Cardiac function after intermittent antegrade warm blood cardioplegia: contribution of the double-indicator dilution technique

Objective: To evaluate cardiac performance following coronary artery surger y using two different techniques of cardioplegia Design: Randomized prospective study Setting: Adult cardiothoracic intensive care unit in a university hospital Study population. Thirty patients undergoing isolated coronary surgery Interventions: Patients were randomized to receive either intermittent ante grade warm blood cardioplegia with normothermic bypass (group 1) or combine d antegrade and retrograde cold crystalloid cardioplegia with hypothermic b ypass (group 2). Hemodynamic evaluation included conventional measurements from a pulmonary artery catheter and data obtained by thermal dye dilution utilizing an arterial thermistor-tipped fiberoptic catheter Results: The only major difference between groups was a significantly highe r right atrial pressure in group 2, from 4 h to 24 h after surgery (8.8 +/- 2.6 vs. 11.8 +/- 3.2 mmHg at 4 h and 11 +/- 3.1 vs. 8.5 +/- 1.8 mmHg at 24 h, P = 0.04). After cold cardioplegia a significant increase in right atri al pressure was observed (7.5 +/- 3.1 before surgery vs. 11.4 +/- 3 mmHg at 8 h, P = 0.003) whereas right ventricular end diastolic volume index did n ot increase significantly, suggesting impaired right ventricular diastolic compliance in this group Conclusions: Until 24 h after surgery cold cardioplegia is associated with impaired right ventricular filling, which seems better preserved by intermi ttent antegrade warm blood cardioplegia. End-diastolic volume measurement w ith the double-indicator technique allows differentiation between systolic and diastolic dysfunction.