Acute effects of beating heart coronary surgery on left ventricular performance.
BACKGROUND
The increasing use of off-pump bypass grafting (OPCABG), requires an evaluation of its effects on left ventricular (LV) performance.


METHODS
In 8 patients with multivessel coronary disease who were undergoing to off-pump coronary artery bypass grafting, LV performance was analyzed from the pressure-volume (P-V) plane by the conductance catheter technique. Measurements were performed at base line, after the exposure of the vessels, after the application of the stabilization system, and at the end of the procedure.


RESULTS
No significant changes in heart rate, LV end-systolic volume, LV end-diastolic pressure, mean pulmonary artery, and mean systemic blood pressure were observed in the various stages of the procedure. Cardiac index decreased during left anterior descending coronary artery grafting after application of the stabilizer with a concomitant decrease in LV end-diastolic volume, together with decreases in LV peak negative -dP/dt and increases in tau, indicating an impairment of LV relaxation but without a change in preload recruitable stroke work, indicating preserved LV contractile state. Exposure of posterior and lateral vessels induced a decrease in cardiac index and preload recruitable stroke work without a decrease in LV preload, indicating a decrease in LV contractile state together with a decrease in peak -dP/dt and increase in tau, indicating an impairment in LV relaxation


CONCLUSIONS
Off-pump coronary artery bypass grafting can be performed without decreasing LV performance. Major cardiac displacement like that used for posterior and lateral exposure induces acutely significant decrease in LV contractile state.
Torracca
Lucia
L
Department of Cardiac Surgery, San Raffaele University Hospital, Milan, Italy. lucia.torracca@hsr.it
Schreuder
Jan J
JJ
Quarti
Andrea
A
Ismeno
Gennaro
G
Franzé
Vincenzo
V
Alfieri
Ottavio
O
D000368:Aged; D001794:Blood Pressure; D002306:Cardiac Volume; D002315:Cardiopulmonary Bypass; D001026:Coronary Artery Bypass / Q000379:methods*; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D016277:Ventricular Function, Left / Q000502:physiology*