electrodes, we attached alligator cables to the suture needle and guidewire and began pacing the patient through the coronary guidewire. The patient was extremely hypotensive and finding a vein would have been challenging. This scenario can be very uncomfortable and almost terrifying for a patient still awake. It took an additional 5 minutes to find a vein to insert the temporary pacer into the right ventricle. We were able to successfully finish the procedure under more stable pacing management.  

Another case, an excellent example of this technique, involved a very complex right coronary artery (RCA). As a precaution, the physician wanted to be ready to perform TCP. He placed the guidewire proximal to the bifurcation of the posterior left ventricular artery (PLV) and posterior descending artery (PDA). We connected the alligator clamp in usual manner and we began to see pacing spikes. However, we had no ventricular capture. Disappointed with this result, we proceeded to access the vein and prepare for transvenous pacing. We later contacted Dr. Morton Kern to get some advice for this scenario. He recommended placing the wire more distal and well into an intramyocardial branch. He also suggested that in patients with severely damaged myocardium or with large infarcted areas, the ability to capture might be more challenging. We see this described in an article by de la Serna et al⁵ which suggests that when coronary pacing was not achieved at a maximum output on the pulse generator, the guidewire must be further advanced into the intramyocardial tissue. If pacing is still not achieved, the authors suggested placing the wire into the left ventricle to pace. Left ventricular pacing was achieved in all cases when coronary pacing failed. They used various guidewire sizes (including the 0.038-inch J diagnostic wire, and 0.014-inch and 0.018-inch coronary interventional wires) and were successful.

Complications or side effects of TCP (transcoronary pacing)

Side effects of coronary pacing include coronary spasm that can be relieved by intracoronary nifedipine or nitrates. As with any PCI, there is the risk of coronary perforation, in particular with hydrophilic guidewires. The electrode site can cause some burning that is alleviated with the use of a steel monofilament suture needle anchored in the subcutaneous tissue near the anesthetized access site.⁷

Complications of TVP (transvenous pacing)

The complications associated with transvenous pacing include, but are not limited to, ventricular tachycardia or fibrillation requiring defibrillation, cardiac tamponade requiring pericardial centesis, and hypotension requiring vasopressors and possibly intra-aortic balloon counterpulsation. Pneumothorax, brachial plexus, septicemia, additional radiation and ventricular perforation⁸ are all complications of TVP. Deep vein thrombosis and pulmonary embolism is rare, but can be seen in some cases.

How can we safely and efficaciously perform TCP? To our knowledge, there have not been any recent studies or trials related to the duration of intracoronary pacing. There was a study on porcine models suggesting intracoronary pacing was achieved up to 30 minutes without complications; however, some intracoronary thrombus had developed in some models with a protocol of minimal antiplatelet therapy. With present-day anticoagulant therapy, thrombus should not be an issue.⁹

Conclusion

With the emergence of a worldwide trend to perform PCI via the radial and brachial approach¹⁰, some centers are beginning to explore the technique of TCP. Additionally, as we continue to see use of new devices in the coronary vessels such as rheolytic thrombectomy (AngioJet, Medrad, Warrendale, Penn.), rotational atherectomy, and various mechanical thrombus devices for chronic total occlusions and in-stent restenosis, the ability to manage bradyarrhythmia and asystolic events with immediate pacing to restore hemodynamics is crucial. In some of the early use of rheolytic therapy, temporary pacing was required in 35% of interventions.¹¹ In the VeGAS 2 trial (Vein Graft AngioJet Study), significant bradycardia occurred in 24% of patients. Our institution has found a fast, safe, and less traumatic method to pace patients out of a life-threatening 3rd degree block, bradycardia, or asystole without the risk of a ventricular perforation. This procedure is time tested and we hope our experience invites more catheterization labs to learn from this “cut to the pace” technique. 

Acknowledgments

We would like to thank the cardiologists and cath lab staff at Presbyterian Intercommunity Hospital (PIH) Whittier, California for their input and a special thanks to Lucinda Allshouse and Christa Wahl from the PIH Medical Library for their tireless research.

This article received double-blind peer review from members of the Cath Lab Digest editorial board.

Cary Lunsford, RCIS, FSICP, can be contacted at carydrum1@yahoo.com. Laura Minarsch, RT(R), CVT, can be contacted at laura22@mmc-medical.com.

References

1. Meier B, Rutishauser W. Coronary pacing during percutaneous transluminal coronary angioplasty. Circulation 1985;71:557–561.
2. Greene DG. Right heart catheterization and temporary pacemaker insertion during coronary arteriography for suspected coronary artery disease. Cathet Cardiovasc Diagn 1984;10(5):429–430.
3. Killeavy E, Ferguson J III. The use of temporary transvenous pacing catheters during PTCA. Tex Heart Inst J 1990;17(1):37–41.
4. Heinroth KM, Carter JM, Buerke M, et al. Optimizing of transcoronary pacing in a porcine model. J Invasive Cardiol 2009 Dec;21(12):634–638.
5. de la Serna F, Meier B, Pande AK, et al. Coronary and left ventricular pacing as standby in invasive cardiology. Cathet Cardiovasc Diagn 1992 Apr;25(4):285–289. 
6. Parakh N, Asotra S, Singh S, et al. Transcoronary pacing: are the modern wires effective? Indian Heart J 2009 Mar-Apr;61(2):160–162.
7. Mixon TA, Dehmer GJ, Santos RA, et al. Guidewire pacing safely and effectively treats bradyarrhythmias induced by rheolytic thrombectomy and precludes the need for transvenous pacing: the Scott & White experience. J Invasive Cardiol 2008 Aug;20(8 Suppl A):5A–8A.
8. Heinroth K, Stabenow I, Moldenhauer I, et al. Temporary transcoronary pacing by coated guidewires: a safe and reliable method during percutaneous coronary intervention. Clin Res Cardiol 2006; 95:206–211.
9. Laird JR, Hull R, Sajduhar KC, et al. Transcoronary cardiac pacing during myocardial ischemia. Cathet Cardiovasc Diagn 1992; 25(4):285–289.
10. Pillai RV, Daniel R, Joseph DJ. Complete heart block following occlusion of the first septal perforator after coronary stenting. Indian Heart J 2005;57(6):728–730.
11. Mueller RI, Sanborn TA. The history of interventional cardiology: cardiac catheterization, angioplasty and related interventions. Am Heart J 1995;129(1):146–172.

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Disclosure: The authors report no conflicts of interest regarding the content herein.