Ventilatory effects of metoprolol in asthmatic patients after administration of ordinary and slow-release tablets.

CHEST, 77: 3, MARCH, 1980 obstructive hypertrophic cardiomyopathy and discrete subaortic stenosis, since this abnormality is seen commonly in both conditions. As pointed out by Dr. Glaser, a recent article by Krajcer et al describes a consistent difference in the timing of midsystolic closure of the aortic valve: in each of 22 patients with obstructive hypertrophic cardiomyopathy, midsystolic aortic closure occurred at least 0.07 sec after aortic valve opening (mean 0.14 sec ± 0.04 SD) and in each of nine patients with discrete subaortic stenosis midsystolic aortic closure occurred no later than 0.06 sec after aortic valve opening (mean 0.05 sec ± 0.01). Each of the patients with discrete subaortic stenosis had severe subvalve gradients; no “mild cases” were described by these authors. If these data are confirmed by further experience, the timing of midsystolic closure would appear to offer a useful means of discriminating between obstructive hypertrophic cardiomyopathy and discrete subaortic stenosis. In the same article, Krajcer et al point out that fluttering of the aortic leaflets can be seen either in obstructive hypertrophic cardiomyopathy or in discrete subaortic stenosis, that this fluttering can be seen both before and after operative treatment, and, indeed, that such fluttering is occasionally seen in normal persons. Our experience has been similar. For this reason, we are reluctant to ascribe pathologic significance to fluttering of the aortic leaflets.