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器質的心疾患に合併する心室期外収縮に対する薬物治療

不整脈薬物治療に関するガイドラインに基づく器質的心疾患に合併する心室期外収縮に対する薬剤選択
出典
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1: 抗不整脈薬ガイドライン委員会編集.抗不整脈薬ガイドライン︲ CD-ROM版 ガイドラインの解説とシシリアンガンビットの概念. ライフメディコム;2000 より改変(不整脈薬物治療に関するガイドライン(2009年改訂版)、p29 図18、日本循環器学会、2009掲載)

特発性心室期外収縮の体表12誘導心電図(左脚ブロック型+下方軸)

動悸を訴え病院を受診した39歳男性。
症状に一致して、左脚ブロック型+下方軸の心室期外収縮が認められた。
出典
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1: 著者提供

不整脈源性右室心筋症で認められた心室期外収縮(左脚ブロック型+下方軸)

動悸を訴え病院を受診した26歳男性。
流出路起源と推測される左脚ブロック型+下方軸型の心室期外収縮が認められたが、心臓超音波検査では、著明な右室拡大および洞調律時の前胸部誘導(V1-V4)で陰性T波が認められ、不整脈源性右室心筋症と診断された。
出典
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1: 著者提供

変行伝導を伴った上室期外収縮

一見、心室期外収縮を疑わせる右脚ブロック型+下方軸のwide QRS波形が認められるが、先行するT波に重なる心房波(P波)が認められることより、wide QRS波形は上室期外収縮の変行伝導であることがわかる。
出典
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1: 著者提供

心室期外収縮の頻度と左室駆出率の関係

心室期外収縮の増加に伴い、左室駆出率の低下が認められることがわかる。心室期外収縮の頻度(>24%)をカットオフ値とした場合、感度79%、特異度78%で心室期外収縮に伴う左室機能低下例の特定が可能となる。
出典
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1: Relationship between burden of premature ventricular complexes and left ventricular function.
著者: Baman TS, Lange DC, Ilg KJ, Gupta SK, Liu TY, Alguire C, Armstrong W, Good E, Chugh A, Jongnarangsin K, Pelosi F Jr, Crawford T, Ebinger M, Oral H, Morady F, Bogun F.
雑誌名: Heart Rhythm. 2010 Jul;7(7):865-9. doi: 10.1016/j.hrthm.2010.03.036. Epub 2010 Mar 27.
Abstract/Text: BACKGROUND: Frequent idiopathic premature ventricular complexes (PVCs) can result in a reversible form of left ventricular dysfunction. The factors resulting in impaired left ventricular function are unclear. Whether a critical burden of PVCs can result in cardiomyopathy has not been determined.
OBJECTIVE: The objective of this study was to determine a cutoff PVC burden that can result in PVC-induced cardiomyopathy.
METHODS: In a consecutive group of 174 patients referred for ablation of frequent idiopathic PVCs, the PVC burden was determined by 24-hour Holter monitoring, and transthoracic echocardiograms were used to assess left ventricular function. Receiver-operator characteristic curves were constructed based on the PVC burden and on the presence or absence of reversible left ventricular dysfunction to determine a cutoff PVC burden that is associated with left ventricular dysfunction.
RESULTS: A reduced left ventricular ejection fraction (mean 0.37 +/- 0.10) was present in 57 of 174 patients (33%). Patients with a decreased ejection fraction had a mean PVC burden of 33% +/- 13% as compared with those with normal left ventricular function 13% +/- 12% (P <.0001). A PVC burden of >24% best separated the patient population with impaired as compared with preserved left ventricular function (sensitivity 79%, specificity 78%, area under curve 0.89) The lowest PVC burden resulting in a reversible cardiomyopathy was 10%. In multivariate analysis, PVC burden (hazard ratio 1.12, 95% confidence interval 1.08 to 1.16; P <.01) was independently associated with PVC-induced cardiomyopathy.
CONCLUSION: A PVC burden of >24% was independently associated with PVC-induced cardiomyopathy.

Copyright 2010 Heart Rhythm Society. All rights reserved.
Heart Rhythm. 2010 Jul;7(7):865-9. doi: 10.1016/j.hrthm.2010.03.036. E...

陳旧性心筋梗塞に合併した心室期外収縮に対する抗不整脈薬投与が予後に及ぼす影響(Cardiac Arrhythmia Suppression試験)

心筋梗塞後に認められる心室期外収縮に対するナトリウムチャネル遮断薬の有効性が検証された。CAST試験では、ナトリウムチャネル遮断薬の使用により生命予後が悪化することが示された。
出典
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1: Mortality and morbidity in patients receiving encainide, flecainide, or placebo. The Cardiac Arrhythmia Suppression Trial.
著者: Echt DS, Liebson PR, Mitchell LB, Peters RW, Obias-Manno D, Barker AH, Arensberg D, Baker A, Friedman L, Greene HL.
雑誌名: N Engl J Med. 1991 Mar 21;324(12):781-8. doi: 10.1056/NEJM199103213241201.
Abstract/Text: BACKGROUND AND METHODS: In the Cardiac Arrhythmia Suppression Trial, designed to test the hypothesis that suppression of ventricular ectopy after a myocardial infarction reduces the incidence of sudden death, patients in whom ventricular ectopy could be suppressed with encainide, flecainide, or moricizine were randomly assigned to receive either active drug or placebo. The use of encainide and flecainide was discontinued because of excess mortality. We examined the mortality and morbidity after randomization to encainide or flecainide or their respective placebo.
RESULTS: Of 1498 patients, 857 were assigned to receive encainide or its placebo (432 to active drug and 425 to placebo) and 641 were assigned to receive flecainide or its placebo (323 to active drug and 318 to placebo). After a mean follow-up of 10 months, 89 patients had died: 59 of arrhythmia (43 receiving drug vs. 16 receiving placebo; P = 0.0004), 22 of nonarrhythmic cardiac causes (17 receiving drug vs. 5 receiving placebo; P = 0.01), and 8 of noncardiac causes (3 receiving drug vs. 5 receiving placebo). Almost all cardiac deaths not due to arrhythmia were attributed to acute myocardial infarction with shock (11 patients receiving drug and 3 receiving placebo) or to chronic congestive heart failure (4 receiving drug and 2 receiving placebo). There were no differences between the patients receiving active drug and those receiving placebo in the incidence of nonlethal disqualifying ventricular tachycardia, proarrhythmia, syncope, need for a permanent pacemaker, congestive heart failure, recurrent myocardial infarction, angina, or need for coronary-artery bypass grafting or angioplasty.
CONCLUSIONS: There was an excess of deaths due to arrhythmia and deaths due to shock after acute recurrent myocardial infarction in patients treated with encainide or flecainide. Nonlethal events, however, were equally distributed between the active-drug and placebo groups. The mechanisms underlying the excess mortality during treatment with encainide or flecainide remain unknown.
N Engl J Med. 1991 Mar 21;324(12):781-8. doi: 10.1056/NEJM199103213241...

心不全患者に対するβ遮断薬群とプラセボ群における累積死亡率(a)、心血管死亡率(b)、突然死率(c)、心不全の増悪率(d)

心不全患者に対するメトプロロールの有効性を検証したMERIT-HF 試験では、メトプロロールの投与により死亡率、心血管死亡率、突然死、心不全の増悪のいずれも改善することが示された。
出典
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1: Effect of metoprolol CR/XL in chronic heart failure: Metoprolol CR/XL Randomised Intervention Trial in Congestive Heart Failure (MERIT-HF).
著者: .
雑誌名: Lancet. 1999 Jun 12;353(9169):2001-7.
Abstract/Text: BACKGROUND: Metoprolol can improve haemodynamics in chronic heart failure, but survival benefit has not been proven. We investigated whether metoprolol controlled release/extended release (CR/XL) once daily, in addition to standard therapy, would lower mortality in patients with decreased ejection fraction and symptoms of heart failure.
METHODS: We enrolled 3991 patients with chronic heart failure in New York Heart Association (NYHA) functional class II-IV and with ejection fraction of 0.40 or less, stabilised with optimum standard therapy, in a double-blind randomised controlled study. Randomisation was preceded by a 2-week single-blind placebo run-in period. 1990 patients were randomly assigned metoprolol CR/XL 12.5 mg (NYHA III-IV) or 25.0 mg once daily (NYHA II) and 2001 were assigned placebo. The target dose was 200 mg once daily and doses were up-titrated over 8 weeks. Our primary endpoint was all-cause mortality, analysed by intention to treat.
FINDINGS: The study was stopped early on the recommendation of the independent safety committee. Mean follow-up time was 1 year. All-cause mortality was lower in the metoprolol CR/XL group than in the placebo group (145 [7.2%, per patient-year of follow-up]) vs 217 deaths [11.0%], relative risk 0.66 [95% CI 0.53-0.81]; p=0.00009 or adjusted for interim analyses p=0.0062). There were fewer sudden deaths in the metoprolol CR/XL group than in the placebo group (79 vs 132, 0.59 [0.45-0.78]; p=0.0002) and deaths from worsening heart failure (30 vs 58, 0.51 [0.33-0.79]; p=0.0023).
INTERPRETATION: Metoprolol CR/XL once daily in addition to optimum standard therapy improved survival. The drug was well tolerated.
Lancet. 1999 Jun 12;353(9169):2001-7.

心筋梗塞およびうっ血性心不全患者に対するアミオダロン投与の予後を検証したメタ解析

心筋梗塞後やうっ血性心不全患者に対するアミオダロンの有効性を検証した13のランダム化比較試験のメタアナリシスでは、アミオダロンの内服により総死亡率が13%、不整脈死が29%低下することが示された。
出典
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1: Effect of prophylactic amiodarone on mortality after acute myocardial infarction and in congestive heart failure: meta-analysis of individual data from 6500 patients in randomised trials. Amiodarone Trials Meta-Analysis Investigators.
著者: .
雑誌名: Lancet. 1997 Nov 15;350(9089):1417-24.
Abstract/Text: BACKGROUND: There have been 13 randomised controlled trials of prophylactic amiodarone in patients with recent myocardial infarction (MI) or congestive heart failure (CHF). None of these was powered to detect a mortality reduction of about 20%. We undertook a meta-analysis, based on data from individual patients, to provide a more sensitive and accurate assessment of the benefits and risks of prophylactic amiodarone.
METHODS: Individual data from the studies were abstracted according to a predefined protocol. The summary odds ratios were calculated according to standard methods.
FINDINGS: There were eight post-MI and five CHF trials; nine trials were double-blind and placebo-controlled, and four compared amiodarone with usual care. 6553 patients were randomly assigned treatment, of which 78% were in post-MI trials and 22% in CHF trials. 89% had had previous MI. The mean left-ventricular ejection fraction was 31%, and median frequency of ventricular premature depolarisation 18 per h. Total mortality was reduced by 13% (odds ratio 0.87 [95% CI 0.78-0.99], p = 0.030) based on classic fixed-effects meta-analysis and by 15% (0.85 [0.71-1.02], p = 0.081) with the more conservative random-effects approach. Arrhythmic/sudden death was reduced by 29% (0.71 [0.59-0.85], p = 0.0003). There was no effect on non-arrhythmic deaths (1.02 [0.87-1.19], p = 0.84). There was no difference in treatment effect between post-MI and CHF studies. The risk of arrhythmic/sudden death in control-group patients was higher in CHF than in post-MI studies (10.7 vs 4.1%), and the best single predictor of risk of arrhythmic/sudden death among all patients was symptomatic CHF. The excess (amiodarone minus control) risk of pulmonary toxicity was 1% per year.
INTERPRETATION: Prophylactic amiodarone reduces the rate of arrhythmic/sudden death in high-risk patients with recent MI or CHF and this effect results in an overall reduction of 13% in total mortality.
Lancet. 1997 Nov 15;350(9089):1417-24.

カテーテル心筋焼灼術が施行された突発性心室性不整脈の患者背景

カテーテル心筋焼灼術が施行された特発性心室性不整脈の約8割が右室もしくは左室流出路起源であり、右室流出路起源の心室性不整脈に対する成績は約90%であった。
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1: Gender and age differences in candidates for radiofrequency catheter ablation of idiopathic ventricular arrhythmias.
著者: Tanaka Y, Tada H, Ito S, Naito S, Higuchi K, Kumagai K, Hachiya H, Hirao K, Oshima S, Taniguchi K, Aonuma K, Isobe M.
雑誌名: Circ J. 2011;75(7):1585-91. doi: 10.1253/circj.cj-10-0941. Epub 2011 May 12.
Abstract/Text: BACKGROUND: The prevalence, gender- and age-related differences, ablation success rate and inter-relationship between the origins of the idiopathic ventricular arrhythmias (I-VA) have not been clarified.
METHODS AND RESULTS: A total of 625 consecutive patients with symptomatic, drug resistant I-VA (315 males and 310 females; mean age, 54 ± 17 years; 218 ventricular tachycardias, 407 premature ventricular contractions) who underwent catheter ablation were studied. The patients were divided into 5 groups based on the VA origin: (1) outflow tract (OT)-VA, consisting of right ventricular (RV) OT-VA and left ventricular (LV) OT-VA; (2) inflow tract (IT)-VA, consisting of tricuspid annulus (TA)-free wall (FW)-VA, IT-septum-VA, and mitral (MA)-FW-VA; (3) LV-inferoseptum-VA; (4) LV-other-VA; and (5) RV-other-VA. RVOT-VA in women were 1.5 times more frequent than in men, while LVOT-VA were more frequent in men. The prevalence of LVOT origin I-VA increased with age compared to that for the RVOT. The mean age of MA-FW-VA patients (62 ± 14 years) was higher than that of TA-FW-VA patients (51 ± 18 years; P = 0.03). The ablation success rate for RVOT-VA (88%) was higher than that for LVOT-VA (58%; P<0.0001). A multivariate analysis revealed that the patient age was one of the valuable predictors of a successful ablation (odds ratio=0.97; 95% confidence interval: 0.95-0.99; P=0.007).
CONCLUSIONS: Distinct gender and age differences were found in the incidence of I-VA according to their site of origin.
Circ J. 2011;75(7):1585-91. doi: 10.1253/circj.cj-10-0941. Epub 2011 M...

特発性心室期外収縮に対する薬剤選択

不整脈薬物治療に関するガイドラインに基づく特発性心室期外収縮に対する薬剤選択
出典
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1: 抗不整脈薬ガイドライン委員会編集.抗不整脈薬ガイドライン︲ CD-ROM版 ガイドラインの解説とシシリアンガンビットの概念.ライフメディコム;2000 より改変(不整脈薬物治療に関するガイドライン(2009年改訂版)、p28 図16、日本循環器学会、2009掲載)

器質的心疾患に合併する心室期外収縮に対する薬物治療

不整脈薬物治療に関するガイドラインに基づく器質的心疾患に合併する心室期外収縮に対する薬剤選択
出典
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1: 抗不整脈薬ガイドライン委員会編集.抗不整脈薬ガイドライン︲ CD-ROM版 ガイドラインの解説とシシリアンガンビットの概念. ライフメディコム;2000 より改変(不整脈薬物治療に関するガイドライン(2009年改訂版)、p29 図18、日本循環器学会、2009掲載)

特発性心室期外収縮の体表12誘導心電図(左脚ブロック型+下方軸)

動悸を訴え病院を受診した39歳男性。
症状に一致して、左脚ブロック型+下方軸の心室期外収縮が認められた。
出典
img
1: 著者提供