Shutaro Satake

Angioplasty for chronic total occlusion by using tapered-tip guidewires

Percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) is still technically challenging. The use of tapered‐tip guidewires in these lesions may improve the success rate of PCI. In order to avoid the needless radiation exposure or contrast consumption, we have to determine a guideline for the termination of procedures in these lesions. We retrospectively analyzed the data of 182 patients between April 1997 and December 1999 (phase 1) and 80 patients between January and August 2001 (phase 2) who underwent angioplasty for CTO lesions ≥ 3 months. There were no significant differences in clinical or lesion characteristics except the use of tapered‐tip guidewires. Tapered‐tip guidewires were used in 60% of patients in phase 2 period but no patients in phase 1 period. The overall success rate of PCI was improved from 67% in phase 1 to 81% in phase 2 (P = 0.019). In the phase 2 period, the success rate was higher in tapered‐type occlusion (P = 0.002) and shorter length of occlusion (P = 0.004). Total procedure time was 46 ± 17 min and total volume of contrast dye was 180 ± 63 ml. The success rate was higher in patients treated by transradial coronary intervention (TRI) than transfemoral coronary intervention (89% vs. 64%; P = 0.008). The use of tapered‐tip guidewires can improve the success rate of PCI in CTO lesions. The following guideline for the termination of the procedures is reasonable: time from arterial access to successful penetration of a guidewire through occlusion ≤ 30 min; total procedure time ≤ 90 min; and total dye volume ≤ 300 ml. TRI can achieve a high success rate even in CTO lesions provided that the case selection is adequate. Cathet Cardiovasc Intervent 2003;59:305–311.

Comparative study on transradial approach vs. transfemoral approach in primary stent implantation for patients with acute myocardial infarction: Results of the test for myocardial infarction by prospective unicenter randomization for access sites (TEMPURA) trial

Transradial coronary intervention (TRI) can be performed in elective patients with low incidence of access site complications. However, the feasibility of primary stent implantation by TRI is still not clear in patients with acute myocardial infarction (AMI). We prospectively randomized 149 patients out of 213 patients with AMI within 12 hr from onset into two groups: 77 patients treated by TRI (TRI group) and 72 patients by transfemoral coronary intervention (TFI; TFI group). We compared the incidences of major adverse cardiac events (MACE; repeat MI, target lesion revascularization, and cardiac death) during the initial hospitalization and 9‐month follow‐up periods in both groups. There were one patient who crossed over to the opposite arm, and two patients with severe bleeding complications in the TFI group. Background characteristics of patients were similar between the two groups. The success rate of reperfusion and the incidence of in‐hospital MACE were similar in both groups (96.1% and 5.2% vs. 97.1% and 8.3% in TRI and TFI groups, respectively). In selected patients with AMI, primary stent implantation by TRI is feasible as compared to TFI. Cathet Cardiovasc Intervent 2003;59:26–33.

New method to increase a backup support of a 6 French guiding coronary catheter.

A 6 Fr guiding catheter is commonly used in the percutaneous coronary intervention (PCI). However, one of the limitations of the 6 Fr guiding catheter is its weak backup support compared to a 7 or an 8 Fr guiding catheter. In this article, we present a new system for PCI called the five‐in‐six system. Between March 2003 and September 2003, this system was tried on eight chronic total occlusion cases. The advantage of the five‐in‐six system is that it increases backup support of a 6 Fr guiding catheter. Catheter Cardiovasc Interv 2004;63:452‐456.

Feasibility of the Radiofrequency Hot Balloon Catheter for Isolation of the Posterior Left Atrium and Pulmonary Veins for the Treatment of Atrial Fibrillation

Background—Atrial fibrillation originates mostly from the pulmonary vein (PV) foci or non-PV foci in the posterior left atrium (LA). The present study was designed to evaluate the feasibility and safety of a novel radiofrequency hot balloon catheter for the treatment of patients with atrial fibrillation by electrically isolating the posterior LA, including all PVs. Methods and Results—One hundred consecutive patients with drug-resistant atrial fibrillation (63 paroxysmal, 37 persistent) were enrolled. The isolation of the PVs was performed by wedging the balloon at each PV antrum to create circumferential lesions in each case. Contiguous linear lesions were also created at the roof between the superior PVs and at the bottom of the posterior LA between the inferior PVs by dragging the balloon along the endocardium. Complete elimination of the posterior LA and PV potentials was achieved in all 100 cases, confirmed by either conventional or electro-anatomic mapping system. The total procedure time was 129±26 minutes, inclusive of 29.9±7.3 minutes of fluoroscopy time. Follow-up during 11.0±4.8 months confirmed that 92 patients (60 paroxysmal, 32 persistent) were free from atrial fibrillation without antiarrhythmic drugs, and in the remaining patients except for 2 with LA tachycardia, sinus rhythm was maintained with antiarrhythmic drugs. With precautions of esophageal cooling by irrigation dictated by temperature monitoring and monitoring phrenic nerve pacing, no LA-esophageal fistula or permanent phrenic nerve injury occurred. Conclusion—This feasibility study supports the safety and efficacy of radiofrequency hot balloon catheter for complete isolation of the posterior LA and PVs.

A new radiofrequency thermal balloon catheter for pulmonary vein isolation

OBJECTIVES We sought to evaluate whether porcine pulmonary vein (PV) isolation (PVI) can be produced by ablation using our novel radiofrequency (RF) thermal balloon catheter (RBC). BACKGROUND It has been proposed that PVI can prevent focal atrial fibrillation (AF) originating in or close to the PV. METHODS The RBC is composed of a 12F main shaft, a 4F inner tube and a balloon. Inside the balloon, there is a unipolar coil electrode with a thermocouple sensor mounted along the tube, the former to deliver RF energy (13.56 MHz) and the latter to monitor the temperature. After the presence of a PV potential was confirmed, the RBC was safely inserted into the left atrium (LA) by the trans-septal approach. Once the balloon was inflated and optimally wedged at the junction between the PV and LA, RF energy was applied for 5 min. Radiofrequency catheter ablation (RFA) was repeated up to three times, until elimination of the PV potential or dissociation between the LA and PV was observed. Finally, each heart was examined histologically. RESULTS In 18 PVs that had PV potentials, PVI was performed, resulting in success in 15 (success rate 83%, 95% confidence interval [CI] 58.0% to 96.3%; failure rate 17%, 95% CI 3.7% to 42.0%). After successful PVI, the PV potentials completely disappeared and the histologic examination revealed circumferential, transmural necrosis around the PV trunks. No major complications, such as PV stenosis or macroscopic thrombosis, were observed. CONCLUSIONS The RBC was useful for PVI.

Usefulness of hydrophilic coating on arterial sheath introducer in transradial coronary intervention.

Radial artery spasm is one of the major problems during transradial coronary intervention (TRI). The sheath introducer with hydrophilic coating may reduce the incidence of spasm and reduce the difficulty in removing it from the radial artery under the situation of spasm artery spasm. After we compared the friction resistance between the sheath introducer with hydrophilic coating and that without coating (nine samples each) in vitro, the sheath introducers with and without hydrophilic coating were randomly used in 37 and 36 patients, respectively, who underwent elective TRI with a 6 Fr introducer sheath. Hydrophilic coating of sheath introducer reduced friction resistance by 70% (P < 0.00001) in in vitro model and facilitated sheath removal after finishing TRI (P = 0.0003). Hydrophilic coating of sheath introducer is useful in TRI. Cathet Cardiovasc Intervent 2002;56:328–332.

Radiofrequency Catheter Ablation for AV Nodal Reentrant Tachycardia Associated with Persistent Left Superior Vena Cava

Slow A V nodal pathway ablation using RF is highly effective for patients with refractory A V nodal reentrant tachycardia (AVNRT). We report three catheter ablation cases using RF current in patients associated with persistent left superior vena cava (PLSVC). Three patients with drug refractory AVNHT of common variety were involved in this study. An electrode catheter introduced through the left subclavian vein inserted directly into the coronary sinus, a typical anatomical finding of PLSVC. The ablation procedure was initially performed at the posteroinferior region of Kochs triangle. A slow pathway potential could not be found from that area; nonsustained junctional tachycardia (NSJT) did not occur during the delivery of RF current; there was failure to eliminate slow AV nodal pathway conduction. The catheter then was moved into the bed of the proximal portion of the markedly enlarged coronary sinus. A slow AV nodal pathway potential was recorded through the ablation catheter, and the delivery of RF current caused NSJT in two patients. Complete elimination of slow AV nodal pathway conduction was accomplished in these two patients by this method. No adverse effects were provoked by this procedure. Catheter ablation of the slow A V nodal pathway guided by a slow pathway potential and the appearance of NSJT was feasible and safe in the area of the coronary sinus ostium in patients associated with PLSVC.

Radiofrequency thermal balloon coronary angioplasty: A new device for successful percutaneous transluminal coronary angioplasty

OBJECTIVES The purpose of this study was to evaluate the effects of thermal balloon percutaneous transluminal coronary angioplasty using radiofrequency energy in the treatment of patients with failed coronary angioplasty and complex lesions. In addition, we evaluated restenosis after radiofrequency thermal balloon applications. BACKGROUND The efficacy of coronary angioplasty is limited by the relatively low success rate in complex lesions and the high frequency of restenosis. Few reports have studied the combined effects of pressure and laser thermal energy. This study describes a new device for coronary angioplasty using radiofrequency thermal energy. METHODS Thirty-two patients with failed conventional coronary angioplasty or complex lesions were treated with radiofrequency thermal balloon coronary angioplasty. Radiofrequency energy was delivered up to 11 times in exposures ranging from 30 to 60 s in duration. This combined effect allowed the vascular wall to be heated to temperatures ranging from 60 to 70 degrees C. Follow-up coronary angiography was performed, on average, 6 months after the procedure. RESULTS Successful radiofrequency coronary angioplasty was achieved in 28 (82%) of 34 lesions. There was one abrupt coronary artery occlusion (3%) and no death, perforation or dissection. Angiographic restenosis occurred in 14 (56%) of 25 lesions. CONCLUSIONS In patients with failed coronary angioplasty and difficult complex lesions, radiofrequency coronary angioplasty could potentially improve angioplasty success rates and may have important implications for bailout cases with abrupt occlusion. However, restenosis remains a significant problem.

Prevalence of Esophageal Ulceration After Atrial Fibrillation Ablation with the Hot Balloon Ablation Catheter: What is the Value of Esophageal Cooling?

Little is known about luminal esophageal temperature (LET) monitoring during catheter ablation for atrial fibrillation (AF) using the radiofrequency hot balloon (RHB) technology.

Demonstration of bidirectional dual A-V nodal pathways in the same patient.

In a patient with documented paroxysmal junctional tachycardia (PJT) electrophysiologic studies were performed using an extrastimulus technique. At an A1-A2 interval of 360 msec, atrial extrastimulus revealed sudden prolongation of an A2-H2 interval from 370 to 540 msec and PJT ensued. This finding was consistent with antegrade dual A-V nodal pathways. On the other hand, at a V1-V2 interval of 540 msec, ventricular estrastimulus showed a jump in ventriculo-atrial (V-A) conduction time with evidence of delay in the A-V node from 285 to 565 msec and a ventricular echo followed. This finding was consistent with retrograde dual A-V nodal pathways. Mechanisms of bidirectional dual A-V nodal pathways are discussed.