Should coronary angiography be performed in district hospitals?

Selective inhibition of the sperm-specific lactate dehydrogenase isozyme-C4 by N-isopropyl oxamate

In the present study, we demonstrated that the attachment of the nonpolar isopropylic carbon chain in the nitrogen of oxamate, converted this competitive inhibitor of LDH isozymes into a powerful selective inhibitor of mouse LDH-C4. The comparative study of the inhibitory effect of oxamate and N-isopropyl oxamate on mouse LDH isozymes pointed out that the isopropylic carbon chain conferred upon N-isopropyl oxamate a high affinity for LDH-C4 and a marked decrease in the affinity for the other isozymes since oxamate showed more inhibitory effect on LDH-1 (Ki = 0.06 mM) and LDH-5 (Ki = 0.08 mM), and less inhibitory effect on LDH-C4 (Ki = 0.25 mM). On the other hand, N-isopropyl oxamate showed the highest inhibitory effect on LDH-C4 (Ki = 0.014 mM) and poor inhibitory effect on LDH-1 (Ki = 0.4 mM) and LDH-5 (Ki = 0.8 mM). Apparently, the enzymatic inactivation proceeded through a reversible binding of N-isopropyl oxamate, facilitated by nonpolar interactions with a hydrophobic region present only in the active site of mouse LDH-C4, resulting in a selective inhibition of this isozyme in comparison with the other LDH isozymes. N-isopropyl oxamate was also a powerful competitive inhibitor of LDH-C4 (Ki = 0.015 mM) compared with oxamate (Ki = 0.35 mM), using alpha-ketoisocaproate as a substrate.

Mortality related to coronary angiography

Coronary angiography is in general regarded as a safe investigation with a low risk of serious complications. Unfortunately, a risk of serious complications exists, especially in patients with left main coronary artery disease or 3-vessel disease. The mortality rate ranges in different studies between 0.10% to 0.25%. The present series, reflecting nine years experience, shows an overall mortality of 0.16%. This figure is influenced by the relatively high mortality rate in the first year of the study. The recent mortality rate of 0.07% has not changed in the last 3 years and almost all deaths occurred in the patients known to be at higher risk.

Emergency coronary artery surgery after refractory cardiac arrest: a single centre experience

OBJECTIVE

To determine the incidence and outcome of refractory cardiac arrest necessitating emergency coronary artery bypass grafting.

DESIGN

Retrospective survey of cardiac catheterisation and surgical records.

SETTING

The London Chest Hospital.

PATIENTS

All patients requiring emergency coronary artery bypass grafting after cardiovascular collapse in the catheterisation suite between January 1984 and December 1989.

MAIN OUTCOME MEASURES

Incidence of refractory cardiac arrest in the study group and perioperative mortality.

RESULTS

Thirteen of 8675 patients undergoing coronary arteriography or angioplasty had refractory cardiac arrests. Five patients died, but the remainder survived to be discharged from hospital without serious morbidity.

CONCLUSION

Without immediate surgical intervention the mortality for these 13 patients would have been 100%.