The presence of a large Q wave in the third lead is frequently observed in electrocardiographic records from patients with the anginal syndrome. In the majority of these records the QRS group shows left axis deviation, though in a few the electrical axis has a normal direction. The frequency of the large Q-3, both in cardiac patients in general and in those with the anginal syndrome in particular, will appear from the following: In a series of 200 cases of heart disease of various sorts recorded alphabetically in a file of office patients, 30 showed a diagnosis of the anginal syndrome, including both the angina of effort and the angina appearing at rest.1 Of these 30 patients with the anginal syndrome 8, or 27 per cent, were found to have a large Q wave in the third lead. In the other 170 cases 6 such records were found; so that