Ischemic preconditioning influence ventricular function in off-pump revascularization surgery.
BACKGROUND
Ischemic preconditioning is a method that prepares and protects cells to tolerate a long period of ischemia with the least possible injury.


OBJECTIVE
Evaluate the influence of ischemic preconditioning over left ventricular function during off-pump myocardial revascularization.


METHODS
Forty patients with clinical indication for off-pump myocardial revascularization were randomized in two groups, with or without ischemic preconditioning. Ischemic preconditioning was carried out by performing coronary occlusion for two minutes and releasing blood flow for one minute; two cycles were performed. Left ventricular contractility was evaluated through transesophageal Doppler by measuring blood flow acceleration in the descending aorta - Hemosonic 100. The acceleration measurements were performed at the start of the surgery, after heart positioning and five and ten minutes after coronary occlusion.


RESULTS
There was no significant difference in left ventricular contractility between the two groups. At the beginning of the procedure flow acceleration was 9.37 +/- 2.9m/s(2) in the preconditioning group and 12.5 +/- 3.1 m/s(2) in no-preconditioning group (p = 0.23); after positioning of heart, it was 8.47 +/- 3.3 and 8.31 +/- 3.6 m/s(2) (p = 0.96); after five minutes - 8.7 +/- 4.1 and 7.94 +/- 2.9 m/s(2) (p = 0.80); and after ten minutes - 9.2 +/- 4.5 and 7.98 +/- 3.4 m/s(2) (p = 0.71). However, contractility evolution was different throughout time in each group. The preconditioning group maintained left ventricular contractility during the entire procedure, since the beginning (0.52), while the group without ischemic preconditioning presented reduction in left ventricular contractility (p = 0.0034).


CONCLUSIONS
Ischemic preconditioning prevented the decrease in left ventricular contractility during off-pump myocardial revascularization surgery.
Succi
José Ernesto
JE
Hospital Bandeirantes em São Paulo, São Paulo, SP, Brasil.
Gerola
Luís Roberto
LR
Succi
Guilherme Menezes
GM
Almeida
Renata A C F de
RA
Novais
Leonardo Sérgio Rocha
LS
Rocha
Bruno
B
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001013:Aorta, Thoracic / Q000601:surgery; D047549:Coronary Artery Bypass, Off-Pump / Q000379:methods*; D003326:Coronary Circulation / Q000502:physiology; D018618:Echocardiography, Doppler, Color; D005260:Female; D006333:Heart Failure / Q000601:surgery*; D006801:Humans; D019157:Ischemic Preconditioning, Myocardial; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000502:physiology*; D013997:Time Factors