| Japanese |
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| Title | 低血圧を呈した接合部調律の二症例 |
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| Subtitle | 症例 |
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| Authors | 横山和子*, 田村高子 |
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| Authors(kana) | |
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| Organization | *日本医科大学付属第1病院麻酔科 |
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| Journal | 循環制御 |
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| Volume | 10 |
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| Number | 2 |
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| Page | 309-314 |
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| Year/Month | 1989/ |
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| Article | 報告 |
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| Publisher | 日本循環制御医学会 |
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| Abstract | 「要旨」笑気-ハロタン麻酔中に房室解離を伴う接合部調律となり, 急激な血圧低下を示した2症例を報告する. 洞整脈の時, 心拍出量に対する心房収縮の寄与は約15%であるが, 循環動態の変化を伴うと, これは40%にも増加する. すなわち, atrial kickが消失すると, 心拍出量は15〜40%減少することになる. 今回の2症例は, ハロタンにより接合部調律発生時にatrial kickが消失した状態となり, 急激な血圧低下を生じたものと考える. 麻酔中に低血圧が生じた時, 接合部調律に伴う低血圧も鑑別診断の一つに入れる必要があろう. 「はじめに」麻酔中の不整脈というと, 多くの場合, 心室性不整脈に注目する傾向がある. しかし, 麻酔中の不整脈の多くは, 上室性不整脈, 特に房室解離を伴う接合部調律である1). ハロタン麻酔下に発生する接合部調律はレートの促進した接合部調律(accelerated A-V junctional rhythm)で等頻度房室解離(isorhythmic A-V dissociation)を伴うことが多い. 心電図モニタを十分注意してみていないと発見できず, たまたま, これが急激な血圧低下の原因となっていることがある. Atrial kickの心拍出量への寄与は心拍出量の約15%とされているが2), ヒトにおけるハロタン麻酔下での寄与率は17%程度である3). |
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| Practice | 基礎医学・関連科学 |
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| Keywords | anesthesia, atrial kick, atrioventricular dissociation, hypotension |
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| English |
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| Title | Hypertention due to transient atrioventricular dissociation in general anesthesia, two case report |
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| Authors | Kazuko Yokoyama, Takako Tamura |
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| Authors(kana) | |
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| Organization | Department of Anesthesiology Daiichi Hospital Nipon Medical School |
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| Journal | Circulation Control |
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| Volume | 10 |
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| Number | 2 |
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| Page | 309-314 |
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| Year/Month | 1989/ |
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| Article | Report |
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| Publisher | Japan Society of Circulation Control |
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| Abstract | Isothythmic atrioventricular dissociation occurs frequently under general anesthesia but is rarely recegnized without continuous electrocardiographic monitoring. Since this arrhythmia was observed in about 20 per cent of all patients under anesthesia, hypotension had been completely escaped from our attention, because of that the consequences of such a pacemaker shift are of no hemodynamic relevance. Recently we have noticed that accelerated junctional rhythm under halothane anesthesia almost always showed some hemodynamic changes a sudden blood pressure drop was observed in two patients during junctional rhythm under halothane anesthesia. One patient was 77 year old male had cholecystectomy and transverscolectomy and the other was 64 year old male had small bowel resection due to ileus. This hypotention highly related to loss of atrial kick. Usually, no clinical relevance is attributed to this kind of arrhythmia, though physiological investigation have pointed out the importance of atrial contraction to cardiac output (atrial kick). A properly timed atrial contraction is supposed to exert its favourable circulatory effects and shortning of the interval between atrial and ventricular contraction leads to a decrease in mean arterial pressure of 18 per cent and cardiac output of 15 per cent. A decrease in cardiac output of 15 per cent is indeed of no importance for healthy patients. However, one has to take into account that sometimes patients with poor circulation, as in hypovolemia or heart failure, are subjected to anesthesia and surgery. Under such circumstances the possible hemodynamic effects of atrioventricular dissociation are likely to be more pronounced and must be suspected as possible cause of sudden circulatory impairment. |
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| Practice | Basic medicine |
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| Keywords | anesthesia, atrial kick, atrioventricular dissociation, hypotension |
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