[Functional evaluation of heart failure patients in primary care. The NYHA system is unreliable since intercurrent illness can give rise to similar symptoms]
A group of 158 patients with congestive heart failure was studied in detail concerning other types of morbidity. The purpose was to evaluate how often classification according to the NYHA system was disturbed by intercurrent disease with a similar set of symptoms. At the same time, a visual analogue scale for the evaluation of physical capacity was tested. Seventy-eight per cent of the patients had intercurrent disease putting them at risk of inadequate NYHA classification. There was no correlation between the patients' NYHA class and grade or type of echocardiographic ventricular dysfunction. However there was a correlation between NYHA class and the presence of intercurrent disease.