不整脈分野

通常型心房粗動に対するクライオアブレーションにおける下大静脈後方偏位の影響

　通常型心房粗動（atrial flutter: AFL）は、三尖弁輪を反時計方向に旋回するマクロリエントリー機序を有する頻拍であり、三尖弁輪と下大静脈の間に位置する狭部（cavotricuspid isthmus: CTI）に線状焼灼を行い、伝導ブロックを形成するカテーテルアブレーションが根治的な治療となります。近年、従来の高周波アブレーションに加えて、クライオアブレーションがCTIアブレーションの治療選択肢となりました。しかし、クライオアブレーションにおいて、CTIの伝導ブロック形成に影響する解剖学的指標は十分に解明されていません。

　本研究では、AFLに対してCTIクライオアブレーションを施行した連続100例を対象とし、CT検査で計測した解剖学的指標とアブレーション手技関連指標との関連性を検討しました。CT水平断面において、三尖弁輪中点と下大静脈中点を結んだ線分をCTIとして定義しました。さらに三尖弁輪中点を通る垂直線とCTIとのなす角度をCTI rotation（CR）角と定義し、下大静脈の後方偏位の大きさを示す指標としました（図1）。手技関連指標として、CTIアブレーション開始から最終的な伝導ブロック確認までの手技時間、ならびにクライオアブレーション時の冷却パラメータを評価しました。


図1

　CR角は手技時間と有意な正の相関を示しました（B = 0.369, P < 0.001）。CR角の中央値で分けた二群間で比較したところ、CR角が大きい群では小さい群と比較して手技時間が有意に長く（P = 0.005）、CTI三尖弁輪側でのクライオアブレーション時の最低温度到達時間も有意に長いという結果でありました（P = 0.031）。CR角が大きい症例と小さい症例について、それぞれの代表症例を図2に示します。


図2

 下大静脈の後方偏位を反映するCR角の増大は、アブレーションカテーテルおよびシース操作性の低下や安定したカテーテル固定を妨げる可能性があります。

 以上より、CR角の増大、すなわち下大静脈の後方偏位が、クライオアブレーション時のCTI伝導ブロック形成を困難にする可能性が示唆されました。

Heart Rhythm. 2026; 23: 123-130.

正常体重心房細動患者における左房周囲脂肪と電気的リモデリングとの関連

　本研究は、正常体重の心房細動患者においても左房周囲の心外膜脂肪（LA-EAT）が心房の電気的特性に影響を及ぼすことを示したものである。LA-EATが多い患者（High LA-EAT group）ではLA-EATが少ない患者(Low LA-EAT group）と比較し、左房の双極電位や低電位領域、左房容積には差がない一方で、P波持続時間が延長し、左房内伝導速度が有意に低下していた。さらに多変量解析により、LA-EAT量はP波持続時間の延長および伝導速度低下と独立して関連していることが示された。これらの結果から、LA-EATは正常体重の心房細動患者において、電気的リモデリングに強く関与している可能性が示唆された。


High LA-EAT groupでは、左房内の伝導速度が低下

J Cardiovasc Electrophysiol. 2023; 34: 565-574.

上大静脈隔離術における超高出力・超短時間通電法の有用性

　近年、心房細動に対するカテーテルアブレーションにおいて、超高出力・短時間通電法（very high-power short-duration: vHPSD法）が導入されています。vHPSD法は、これまでの高出力・短時間通電法（high-power short-duration: HPSD法）に比し浅く・広い焼灼巣を形成するため、周辺臓器傷害のリスクを減少させうることが示されています。心房細動アブレーション時に施行される上大静脈隔離術（superior vena cava isolation：SVCI）では、隣接する横隔神経傷害（phrenic nerve injury: PNI）の合併が懸念されます。SVCは壁厚が薄く浅い焼灼巣で十分なため、PNI予防の観点からもvHPSD法が理論上好適ですが、その有用性・安全性は示されていません。

　当院でSVCIを施行した連続51例（HPSD群：25例、vHPSD群：26例）において、PNIの頻度と各焼灼パラメータを比較しました。全例でSVCIを完遂しました。全焼灼巣（817箇所）の比較において、vHPSD群では総通電時間（47.8 ± 10.9 vs. 103.0 ± 28.3 秒, P < 0.001）および総通電エネルギー（3762 ± 837 vs. 5363 ± 1512 J, P < 0.001）が有意に低値でした。一方、HPSD群で軽度のPNIを3例（6%）に認めましたが、vHPSDでは認めませんでした。これらの結果から、SVCIにおけるvHPSD法の有用性・安全性が示されました。

Europace 2025; doi: 10.1093/europace/euaf056.

これまでの主な業績

  1. 1.Nodera M, Kaneshiro T, Murota S, Yamada S, Oikawa M, Takeishi Y. Complex signal identification as a marker of left atrial remodeling and very early recurrence after atrial fibrillation ablation. Heart Rhythm O2 7, 786-789, 2026
  2. 2.Murota S, Nodera M, Ohashi N, Ogawara R, Sato Y, Yokokawa T, Misaka T, Yamada S, Kaneshiro T, Oikawa M, Yoshihisa A, Takeishi Y. Higher very short-term blood pressure variability is associated with lower atrial fibrillation recurrence after catheter ablation. Front Cardiovasc Med 13, 1779540, 2026
  3. 3.Nodera M, Kaneshiro T, Murota S, Yamada S, Oikawa M, Takeishi Y. Posterior offset of inferior caval vein and its impact on cavotricuspid conduction block difficulty during cryoablation for common-type atrial flutter. Heart Rhythm 23, 123-130, 2026
  4. 4.Yamada S, Kaneshiro T, Nodera M, Amami K, Murota S, Oikawa M, Ishida T, Takeishi Y. Atrial to brain natriuretic peptide ratio as a marker of atrial remodeling severity and post-ablation recurrence risk in atrial fibrillation patients with left atrial enlargement. J Interv Card Electrophysiol 69, 125-134, 2026
  5. 5.Nodera M, Kaneshiro T, Murota S, Yamada S, Oikawa M, Takeishi Y. Impact of the distance from the cavotricuspid isthmus to the right coronary artery on first-pass conduction block during cryoablation for atrial flutter. J Arrhythm 41, e70159, 2025
  6. 6.Kaneshiro T, Murota S, Nodera M, Yamada S, Oikawa M, Takeishi Y. Feasibility of a 90-watt, 3-second radiofrequency application for superior vena cava isolation during atrial fibrillation ablation. Europace 27, euaf056, 2025
  7. 7.Kaneshiro T, Murota S, Nehashi T, Nodera M, Yamada S, Ikeda M, Takeishi Y. Achieving reduced radiation exposure with maintained fluoroscopy effectiveness using ultralow-dose settings in cryoballoon ablation. J Arrhythm 40, 1400-1407, 2024
  8. 8.Yamada S, Kaneshiro T, Nodera M, Amami K, Nehashi T, Oikawa M, Yamaki T, Nakazato K, Ishida T, Takeishi Y. Associations of the fibrosis-4 index with left atrial low-voltage areas and arrhythmia recurrence after catheter ablation: Cardio-hepatic interaction in patients with atrial fibrillation. J Arrhythm 40, 585-593, 2024
  9. 9.Yamada S, Kaneshiro T, Nodera M, Murota S, Takeishi Y. Critical ablation targets of ventricular tachycardia revealed by activation mapping with both last deflection and peak frequency annotations in a patient of cardiac sarcoidosis. J Arrhythm 40, 1510-1513, 2024
  10. 10.Nehashi T, Kaneshiro T, Nodera M, Yamada S, Takeishi Y. Characteristics of right pulmonary vein with an epicardial connection needing additional carina ablation for isolation. J Arrhythm 39, 884-893, 2023
  11. 11.Kamioka M, Makimoto H, Watanabe T, Watanabe H, Okuyama T, Kaneshiro T, Hijioka N, Yokota A, Komori T, Kabutoya T, Imai Y, Kario K. Unipolar-voltage-based evaluation of left atrial tissue properties and ablation outcome in patients with atrial fibrillation. Europace 25, euad240, 2023
  12. 12.Yamada S, Kaneshiro T, Nodera M, Amami K, Nehashi T, Horikoshi Y, Yamadera Y, Takeishi Y. Utility of short-time electrocardiogram to assess risk for atrial arrhythmia recurrence: Impact of atrial premature beat occurrence 1 day after pulmonary vein isolation for atrial fibrillation. J Cardiovasc Electrphysiol 34, 1969-1978, 2023
  13. 13.Yamada S, Kaneshiro T, Nodera M, Amami K, Nehashi T, Takeishi Y. Left atrial epicardial adipose tissue exacerbates electrical conduction disturbance in normal-weight patients undergoing pulmonary vein isolation for atrial fibrillation. J Cardiovasc Electrphysiol 34, 565-574, 2023
  14. 14.Amami K, Yoshihisa A, Horikoshi Y, Yamada S, Nehashi T, Hijioka N, Nodera M, Kaneshiro T, Yokokawa T, Misaka T, Takeishi Y. Utility of a novel wearable electrode embedded in an undershirt for electrocardiogram monitoring and detection of arrhythmias. PLoS One 17, e0273541, 2022
  15. 15.Hijioka N, Kaneshiro T, Nehashi T, Amami K, Nodera M, Yamada S, Yokokawa T, Misaka T, Takeishi Y. Influence of power setting on superior vena cava potential during right pulmonary vein isolation. J Interv Card Electrophysiol 65, 25-31, 2022
  16. 16.Yamada S, Kaneshiro T, Hijioka N, Amami K, Horikoshi Y, Yamadera Y, Hikichi T, Yoshihisa A, Takeishi Y. Autonomic cardiogastric neural interaction after pulmonary vein isolation in patients with atrial fibrillation. J Interv Card Electrophysiol 65, 357-364, 2022
  17. 17.Kamioka M, Hijioka N, Nodera M, Yamada S, Kaneshiro T, Takeishi Y. Electrophysiological properties and involvement of anatomical factors for the prediction of intramural origin in patients with ventricular tachyarrhythmia arising from the left ventricular outflow tract. J Interv Card Electrophysiol 63, 115-123, 2022
  18. 18.Hijioka N, Kaneshiro T, Nehashi T, Amami K, Nodera M, Yamada S, Kamioka M, Ishida T, Takeishi Y. Procedural characteristics of pulmonary vein isolation with high-power short-duration setting ablation compared to conventional setting. BMC Cardiovasc Disord 22, 14, 2022
  19. 19.Amami K, Yamada S, Yoshihisa A, Kaneshiro T, Hijioka N, Nodera M, Nehashi T, Takeishi Y. Predictive impacts of chronic kidney disease and cardiac sympathetic nervous activity on lethal arrhythmic events in chronic heart failure. Ann Noninvas Electro 27, e12900, 2022
  20. 20.Yamada S, Kaneshiro T, Yoshihisa A, Nodera M, Amami K, Nehashi T, Takeishi Y. Albumin-bilirubin score for prediction of outcomes in heart failure patients treated with cardiac resynchronization therapy. J Clin Med 10, 5378, 2021
  21. 21.Tomita Y, Yamada S, Kaneshiro T, Hijioka N, Shimizu T, Takeishi Y. A sudden rise in pacing threshold of left ventricular lead associated with myocardial ischemia. J Arrhythm 37, 693-695, 2021
  22. 22.Kaneshiro T, Amami K, Hijioka N, Nodera M, Yamada S, Yokokawa T, Misaka T, Hikichi T, Yoshihisa A, Takeishi Y. Significance of contact force on esophageal thermal injury during relative high-power short-duration ablation of atrial fibrillation. Circ Arrhythm Electrophysiol 14, e009897, 2021
  23. 23.Kamioka M, Kaneshiro T, Hijioka N, Amami K, Nodera M, Yamada S, Takeishi Y. Visit-to-visit blood pressure variability predicts atrial fibrillation recurrence after pulmonary vein isolation in patients with hypertension and atrial fibrillation. Circ Rep 3, 187-193, 2021
  24. 24.Yamada S, Yoshihisa A, Hijioka N, Amami K, Kaneshiro T, Ishida T, Takeishi Y. Associations of the prognostic nutritional index with the cardiac function and survival after cardiac resynchronization therapy. Intern Med 60, 985-991, 2021
  25. 25.Yamada S, Yoshihisa A, Kaneshiro T, Amami K, Hijioka N, Misaka T, Yokokawa T, Takeishi Y. Clinical impact of long PR-interval and presence of late gadolinium enhancement on hospitalized patients with non-ischemic heart failure. Ann Noninvas Electro 26, e12818, 2021
  26. 26.Yamada S, Yoshihisa A, Kaneshiro T, Amami K, Hijioka N, Oikawa M, Takeishi Y. The relationship between red cell distribution width and cardiac autonomic function in heart failure. J Arrhythm 36, 1076-1082, 2020
  27. 27.Kaneshiro T, Hijioka N, Matsumoto Y, Nodera M, Yamada S, Kamioka M, Takeishi Y. Temperature drop in thawing phase reflects sufficient ice formation and better outcome of pulmonary vein isolation using second-generation cryoballoon. J Interv Card Electrophysiol 59, 357-364, 2020
  28. 28.Kamioka M, Yoshihisa A, Hijioka N, Nodera M, Yamada S, Kaneshiro T, Oikawa M, Kobayashi A, Kunii H, Takeishi Y. The efficacy of combination of transcatheter atrial septal defects closure and radiofrequency catheter ablation for the prevention of atrial fibrillation recurrence through bi-atrial reverse remodeling. J Interv Card Electrophysiol 59, 365-372, 2020
  29. 29.Kaneshiro T, Kamioka M, Hijioka N, Yamada S, Yokokawa T, Misaka T, Hikichi T, Yoshihisa A, Takeishi Y. Characteristics of esophageal injury in ablation of atrial fibrillation using a high-power short-duration setting. Circ Arrhythm Electrophysiol 13, e008602, 2020
  30. 30.Kamioka M, Yoshihisa A, Nodera M, Misaka T, Yokokawa T, Kaneshiro T, Nakazato K, Ishida T, Takeishi Y. The clinical implication of new-onset in‐hospital atrial fibrillation in patients with acute decompensated heart failure. J Arrhythm 36, 874-882, 2020
  31. 31.Yamada S, Yoshihisa A, Hijioka N, Kamioka M, Kaneshiro T, Yokokawa T, Misaka T, Ishida T, Takeishi Y. Autonomic dysfunction in cardiac amyloidosis assessed by heart rate variability and heart rate turbulence. Ann Noninvas Electro 25, e12749, 2020
  32. 32.Yamada S, Yoshihisa A, Sato T, Kamioka M, Kaneshiro T, Oikawa M, Kobayashi A, Ishida T, Takeishi Y. Prognostic significance of premature ventricular complex burden on hospitalized patients with heart failure. J Arrhythm 36, 134-142, 2019
  33. 33.Yamada S, Kaneshiro T, Kamioka M, Onuma H, Yamadera Y, Takeishi Y. Clinical impact of speckle tracking echocardiography for detecting the origin of posterior papillary muscle ventricular arrhythmia. Europace 21, 917, 2019
  34. 34.Hijioka N, Kamioka M, Matsumoto Y, Nodera M, Yamada S, Kaneshiro T, Yoshihisa A, Ishida T, Takeishi Y. Clinical impact of insulin resistance on pulmonary vein isolation outcome in patients with paroxysmal atrial fibrillation. J Cardiovasc Electrphysiol 30, 479-486, 2019
  35. 35.Matsumoto Y, Kaneshiro T, Hijioka N, Nodera M, Yamada S, Kamioka M, Yoshihisa A, Ohkawara H, Hikichi T, Suzuki H, Takeishi Y. Predicting factors of transmural thermal injury after cryoballoon pulmonary vein isolation. J Interv Card Electrophysiol 54, 101-108, 2019
  36. 36.Kaneshiro T, Matsumoto Y, Hijioka N, Nodera M, Yamada S, Kamioka M, Yoshihisa A, Ohkawara H, Suzuki H, Takeishi Y. Distinct forms of esophageal lesions after radiofrequency and cryoballoon pulmonary vein isolation. JACC Clin Electrophysiol 4, 1642-1643, 2018
  37. 37.Yamada S, Yoshihisa A, Sato Y, Sato T, Kamioka M, Kaneshiro T, Oikawa M, Kobayashi A, Suzuki H, Ishida T, Takeishi Y. Utility of heart rate turbulence and T-wave alternans to assess risk for readmission and cardiac death in hospitalized heart failure patients. J Cardiovasc Electrphysiol 29, 1257-1264, 2018
  38. 38.Nodera M, Suzuki H, Matsumoto Y, Kamioka M, Kaneshiro T, Yoshihisa A, Ohira T, Takeishi Y. Association between serum uric acid level and ventricular tachyarrhythmia in heart failure patients with implantable cardioverter-defibrillator. Cardiology 140, 47-51, 2018
  39. 39.Kamioka M, Hijioka N, Matsumoto Y, Nodera M, Kaneshiro T, Suzuki H, Takeishi Y. Uncontrolled blood pressure affects atrial remodeling and adverse clinical outcome in paroxysmal atrial fibrillation. Pacing Clin Electrophysiol 41, 402-410, 2018
  40. 40.Kaneshiro T, Matsumoto Y, Nodera M, Kamioka M, Kamiyama Y, Yoshihisa A, Ohkawara H, Suzuki H, Takeishi Y. Anatomical predisposing factors of transmural thermal injury after pulmonary vein isolation. Europace 20, 1122-1128, 2018
  41. 41.Suzuki H, Nodera M, Kamioka M, Kaneshiro T, Kamiyama Y, Takeishi Y. Intracardiac impedance after cardiac resynchronization therapy is a novel predictor for worsening of heart failure. Heart Vessels 32, 926-931, 2017
  42. 42.Kaneshiro T, Matsumoto Y, Nodera M, Kamioka M, Suzuki H, Takeishi Y. Spastic occlusion of coronary artery during cryoballoon pulmonary vein isolation. HeartRhythm Case Rep 3, 509-512, 2017
  43. 43.Kaneshiro T, Yoshida K, Sekiguchi Y, Tada H, Kuroki K, Kuga K, Kamiyama Y, Suzuki H, Takeishi Y, Aonuma K. Crucial role of pulmonary vein firing as an initiator of typical atrial flutter: Evidence of a close relationship between atrial fibrillation and typical atrial flutter. J Arrhythm 33, 86-91, 2017
  44. 44.Kaneshiro T, Suzuki H, Nodera M, Kamioka M, Kamiyama Y, Takeishi Y. Fibrillatory excitation in the pulmonary vein is associated with the presence of dissociated pulmonary vein activity after isolation. J Interv Card Electrophysiol 47, 231-236, 2016
  45. 45.Hijioka N, Kamioka M, Suzuki H, Takeishi Y. A case of atrial tachycardia circulating around a left atrial roof scar with diabetes mellitus and renal failure on hemodialysis. Case Rep Med 2016, 6485939, 2016
  46. 46.Kaneshiro T, Suzuki H, Nodera M, Yamada S, Kamioka M, Kamiyama Y, Takeishi Y. Mapping strategy associated with QRS morphology for catheter ablation in patients with idiopathic ventricular outflow tract tachyarrhythmia. Pacing Clin Electrophysiol 39, 338-344, 2016
  47. 47.Kamioka M, Nodera M, Suzuki H, Takeishi Y. The utility of shock coil and left ventricular tip–right ventricular coil impedance as a predictor of pneumothorax in cardiac resynchronization therapy implantation. J Cardiol Cases 13, 193-195, 2016
  48. 48.Nodera M, Suzuki H, Yamada S, Kamioka M, Kaneshiro T, Kamiyama Y, Takeishi Y. Association of serum n-3/n-6 polyunsaturated fatty acid ratio with T-wave alternans in patients with ischemic heart disease. Int Heart J 56, 613-617, 2015
  49. 49.Kamiyama Y, Suzuki H, Yamada S, Kaneshiro T, Takeishi Y. Serum phosphate levels reflect responses to cardiac resynchronization therapy in chronic heart failure patients. J Arrhythm 31, 38-42, 2015
  50. 50.Suzuki H, Ohira T, Takeishi Y, Hosoya M, Yasumura S, Satoh H, Kawasaki Y, Takahashi A, Sakai A, Ohtsuru A, Kobashi G, Ozasa K, Yamashita S, Kamiya K, Abe M, for the Fukushima Health Management Survey Group. Increased prevalence of atrial fibrillation after the Great East Japan Earthquake: Results from the Fukushima Health Management Survey. Int J Cardiol 198, 102-105, 2015
  51. 51.Yamada S, Suzuki H, Kaneshiro T, Kamiyama Y, Saitoh S, Takeishi Y. Prognostic value of T-wave alternans in survivors of ventricular fibrillation or hemodynamically unstable ventricular tachycardia. J Arrhythm 30, 485-490, 2014
  52. 52.Yamada S, Suzuki H, Kamiyama Y, Saitoh S, Takeishi Y. Predictive impact of the decreasing rate of intrathoracic impedance in worsening chronic heart failure. J Interv Card Electrophysiol 40, 87-91, 2014
  53. 53.Suzuki H, Yamada S, Kamiyama Y, Takeishi Y. Efficacy of intrathoracic impedance and remote monitoring in patients with an implantable device after the 2011 Great East Japan Earthquake. Int Heart J 55, 53-57, 2014
  54. 54.Yamada S, Suzuki H, Kamioka M, Suzuki S, Kamiyama Y, Yoshihisa A, Saitoh S, Takeishi Y. Sleep-disordered breathing increases risk for fatal ventricular arrhythmias in patients with chronic heart failure. Circ J 77, 1466-1473, 2013
  55. 55.Nakamura Y, Suzuki H, Takeda H, Takeishi Y. DDTA mode pacing in the treatment of complete conduction block from the right atrium to the ventricles and interatrial electrical dissociation after surgical procedures. J Arrhythm 29, 235-237, 2013
  56. 56.Yamada S, Suzuki H, Kamioka M, Kamiyama Y, Saitoh S, Takeishi Y. Uric acid increases the incidence of ventricular arrhythmia in patients with left ventricular hypertrophy. Fukushima J Med Sci 58, 101-106, 2012
  57. 57.Kaneshiro T, Suzuki H, Yamada S, Kamiyama Y, Saitoh S, Takeishi Y. Intrathoracic impedance changes reflect reverse left ventricular remodeling in response to cardiac resynchronization therapy in chronic heart failure patients. Int Heart J 53, 249-252, 2012
  58. 58.Kamioka M, Suzuki H, Yamada S, Kamiyama Y, Saitoh S, Takeishi Y. High sensitivity C-reactive protein predicts nonresponders and cardiac deaths in severe heart failure patients after CRT implantation. Int Heart J 53, 306-312, 2012
  59. 59.Suzuki H, Takeishi Y. Inducibility of atrial fibrillation caused by acute increase of atrial pressure in rat diseased heart with chronic atrial dilation. Int Heart J 53, 257-260, 2012

文責:野寺穣、山田慎哉、金城貴士

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