Electrocardiographic findings in alkalosis were first noted in 1922 by Carter and Andrus, who observed that the Q-T interval was prolonged by more than 30 per cent in three of their cases; this was associated with a lowering of the blood calcium. Barker, Arbor, Shrader, and Ronzoni (1939) produced artificial alkalosis by voluntary overventilation or by ingestion of sodium bicarbonate, the Q-T interval being slightly increased by the latter procedure. In a hysterical patient with hyperventilation a similar effect was produced, but this did not exceed normal limits; a reduction of the T wave was also observed.An opportunity occurred recently of studying the cardiac function in alkalosis.CASE REPORT A woman of 47 was admitted to St. Nicholas Hospital on December 4, 1941. She stated that she had been well till three years previously when she began to suffer from occasional vomiting after meals and during the night. Abdominal pain was troublesome at times and was relieved by vomiting or alkalis. Since then she had never been free from the trouble for more than a day at a time. For the few weeks before admission the severity of the attacks increased and she took MacLean's powder frequently. On the day before admission she suddenly felt as though about to die and her hands and arms went into spasms and felt numb and tingling. This soon passed off, but returned the following morning. On admission, both arms were found to be in tonic spasm with elbows and wrists flexed, fingers and thumb in the position of main d'accoucheur. The abdomen was held tense. Blood taken at this time had a bicarbonate content of 150 vol., a blood urea of 132 mg., and a serum calcium of 10-2 mg., each per 100 c.c. Next day she became confused, disorientated in time, suspicious, and apprehensive. At this time she was having repeated cramps in her limbs and her tongue was dry and thickly coated. After administration of 5 c.c. of 5 per cent calcium chloride intravenously, she improved considerably.On the third day in hospital she was again restless and confused, and kept trying to get out of bed with the intention of going home. Every piece of paper she could lay hands on (including her case notes) she would fold up and put in her bag. During the course of the morning she vomited three pints of greenish fluid. On examination she was found to be very emaciated, but had a good colour. The Chvostek sign was negative, Trouseau faintly positive. The blood pressure was 100/60. The heart was regular at a rate of 75; the two sounds were unusually close together but the apex beat was not displaced. The abdomen showed marked peristalsis, apparently gastric in origin, over almost its entire extent, and splashing could be elicited over a wide area. The temperature was 98.8°, respirations 22. The urine was neutral and contained much albumin. A cardiogram showed low voltage complexes in lead I and a greatly prolonged Q-T interval (0 56 sec.).The serum bicarbonate at this time was 150 vol., chloride 166 mg., sodium 320 mg., and blood urea 310 mg., each per 100 c....