[Electrical cardioversion and myocardial injury: evaluation by new cardiac injury markers].
OBJECTIVE
Evaluate, based on the evolution of new biochemical markers of cardiac damage, if electrical cardioversion (ECV) causes myocardial injury.


METHODS
Seventy-six patients (P) submitted to elective ECV for atrial fibrillation or atrial flutter were evaluated. Creatine phosphokinase (CPK), CK-MB activity, CK-MB mass, myoglobin and cardiac troponin I (cTnI) were measured before, and 6 and 24 hours after ECV.


RESULTS
ECV was successful in 58 P (76.3%). Cumulative energy (CE) was up to 350 joules (J) in 36 P, from 500 to 650 J in 20 P and from 900 to 960 J in 20 P; the mean energy delivered being 493 J (+/- 309). The levels of cTnI remained within normal limits in all 76 P. The increase of cumulative energy led to an elevation of CPK levels (> p value = 0.007), CK-MB activity (> p value = 0.002), CK-MB mass (> p value = 0.03), and myoglobin (> p value = 0.015). A positive correlation between the cumulative energy and CPK peaks was observed (r = 0.660; p < 0.001), CK-MB activity (r = 0.429; p < 0.0001), CK-MB mass (r = 0.265; p = 0.02), and myoglobin (r = 0.684; p < 0.0001), as well as between the number of shocks and the CPK peaks (r = 0.770; p < 0.001), CK-MB activity (r = 0.642; p < 0.0001), CK-MB mass (r = 0.430; p < 0.0001), and myoglobin (r = 0.745; p < 0.0001).


CONCLUSIONS
ECV does not cause myocardial injury detectable by cTnI measurement. Elevations of CPK, CK-MB activity, CK-MB mass and myoglobin result from skeletal muscle injury and are positively correlated with the CE delivered or with the number of shocks.
Santos
Elizabete Silva dos
ES
Instituto Dante Pazzanese de Cardiologia, São Paulo, SP. elizabetssantos@cardiol.br
Pereira
Marcos Paulo
MP
Minuzzo
Luiz
L
Moreira
Dalmo A R
DA
Ramos
Rui
R
Avezum
Alvaro
A
Timerman
Ari
A
Piegas
Leopoldo S
LS
D000704:Analysis of Variance; D001281:Atrial Fibrillation / Q000628:therapy; D001282:Atrial Flutter / Q000628:therapy; D015415:Biomarkers / Q000097:blood; D052279:Creatine Kinase, MB Form / Q000097:blood*; D004554:Electric Countershock / Q000009:adverse effects*; D005260:Female; D006335:Heart Injuries / Q000097:blood / Q000209:etiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009211:Myoglobin / Q000097:blood*; D013997:Time Factors; D019210:Troponin I / Q000097:blood*
D015415:Biomarkers; D009211:Myoglobin; D019210:Troponin I; D052279:Creatine Kinase, MB Form