Biomedical subjects
N H Whitaker
Publications and source records attributed to N H Whitaker.
Evaluation of the RCGP report on the prevention of arterial disease.
For this pilot study 349 patients aged between 20 and 64 years were seen following their consultations with their own general practitioners. The recommendations of the recent RCGP report on the prevention of arterial disease in general practice were carried out. An average of seven minutes was spent with each patient. A considerable number of patients had risk factors for arterial disease; 25 per cent of the sample were smokers, 32 per cent were obese and 15 per cent had a single blood pressure reading greater than 150/90. Two new cases of diabetes were discovered.Case-finding for risk factors for arterial disease, as recommended in the RCGP report, was considered worthwhile but might be most effectively carried out by a suitably trained practice nurse.
Treatment of chronic heart failure with pirbuterol: acute haemodynamic responses.
Fifty-nine patients with severe chronic heart failure were given pirbuterol, a beta agonist with vasodilator and positive inotropic properties. The acute haemodynamic responses to both single (20 patients) and incremental doses (39 patients) were measured. Pirbuterol increased cardiac index and reduced left ventricular filling pressure and systemic vascular resistance with only small changes in heart rate and blood pressure. Maximal effects were observed at an average of 170 minutes after a single oral dose of pirbuterol. In the incremental dose studies the plasma pirbuterol concentration was found to increase with increasing doses and was related to the magnitude of the haemodynamic response. Pirbuterol was well tolerated, and no drug-related side effects were recorded. Oral pirbuterol clearly improved pump performance in these patients, the haemodynamic changes being consistent with vasodilatation as the dominant mechanism rather than a direct inotropic effect.
Calcium antagonist drugs in chronic stable angina. Comparison of verapamil and nifedipine.
The relative efficacy of two calcium antagonist drugs, verapamil, 120 mg three times a day and nifedipine, 20 mg three times a day, was examined in a double-blind randomised trial. Patients were assessed at the end of four week periods by a maximal treadmill exercise test, the frequency of anginal attacks, glyceryl trinitrate consumption, and side effects. Sixteen point praecordial maps were recorded at rest, immediately after exercise, and at minute intervals for 10 minutes. Total ST segment depression (epsilon ST) was used as a measure of myocardial ischaemia. Both verapamil and nifedipine increased maximal work capacity but epsilon ST at the termination of the test remained constant. Both drugs reduced the frequency of anginal attacks and glyceryl trinitrate consumption. Systolic blood pressure at rest and on exercise was reduced by both drugs. Verapamil and nifedipine were equally effective in treating angina, but side effects were more common with nifedipine.