Intermittent arrest with esmolol did not enhance protection of intermittent crossclamping with fibrillation; however, multiple esmolol infusions during global ischemia provided improved protection. Administration (constant flow or constant pressure) of arresting solutions influenced outcome only during continuous infusion. Multidose esmolol arrest may be a beneficial alternative to intermittent crossclamping with fibrillation or conventional cardioplegia.

Oxygenation of esmolol cardioplegia (Krebs-Henseleit buffer plus 1.0 mmol/L esmolol) was essential for optimal myocardial protection. Multidose infusion of oxygenated esmolol cardioplegia provided good myocardial protection during extended periods of normothermic ischemia. Esmolol cardioplegia may provide an efficacious alternative to hyperkalemia.

A similar level of myocardial protection was achieved with multidose (intermittent) cardioplegia or intermittent crossclamping (with or without fibrillation), indicating that intrinsic preservation by intermittent crossclamping with fibrillation does not exacerbate ischemic injury.

No abstract

高カリウムを用いた脱分極型心筋保護液は確立された心筋保護法である．しかしながら，高カリウム自体が 虚血中に細胞内カルシウム負荷をもたらし心筋障害をきたすという問題があることも知られており，今後よ り優れた心筋保護法の開発が期待されている．高カリウムを用いない非脱分極型心筋保護液について， (1) 急速な心停止， (2)心筋保護効果， (3)可逆性， (4)毒性という観点から，おのおのの心筋保護液の特 徴を検討したが，いずれもまだ確立したものとはいいがたい．そのなかでも，高マグネシウム心筋保護液， エスモロール心筋保護液は，高カリウム心筋保護液を凌駕する心筋保護効果をもち，可逆性，毒性という点 でも問題がなく，今後さらなる臨床応用が期待される．また内因性心筋保護効果を誘導する手段として， ischemic preconditioningとischemic postconditioningという概念が注目されている．しかしなが ら，心臓手術におけるこれらの付加的心筋保護効果は確立されておらず，いずれも複数回の大動脈遮断によ る脳塞栓症というリスクを伴うため，すべての心臓手術に適用するには難しいかもしれない．一方，虚血前 または再灌流時に薬剤を使用するpharmacological preconditioningとpharmacological postcondi-tioningは，複数回の大動脈遮断を必要としない簡便な方法であり，今後心臓手術への適用が期待される． 日心外会誌 43 巻 5 号：239-253(2014) キーワード：心筋保護；マグネシウム；エスモロール；ischemic preconditioning；ischemic postconditioning

A 61-year-old woman presented with loss of consciousness. Echocardiography revealed a hypoechoic, round mass of 12 13 mm with a smooth border in the left ventricular outflow tract, leading to a diagnosis of loss of consciousness caused by left ventricular outflow tract obstruction, and surgical excision of the mass was performed. The mass, with a smooth, elastic soft surface and filled with yellow, creamy contents, was observed within a range from the subannular region of the left coronary cusp to the anterior mitral leaflet. Pathological examination showed central degeneration and liquefaction, as well as cystic, coarse-granular calcium deposition surrounded by inflammatory cell infiltration and fibroblast proliferation. No tumor cells were seen. Abscess was excluded by preoperative clinical presentations, hematologic data, and culture testing, and thus the mass was considered as caseous calcification of the mitral annulus. Here, we report a case of caseous calcification of the mitral annulus, a rare nonneoplastic lesion thought to be a variant of mitral annular calcification, with literature review.