川合 真由美

AIMS: We examined whether the severity of central sleep apnoea (CSA) and the level of C-reactive protein are associated with the prevalence and complexity of arrhythmias, and whether these factors contribute to increased risk of nocturnal sudden death. METHODS AND RESULTS: We prospectively examined 178 patients (age 70 ± 1 years) who were admitted to our hospital due to worsening heart failure. We recorded a simultaneous overnight cardiorespiratory polygraph and Holter ECG. Obstructive sleep apnoea was excluded and patients were dichotomized based on the median value of the central apnoea index (CAI) of 7.5/h. The prevalence and complexity of arrhythmias were compared between daytime (06:00 h to 15:00 h) and night-time (21:00 h to 06:00 h). A multivariate logistic regression analysis revealed that the CAI was associated with prevalence of atrial fibrillation (AF) [odds ratio 1.03, 95% confidence interval (CI) 1.02-2.51)] and sinus pause during the night-time period (1.12, 95% CI 1.08-1.35). The CAI and C-reactive protein were independently associated with non-sustained ventricular tachycardia during both daytime (1.22, 95% CI 1.00-6.92; and 5.82, 2.58-56.1, respectively) and night-time periods (3.57, 95% CI 1.06-13.1; and 10.7, 3.30-44.4, respectively). During a mean follow-up period of 22 months, 30 (17%) patients had cardiovascular deaths and the CSA was an independent predictor (hazard ratio 1.29, 95% CI 1.16-2.32); only 5 (2.8%) of them died due to ventricular tachyarrhythmia, occurring during wakefulness. CONCLUSIONS: We demonstrated that the severity of CSA and C-reactive protein levels are independently associated with the prevalence and complexity of arrhythmias. CSA was associated with increased mortality risk, but it was not related directly to nocturnal death due to ventricular tachyarrhythmia.

Background: Atrial fibrillation (AF) and heart failure (HF) are associated with significant mortality and morbidity. We sometimes encounter patients who have AF upon admission to the hospital, but it spontaneously converts to sinus rhythm within several days (i.e. converter). Purpose: We examined the association between the outcome and types of strategy for AF treatment in converters. Methods: From January 2000 to December 2005, we identified 95 converters (age 69 +/- 12 years) presenting with worsening HF and AF upon admission, in which sinus rhythm was restored within 7 days without either electrical or pharmacological cardioversion. The patients were classified into three groups according to the antiarrhythmic drug (AAD) therapy used: class I AAD, class III AAD, and rate-control drug. The patients were followed for 36 +/- 23 months. Results: The left ventricular ejection fraction (LVEF) significantly improved with conversion to sinus rhythm (38 +/- 14% vs. 47 +/- 13%, p < 0.05). Those receiving class I AAD had a trend toward a well-preserved LVEF (50 +/- 13%, n = 35) as compared to those receiving class III AAD (43 +/- 12%, n = 24) or rate-control drug (47 +/- 14%, n = 36). In the patients receiving class I AAD, the rate of all-cause death increased 1.9-fold (p = 0.009) compared to those receiving class III AAD, and 1.7-fold (p = 0.010) compared to those taking rate-control drug. A hospitalization for HF was observed in 49 (52%) patients, however there was no significant difference in the rate of hospitalization among the three groups (p = 0.890). Those receiving rate-control drugs had a 50% lower rate of the development of persistent AF than those taking class III AAD (p = 0.019). Conclusions: A rate-control strategy should be the primary approach for converters to reduce mortality and development of persistent AF. (c) 2012 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

Aims Increased temporal repolarization lability, assessed by beat-to-beat variability of T-wave amplitude (TAV), has been shown to be associated with ventricular tachyarrhythmia in patients with a variety of clinical conditions. The aim of this study was to test the ability of TAV to identify patients presenting with malignant ventricular arrhythmia and to predict subsequent occurrences. Methods and results We studied 20 consecutive patients (age 42 +/- 15 years, mean +/- standard deviation) presenting with ventricular tachyarrhythmia who did not have substantial underlying heart disease and compared them with 40 age-and sex-matched control subjects. The TAV was determined by Holter recording (Ela Medical). Patients with ventricular tachyarrhythmia had a higher maximum value of TAV (max TAV: 38 +/- 18 vs. 22 +/- 15 mu V, P < 0.001) than did the controls. The sensitivity and specificity of max TAV > 22.4 mu V for detecting the occurrence of ventricular tachyarrhythmia were 77 and 90%, respectively. During a mean follow-up period of 23 months, three patients had relapses of ventricular tachyarrhythmia. Patients with a recurrence of ventricular tachyarrhythmia had a trend towards a higher wmax TAV as compared with those who had ventricular tachyarrhythmia but did not relapse (56 +/- 23 vs. 36 +/- 16 mu V, P = 0.061). Conclusion Our results suggest that Holter-derived TAV might be associated with the occurrence and recurrence of ventricular tachyarrhythmia in patients without structural heart disease. Prospective validation will be necessary to assess the potential diagnostic value of the TAV in a large general population.

Background: n-3 polyunsaturated fatty acids, primarily eicosapentaenoic acid (EPA), has been reported to have antiarrhythmic and antiinflammatory effects. The aim of the present study was to examine whether the combination of antiarrhythmic drugs and EPA reduced the frequency of atrial fibrillation (AF) in patients with paroxysmal AF. Methods: We studied 50 patients with paroxysmal AF (age, 54 +/- 9 years) after excluding the clinical conditions associated with an increased risk of AF. Patients were initially treated with antiarrhythmic drugs for 6 months (the observation period), and thereafter, EPA was added at a dose of 1.8 g/day for 6 months (the intervention period). During a one-year period, patients obtained an ECG recording using a portable device each morning and when arrhythmia-related symptom occurred. The end point was the difference of the AF burden (defined by the days of AF per month) between observation period and intervention period. Plasma EPA and C-reactive protein (CRP) levels were also determined. Results: There was no significant difference in the AF burden before and after intervention (2.6 +/- 2.2 days/months vs. 2.5 +/- 2.2 days/months, P = 0.45). Although EPA level was significantly increased (42 +/- 15 mu g/mL to 120 +/- 47 mu g/mL, P < 0.001), CRP level was unchanged (1.04 +/- 0.69 mg/L to 0.96 +/- 0.56 mg/L, P = 0.24) following EPA treatment. Conclusions: Treatment of EPA in combination with antiarrhythmic drugs did not reduce the AF burden or the CRP levels in paroxysmal AF patients who had no evidence of substantial structural heart disease. Ann Noninvasive Electrocardiol 2011; 16(4): 373-378

Background: Prolonged duration of the QRS complex is a prognostic marker in patients with heart failure (HF), whereas electrocadiographic markers in HF with narrow QRS complex remain unclear. We evaluated the prognostic value of the T-wave amplitude in lead aVR in HF patients with narrow QRS complexes. Methods: We examined 331 patients who were admitted to our hospital for worsening HF (68 +/- 15 years, mean +/- standard deviation) from January 2000 to October 2004 who had sinus rhythm and QRS complex <120 ms. The patients were categorized into three groups according to the peak T-wave amplitude from baseline in lead aVR: negative (<-0.1 mV; n = 209, 63%), flat (-0.1-0.1 mV; n = 64, 19%), and positive (> 0.1 mV; n = 58, 18%). Results: During a mean follow-up of 33 months, 113 (34%) patients had all-cause death, the primary end point. After adjusting for clinical covariates, flat T wave (hazard ratio [HR] 1.86, 95% confidence interval [CI] 1.42-2.46), and positive T wave (HR 6.76, 95% CI 3.92-11.8) were independent predictors of mortality, when negative T wave was considered a reference. Conclusions: As the peak T-wave amplitude in lead aVR becomes less negative, there was a progressive increase in mortality. The T wave in lead aVR provides prognostic information for risk stratification in HF patients with narrow QRS complexes. Ann Noninvasive Electrocardiol 2011; 16(3): 250-257

心室内伝導障害を伴う左心機能低下例では，両室ペーシングによる心臓再同期療法（CRT）を行うと予後が改善する．しかし，心房細動（AF）では労作や心不全の悪化などにより心室応答が速くなると心室ペーシング率が低くなるため，洞調律に比べて効果が低い可能性がある．本研究ではCRT施行例を洞調律およびAFの2群に分けて，心エコー図指標の変化と予後を比較した．対象は両室ペースメーカ植込み基準を満たした38例（年齢61±11歳，洞調律24例，AF14例）である．両室ペーシング率は2群とも95％以上であり有意差はなかった（p=0.84）．AFで房室結節アブレーションを必要とした症例はなかった．CRT施行前に比べて施行6ヵ月後の左室収縮末期容積は両群とも有意に減少し（洞調律 −16±39ml，AF−26±38ml），その減少量は両室ペーシング率と有意な相関を認めた（r =−0.42, p<0.01, n=38）．心不全による入院と心臓死をエンドポイントとし，平均25ヵ月の観察を行ったが，2群間でエンドポイント発生率に差はなかった（洞調律10例，AF7例, log-rank検定p=0.87）．心不全に合併したAFではレートコントロール薬によって心室応答を調整し，高い心室ペーシング率を維持することで洞調律と同様のCRT臨床効果が得られる可能性が示唆された．

中間径線維のひとつであるLamin A/Cは，核膜内膜を裏打ちして核膜構造を維持するとともに，遺伝子転写調節や遺伝子発現制御などの機能を有する．Lamin A/C遺伝子（LMNA）は，関節拘縮，骨格筋異常，および刺激伝導障害に伴う拡張型心筋症を3主徴とするEmery-Dreifuss型筋ジストロフィーの責任遺伝子として報告された．その後，関節拘縮や骨格筋異常を有さないものの，拡張型心筋症に刺激伝導障害を合併した症例にLMNA変異を認めることが報告され，Lamin関連心筋症とよばれる．本疾患は心不全に加え，心室性頻脈性不整脈による突然死が多いのを特徴とする．今回，われわれは，徐脈性不整脈の治療目的にペースメーカを植込まれた3同胞（ペースメーカ植込み時平均年齢49.6歳，男性：女性＝1例：2例）に遺伝子検索を行い，新たなLMNA変異（Q258X）を認めたため，文献的な考察を加えて報告する．