Hiroki Kamiya

Hiroshima University, Hirosima, Hiroshima, Japan

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Publications (4)13.27 Total impact

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    ABSTRACT: BACKGROUND: Sleep-disordered breathing (SDB) frequently is induced by sedation during ablation of atrial fibrillation (AF). We tested whether or not sedative-induced SDB is associated with clinical sleep apnea syndrome (SAS). METHODS: We examined SDB observed during intra-ablation sedation with a novel portable respiratory monitor (PM), SD-101, in 140 patients undergoing AF ablation without any known SAS. A sleep study was repeated the next night of the ablation with the simultaneous use of the SD-101 and type 3 PM, APNOMONITOR V. RESULTS: The respiratory disturbance index (RDI) during sedation (20.0±7.8events/h) was significantly correlated with the RDI measured by the SD-101 during the night (15.8±13.7events/h; r=0.50) and the RDI assessed by the APNOMONITOR V during the night (12.7±12.3events/h; r=0.55). An excellent agreement was found between the RDIs simultaneously measured with the 2 PMs (intraclass correlation coefficient, 0.84), especially for an RDI of ⩾30events/h (κ statistic value, 0.82). The area under the receiver-operating characteristic curve for the RDI with the use of the SD-101 during sedation to identify the patients with an RDI of ⩾30events/h by both PMs during the night was 0.92. A left atrial diameter of >40mm (odds ratio [OR], 4.10) and an RDI during sedation of >20events/h (OR, 17.75) were independently associated with having an RDI of ⩾30events/h with both PMs during the night. CONCLUSIONS: Frequent episodes of sedative-induced SDB may have a diagnostic value for SAS in patients with AF.
    Sleep Medicine 05/2013; · 3.49 Impact Factor
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    ABSTRACT: BACKGROUND: We aimed to evaluate the feasibility of an oral direct thrombin inhibitor, dabigatran, as a periprocedural anticoagulant for use with ablation of atrial fibrillation (AF). METHODS: Consecutive patients scheduled to undergo an AF ablation were randomly assigned to receive dabigatran (n = 45) or warfarin (n = 45) to compare their clinical feasibility. Both of those oral anticoagulants were discontinued the day before the ablation and were resumed after confirming hemostasis of the venipuncture site. A bridging therapy with heparin was not used in either of the patient groups. RESULTS: Dabigatran was switched to warfarin before the ablation because of dyspepsia in three patients. An occurrence of rebleeding from the venipuncture site was less common in dabigatran-allocated patients than in warfarin-allocated patients (20% vs 44%; P = 0.013). The reduction in the D-dimer level after the initiation of oral anticoagulants was greater in the dabigatran-allocated patients than in the warfarin-allocated patients. The time from the initiation of the anticoagulants to the ablation was significantly shorter in the dabigatran-allocated patients than in the warfarin-allocated patients (43 ± 7 vs 63 ± 13 days; P < 0.0001). There was only one fatal periprocedural complication in a patient receiving warfarin, who had a mesenteric arterial thrombosis after the ablation. CONCLUSIONS: An anticoagulation strategy with dabigatran may surpass that with warfarin in reducing both the periprocedural risk of minor bleeding and a hypercoagulable state, and the time to ablation in patients undergoing ablation of AF.
    Pacing and Clinical Electrophysiology 11/2012; · 1.75 Impact Factor
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    ABSTRACT: AF Ablation in HD Patients. Introduction: It is not common for patients on chronic hemodialysis (HD) to undergo catheter ablation of atrial fibrillation (AF). We aimed to show the outcomes of AF ablation in the HD patients. Methods and Results: Thirty HD patients who underwent pulmonary vein (PV) isolation for drug refractory paroxysmal AF were retrospectively studied, and their AF recurrence free rate and frequency of periprocedural complications were compared to 60 age- and gender-matched control patients not requiring HD. A nonirrigated ablation catheter was used in both patient groups. During a mean follow-up period of 821 ± 218 days, 16 (54%) of the HD patients remained free from AF recurrence without any antiarrhythmic agents versus 47 (78%) of the control patients with an initial ablation (P = 0.013). A second ablation procedure was performed in 12 patients with an AF recurrence, and consequently 20 (67%) of the HD patients were in sinus rhythm compared to 53 (88%) of the controls during a follow-up duration of 747 ± 221 after the last ablation (P = 0.012). Bleeding from the venipuncture site requiring a prolonged hospital stay was identified in 2 HD patients and 1 control subject, while no life-threatening complications were observed in either patient group. Conclusion: Although the success rate of the PV isolation in HD patients was far from satisfactory, it may be considered as one of the therapeutic options for them. (J Cardiovasc Electrophysiol, Vol. pp. 1-6).
    Journal of Cardiovascular Electrophysiology 07/2012; · 3.48 Impact Factor
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    ABSTRACT: High-frequency stimulation (HFS) of the atria induces atrial fibrillation (AF) when applied during sinus rhythm and elicits a parasympathetic response when delivered at sites where ganglionated plexi (GPs) are located. However, little is known about its impact after an electrophysiological study. To evaluate the impact of HFS on the short-term and long-term outcomes after the ablation of persistent AF. Thirty consecutive patients with persistent or long-standing persistent AF were randomly assigned to either receive HFS of the left atrium (n = 15) or not (n = 15) during their electrophysiological studies. Patients receiving HFS were examined to determine whether or not a vagal response was elicited by the HFS at sites where GPs were located before and after conventional pulmonary vein isolation without any ablation targeting the GPs. Patients not receiving the HFS underwent the ablation procedure alone. The rate of recurrence of AF within 3 months of the procedure (early recurrence [ER]) and the frequency of that occurring after that period (late recurrence) were compared between the patient groups. The incidence of ER occurred more frequently in patients with HFS than in those without (80% vs 40%; P = .015), whereas the occurrence of late recurrence was similar between the 2 groups (27% vs 33%; P = .73). In the HFS group, the number of GPs decreased from 3.4 ± 1.1 to 1.5 ± 0.8 after the pulmonary vein isolation (P < .0001), and the decrease was smaller in the patients experiencing ER than in those without. HFS increases the incidence of ER in patients with persistent AF despite a partial GP modification resulting from the pulmonary vein isolation.
    Heart rhythm: the official journal of the Heart Rhythm Society 05/2012; 9(9):1386-92. · 4.56 Impact Factor