1. Field of the Invention
This invention is concerned with carbostyril derivatives useful in treating cardiovascular diseases, particularly in treating arrhythmias.
2. Background to the Invention
Carbostyril derivatives are disclosed in the patent literature as having cardiotonic, anti-arrhythmic, .alpha.- and .beta.-adrenoceptor blocking activities, and as being calcium antagonist, antihistaminic and local anesthetic agents. See, for example, U.S. Pat. Nos. 4,210,753 and 4,482,560, and Japanese Kokai Tokyo Koho Sho 57-018,674 (Derwent Abstract 18695E/10).