Hypertension: Yokoyama N

Hirasawa K, Tokoro C, Yasuzaki H, Yokoyama N, Tomiyama M, Matsukawa H, Nagano A, Kawano N. · Department of Gastroenterology, Yokohama Minamikyousai Hospital. · Nippon Shokakibyo Gakkai Zasshi. · Pubmed #15065351 No free full text.

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Yokoyama N, Nishikawa K, Takazawa T, Saito S, Goto F. · Department of Anesthesiology, Gunma University Graduate School of Medicine, Maebashi 371-8511, Japan. · Masui. · Pubmed #15446682 No free full text.

Abstract: We report here a case of ventricular tachycardia (VT) induced by the change of position for insertion of an epidural catheter before the induction of general anesthesia. A 79-yr-old woman was scheduled for elective right lung surgery. Past history included hypertension and hypertrophic obstructive cardiomyopathy (HOCM), which were treated with a calcium channel blocker and an anti-arrhythmic drug. Preoperative echocardiogram (ECG) showed first degree arterio-ventricular block and left ventricular hypertrophy. Before the induction of general anesthesia, the patient was turned into the left lateral position for the insertion of an epidural catheter. Shortly after the change of position, ECG showed transient VT, which lasted for approximately 40 sec, and she was forced to be turned to the supine position and required recovery for a time. VT was successfully treated and terminated by changing to the supine position and intravenous injection of 2% lidocaine (2 ml). The left radial artery was cannulated for monitoring arterial blood pressure and sampling. Since no abnormality was observed in ECG for the next twenty minutes, the patient was turned to the left lateral position again and epidural catheterization was performed through T 7-8 interspace. Considering some risk factors such as intraoperative change of position, the surgery was cancelled on that day. Postoperatively amiodarone was used and an implantable cardioverter defibrillator (ICD) was planted for risk reduction of sudden cardiac death due to ventricular arrhythmia. The cause of VT in our case is not certain; we believe that VT might be closely related to the left lateral position, especially keeping of the forward-bending position, which might cause compression to the heart and produce stenosis of the left ventricular outflow tract. It should be noted that severe tachyarrhythmia might occur after turning patients with HOCM.

Sato Y, Yokoyama N, Suzuki S, Tani T, Nomoto M, Hatakeyama K. · First Department of Surgery, Niigata University School of Medicine, 1-757 Asahimachi-dori, Niigata 951-8510, Japan. · Hepatogastroenterology. · Pubmed #12397726 No free full text.

Abstract: A 55-year-old woman with ascites, pancytopenia by hypersplenism, recurrent hemorrhagic esophagogastric varices, and large rectal varices due to congenital hepatic polycystic disease underwent splenectomy and simultaneous double selective shunt; a left gastric venacaval direct shunt for esophagogastric varices and a sigmoid venous left ovarian vein shunt for rectal varices. Her preoperative Child-Pugh grade was A (score 6). Postoperative course was uneventful. Serum NH3 level decreased from 90 micrograms/dL to 36 micrograms/dL after shunt surgery. She was discharged on the 21st postoperative day. The remarkable improvement of both the esophagogastric varices and the rectal varices was demonstrated by postoperative fiberscope. We strongly consider sigmoid venous left ovarian shunting to be as selective as the Inokuchi shunt preventing encephalopathy and an effective surgical approach to anorectal varices.

Takeshita S, Tomiyama H, Yokoyama N, Kawamura Y, Furukawa T, Ishigai Y, Shibano T, Isshiki T, Sato T. · Department of Medicine, Teikyo University School of Medicine, 2-11-1 Kaga, Itabashi-ku, 173-8605, Tokyo, Japan. · Cardiovasc Res. · Pubmed #11684080 links to  free full text

Abstract: OBJECTIVES: Natural angiogenesis has been shown to be impaired in spontaneously hypertensive rats (SHR). The purpose of this study was to determine whether pathological angiogenesis in the setting of tissue ischemia is also impaired in SHR, and to what extent it is modified by angiotensin-converting enzyme (ACE) inhibition. METHODS: Ischemia was induced in the hindlimb of SHR by excision of the femoral artery, after which the animals were randomly assigned to receive low-dose perindopril (sub-antihypertensive, 0.2 mg/kg/day), high-dose perindopril (antihypertensive, 2.0 mg/kg/day), or vehicle for 3 weeks. Wistar-Kyoto rats (WKY) with femoral artery excision served as a control group. RESULTS: Tissue ACE activity in SHR was significantly increased compared to WKY (49.4+/-6.2 vs. 34.0+/-14.2 IU/mg, P<0.01). Administration of perindopril significantly reduced ACE activity in SHR (low dose: 12.4+/-2.3; high dose: 11.0+/-2.1 IU/mg, P<0.005). Angiogenesis of the ischemic limb muscles was significantly impaired at 4 weeks in SHR versus WKY as indicated by the lower capillary density in the former (364.5+/-43.0 vs. 463.8+/-63.0/mm(2), P<0.05) as well as the reduced hindlimb perfusion assessed by laser Doppler imaging (0.86+/-0.08 vs. 1.03+/-0.09, P<0.05). Administration of perindopril significantly augmented both the capillary density (low dose: 494.3+/-69.8; high dose: 543.9+/-76.9/mm(2), P<0.005) and the limb perfusion (low dose: 1.06+/-0.15; high dose: 1.05+/-0.12, P<0.05) of the ischemic limb in SHR. CONCLUSIONS: These findings indicate that pathological angiogenesis in the setting of tissue ischemia is impaired in SHR compared with WKY, and that this impairment can be reversed by ACE inhibition. The angiogenic properties of an ACE inhibitor may benefit patients with essential hypertension presenting with lower limb vascular insufficiency.

Suzuki N, Kozuma K, Ueno Y, Nagaoka K, Kyono H, Ishikawa S, Watanabe H, Yokoyama N, Takeshita S, Isshiki T. · Department of Medicine, Teikyo University School of Medicine, Tokyo, Japan. · Ann Thorac Surg. · Pubmed #18222257 No free full text.

Abstract: BACKGROUND: A paucity of data exists with respect to changes in whole saphenous vein grafts (SVGs) despite accelerated atherosclerosis within grafted saphenous vein conduits. In the present study, we evaluated the one-year change in SVGs by means of quantitative coronary analysis. METHODS: This study enrolled consecutive 52 patients with 109 SVGs, who underwent coronary artery bypass graft surgery successfully. A follow-up study was performed in 33 patients with 65 SVGs after one year because 16 SVGs were obstructed (baseline, 8; follow-up period, 8), and 15 patients with 28 SVGs dropped out within one year. RESULTS: Both minimal and mean lumen diameters decreased significantly (3.17 +/- 0.64 mm vs 2.41 +/- 0.57 mm, p < 0.001; 3.70 +/- 0.69 mm vs 2.92 +/- 0.70 mm, p < 0.001; respectively). Graft length also decreased significantly (107.1 +/- 25.8 vs 100.6 +/- 25.2 mm, p < 0.001). The graft shortening rate (graft shortening length/baseline graft length x 100) was greater than 5% in 33 vessels (51%) and greater than 10% in 23 vessels (35%). Coronary risk factors (smoking, diabetes mellitus, hypertension, dyslipidemia) did not reveal significant relationship with late loss of minimal and mean lumen diameters. CONCLUSIONS: The present study showed a considerable and uniform lumen loss of SVGs after one year, irrespective of coronary risk factors. Graft length shortening was seen more than elongation.