In preparation for our fourth medical relief trip to the Yucatan Peninsula, we thought we had everything figured out — what could possibly go wrong? More than an hour and a half had passed since we were asked to take a seat in the customs office in Progresso, Mexico, the port of entrance for the Yucatan Peninsula. Dr. Eddie Favela (an adult electrophysiologist who was assisting me in the customs process), a young man (whose name I cannot recall) who represented the shipping company, and I were instructed to wait there while our case was presented to the top customs official. The room was utilitarian; well-worn industrial tile on the floor, chipped and faded yellow paint on the plastered walls, cracked vinyl office chairs, tape that had been placed on the windows a few years back when a hurricane came across the peninsula, and countless rows of importation guideline manuals lined up on shelves across the walls. Staring at the manuals, it occurred to me that the odds of receiving all the supplies and equipment for our medical relief trip were growing slimmer by the minute. The customs official working behind the desk seemed pleasant, but seldom smiled, and this too I took to be a bad omen. This was our fourth medical relief trip to the Yucatan Peninsula. Having three trips under our belt, we naively thought that we had worked out all the kinks. We had planned on performing at least 20 procedures on children and young adults, including radiofrequency ablation procedures and pacemaker implantations. Supplies had been gathered (many donated by our industry colleagues) and arrangements had been made to use a “demo” pacing and recording system from Bard. By this time, five days of the planned seven-day trip had passed, and the catheterization supplies or “demo” system remained locked in customs, despite countless calls and letters. While our team was growing restless and optimism was fading, surprisingly, the families waiting for the procedures seemed calm. Perhaps ignorance really is bliss, or perhaps they knew something we did not. Creating our own EP Lab Plato said necessity is the mother of invention. During the drive from Merida to Progresso, I was amazed to see how ingenious the local people were: bikes were modified to transport large cartons of produce, dwellings were constructed from whatever materials were available, and cars were customized to carry large quantities of people or packages. This ingenuity did not surprise me; growing up in a family of nine with a limited toy budget, my three brothers and I often found ourselves surveying our surroundings for supplies that could be used to build a fort or make a go-cart. Similar to the Progresso locals, the end results were not always things of beauty but they served their purpose well. Little did we know that the skill set to build a go-cart from scratch would come in handy when performing electrophysiology procedures. We were fortunate to have evaluated a patient with Wolff-Parkinson-White (WPW) syndrome, who had a cousin who worked in customs. With their help, along with hours of negotiating in both Progresso and Merida customs, we were eventually able to secure our catheterization supplies, and it initially appeared the Bard EP system would clear. Though approaching 5 pm, this prompted us to place IVs and prepare the first three children for procedures. By 7 pm, it became quite apparent that the pacing and recording would remain in the customs warehouse for the duration of the trip. With only two days remaining in our medical relief trip, we reluctantly returned to the hospital to inform the waiting families that no procedures would be performed that day. Our hopes of completing our medical mission were rapidly fading. Following an evening meal, our team returned to our hotel to discuss options. We cataloged our resources: sheaths, catheters, cables, medicine, a radiofrequency ablation generator, and a Medtronic stimulator (circa 1959, and works on D cell batteries, brought as a back-up). All that was lacking was a way to record the intracardiac signals so that we could map the arrhythmia substrate. Then it occurred to us that perhaps the Medtronic pacing system analyzer (PSA), which we had used to test pacemaker leads during three pacemaker implants performed earlier that week, could be used to display intracardiac electrograms during electrophysiology procedures. It should also allow pacing from these leads and recording of a surface ECG. Unfortunately, this limited us to only two channels and a few surface ECG leads to be displayed at one time. However, maybe that would be enough. The following day, after confirming that customs would not release the demo Bard system, we returned to the hospital to test out our improvised recording system. A quick trip to the local “Electronica” shop was required to purchase some alligator clips and wire, enabling us to make all the necessary electrical connections. Prior to performing an electrophysiology study and ablation procedure on a child, we decided that our customized equipment and set-up should be tested. One of our team members bravely “volunteered” to undergo a limited EP study. A 5 French (Fr) brachial sheath was placed and a quadripolar electrophysiology catheter was advanced into the right atrium (without fluoroscopy). Atrial signals were recorded and a Wenckebach cycle length was determined. The volunteer (who survived without consequence) bragged about the excellent health of her AV node, and the system was deemed functional (and a tad bit off label). First and Last Cases Our attention was then directed toward performing the procedures we had long anticipated. Due to the straightforward nature of a manifest accessory pathway, we decided to first attempt this technique on a 14-year-old boy with WPW syndrome. He had been having frequent episodes of SVT despite antiarrhythmic therapy and was eager to have his procedure done. Following induction to a moderate sedation state, a 7.5 Fr and 5 Fr sheath were placed in the right femoral vein. A 5 Fr quadripolar catheter was advanced to the high right atrium, and a 7 Fr radiofrequency ablation catheter was advanced to the right ventricular apex. Pacing thresholds were established and baseline electrograms were obtained with the Medtronic PSA. There appeared to be a slight time delay between the surface ECG and intracardiac signals (ECG proceeding the intracardiac signals), but the Medtronic PSA system otherwise seemed to be functional. Using the Medtronic stimulator, the accessory pathway properties were determined and SVT was induced. During sinus rhythm the tricuspid valve annulus was mapped, and a short AV conduction interval was found in the right posteroseptal area. The coronary sinus and area of His potentials were mapped and fluoroscopic images were stored to ensure that the pathway was not parahisian or too close to the coronary sinus. A few short applications of radiofrequency energy were delivered without success, but following slight catheter manipulations, the pre-excitation was eliminated at a temperature of 45ºC and a full one-minute application was completed (maximum temperature: 55ºC). An additional 30-second “insurance” application was delivered in the same area. Needless to say, our team was speechless and grinning from ear to ear. The staff assisting us in the lab were not entirely clear what had just happened, but the excitement was palpable. After an observation period, the catheters and sheaths were removed and the patient was taken to a recovery area as a cheer erupted from the physicians and staff. A second patient with WPW was bought to the lab and the procedure was repeated, resulting in the successful ablation of a right lateral accessory pathway. The third patient was found to have a possible left-sided automatic atrial tachycardia, and we decided not to press our luck with our 2-channel “MacGyver” system. After a final EP study on a fourth patient revealed no inducible arrhythmias, the team decided to call it a night. On the last full day of the trip, we were informed that there was a portable recording system in Mexico City that could be rented by the day. The 12,000 peso fee ($1,000) seemed reasonable, and the proprietor flew into Merida that morning with a suitcase-sized system. We were pleased to see that it displayed up to 20 intracardiac channels and was able to record and print; the fact that all the instructions and icons were in Spanish was a minor inconvenience. The learning curve was steep but short, and soon we were on our way. There were slight equipment delays and the fluoroscopic equipment had a minor glitch, so we started our first EP procedure just before noon and finished our eighth at 1:30 am the following morning. During the day, our team ablated 7 patients (2 WPW, 2 concealed left-sided accessory pathways, 1 AVNRT, 1 automatic atrial tachycardia, and 1 AV node in an elderly man who had failed two previous atrial flutter/fibrillation ablations and had a pacemaker in place), performed 1 EP study (no inducible arrhythmias), as well as consumed 10 homemade tamales, 6 bowls of turkey soup (very tasty), drank countless bottles of water, and concluded with a bottle of wine (after the caths). Patient throughput was increased by hooking up ECG pads prior to bringing the patient into the room, pulling sheaths in the recovery area, and having all hands available assisting in cleaning and prepping the room between cases; therefore, room turnover averaged ~10 minutes. All in all it was a very productive day, and there were many smiles on the faces of staff, patients and family despite the noticeable fatigue. By the end of the trip we had performed 12 electrophysiology studies, including 9 radiofrequency ablations. Four of these procedures were performed on the “MacGyver” system. We also implanted 3 transvenous pacemaker systems. All were accomplished without complications. Lessons Learned If given the opportunity, I would do it again in a heartbeat (pun intended), and I am positive that I would have a long list of volunteers from this year’s team that would join me. However, I did walk away with a few very important lessons learned: 1) Ship equipment and supplies as far in advance as possible 2) Double and triple check the custom paperwork requirements 3) If you must go to the customs office, bring a good book to read 4) Have a back-up plan (extra stimulator, extra cables) 5) Think outside the box 6) Remember why you are there — do not stress over those things which you cannot control. As those who have participated in medical relief know, there is no monetary gain in this line of work, but the rewards are innumerable. We made many friends and received countless hugs from patients and families. Our team looks forward to our next trip. Acknowledgements. We are extremely grateful for the generous support of our industry colleagues who provided catheters, sheaths, pacemakers, leads, and moral support: Bard CR, St. Jude Medical, and Medtronic, Inc. We are also deeply indebted to the physicians, nurses, cath lab staff and the numerous other support staff that helped perform the procedures; we cherish your compassionate commitment to care and most of all, your friendship.