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Taishi Kuwahara,
Atsushi Takahashi,
Yoshihide Takahashi,
Atushi Kobori,
Shinsuke Miyazaki,
Asumi Takei, Tadashi Fujino,
Kenji Okubo,
Katsumasa Takagi,
Akira Fujii,
Masateru Takigawa,
Yuji Watari,
Hiroyuki Hikita,
Akira Sato,
Kazutaka Aonuma
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ABSTRACT: INTRODUCTION: This study aimed to elucidate the clinical characteristics and management of periesophageal vagal nerve injury complicating the ablation of atrial fibrillation (AF). METHODS AND RESULTS: A total of 3,695 patients with drug-resistant AF underwent extensive pulmonary vein isolation at our institution. Either a nonirrigated or an irrigated ablation catheter was employed, with radiofrequency power of 25-40 W. Esophageal temperature was monitored in 3,538 patients: when the esophageal temperature reached 42°C radiofrequency delivery was stopped. A total of 11 patients (60 ± 11 years, 10 males) were diagnosed as having a periesophageal vagal nerve injury after the AF ablation. Symptoms included nausea, vomiting, bloating, constipation, and gastric pain, which occurred within 72 hours after the procedure. Gastrointestinal fluoroscopy and/or endoscopy revealed gastric hypomotility (10 patients) and pyloric spasm (1 patient). Intravenous erythromycin (3 mg/kg every 8 hours) was effective in relieving symptoms in 5 patients, and the patient with pyloric spasm underwent esophagojejunal anstomosis. Eight patients almost fully recovered within 40 days; however, 3 patients suffered from severe symptoms for 3-12 months. This complication occurred in 4 of the 157 patients (2.5%) who did not have esophageal temperature monitoring, and 7 of the 3,538 (0.2%) who did (P = 0.0007). The 3 patients with persistent severe symptoms received no esophageal temperature monitoring. CONCLUSION: The clinical course and severity of the periesophageal vagal nerve injury varied, but most patients finally recovered with conservative treatment. Radiofrequency delivery under esophageal temperature monitoring might reduce both the incidence and the severity of this complication.
Journal of Cardiovascular Electrophysiology 03/2013; · 3.06 Impact Factor
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Taishi Kuwahara,
Atsushi Takahashi,
Yoshihide Takahashi,
Atushi Kobori,
Shinsuke Miyazaki,
Asumi Takei, Tadashi Fujino,
Kenji Okubo,
Katsumasa Takagi,
Akira Fujii,
Masateru Takigawa,
Yuji Watari,
Hiroyuki Hikita,
Akira Sato,
Kazutaka Aonuma
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ABSTRACT: INTRODUCTION: This study aimed to determine the effects of continuing warfarin administration during the periprocedural period of catheter ablation for atrial fibrillation (AF) on the prevention of stroke complications and to evaluate the management of hemorrhagic complications occurring with this approach. METHODS AND RESULTS: A total of 3,280 patients undergoing AF catheter ablation at our institution were divided into 2 groups: the first 1,953 patients who discontinued warfarin 3-4 days before AF ablation and were bridged with heparin (warfarin-discontinued group), and the last 1,327 patients who continued warfarin throughout the periprocedural period (warfarin-continued group). Symptomatic stroke or transient ischemic attack occurred in 13/1,953 patients (0.67%) in the warfarin-discontinued group and in 2/1,327 patients (0.15%) in the warfarin-continued group (P = 0.021). None of the patients with therapeutic international normalized ratio at the time of the procedure had periprocedural thromboembolism in the warfarin-continued group. Major hemorrhagic complications occurred in 26/1,953 patients in the warfarin-discontinued group (1.3%; 25 with cardiac tamponade and 1 with retroperitoneal bleeding), and in 15/1,327 patients in the warfarin-continued group (1.1%; 14 with cardiac tamponade and 1 with abdominal wall bleeding) (P = 0.80). Of the 14 warfarin-continued patients with cardiac tamponade, 13 were administered prothrombin complex concentrate (PCC) and vitamin K; the bleeding was stopped safely without surgical repair. CONCLUSION: The continuation of warfarin during the periprocedural period of AF ablation could reduce the incidence of stroke without increasing hemorrhagic complications. When cardiac tamponade occu-rred with this approach, it was safely treated with PCC and vitamin K.
Journal of Cardiovascular Electrophysiology 12/2012; · 3.06 Impact Factor
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Atsuko Abe,
Kenzaburo Kobayashi,
Hitomi Yuzawa,
Hideyuki Sato,
Shunji Fukunaga, Tadashi Fujino,
Yoshifumi Okano,
Junichi Yamazaki,
Yosuke Miwa,
Hideaki Yoshino,
Takanori Ikeda
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ABSTRACT: Late potentials (LP) detected with signal-averaged ECGs are known to be useful in identifying patients at risk of Brugada syndrome (BS) and arrhythmogenic right ventricular cardiomyopathy (ARVC). Because the pathophysiology is clearly different between these disorders, we clarified the LP characteristics of these disorders.
This study included 15 BS and 12 ARVC patients and 20 healthy controls. All BS patients had characteristic ECG changes and symptomatic episodes. All ARVC patients had findings that were consistent with recent criteria. Three LP parameters (filtered QRS duration, root mean square voltage of the terminal 40 ms of the filtered QRS complex, and duration of low-amplitude signals [<40 µV] in the terminal, filtered QRS complex) were continuously measured for 24 hours using a novel Holter-based signal-averaged ECG system. The incidences of LP determination in BS (80%) and ARVC (91%) patients were higher than in healthy controls (5%; P<0.0001 in both) but did not differ between BS and ARVC patients. In BS patients, the dynamic changes of all LP parameters were observed, and they were pronounced at nighttime. On the contrary, these findings were not observed in ARVC patients. When the SD values of the 3 LP parameters (filtered QRS duration, root mean square voltage of the terminal 40 ms of the filtered QRS complex, and duration of low-amplitude signals [<40 µV] in the terminal, filtered QRS complex) over 24 hours were compared for the 2 patient groups, those values in BS patients were significantly greater than those in ARVC patients (P<0.0001 in all).
LP characteristics detected by the Holter-based signal-averaged ECG system over 24 hours differ between BS and ARVC patients. Dynamic daily variations of LPs were seen only in BS patients. This may imply that mechanisms of lethal ventricular arrhythmia in BS may be more correlated with autonomic abnormality than that of ARVC.
Circulation Arrhythmia and Electrophysiology 06/2012; 5(4):789-95. · 6.46 Impact Factor
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Yoshihide Takahashi,
Atsushi Takahashi,
Taishi Kuwahara,
Kenji Okubo, Tadashi Fujino,
Katsumasa Takagi,
Emiko Nakashima,
Tetsuo Kamiishi,
Hiroyuki Hikita,
Kenzo Hirao,
Mitsuaki Isobe
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ABSTRACT: Kidney function is a known predictor of cardiovascular morbidity and mortality. Although patients with atrial fibrillation (AF) often have kidney dysfunction, less is known about the association between AF and kidney function. We sought to assess changes in kidney function after catheter ablation of AF.
Patients who underwent catheter ablation of AF were recruited for the present prospective study. Estimated glomerular filtration rate (eGFR) was evaluated before and 1 year after the ablation. Three hundred eighty-six patients (paroxysmal AF, 135; persistent AF, 106; longstanding persistent AF, 145) were studied. Their baseline eGFR was 68 ± 14 mL · min(-1) · 1.73 m(-2). Sixty-six percent and 26% of patients had eGFR of 60 to 89 and 30 to 59 mL · min(-1) · 1.73 m(-2), respectively. Overall, 278 patients (72%) were arrhythmia free over a 1-year follow-up. In patients free from arrhythmia, eGFR increased 3 months later and was maintained until 1 year, whereas in patients with recurrences, eGFR had decreased over 1 year. Changes in eGFR over 1 year in patients free from arrhythmia differed significantly compared with those with recurrences (3 ± 8 versus -2 ± 8 mL · min(-1) · 1.73 m(-2); P<0.0001). In all quartiles of baseline eGFR, changes in eGFR over 1 year after the ablation were greater in patients free from arrhythmia compared with those with recurrences.
Elimination of AF by catheter ablation was associated with improvement of kidney function over a 1-year follow-up in patients with mild to moderate kidney dysfunction.
Circulation 11/2011; 124(22):2380-7. · 14.74 Impact Factor
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Taishi Kuwahara,
Atsushi Takahashi,
Yoshihide Takahashi,
Atsushi Kobori,
Shinsuke Miyazaki,
Asumi Takei,
Akira Fujii,
Shigeki Kusa,
Atsuhiko Yagishita,
Kenji Okubo, Tadashi Fujino,
Toshihiro Nozato,
Hiroyuki Hikita,
Akira Sato,
Kazutaka Aonuma
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ABSTRACT: This study aimed to elucidate the clinical characteristics of massive air embolism occurring during atrial fibrillation (AF) ablation.
Of 2976 patients undergoing AF ablation, 5 patients complicated by serious air embolism were examined. Atrial fibrillation ablation was performed with the use of three long sheaths for circular mapping and ablation catheters under conscious sedation. Two patients had air spontaneously introduced through a haemostasis valve of the long sheaths, at the end of long apnoea caused by the sedation, even though the catheters were placed within the long sheaths. The remaining three patients, all of whom also exhibited long apnoea, had air entry at the circular mapping catheter exchanges. Air accumulated in the right and left ventricles, left atrial appendage, right coronary artery, and ascending aorta. Haemodynamic collapse and hypoxaemia occurred in all and two patients, respectively, and supportive treatment and the accumulated air were aspirated. ST elevation, haemodynamic collapse, and hypoxaemia persisted for 10-35 min; however, all patients recovered completely. After we changed the sedative to one with less respiratory depressive effects and the timing of the saline flush at the circular mapping catheter exchanges, we never experienced such serious complications any further.
Serious air embolism can occur in patients with long apnoea under sedation during AF ablation with the use of long sheaths. Supportive therapy and air aspiration were effective in resolving the complication. A sedative that causes less respiratory depression and the timing of the saline flush were important for preventing air embolism.
Europace 09/2011; 14(2):204-8. · 1.98 Impact Factor
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ABSTRACT: A low incidence of thromboembolic events after successful catheter ablation of atrial fibrillation (AF) during a mid-term follow-up period was recently reported. However, because the incidence of such events over the long term is unknown, we investigated the late incidence of thromboembolic events after catheter ablation.
Patients with paroxysmal and persistent AF undergoing catheter ablation and being followed up for at least 24 months formed the study group (n = 524); 82 patients (16%) had CHADS₂ scores of at least 2. Mean follow-up was 44 ± 13 months. Warfarin was discontinued in 400 (93%) of 429 patients (82% of 524 patients) without AF recurrence. None of the patients without AF recurrence suffered thromboembolic events, whereas 3 of 95 patients (3%) with AF recurrence did (P < 0.001). One of the 3 was a late AF recurrence occurring > 12 months after catheter ablation. There were 2 nonfatal major hemorrhagic events in patients with AF recurrence who continued on warfarin, but no hemorrhagic events were observed in patients free from AF (P = 0.002).
Maintenance of sinus rhythm after catheter ablation of AF was associated with a lower incidence of thromboembolic events during long-term follow-up >3 years. This result suggests that catheter ablation reduces thromboembolic events if patients continue anticoagulation regardless of the ablation outcome.
Circulation Journal 07/2011; 75(10):2343-9. · 3.77 Impact Factor
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Yoshihide Takahashi,
Atsushi Takahashi,
Taishi Kuwahara, Tadashi Fujino,
Kenji Okubo,
Shigeki Kusa,
Akira Fujii,
Atsuhiko Yagishita,
Shinsuke Miyazaki,
Toshihiro Nozato,
Hiroyuki Hikita,
Kenzo Hirao,
Mitsuaki Isobe
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ABSTRACT: We sought to characterize patients with persistent atrial fibrillation (AF) who were successfully treated by ablation targeting the left atrium (LA).
Ninety-three patients (58±10 years, 79 male) undergoing ablation of persistent AF were studied. During the first procedure, ablation was performed in the LA and coronary sinus, consisting of pulmonary vein isolation, linear ablation, and electrogram-based ablation. During follow-up after the first procedure, 35 patients (38%) remained free from tachyarrhythmias, 27 patients (29%) had atrial tachycardia, and 31 patients (33%) had AF. Duration of persistent AF according to medical history and whether AF was terminated by ablation were associated with the outcome (P=0.005, P=0.004, respectively). In multivariate analysis, the duration of persistent AF was the only predictor of freedom from AF (sinus rhythm or atrial tachycardia) (odds ratio, 0.80 for a 1-year increase; 95% confidence interval, 0.67 to 0.95; P=0.01). Of 31 patients in whom AF recurred during follow-up, electrogram-based ablation was performed in the right atrium in 26 patients. Sixteen of those patients (62%) remained free from AF during follow-up. Overall, 82% of patients were free from any tachyarrhythmias at 2-year follow-up after a median of 2 procedures.
Patients with shorter duration of persistent AF were more likely to be free from AF by LA ablation. Right atrial ablation may provide incremental efficacy in patients who are refractory to LA ablation.
Circulation Arrhythmia and Electrophysiology 10/2010; 3(5):465-71. · 6.46 Impact Factor
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Yoshihide Takahashi,
Atsushi Takahashi,
Shinsuke Miyazaki,
Taishi Kuwahara,
Asumi Takei, Tadashi Fujino,
Akira Fujii,
Shigeki Kusa,
Atsuhiko Yagishita,
Toshihiro Nozato,
Hiroyuki Hikita,
Akira Sato,
Kenzo Hirao,
Mitsuaki Isobe
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ABSTRACT: Mapping of recurrent atrial tachycardia (AT) after extensive ablation for long-lasting persistent atrial fibrillation (AF) is complex. We sought to describe the electrophysiological characteristics of localized reentry occurring after ablation of long-lasting persistent AF.
Out of 70 patients undergoing catheter ablation of long-lasting persistent AF, 9 patients (13%, 55 +/- 8 years, 8 males) in whom localized reentry was demonstrated in a repeat ablation were studied. Localized reentry was defined as reentry in which the circuit was localized to a small area and did not have a central obstacle. The mechanism of AT was determined by electroanatomical and entrainment mapping.
Nine localized reentries with cycle length of 243 +/- 41 ms were mapped in 9 patients. The location of AT was the left atrial appendage in 4 patients, anterior left atrium in 2, left septum in 2, and mitral isthmus in 1. In all ATs, a critical isthmus of <10 mm in width was identified in the vicinity of the prior linear lesions or ostia of isolated pulmonary veins. Ablation of the critical isthmus, which was characterized by continuous low-voltage activity (median voltage: 0.15 mV, mean duration: 117 +/- 31 ms), terminated AT and rendered it noninducible. Additionally, ablation was performed for all of inducible ATs. At 11 +/- 7 months after the procedure, 8 of 9 patients (89%) were free from any arrhythmias.
After ablation of long-lasting persistent AF, localized reentry may arise from a site in the vicinity of the prior ablation lesions. Ablation of the critical isthmus eliminates the arrhythmia.
Journal of Cardiovascular Electrophysiology 01/2009; 20(6):623-9. · 3.06 Impact Factor
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ABSTRACT: Sustained tachycardia causes left ventricular (LV) systolic dysfunction leading to heart failure (HF), which is widely known as "tachycardia-induced cardiomyopathy (TIC)", but its prevalence and prognosis in Japanese remain unclear.
Of 213 consecutive patients with HF associated with atrial fibrillation (AF) requiring hospitalization (n=213) between January 1999 and December 2004, and 104 (83 males, 67+/-12.6 years) were identified as not having any structural heart disease. Of them 41 (39%) had a normal LV ejection fraction (LVEF) at the initial admission, and the remaining patients fell into 2 groups: those with rapid (<6 months) normalization of the LVEF after AF management (presumed TIC, 30 patients, 29%) and those with persistent LV systolic dysfunction (dilated cardiomyopathy (DCM), 33 patients, 32%). Although the B-type natriuretic peptide value and LVEF did not differ between the 2 groups, the LV size on admission was significantly smaller in the TIC group (LV end-diastolic dimension (LVDd) 57.6+/-7.2, LV end-systolic dimension (LVDs) 49.4+/-8.0) than in the DCM group (LVDd 63.4 +/-8.8, LVDs 55.3+/-9.6, p<0.05). During a follow-up period of 42.1+/-21.2 months, cardiac death and recurrent HF hospitalization were significantly less frequent in the TIC group than in the DCM group.
In AF-associated HF requiring hospitalization, TIC is the presumed cause in approximately one-third of patients without any previously known structural heart disease. That particular group is characterized by a relatively smaller LV and better prognosis under medical treatment.
Circulation Journal 06/2007; 71(6):936-40. · 3.77 Impact Factor
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ABSTRACT: During anticoagulation for prevention of stroke in patients with non-valvular atrial fibrillation (NVAF), bleeding is the most serious complication. In Western countries, the incidences of major bleeding and intracranial hemorrhages with low-dose warfarin are known to occur at a rate of 0.4-1.3% and 0.2% per year, respectively. The purpose of this study was to investigate the incidence and risk factors for major bleeding related with warfarin therapy in Japanese patients with NVAF.
From August 2004 to July 2005, 667 NVAF patients treated with warfarin for NVAF were followed-up. The target prothrombin time-international normalized ratio (PT-INR) value was set at 1.6-2.6 (low-dose warfarin). The exposure on warfarin was 503 patient-years (average PT-INR 2.00 +/-0.40). During the follow-up period, 12 major bleeding complications occurred (2.38% per patient-year), which included 3 intracranial hemorrhages (0.60% per patient-year). Among the patients' characteristics, average PT-INR > or =2.27 during the study was identified as an independent risk factor for major bleeding.
The incidence of major bleeding and intracranial hemorrhages in Japanese NVAF patients with low-dose warfarin therapy was 2.38% and 0.60% per patient-year, respectively, which is higher than in Westerners.
Circulation Journal 05/2007; 71(5):761-5. · 3.77 Impact Factor
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ABSTRACT: We propose a scheme for mobile communications to combat the channel blocking. The scheme is of the MIMO-STBC for the downlink MC-CDMA, which enables receivers to extract all the signals even when they encounter the blocking.
3G and Beyond, 2005 6th IEE International Conference on; 12/2005
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Masaki Igarashi, Tadashi Fujino,
Miwako Toyoda,
Keishi Sugino,
Kenichirou Sasao,
Shuichi Sasamoto,
Takayuki Otsuka,
Kenzaburo Kobayashi,
Yoshifumi Okano,
Katsunori Yosiwara,
Nobuya Koyama
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ABSTRACT: Nifekalant (NF), a pure K(+) channel blocker developed in Japan, has been reported to be effective in the treatment of life-threatening ventricular arrhythmias. We studied its efficacy in 18 men and 4 women with out-of-hospital ventricular fibrillation (VF) admitted to our emergency department between August 2001 and March 2004. The number of DC shocks delivered for out-of-hospital VF, serum Na(+) and K(+), arterial blood pH, and base excess were compared in 8 patients treated with NF, 0.3 mg/kg i.v. followed by a continuous intravenous (group N) versus 14 patients treated with lidocaine, 2 mg/kg, i.v. (group C). The two groups were similar with respect to their baseline characteristics. Sinus rhythm returned in 5 of 8 patients in group N versus 2 of 14 patients in group C (P < 0.05). These seven patients were admitted to the intensive care unit, though all died within 1 month. The results of this study suggest that NF may be effective in defibrillation of out-of-hospital VF, though controlled studies are needed to confirm our observations.
Pacing and Clinical Electrophysiology 02/2005; 28 Suppl 1:S155-7. · 1.35 Impact Factor
