Leon Billiet

Acute and chronic systemic and pulmonary hemodynamic effects of angiotensin converting enzyme inhibition with captopril in hypertensive patients

Abstract The effects of the angiotensin converting enzyme inhibitor captopril were studied in 14 patients with essential or renovascular hypertension 75 minutes after ingestion of 25 mg of the drug, and after 2 months of therapy with 150 to 600 mg/day. Captopril acutely decreased mean brachial arterial pressure by 16.3 mm Hg (p The data indicate that the action of captopril is characterized by arteriolar and possibly venous dilatation. The increase in cardiac output during long-term treatment seems to be associated with a hypermetabolic state and in patients with very severe hypertension, with restoration to normal of mildly decreased left ventricular function.

Response of the systemic and pulmonary circulation to alpha- and beta-receptor blockade (labetalol) at rest and during exercise in hypertensive patients.

Labetalol (L), a drug with both aand fl-adrenoceptor blocking properties, was administered to 18 hypertensive patients for an average duration of 2.44 weeks, with an average final daily dose of 1.65 g. L decreased resting heart rate (HR) by 16% and maximal exercise HR by 21%; the phenylephrine-induced rise of brachial artery pressure (BAP) was reduced by 30-40%, and the rise of systemic vascular resistance (SVR) by 50%. L lowered BAP by 29/15 mm Hg in the recumbent position (RR), by 41/23 mm Hg at rest sitting (RS), and by 53/23 mm Hg at maximal exercise; SVR was not significantly affected at RR but was reduced at RS and at exercise; cardiac output (CO) decreased in all conditions. L reduced mean pulmonary artery and capillary wedge pressures only at RS. These hemodynamic observations suggest that the antihypertensive action of L is based mainly on its f-receptor blocking properties at RR, and on both its aand f-receptor blocking effects sitting and at exercise. Finally pulmonary vascular resistance (PVR) was not influenced by L, and the phenylephrine-induced increase of PVR was unaffected; the pulmonary arterioles thus seem to react differently to L than the systemic arterioles.

Preliminary report on the haemodynamic response of hypertensive patients treated with a beta blocker (ICI 66082).

SummaryHaemodynamic studies were performed in 11 hypertensive patients, first while they were receiving placebo and then after one months treatment with a beta-adrenergic blocking agent (I.C.I. 66,082).An average fall in mean arterial blood pressure of 26.2 mmHg was obtained. Although the mean total peripheral resistance showed little change, data from individual patients show a correlation between changes in blood pressure and resistance. There was no correlation between fall in pressure and fall in cardiac output.

Haemodynamic response to graded exercise during chronic beta-adrenergic blockade with bunitrolol, an agent with intrinsic sympathomimetic activity

SummaryThe effect of chronic beta blockade on the haemodynamic response to graded exercise was studied in 18 hypertensive patients treated with bunitrolol, which has partial agonist activity. The patients first received a placebo for 5 to 12 days, then bunitrolol 30 mg daily for one week and subsequently the dose was doubled weekly as necessary upto 240 mg daily. At rest haemodynamic changes after beta blockade were only minor; heart rate decreased by 8% and no significant change was observed in stroke index, cardiac index, (a-v)O2 difference and VO2. The hypotensive effect was not significant and no significant change in mean pulmonary arterial and wedge pressure was observed. Maximal exercise capacity remained unchanged, because of haemodynamic responses. The maximal exercise heart rate was reduced by 25% during beta blockade, which was compensated by a 34% elevation in stroke index, whereas maximal cardiac index and (a-v)O2 difference remained unchanged. There was no consistent change in mean pulmonary artery pressure during maximal exercise, but the mean brachial artery pressure fell by 12%.

Phentolamine Therapy in Severe Chronic Asthmatiform Bronchitis

Continuous phentolamine infusion for 3 days in 6 patients with severe chronic bronchial obstruction produced a marked improvement in subjective well-being and arterial blood gas values. Ventilatory function and pulmonary arterial pressure remained virtually unchanged but a chronic oral corticosteroid therapy could be substantially reduced during 4 weeks of oral treatment with phentolamine 100 mg three times daily.

Emphysema with Minor Airway Obstruction and Abnormal Tests of Small Airway Disease

In 9 patients complaining primarily of exertional dyspnea, the diagnosis of early emphysema was made on the basis of a decrease of the elastic recoil of the lung and of the single breath diffusing capacity, in the presence of only minor airway obstruction as estimated from the routine pulmonary function tests. Closing volume, the alveolar plateau, dynamic compliance and maximal flow at 50% of the vital capacity were markedly abnormal; the maximal flow-static recoil pressure relationships suggest, however, that none of the patients suffered from small airway disease. We conclude that one should systematically consider early emphysema in the differential diagnosis of small airway disease.

Severe Pulmonary Thromboembolism Following Lymphography

SummaryWe report the case of a 74-year-old-man, who developed severe progressively increasing dyspnea, during the 24 hours following a staging bipedal lymphography for non-Hodgkin lymphoma.The diagnosis of pulmonary thromboembolism has been established.The authors discuss the differential diagnosis with pulmonary oil embolism and suggest periodically passive exercise of the legs during lymphography in patients with high risk of venous thromboembolism, or even prophylactic heparinisation during the procedure in certain cases with extensive compression on larger veins.

EFFECTS OF 1‐SAR‐8‐ALA‐ANGIOTENSIN II ON SYSTEMIC AND PULMONARY HAEMODYNAMICS IN HYPERTENSIVE PATIENTS

1.The angiotensin II antagonist, 1‐Sar‐8‐Ala‐angiotensin II (saralasin), was infused intravenously at a rate of 10 μg/kg per min in thirty‐three hypertensive patients, on a normal sodium diet (130 mmol per day) and/or during sodium depletion by low sodium diet (20 mmol per day) and chlorthalidone.

Effect on pulmonary function of surgical treatment of bullous lung disease.

SummaryThe effects on pulmonary function of removal of bullae occupying at least 30 per cent of a hemithorax are reported in 15 patients, 10 of whom had associated chronic obstructive lung disease. All patients with dyspnea improved symptomatically after surgery. Lung function, measured six to twelve months after surgery, was significantly improved: mean (± I SD) FEV, preoperative was 48 ±26% predicted and postoperative 70 ± 26 % predicted (p < 0.001); Pa02 preoperative 66 ± 9 mm Hg vs. postoperative 78 ± 10 mm Hg (p < 0.05). The largest increase of FEV, was obtained in patients with giant bullae and only slight generalised emphysema. In the seven patients with a follow-up of two to five years after surgery, the mean postoperative annual decline in FEV, was 49 ± 51 ml.

Effect of bronchodilation on regional lung function measured by 133Xe and gamma camera

Using 133Xe, a gamma camera and off-line data handling the effect of inhaled Salbutamol on regional lung function was measured in six patients with chronic obstructive lung disease and associated bronchospasm.After bronchodilation only minor changes were obtained in regional ventilation or in the arterial hypoxemia, although the overall airways obstruction improved markedly. These findings suggest that the bronchodilating agent had an effect mainly on the larger airways and almost did not influence the function of the more peripheral lung units responsible for gas exchange. Also, a slight but direct effect on the perfusion was demonstrated. The effect on the 133Xe ventilation-perfusion ratio was not correlated with that on the hypoxemia, indicating that the first is not a good representation of the latter.