Kazutoshi Yamamoto

Sodium sensitivity of blood pressure and baroreceptor reflex function in patients with essential hypertension.

In order to define the role of the baroreceptor reflex function in the sodium sensitivity of blood pressure in patients with mild essential hypertension, 25 patients were classified into two groups, salt-sensitive and salt-insensitive, depending on the difference in the averages of the resting systolic blood pressure, taken hourly on the fifth day of 7 days of sodium depletion and on the fifth day of 7 days of repletion. Increases in urinary sodium excretion and body weight and a decrease in haemotocrit during the sodium repletion period were similar in both groups. Baroreceptor reflex function, estimated from the baroreceptor slope and the blood pressure change on a 70° tilting test, was enhanced by the sodium repletion period in the sodium-insensitive group but not in the sodium-sensitive group. These results suggest that sodium sensitivity might be due to differences in the ability of the baroreceptor reflex function to become sensitized during a high sodium intake.

Effect of celiprolol on 24-hour ambulatory blood pressure and hemodynamics in patients with essential hypertension

Abstract Celiprolol is a selective beta 1 -antagonist with intrinsic sympathomimetic activity. The effects of celiprolol on ambulatory blood pressure during daily activity and its hemodynamic effects at rest were investigated in 11 patients with mild to moderate essential hypertension. Patients who had been weaned from all other medications for 4 weeks were treated with celiprolol 200 mg once daily for 4 to 6 weeks, followed by an increased dose of 400 mg daily for 12 to 14 weeks. The 24-hour ambulatory blood pressure was monitored using a portable, automatic, noninvasive device. Blood pressures measured during clinic visits and 24-hour ambulatory blood pressures were reduced significantly ( P ⩽ 0.01) by celiprolol treatment. Significant decreases in 24-hour ambulatory blood pressure were recorded when patients were awake but not during sleep. Mean heart rate decreased when patients were awake but increased during sleep. There was a significant change in total peripheral resistance ( P ⩽ 0.01) but not cardiac output at rest. Celiprolol reduced blood pressure when patients were awake rather than during sleep and did not obviously affect the variability of 24-hour ambulatory blood pressure. Because celiprolol produced its antihypertensive effect by reducing total peripheral resistance without decreasing cardiac output, it may have an advantage in the treatment of patients with essential hypertension.

Exercise-loaded blood pressure and Li-Na countertransport system in the erythrocyte membrane as predictors of mild essential hypertension prognosis.

1. The blood pressure response to exercise loading, Na concentration in the erythrocyte and Li–Na countertransport (Li–Na CT) system in the erythrocyte membrane in 40 male volunteers and 98 patients with mild essential hypertension were investigated. Subjects were divided into a juvenile group (<36 years) and a middle‐aged (>36 years and <65 years) group. Exercise‐loaded blood pressure in patients with mild essential hypertension was followed up for more than 5 years.

Sympathetic Nervous Function and Erythrocyte Cation Transport Systems in Normotensive Individuals with Family History of Hyperension

To investigate the influence of heredity to the sympathetic nervous function and the cell membrane cation transport systems, we studied the blood pressure and plasma catecholamine response to supine exercise testings by bicycle ergometer, the pressure response to noradrenaline infusion tests and the heart rate response to isoproterenol infusion tests in 88 healthy Japanese sedentary normotensive men with and without a family history of essential hypertension [FHH(+) and FHH(-)]. Several erythrocyte monovalent cation transport parameters were also measured in 74 of these individuals. In the results, (1) the systolic blood pressure response to exercise testings and noradrenaline infusion tests were larger in FHH(+) than FHH(-): (2) there was no difference between FHH(+) and FHH(-) in the heart rate response to isoproterenol infusion tests: (3) there was no significant difference between FHH(+) and FHH(-) in the increased plasma catecholamine levels to exercise testings: (4) the intraerythrocytic sodium content was significantly higher in FHH(+) than in FHH(-): and (5) several erythrocyte monovalent cation transport systems (Li-Na countertransport, Na-K cotransport and Na-K pump activity) were clearly accelerated in FHH(+). We concluded that in spite of normotension there were abnormalities of sympathetic nervous function, intracellular sodium content and several cell membrane cation transport systems in individuals with a family history of essential hypertension.

1003-90 Successful embolization protection using guardWire system for acute myocardial infarction: Multicenter registry in Japan

Background: Distal embolism is one of the major complications during percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI). These complications may be potentially mitigated by distal protection. The GuardWire system (GS) consists of an occlusion balloon which is inflated distally allowing ‘protected’ PCI has recently become available. Aim: To evaluate the efficacy and safety of this device, we studied a total of 212 patients (male 69.8%) of AMI who underwent PCI using GS. The GS was successfully placed in all of the cases. Gross inspection of the filter after retrieval demonstrated macroscopic emboli including thrombus in 93.9% of patients. Results: See table. Conclusion: The preliminary results suggest that PCI for AMI using GS is technically feasible, safe and early clinical outcomes appear to be favorable. 6 months and 1 year follow-up clinical outcome will be available at time of presentation.

Nicorandil, a KATPchannel opener, facilities the recovery of ventricular contraction after reperfusion therapy in acute myocardial infarction: Multicenter registry in Japan

observed: there were no arrhythmias, no conduction disturbances and no ST-segment modifications. Cardiac enzymes remained unchanged. Conclusion: Gadolinium enhanced coronary angiography is safe and well tolerated. The mixture of Gadolinium with non-ionic contrast allowed us to obtain diagnostic angiograms of excellent quality in all cases. In patients at high-risk for renal failure, Gadolinium constitutes an interesting adjunct to contrast agents for coronary artery imaging.

Effect of celiprolol on hemodynamics during exercise loading and the responses caused by sympathomimetic drugs in essential hypertension

Abstract Celiprolol is a beta 1 -selective beta-adrenoreceptor antagonist with intrinsic sympathomimetic activity. The hemodynamic effects of celiprolol during exercise loading as well as responses to adrenergic drugs (norepinephrine and isoproterenol) and changes in body position (electric tilt table) were investigated in nine patients with mild to moderate essential hypertension. Patients were treated with celiprolol 200 mg once daily for 4 to 6 weeks, followed by 400 mg for 12 to 14 weeks. Hemodynamics during exercise loading were measured in the supine position using a bicycle ergometer with a constant load of 1.25 W/kg for 6 minutes. Celiprolol significantly reduced the increase in blood pressure and heart rate associated with exercise loading, but the reduction in the increase in cardiac output was not significant. Total peripheral resistance did not change significantly during exercise loading. Celiprolol did not affect the increase in blood pressure caused by norepinephrine, but the increase in systolic blood pressure and heart rate caused by isoproterenol was significantly suppressed. Celiprolol had no apparent effect on the blood pressure and heart rate response caused by standing. The results of this study suggest that the hemodynamic mechanism for the hypotensive effect of celiprolol is different during the effort and resting states and that celiprolol is a unique beta-adrenoreceptor antagonist.

Hemodynamic effects of amosulalol (YM-09538) in patients with essential hypertension

Abstract Amosulalol 40 to 60 mg was orally administered for approximately 3 months to 14 patients with mild to moderate essential hypertension to investigate the drugs hemodynamic effects. Eight patients who responded well to the therapy showed an increase in cardiac output and stroke volume and a decrease in total peripheral resistance and volume elasticity, but no changes in heart rate. These hemodynamic effects of amosulalol noticeably differed from those of propranolol. The important hemodynamic features of amosulalol include decreased total peripheral resistance and suppression of reflex tachycardia; these effects result from the drugs selective alpha 1 -blocking and beta-blocking activity. From a hemodynamic aspect, amosulalol is preferable to a beta-blocker in the treatment of hypertension.