[Macro creatine kinase as a pitfall in diagnosis of acute myocardial infarction]. / Makrokreatinkinase som diagnostisk faldgrube ved AMI-diagnostik.

Measurement of creatine kinase and the more heart-specific creatine kinase B has been a mainstay in the diagnosis of acute myocardial infarction in Denmark since the 1970's. However, an elevated creatine kinase B may reflect other conditions than myocardial damage, for example the presence of other isoenzymes or macro creatine kinase. A case is presented with a review of the literature.

Atrial natriuretic peptide in congestive heart failure after acute myocardial infarction.

The concentration of atrial natriuretic peptide, a newly discovered hormone produced in the atrial wall, was measured in 55 patients during the first 72 h after acute myocardial infarction. 37 patients became clinically congested, while 18 patients avoided this complication. 13 patients (9 congested and 4 uncongested) experienced tachycardia, known to raise the concentration of atrial natriuretic peptide both with and without congestive heart failure. In the remaining 42 patients, the congested group had a significantly higher plasma atrial natriuretic peptide concentration than the uncongested group (p < 0.05) on all 3 days. In the congested group the concentration of atrial natriuretic peptide did not normalize after initiation of treatment. We conclude that the concentration of atrial natriuretic peptide is increased in all patients with acute myocardial infarction and that the level of atrial natriuretic peptide declines during the first 24 h in all patients and normalizes in the uncongested patients while the level of atrial natriuretic peptide is still elevated (at least for 72 h) in the congested patients.

Plasma concentration of atrial natriuretic peptide at admission and risk of cardiac death in patients with acute myocardial infarction.

OBJECTIVE: To compare the concentration of plasma atrial natriuretic peptide in patients with acute myocardial infarction with a healthy population and to determine whether a raised concentration of plasma atrial natriuretic peptide at admission was a predictor of mortality after acute myocardial infarction. DESIGN: Patients with acute myocardial infarction were divided into a group with no congestion (class I) and a group with congestion (class II-IV) according to their highest Killip classification in the first 24 hours after infarction. The concentration of plasma atrial natriuretic peptide was measured at admission. On the basis of the concentration of atrial natriuretic peptide measured in the healthy population, patients were separated into two groups: a group with a high (greater than 200 pg/ml) and a group with a low concentration of atrial natriuretic peptide (less than or equal to 200 pg/ml). The patients were followed for three years. PATIENTS: 55 patients admitted to the coronary care unit within 12 hours of the appearance of symptoms of acute myocardial infarction were compared with 51 healthy individuals. MAIN OUTCOME MEASURES: Plasma atrial natriuretic peptide, Killip class, mortality. RESULTS: The patients had significantly higher concentrations of atrial natriuretic peptide than the healthy controls. Furthermore, patients with congestion had a significantly higher concentration of atrial natriuretic peptide than the uncongested group of patients. Total mortality was 34.5%. In the group with a low concentration of atrial natriuretic peptide the mortality was only 13.6%, whereas mortality was significantly higher (48.5%) in the group with a high concentration. CONCLUSIONS: The measurement of atrial natriuretic peptide separated the patients into low and high risk groups after acute myocardial infarction.

Physiological hypertrophy of the heart and atrial natriuretic peptide during rest and exercise.

The influence of physiological cardiac hypertrophy on the concentration of plasma atrial natriuretic peptide was studied in six male athletes and six normally active, matched control men. They were examined by echocardiography during a graded exercise test on a bicycle ergometer. Plasma atrial natriuretic peptide was measured at rest, at each workload until exhaustion, and 15 and 30 minutes after the exercise test. Echocardiography showed that the athletes had a significantly larger left atrium, left ventricular end diastolic diameter, left ventricular posterior wall, interventricular septum, left ventricular ejection fraction, and left ventricular mass than the controls. The athletes performed significantly more work than the control group--325 W v 277 W. The plasma concentration of atrial natriuretic peptide rose by a mean factor of 2.76 (range 1.78-4.28) in all men from rest to maximum exercise. There were no differences between the athletes and the controls in the concentrations of plasma atrial natriuretic peptide at rest, at any workload, or at maximum workload. Neither was there any difference in the increase in plasma atrial natriuretic peptide between the groups. There was no correlation between the plasma concentrations of atrial natriuretic peptide and any of the variables measured by echocardiography. In healthy young men plasma atrial natriuretic peptide rises by a factor of about 2.8 during maximum exercise and the size of the chambers on the left side of the heart or left ventricular hypertrophy does not seem to influence the concentration of plasma atrial natriuretic peptide at rest or during exercise.