The aim of this study was to examine the prevalence of exercise limitation due to diastolic heart failure among patients felt to have cardiac breathlessness by their general medical practitioner but not referred to hospital. We found that 18% of patients had a simple investigated profile compatible with isolated diastolic dysfunction as a cause of their symptoms. Symptoms appeared to pre-date major cardiac events (infarction; stroke; arrhythmia) that dominated the subsequent clinical course. The patients in this group have adverse cardiovascular risk profiles. Obesity was a common co-morbidity which may impair detailed 2-D echocardiographic assessment.