Sir.—The clinical memorandum "An Unusual Cardiac Arrhythmia Caused by Hypocalcemia" by Fishbein and colleagues (Journal 1982;136:372-373) deserves further discussion.
If the authors had searched the medical literature of some years ago, they would have found many articles written on the same subject.1-5
Bucci et al,4 in a controlled study of newborns with low birth weights, found that 2:1 heart block did not appear in any of the 16 newborns who received intravenous (IV) infusion of 10% glucose and sodium bicarbonate, while a 2:1 heart block developed in six of 21 newborns who were given oral feedings of 10% glucose and human milk. The difference was statistically 2.4 times its SE (z = 2.4, P =.016), thus it was considered to be significant. Furthermore, there was no correlation between the degree of ECG change and the serum calcium level. The ECG abnormalities were shown to correlate better with the