Setsuko Kato

Antihypertensive effect of cardiovascular Ca2+-antagonist in hypertensive patients in the absence and presence of beta-adrenergic blockade

Abstract The effect of the administration of a cardiovascular Ca2+-antagonist (nifedipine) on arterial blood pressure, heart rate, and plasma renin activity was investigated. Blood pressure of normotensive healthy volunteers (n = 4) does not change significantly by administration of 10 mg. (from 119 78 to 120 75 mm. Hg ) and 30 mg. (from 114 69 to 105 66 mm. Hg ) of nifedipine. When nifedipine (30 mg.) is administered with propranolol (beta-blockade), a slight decrease of systolic and diastolic blood pressure was observed (from 119 73 to 104 67 mm. Hg ). Blood pressure of hypertensive patients is significantly lowered by 10 mg. of nifedipine from 172.9 to 130.3 mm. Hg (25 per cent reduction) systolic, and from 112.9 to 86.6 mm. Hg (23 per cent) diastolic (n = 7). Thirty mg. nifedipine had a slightly stronger hypotensive effect, namely 27 per cent reduction in systolic and 28 per cent in diastolic values (n = 9). Combined administration of nifedipine and propranolol, resulted in lowering initial blood pressure by 32 per cent and 30 per cent reduction in systolic and diastolic (n = 8), respectively. The heart rate of normotensive patients hardly changes with administration of 10 and 30 mg. of nifedipine and combined medication. But in hypertensive subjects it is significantly increased by nifedipine; from 66.3 to 80.3 (p Plasma renin activity of normotensive and hypertensive subjects is increased by 30 mg. of nifedipine. Combined administration of nifedipine and propranolol decreases plasma renin activity in both normotensive and hypertensive patients. The antihypertensive effect of nifedipine is enhanced and prolonged by propranolol. The observed increase in heart rate and plasma renin activity with nifedipine is inhibited by propranolol, probably by inhibiting the cardiovascular effects of the activity of the sympathetic nervous system. The results of this study indicate that oral administration of nifedipine is very effective in lowering arterial blood pressure in hypertensive patients, especially when combined with propranolol. Administration of nifedipine with beta-blockade resulted in satisfactory management of hypertension with minimal adverse drug reactions which could be possibly attributed to the preparation, especially in the management of hypertensive emergencies including hypertension associated with acute myocardial infarction and coronary insufficiency.

Significance of Hemodynamic and Electrocardiographic Changes in Elderly Hypertension

高齢者高血圧の血行力学的特徴を解明し, 心電図所見が心機能評価の指標となりえるか否かを検討するために, 60歳以上の高血圧患者126例と正常血圧, 正常心電図の老人36例を対象に心電図所見と色素希釈法による心機能測定値を比較検討し, 次の結果を得た.(1) 老人の高血圧は収縮期高血圧が多く, 心電図異常は男が69%, 女は75%にみられた. (2) 老人の高血圧は心係数が男2.58±0.69, 女2.32±0.55L/min/M2で正常血圧の男2.97±0.44, 女2.56±0.51=L/min/M2より小であり, 高血圧の1回拍出係数は男37.0±8.6, 女32.5±7.5ml/beat/M2で正常血圧の男44.1±7.9, 女35.6±5.7より小であり, 高血圧の総末梢循環抵抗は男3690±1240, 女3860±930dynes・sec・cm-5/M2で正常血圧の男2690±520, 女2970±670dynes・sec・cm-5/M2より大であった. (3) 高血圧の心機能低下は血圧レベルとは相関せず, 収縮期高血圧と収縮期拡張期高高血圧とでは心機能に差を認めなかった. (4) 高血圧の心機能低下は中等度以上の心電図異常例に強い. (5) 心電図所見とくにST・T波形の相異により心機能は異なり, Strain Pattern 例は他のST・T変化例に比して心機能低下が大であり, Strain Pattern 例ではSTj降下度と心機能低下が平行した. したがって, 心電図所見とくにST・T波形が老人の高血圧の心機能評価と予後, 治療方針決定の1指標になり得ることが示された. (6) 老人の心機能は高血圧, 正常血圧ともに男女差を示し, 男では60歳以上においても年齢と有意の相関を示した. したがって, 老人の心機能評価には性差, 年齢を考慮する必要がある.