Enzyme release after elective cardioversion.

Area of Science:

• Biochemistry
• Cardiology
• Clinical Chemistry

Background:

• Electrical cardioversion is a critical procedure for managing cardiac arrhythmias.
• Previous reports suggest potential for skeletal muscle and myocardial damage following electrical cardioversion.

Purpose of the Study:

• To quantify serum total creatine kinase (S-CK) and S-CK-B activity post-elective cardioversion.
• To investigate the correlation between enzyme release and delivered energy.
• To assess the diagnostic implications of S-CK and S-CK-B levels for myocardial infarction.

Main Methods:

• Serum samples were collected from 30 patients undergoing elective cardioversion.
• Measurements of total creatine kinase (S-CK) and S-CK-B activity were performed.
• Enzyme activity was monitored over a 28-hour period post-procedure.

Main Results:

• Both S-CK and S-CK-B levels significantly increased, peaking within 28 hours.
• S-CK increased from 72 to 990 U/L, and S-CK-B rose from 3.0 to 10.2 U/L.
• Elevated S-CK-B in seven patients exceeded the myocardial infarction discrimination limit, but analysis indicated skeletal muscle origin.
• Enzyme release correlated positively with cumulative delivered energy (S-CK: r=0.79, S-CK-B: r=0.70).

Conclusions:

• Post-cardioversion S-CK and S-CK-B release is primarily from skeletal muscle.
• The extent of enzyme release is directly related to the cumulative energy delivered during cardioversion.
• Interpreting S-CK levels alone without S-CK-B can lead to misdiagnosis of myocardial infarction.