[Increase of creatine kinase mb isoenzyme out of a context of acute myocardial infarct]. / Elevação da isoenzima mb da creatinaquinase fora de um contexto de enfarte agudo do miocárdio.

The increased serum level of the MB isoenzyme of creatine kinase is a very useful test for the diagnosis of acute myocardial infarction. However, there are several situations of false positives for this test that are scarcely mentioned in the standard medical references. We report a case of prostate carcinoma with a high serum creatine kinase BB fraction. The immunoinhibition method may cause a false increase in creatine kinase MB in this situation, which in the case presented suggested the diagnosis of myocardial infarction. We discuss patient diagnosis, laboratory methods for the determination of creatine kinase and the technical reasons for the false positives.

[Electrocardiographic changes after coronary angiography: effect of the contrast media used]. / Alterações electrocardiográficas após coronariografia: influência do contraste utilizado.

UNLABELLED: Prospective study to evaluate the influence of 2 different iodine contrasts (used in coronariography) on the electrocardiographic changes recorded after intra-coronary injection. MATERIAL AND METHODS: Sixty-six patients (pts) - 50 men and 16 women - 59 +/- 4 years underwent coronariography to confirm and/or evaluate coronary artery disease (CAD). Group I (33 pts) received a hyperosmolar contrast; group II received a low osmolarity contrast. The electrocardiograms were recorded during and until 20 seconds after intra-coronary injection, in standard leads and V5. Tracings were analysed regarding the development of: arhythmias, mean axis deviation and QRS enlargement - type A abnormalities; ventricular repolarization (ST/T) changes - type B abnormalities. ECG changes were compared with: 1. contrast used; 2. presence (or absence) of CAD; 3. correlation between type B abnormalities and the arteries affected. RESULTS: 1. a) Twenty nine pts (88%) of group I had A and/or B electrocardiographic changes, compared with 16 (48%) of group II (p < 0.01). b) There were type A changes in 13 pts of group I (39%) versus 3 pts (9%) of group II (p < 0.01). c) Type B changes were present in 25 pts (76%) of group I and in 20 pts (60%) of group II (p-NS). 2. a) Type A abnormalities were recorded in 13 of 48 pts with CAD (27%) against 3 of 18 (17%) cases with normal coronariography (p-NS). b) Type B abnormalities were present in 30 of 48 pts (63%) with CAD and in 10 of 18 cases (56%) of people with normal coronariography (p-NS). 3. In 21 pts with isolated right (or left) CAD, contrast injection in the right coronary artery induced type B ECG changes on the homo-lateral supplied territory in 14 cases, no change at all in 4 cases and changes in the contra-lateral area in only 3 pts. Injections in the left coronary artery produced similar results. CONCLUSIONS: 1. Hyperosmolar contrast produced significantly more electrocardiographic abnormalities, mainly type A, than low osmolarity contrast. This one may be, therefore, preferable. 2. Both types of electrocardiographic changes were equally recorded in pts with CAD and in people with normal coronariography. 3. Type B changes seem to be related with the location of the injection, irrespective of the presence or absence of coronary artery disease.