The comparison of endothelial function between conduit artery and microvasculature in patients with coronary artery disease

Background: Flow-mediated dilation (FMD) and reactive hyperemia-peripheral arterial tonometry (RH-PAT) are both established modalities to assess vascular endothelial function. However, clinical significance of FMD and RH-PAT may be different because these methods measure vascular function in different vessels (conduit arteries and resistance vessels). Methods: To elucidate differences in the clinical significance of FMD and RH-PAT, a simultaneous determination of FMD was performed and reactive hyperemia index (RHI) measured by RH-PAT in 131 consecutive patients who underwent coronary angiography for suspicion of coronary artery disease (CAD). Results: There was no significant correlation between FMD and RHI in patients overall. When patients were divided into four groups: FMD ≥ 6%/RHI ≥ 1.67 group, FMD ≥ 6%/RHI < 1.67 group, FMD < 6%/RHI ≥ 1.67 group and FMD < 6%/RHI < 1.67 group, the highest incidence of multivessel CAD was seen in the FMD < 6%/RHI < 1.67 group (52%). Multiple logistic regression analysis showed that a prevalence of both FMD < 6% and RHI < 1.67 was an independent predictor of multivessel CAD (odds ratio: 4.160, 95% confidence interval: 1.505–11.500, p = 0.006). RHI was negatively correlated with the baseline vessel diameter (R = –0.268, p = 0.0065) and maximum vessel diameter (R = –0.266, p = 0.0069) in patients with FMD < 6%, whereas these correlations were absent in patients with FMD ≥ 6%. Conclusions: Present results suggest that noninvasive assessment of vascular endothelial functions provide pathophysiological information on both conduit arteries and resistance vessels in patients with CAD

ジュンカンキ シッカン (<トクシュウ>キュウキュウ シッカン ノ シンリョウ ノ ジッサイ)

少子高齢化が指摘されて久しい我が国は,世界に冠たる長寿国である.国民の平均寿命がのびるにつれ,介護医療を要する高齢者が激増し,それを見守ってゆくべき若年者の人口は伸び悩み,今後我が国は"手のかかる年寄り"でいっぱいになってゆく構図がみてとれる.命が終わるぎりぎりまで健康に過ごし,「死ぬ時は苦しまないでコロっと逝きたい」と願うのは多くのヒトの望むところであろうが,循環器疾患,殊に心血管疾患では若年での突然死も珍しくなく,まだ若いのにもかかわらず,突然の心血管疾患発症の後に生き残ったとしても,最も忌むべき後遺症に苛まれながらの人生を送るヒトも少なくない.外傷や災害では年齢を問わず偶然性もあろうが,循環器疾患の場合には,近年の生活習慣病の増加にともなう心血管疾患の急性発症の増加により,主に40歳から60歳くらいまでの社会を担う世代がポックリ死んでしまったり,あるいは苦しんだあげくにコロっとは逝けないのである.約30年前の日本の救急医療の黎明期には,急速に増加した交通外傷への対応に主眼が置かれていた.戦後の欧米化生活習慣が定着した後, 1980年代になりその反動のように心血管疾患が増加し,これに対する我々医療サイドの努力の結果,冠疾患への緊急冠動脈バイパス技術やカテーテルインターベンションの進歩,緊急時ペースメーカー治療,大動脈バルンパンピングなどの循環補助ディバイスの積極的導入が容易なものとなり,近年の救急医療の主眼は高度外傷救急,心血管救急,災害医療へと主だってきている. 2006年3月から2007年4月までの期間,獨協医科大学救命センター病棟に入院した825症例中,循環器疾患は271症例, 32.8%であった.しかしこれは病室までたどりついた患者の数といえる.循環器救急の特徴は患者が死亡するまでの時間が短いことにある2006年5月から2007年4月まで当院ERに救急搬送された1,376症例のうち来院時心肺停止CPAOAは106例であった.そのうち原疾患不明のものが79例(75%),原因があきらかに心血管疾患と診断されたものはわずか8例(8%)であった. CPAOA症例は心肺停止に至った状況が明らかでない場合や,一度も心拍再開できなかった場合など原因が特定できないことが少なくない.発症から数秒間のうちに心停止へと進む瞬間死の原因の98%が循環器疾患であり, 1時間以内の死亡の85%が循環器疾患であると言われている.故に当院へ搬送されたCPAOAにおいても,原疾患不明例の大部分が循環器疾患であったことが予想される.であるなら瞬間死しようとしている命の大部分をいかに引き止めるかが循環器救急の本懐であると言える.本稿では循環器救急の最大の関心である心停止とその原因の大部分を占める急性心筋梗塞に関して他科の医師や看護師の日常臨床の一助になるべく解説したい

Effects of Norepinephrine on Left Ventricular Hemodynamics and Myocardial Blood Flow in Rats with and without Calcium Overload

Heart failure patients have been shown to have an increased blood norepinephrine concentration, and patients with a high norepinephrine concentration have a poor prognosis. Norepinephrine is a catecholamine with α_1 and β_1 effects, which lead to a vasoconstrictive action and enhancement of myocardial contraction. However, the consequences of norepinephrine-induced changes in myocardial blood flow in heart failure patients remain unknown. In this study, the influence of norepinephrine on hemodynamics and blood flow in the left ventricular myocardium was investigated using rats with and without a calcium load. Norepineph-rine without a calcium load induced a 29.3% reduction of myocardial blood flow (MBF), but had no significant effect on ejection fraction (EF) and left ventricular end-diastolic pressure (LVEDP). With simultaneous calcium administration, norepinephrine induced a 33.2% reduction of MBF and increased LVEDP significantly, but caused no reduction in EF. These results suggest that norepinephrine decreases MBF but has no effects on systolic function, and increases LVEDP and decreases MBF more markedly in combination with calcium

Qualitative Improvement of a Coronary Plaque after Treatment with a Strong Statin : Observation using Virtual Histology Intravascular Ultrasound

Statins are used currently for treatment and prevention of coronary artery disease, but it is difficult to assess the therapeutics effects and patient responses to different statins. Virtual histology intravascular ultrasound (VH-IVUS) has been used to evaluate detailed quantitative changes in coronary plaques, and here we report a case in which marked qualitative improvement in a coronary plaque was observed using VH-IVUS after a change in treatment from a conventional statin to a strong statin

Hemodynamic Effects of Positive end-expiratory Pressure on Right Ventricular Diastolic Function in Patients with Acute Myocardial Infarction

The effects of positive end-expiratory pressure (PEEP) on the right ventricular (RV) diastolic function in patients with congestive heart failure (CHF) due to acute myocardial infarction (AMI) are unknown. The aim in this study was to investigate PEEP associated variations in RV diastolic function in CHF due to AMI. The subjects comprised the control group (26 subjects) and the AMI group (36 subjects) classified as 20 patients with pulmonary capillary wedge pressure (PCWP) < 18 mmHg (CHF-low PCWP group) and 16 patients with PCWP≧18mmHg (CHF-high PCWP group). PEEP was applied for 30 minutes at 0, 5, 10 and 15 cmH_20. Two-dimensional echocardiography with continuous and pulse wave Doppler studies was performed. RV diastolic functional parameters included the ratio of peak early tricuspid valve filling and peak atrial filling velocities, the decelation time of the tricuspid E valve and the RV isovolumic relaxation time. In the control and CHF-low PCWP groups, right atrial pressure, mean pulmonary arterial pressure (mPAP), total pulmonary resistance (TPR) and systemic vascular resistance (SVR) increased, output (CO) decreased and RV diastolic functional parameters worsened significantly at the transition from 10 to 15 cmH_20 PEEP. In the CHF-high PCWP group, mPAP, TPR and SVR decreased, while CO increased and RV diastolic functional parameters improved significantly at the transition from 10 to 15 cmH_20 PEEP. From these findings, it is clear that PEEP induced hemodynamic deterioration and reduces RV diastolic function in intact and mildly failing hearts. On the other hand, in severely failing hearts, PEEP effers hemodynamic improvement and ameliorates RV diastolic function. It appears possible to predict responses to PEEP by determining RV diastolic function in CHF. Therefore, we conclude that evaluation of the RV diastolic function during PEEP is highly important in terms of recognizing the effectiveness of PEEP therapy in CHF

Ultrastructural features of goat oviductal secretory cells at follicular and luteal phases of the oestrous cycle

The aim of the present study was to investigate the ultrastructure of secretory cells in the various regions of the goat oviduct during the follicular and luteal phases of the oestrous cycle. During the follicular phase in the fimbriae, the secretory cells contained small secretory granules with electron-dense matrices. In the luteal phase, the secretory granules disappeared and cytoplasmic protrusions, extending beyond the luminal border of the ciliated cells and often containing the nucleus, were predominant. During the follicular phase in ampullary secretory cells, numerous secretory granules with moderately electron-dense matrices were present in the supranuclear cytoplasm and exocytosis of secretory granules was observed. The number of secretory granules was dramatically reduced in the ampullary secretory cells at the luteal phase. Conspicuous cytoplasmic protrusions of secretory cells were observed similar to those of the fimbrial epithelium. Isthmic cells were almost free of secretory granules and lysosome-like bodies were found both at the follicular and luteal phases. In conclusion, our ultrastructural observations of goat oviduct revealed marked cyclic changes in the ultrastructural features of secretory cells and the ultrastructural features and the numbers of secretory granules were distinctive for each particular segment