Myocardial metabolism and hemodynamics during coronary surgery without cardiopulmonary bypass

Assessment of myocardial injury by troponin T in off‐pump coronary artery grafting and conventional coronary artery graft surgery

“…Our values for TnT at individual sampling points were significantly higher in the CABG group at each interval from 2 through to 24 h. In the absence of infarction, we would not expect the 72 h samples to be significantly different 25 . While Pentilla et al 19 and Krejca et al 20 have recently shown lower TnT values with OPCAB surgery, we have demonstrated the release profile for TnT after OPCAB surgery and shown peak release to occur 6–8 h following initiation of the ischaemic load. Calculations of the area under the curve were performed on the multiple sampling subgroups to assess cumulative TnT release from the induced ischaemic load with each technique.…”

“…For the OPCAB group, we have recorded the length of time the proximal coronary snare was applied, occluding anterograde flow, as the ischaemic time. While Pentilla et al 19 have shown only minor alterations in haemodynamics and myocardial metabolism, Grundeman et al 28 have shown significant alterations in coronary flow and LV function (stroke volume and mean arterial pressure) with vertical displacement of the heart in animal studies. We believe the occasional periods of hypotension and intermittent cardiac manipulation must be significant in assessing the total ischaemic exposure; the difficulty lies in quantitating these periods.…”

“…Inter‐ventricular septal function has been shown to be preserved in coronary artery grafting (CAG) without CPB by Akins et al as early as 1984 17 . Recently, no significant change in TnT 18 or CK‐MB mass 19 and only minor changes in haemodynamics and myocardial energy metabolism have been reported with OPCAB surgery 19 . Other literature, using TnT to assess myocardial protection, has shown that off‐pump surgery results in significantly lower TnT release compared with beating heart surgery performed with CPB and traditional CABG with cardioplegic arrest 20 …”

Right Ventricular Function After Coronary Surgery with or Without Bypass

“…OPCAB leads to fewer postoperative infarctions, fewer low output states, and lower release of troponin, 5 as found in our study. Changes in myocardial metabolism were limited during OPCAB surgery 14 and β‐receptor activity was well preserved 15 . During OPCAB, significant changes in left ventricular function were observed: surgical exposure of the circumflex coronary artery was responsible for a significant reduction in ventricular compliance.…”

Leukocyte filtration and aprotinin: synergistic anti-inflammatory protection

“…Consequently, oxidative metabolism is impaired, causing ATP degradatives and lactate to accumulate in the underperfused myocardium. 36 Direct cardiac sequelae include atrial fibrillation rates as high as 24 ¡/37%; 20,37,38 indeed, several reports indicate similar rates of atrial fibrillation in off-pump versus on-pump coronary bypass surgeries. 18 ¡ 21 Pulmonary complications in off-pump cases were documented by Kochamba et al 39 In their study, postoperative gas exchange did not differ in cardiopulmonary bypass versus off-pump procedures.…”