Dolor precordial y elevación de CPK-MB posejercicio que simula infarto agudo de miocardio: presentación de 2 casos y revisión de la literatura / Precordial pain with increase of CK-MB fraction after exercise that mimics acute myocardial infarction: report of two cases, with review of references

Se detallan 2 casos de dolor y elevación de la fracción B de la creatinfosfoquinasa posejercicio, que requirieron coronariografía (coronarias normales) para descartar infarto agudo de miocardio. En ambos casos hubo una elevación absoluta de la creatinfosfoquinasa y de la fracción MB de la creatinfosfoquinasa; en el segundo caso también aumentó la relación porcentual de la fracción MB de la creatinfosfoquinasa (18,6 por ciento de la creatinfosfoquinasa total). Es común el aumento de la fracción MB de la creatinfosfoquinasa luego de lesiones y/o traumatismos musculares; en algunos casos incluso aumenta la relación aumento de la fracción MB de la creatinfosfoquinasa/creatinfosfoquinasa total o el índice de las subformas de aumento de la fracción MB de la creatinfosfoquinasa, semejándose su perfil enzimático al del infarto agudo de miocardio

Desgarro muscular, arritmia supraventricular y aumento de la CPK-MB que simula un evento coronario: reporte de un caso / Muscular dilaceration, supraventricular arrhytmia and increase of CPK-MB that seems a coronary event: report of a case

A 47 year old man without coronary risks factors had an acute pain in his right quadriceps following a kick to a soccer ball. Four hours later, he had a paroxysmal atrial fibrillation with a moderate ventricular response. He never had precordial pain. His first CK was increased, and the MB fraction was 20 per cent of total CK. He was admitted to the Coronary Care Unit, and the second sample shows again an increase of both CK and its MB fraction. He recovered his sinus rhythm with amiodarone and quinidine, and his EKG's never showed ST-T segments alterations. A bidimensional echocardiography, and a stress test with Tc99-pirophosphate showed no abnormality. An ecography of his right quadriceps shows an 20 x 25mm lesion in the rectus anterior portion, which was compatible with an acute strain of thid muscle. An electrophoretic study of the CK (done on the fouth day), shows that 95 per cent was MM-CK and 5 per cent MB-CK, without BB fraction present in the sample. The patient was discharged with betablockers and remained asymptomatic in the follow-up. In the discussion, it is showed that MB-CK could increase its absolute values following several events: after marathon training and/or race, in professional athletes, and after acute muscular injuries. In some cases the enzymatic curve an the ratio MB/total CK (no matter which test is used) could mimic an acute myocardial pirophosphate scan wich is always normal, and also can show the skeletal lesion. Although troponin T test was claimed to be more specific than MB-CK, there are exceptions, so it could be better to do a troponin I test, if there is any diagnostic incertainty.(A U)