Determination of the origin of elevated plasma CPK after cardiac catheterization

Effect of percutaneous balloon mitral valvuloplasty on serum creatinine phosphokinase MB-isoenzyme levels

Twenty-one patients with moderate to severe mitral stenosis were treated with percutaneous balloon mitral valvuloplasty (PBMV) using Inoue mitral double-lumen balloon catheters. Creatinine phosphokinase MB isoenzyme (CPK-MB) levels were measured at baseline, 5 min, 6 h, and 18 h post dilatation. Haemodynamic indexes, 12-lead ECGs, and 2-dimensional echocardiograms were performed to evaluate systolic function postprocedure. CPK-MB levels were modestly increased at 5 min and at 6 h postprocedure compared with the baseline level (p < 0.001) but were still within the normal reference range, except for one patient who had a level at 5 min minimally above the upper limit of normal. CPK-MB levels were not significantly increased at 18 h after the procedure. No significant changes in ejection fractions, 12-lead ECGs, and regional wall motion occurred in any of the patients studied. In conclusion, PBMV causes modest early elevation of CPK-MB. This elevation is not associated with changes in LV systolic function and does not interfere with the diagnosis of acute myocardial infarction using the enzyme elevation criteria.

Time course of creatine kinase release after termination of sustained ventricular dysrhythmias

Differentiation between primary and secondary (caused by acute myocardial infarction) ventricular fibrillation has important therapeutic and prognostic implications. The diagnosis of myocardial infarction is based on clinical, ECG, and creatine kinase MB isoenzyme (MBCK) activity. Enzymatic criteria might not be able to confirm the diagnosis of myocardial infarction after recent cardioversion. The routine use of electrophysiologic studies involving the induction and termination of ventricular dysrhythmias provides a setting in which enzyme release as a result of cardioversion alone can be examined. Therefore a systematic investigation of the magnitude and time course of creatine kinase (CK) and MBCK release was performed after termination of ventricular dysrhythmias in 57 patients undergoing electrophysiologic studies. Of patients requiring external cardioversion, only 50% had an elevation in CK and MBCK activity. Elevation when present corrected with the number of shocks and cumulative energy delivered. The magnitude of MBCK release exceeded 10% of the total CK activity in 9% of observations. Pace-termination of ventricular tachycardia did not result in enzyme release. Arrhythmia characteristics, coronary artery disease, and left ventricular function did not affect the magnitude of the time course of enzyme release. These data suggest that cardioversion with multiple shocks may result in a component of MBCK release, and thus a false positive diagnosis of primary acute myocardial infarction may be made by relying exclusively on the enzyme release pattern.

Electrocardiographic, enzymatic and scintigraphic criteria of acute myocardial infarction as determined from study of 726 patients (A MILIS Study)

Methods for detecting acute myocardial infarction (AMI) were compared in a prospective study of 726 patients with pain presumed to be caused by ischemia that lasted 30 minutes or longer and was associated with electrocardiographic changes (ST-segment deviation greater than or equal to 0.1 mV and/or new Q waves or left bundle branch block). Using MB-CK values of more than 12 IU/liter as the standard criterion for detection of AMI, 639 patients (88%) were judged to have AMI. Total plasma CK values, technetium-99m stannous pyrophosphate images 48 to 72 hours after admission, and serial 12-lead electrocardiograms over 10 days were analyzed by investigators blinded to other clinical and laboratory data. For detection of AMI, total CK, electrocardiograms (ECGs) and pyrophosphate imaging were all highly accurate and sensitive (total CK accuracy 97%, ECG 92%, pyrophosphate 88%; total CK sensitivity 98%, ECG 96% and pyrophosphate 91%). However, both pyrophosphate and ECG were less specific than total CK (p less than 0.01) (total CK specificity 89%, pyrophosphate 64% and ECG 59%). The sensitivity (p less than 0.05) and accuracy (p less than 0.01) of total CK and pyrophosphate for those patients with Q-wave development were slightly greater than for those in whom Q waves did not evolve. The ECG was less accurate (p less than 0.02) and pyrophosphate was less specific (p less than 0.04) in patients with prior MI compared with those with initial infarction.(ABSTRACT TRUNCATED AT 250 WORDS)

Significance of elevated MB creatine kinase in patients after cardiac catheterization

To clarify the etiology of elevations in plasma MB creatine kinase (CK) in patients after cardiac catheterization, we studied 32 consecutive patients undergoing cardiac catheterization and coronary arteriography. Total CK and MB CK were within the normal range in all patients prior to catheterization. Total CK activity rose from a mean of 61.46 +/- 33.8 IU/1 (SD) to 141 +/- 105 in the first sample after catheterization (p less than .005) and 121.6 +/- 92.4 in the second catheterization sample (p less than .0005). The MB CK activity also rose from a mean of 3.2 +/- 1.6 IU/1 prior to catheterization to a maximum value of 5.0 +/- 2.9. The mean increase in MB CK, though statistically significant (p less than .005), was only 1.8 IU/1. Only one patient's value for MB CK rose to outside of the normal range (greater than 12) likely due to cardiac injury. Thus, our data document that marked elevations in MB CK after cardiac catheterization are unusual. They likely represent cardiac muscle injury rather than MB CK released due to skeletal muscle injury induced by the catheterization itself.

Effects of treadmill exercise on total and myocardial creatine phosphokinase

The percentage of increase in total and MB creatine phosphokinase (CPK) after treadmill exercise was determined in 29 patients--ten patients with ST segment depression greater than 1 mm (group 1) and 19 patients with no ST segment depression (group 2). Values were determined pretest and 6, 12, and 24 hours after exercise. The mean exercise duration was 8 min, 18 sec. Total CPK increased within the normal range 12 hours after exercise in group 1 patients exercising less than 8 min, 18 sec, and in all patients exercising longer. The MB CPK remained unchanged after exercise in all patients. These data suggest that while normal range variation of total CPK occurs after treadmill exercise testing, the myocardium does not release MB CPK, regardless of the level of treadmill exercise our patients performed or the development of presumed ischemic ST segment responses. Abnormal elevation of MB CPK suggests myocardial damage.

CPK-MB isoenzyme determinations: diagnostic and prognostic value in evaluation of blunt chest trauma

The incidence of myocardial contusion in patients with blunt chest trauma was examined. The criterion used for diagnosing contusion--actual cellular injury--was based on detection of the MB-isoenzyme of creatine phosphokinase, a sensitive and specific marker for cardiac cellular injury. Forty-nine patients with blunt chest trauma were evaluated using this diagnostic approach. Twenty-six demonstrated measurable serum levels of MB-CPK. Electrocardiographic (ECG) evaluation of this subgroup revealed that 85% exhibited anatomically localized ST-T wave abnormalities while 15% showed nonlocalized and nonspecific changes. Sixty-eight percent of those with localized abnormalities demonstrated ST segment changes depicting injury, most of which were localized to the anterior septal leads. The remaining 23 patients demonstrated non-detectable serum levels of MB-CPK and were classified as cardiac concussion on the basis of other clinical criteria. Twenty-six percent with concussion exhibited anatomically localized ECG changes. The remaining 74% had nonlocalized and nonspecific ECG changes.