Bronchial hyper-responsiveness to methacholine remained unchanged Following diuretic therapy for chronic L VF

Chronic left ventricular failure (LVF) is believed to be associated with increased bronchial hyper­responsiveness to pharmacological agents.

Therefore, a study was conducted to assess the level of bronchial hyper-responsiveness to inhaled methacholine at baseline and following 5-15 days of intensive diuretic therapy in 12 patients with acute decompensation of chronic left ventricular failure, with no previous history of asthma. All patients were smokers or ex-smokers.

At baseline, 11/12 patients frequently experienced asthmatic symptoms, including cough, wheeze and respiratory symptoms in response to cold air, irritants or exercise. Bronchial hyper­responsiveness was significant in 8 patients with provocative concentration of methacholine to cause a 20% reduction of FEV 1 (PC20) of ~ 16 mg/ml; of these, 6 showed significant airway obstruction with reduced FEVl and FEV1/FVC.

Following intensive diuretic therapy, mean vital capacity and FEV 1 were significantly improved. Only 3 patients showed Significantly improved bronchial hyper-responsiveness to methacholine. Overall there was no significant mean change in PC20 or FEV l/FVC.

'Although It seems likely that cardiac failure per se had brought about airway changes, in particular muscular hypertrophy, which then led to bronchial hyperresponslveness, it Is not excluded that smoking had played a contributing role.' This would explain the lack of significant improvement in bronchial hyper-responsiveness in the majority of patients following diuretic therapy. Plson C. Malo J.L. Rouleau J.l. ChalaoUi J. Ghezzo H. el al Bronchial hyperresponSlveness to Inhaled methacholine In sublects with chrOniC left heart failure at a lime of exacerbation and after Increasing diuretic therapy Chest 96 230·235. Aug 1989 010'

16 INPHARMA' 26 Aug 1989 0156·2703/89/0826·0016/0$01.00/0 © ADIS Press