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P4-120
Poster 4 performed in a zone of slowed conduction, consistent with the isthmus of the circuit, which had an excellent pace-map (Figure 3). We report the first case of MVT related to previous cardiac surgical correction for WPW and suggest that any iatrogenic ventricular scar may form the substrate for MVT and ablated using standard electrophysiology techniques. P4-118 LATE PACEMAKER/IMPLANTABLE CARDIOVERTER DEFIBRILLATOR LEAD PERFORATIONS ASSOCIATED WITH SPASMODIC COUGHING EVENTS Raymond H. M. Schaerf, MD. Providence St. Joseph Medical Center, Burbank, CA. Cardiac perforation by pacemaker or ICD leads is a rare but serious complication of device therapy. Perforations typically occur during implant or soon thereafter, but can also occur later. Unfortunately, the causes of late perforation are not known, and there does not appear to be a common risk factor. We report on three patients whose perforations were confirmed several days after intense coughing episodes. One week after CRT-D implant, a 43-year old female reported an episode of spasmodic coughing. HF symptoms returned the next day. Follow-up revealed loss of RV capture, reduced LVEF and myocardial perforation at the RV apex. The same lead was repositioned in the RVOT without complication. A 67-year old male experienced a bout of intense coughing about one month after prophylactic ICD implant. He suffered a syncopal episode, and an office visit revealed loss of RV capture. Chest X-ray confirmed perforation, with the lead tip lying close to the spleen. A new active-fixation lead was implanted, and the original lead was extracted without incident. A 94-year old female had a severe coughing episode about three months after receiving a dual-chamber pacemaker for sinus bradycardia. She presented with complaints of fatigue and near-syncope. Follow-up revealed loss of RV capture and new-onset AF, which caused a lower stimulation rate. A new active-fixation lead was implanted but, because of the patient’s age, aortic stenosis, absence of symptoms attributable to the original lead, and concerns that extraction might lead to tamponade, the original lead was left in place. Based on this experience, severe coughing episodes should be considered as a potential risk factor for late perforation. In addition, severe or spasmodic coughing may be a sign of perforation in pacemaker or ICD recipients, regardless of how long the device has been implanted and may warrant a pacemaker or ICD evaluation including chest ⫻-rays or echocardiogram. P4-119 A NEW APPROACH FOR A NON-PHARMACOLOGICAL TREATMENT OF REFRACTORY VENTRICULAR TACHYCARDIA Koji Kumagai, MD, Yuji Wakayama, MD, Koji Fukuda, MD, Yishinao Sugai, MD, Hideaki Endou, MD, Yasuteru Yamauchi, MD, Yasuhiro Yokoyama, MD, Atsushi Takahashi, MD, Kazutaka Aonuma, MD and Hiroaki Shimokawa, MD. Tohoku University School of Medicine, Sendai, Japan, Musashino Red Cross Hospital, Tokyo, Japan, Yokosuka Kyosai General Hospital, Yokosuka, Japan, University of Tsukuba Graduate School of Comprehensive Human Sciences, Tsukuba, Japan and Tohoku University Graduate School of Medicine, Sendai, Japan. Background: Radiofrequency catheter ablation (RFCA) is widely used to treat ventricular tachycardia (VT) refractory to anti-arrhythmic drugs. The current electroanatomical mapping system has made it possible to treat unmappable VT associated with cardiac disease. However, the efficacy of the current RFCA therapy is limited in treating refractory VT originating from left ventricular (LV) epicardial sites because the endocardial activation and pace mapping alone are not always enough to identify the critical LV epicardial site. A cooled-tip/ irrigation ablation catheter system or epicardial approach has not yet been established. To overcome this remaining problem of VT of an epicardial origin, we developed a new endocardial RFCA therapy method using intracoronary mapping.
S259 Methods and Results: We report a case in which endocardial RFCA guided by unipolar intracoronary mapping with a PTCA guidewire was effective in treating VT originating from an LV epicardial site. A 55 year-old man with dilated cardiomyopathy was referred to treat his refractory sustained monomorphic VT. Endocardial RFCA using only the endocardial activation and pace mapping failed to abolish the VT. Due to a previous surgery, pericardial mapping and intra-cardiac venous mapping could not be performed. Unipolar intracoronary mapping was performed to gather epicardial electrophysiological information, and the critical site was determined with activation mapping by identifying the earliest activation site during the VT, pace mapping, and the response to injecting cold saline. The earliest unipolar electrogram with a near-perfect pace map was identified at segment #8 of the left anterior descending artery during the VT. The VT was terminated by an endocardial RF application at an upper mid ventricular septal site which did not have a good pacemap or the earliest electrogram, and which was the most adjacent anatomical endocardial site to the guidewire tip. No VT was clinically observed during a follow up period of 14 months. Conclusions: Our novel approach is expected to improve the usefulness of the RFCA by overcoming the remaining problem of VT originating from an LV epicardial site. P4-120 THE MECHANISM OF RECURRENCE OF ATRIAL TACHYARRHYTHMIA AFTER THE SURGICAL ISOLATION OF THE POSTERIOR PART OF THE LEFT ATRIUM Kohei Yamashiro, MD, Katsunori Okajima, MD, Kazuo Mizutani, MD, Hiroyuki Kumagai, MD, Takatoshi Hayashi, MD, Yoshihiro Ikeda, MD, Shinichiro Yamada, MD, Sachiyo Iwata, MD, Yasue Tsukishiro, MD, Kensuke Matsumoto, MD, Takafumi Akagami, MD, Naoki Murai, MD, Mitsuo Kinugasa, MD, Michihiko Inoue, MD, Yohei Gen, MD and Teishi Kajiya, MD. Himeji Cardiovascular Center, Himeji, Japan. It has been reported that recovered pulmonary vein (PV) conduction as a dominant factor for recurrent atrial tachyarrhythmia (ATa) exists after circular isolation of the PVs by catheter ablation (CA). However, the mechanism of recurrence of ATa after the surgical isolation of the posterior part of left atrium (LA) is not known well. Case 1: A 41-year old man underwent surgical isolation concomitant with MVP. The posterior part of LA was isolated by an incision and radiofrequency (RF) ablation. The LA paraseptal incision was extended to the left margin of PVs, and the RF ablation was directed towards the edges of incision along anterior of left PVs. He recurred atrial fibrillation (AF) immediate after. At two years post surgery, he had frequent episodes every day even with drug treatment. The patient then underwent CA using CARTO. We performed LA mapping under CS pacing. Continuous potential under the LIPV was observed, and ablating this point could close the conduction gap. After CA, we observed spontaneous firing and induced AF in the isolated posterior area of LA. After the procedure, he had no recurrence of ATa with the former drug treatment. Case 2: A 74-year old woman had a recurrent ATa after Maze operation. She underwent surgical isolation of the PVs concomitant with MAP. The posterior part of LA was isolated by an incision and RF ablation. RF applications were delivered from upper or lower margin of the LA paraseptal incision to the left margin of PVs, and from the edge of the upper ablation line to that of the lower one along anterior of left PVs. ATa recurred one day after the operation. She underwent CA using CARTO for drug refractory ATa. At the procedure, APC from LSPV triggered ATa. A conduction gap existed over the RSPV. We could close the conduction gap by ablating this point. After ablation, she had no recurrence of ATa without medication. Conclusion: In these patients with recurrent ATa after surgical isolation of LA, the mechanism of recurrence of ATa was incomplete isolation of LA. These patients were cured with isolation of LA with additional applications by CA. A conduction gap may exist between the connection of atriotomy and the edge of ablation.
S259 Methods and Results: We report a case in which endocardial RFCA guided by unipolar intracoronary mapping with a PTCA guidewire was effective in treating VT originating from an LV epicardial site. A 55 year-old man with dilated cardiomyopathy was referred to treat his refractory sustained monomorphic VT. Endocardial RFCA using only the endocardial activation and pace mapping failed to abolish the VT. Due to a previous surgery, pericardial mapping and intra-cardiac venous mapping could not be performed. Unipolar intracoronary mapping was performed to gather epicardial electrophysiological information, and the critical site was determined with activation mapping by identifying the earliest activation site during the VT, pace mapping, and the response to injecting cold saline. The earliest unipolar electrogram with a near-perfect pace map was identified at segment #8 of the left anterior descending artery during the VT. The VT was terminated by an endocardial RF application at an upper mid ventricular septal site which did not have a good pacemap or the earliest electrogram, and which was the most adjacent anatomical endocardial site to the guidewire tip. No VT was clinically observed during a follow up period of 14 months. Conclusions: Our novel approach is expected to improve the usefulness of the RFCA by overcoming the remaining problem of VT originating from an LV epicardial site. P4-120 THE MECHANISM OF RECURRENCE OF ATRIAL TACHYARRHYTHMIA AFTER THE SURGICAL ISOLATION OF THE POSTERIOR PART OF THE LEFT ATRIUM Kohei Yamashiro, MD, Katsunori Okajima, MD, Kazuo Mizutani, MD, Hiroyuki Kumagai, MD, Takatoshi Hayashi, MD, Yoshihiro Ikeda, MD, Shinichiro Yamada, MD, Sachiyo Iwata, MD, Yasue Tsukishiro, MD, Kensuke Matsumoto, MD, Takafumi Akagami, MD, Naoki Murai, MD, Mitsuo Kinugasa, MD, Michihiko Inoue, MD, Yohei Gen, MD and Teishi Kajiya, MD. Himeji Cardiovascular Center, Himeji, Japan. It has been reported that recovered pulmonary vein (PV) conduction as a dominant factor for recurrent atrial tachyarrhythmia (ATa) exists after circular isolation of the PVs by catheter ablation (CA). However, the mechanism of recurrence of ATa after the surgical isolation of the posterior part of left atrium (LA) is not known well. Case 1: A 41-year old man underwent surgical isolation concomitant with MVP. The posterior part of LA was isolated by an incision and radiofrequency (RF) ablation. The LA paraseptal incision was extended to the left margin of PVs, and the RF ablation was directed towards the edges of incision along anterior of left PVs. He recurred atrial fibrillation (AF) immediate after. At two years post surgery, he had frequent episodes every day even with drug treatment. The patient then underwent CA using CARTO. We performed LA mapping under CS pacing. Continuous potential under the LIPV was observed, and ablating this point could close the conduction gap. After CA, we observed spontaneous firing and induced AF in the isolated posterior area of LA. After the procedure, he had no recurrence of ATa with the former drug treatment. Case 2: A 74-year old woman had a recurrent ATa after Maze operation. She underwent surgical isolation of the PVs concomitant with MAP. The posterior part of LA was isolated by an incision and RF ablation. RF applications were delivered from upper or lower margin of the LA paraseptal incision to the left margin of PVs, and from the edge of the upper ablation line to that of the lower one along anterior of left PVs. ATa recurred one day after the operation. She underwent CA using CARTO for drug refractory ATa. At the procedure, APC from LSPV triggered ATa. A conduction gap existed over the RSPV. We could close the conduction gap by ablating this point. After ablation, she had no recurrence of ATa without medication. Conclusion: In these patients with recurrent ATa after surgical isolation of LA, the mechanism of recurrence of ATa was incomplete isolation of LA. These patients were cured with isolation of LA with additional applications by CA. A conduction gap may exist between the connection of atriotomy and the edge of ablation.