Abstract: Sulfonamide-substituted chromans, processes for their preparation, their use as a medicament or a diagnostic, and medicament comprising them Chromans of the formula I and of the formula 1a having the meanings R(A), R(B), R(C) and R(1) to R(8) indicated in the claims are outstandingly suitable for preparing a medicament for blocking the K+ channel which is opened by cyclic adenosine monophosphate (cAMP); and further for preparing a medicament for inhibiting gastric acid secretion; for the treatment of ulcers of the stomach and of the intestinal region, in particular of the duodenum, for the treatment of reflux esophagitis, for the treatment of diarrheal illnesses, for the treatment and prevention of all types of arrhythmias including ventricular and supraventricular arrhythmias, and for the control of reentry arrhythmias and for the prevention of sudden heart death as a result of ventricular fibrillation.