Postoperative Changes in Pulmonary Function after Valve Surgery: Oxygenation Index Early after Cardiopulmonary Is a Predictor of Postoperative Course.

OBJECTIVE: To determine pulmonary functional changes that predict early clinical outcomes in valve surgery requiring long cardiopulmonary bypass (CPB). METHODS: This retrospective study included 225 consecutive non-emergency valve surgeries with fast-track cardiac anesthesia between January 2014 and March 2020. Blood gas analyses before and 0, 2, 4, 8, and 14 h after CPB were investigated. RESULTS: Median age and EuroSCORE II were 71.0 years (25-75 percentile: 59.5-77.0) and 2.46 (1.44-5.01). Patients underwent 96 aortic, 106 mitral, and 23 combined valve surgeries. The median CPB time was 151 min (122-193). PaO2/FiO2 and AaDO2/PaO2 significantly deteriorated two hours, but not immediately, after CPB (both p < 0.0001). Decreased PaO2/FiO2 and AaDO2/PaO2 were correlated with ventilation time (r2 = 0.318 and 0.435) and intensive care unit (ICU) (r2 = 0.172 and 0.267) and hospital stays (r2 = 0.164 and 0.209). Early and delayed extubations (<6 and >24 h) were predicted by PaO2/FiO2 (377.2 and 213.1) and AaDO2/PaO2 (0.683 and 1.680), measured two hours after CPB with acceptable sensitivity and specificity (0.700-0.911 and 0.677-0.859). CONCLUSIONS: PaO2/FiO2 and AaDO2/PaO2 two hours after CPB were correlated with ventilation time and lengths of ICU and hospital stays. These parameters suitably predicted early and delayed extubations.

Preserved autoregulation of coronary flow after off-pump coronary artery bypass grafting: retrospective assessment of intraoperative transit time flowmetry with and without intra-aortic balloon counterpulsation.

BACKGROUND: Intra-aortic balloon pumping (IABP) markedly increases graft flow after coronary artery bypass grafting (CABG) with cardiopulmonary bypass. We sought to delineate the effects of IABP on graft flow after off-pump CABG (OPCAB). METHODS: The clinical records of 32 patients (25 male, 7 female; mean age: 70 ± 9 years) who underwent OPCAB with IABP between January 2011 and May 2015 were retrospectively reviewed. Thirteen patients (41%) had a history of myocardial infarction, and 13 patients (41%) had a history of percutaneous coronary intervention. In total, there were 76 bypass grafts with 102 distal anastomoses. These included 50 in situ or pedicled grafts and 26 aortocoronary grafts. After completion of the anastomoses, the heart was positioned normally, and graft flow with IABP was measured using transit-time flowmetry under stable circulation. Then, IABP was turned off for 30 s to a few minutes, until graft flow was constant, for measurement of flow off IABP. RESULTS: The angiographic patency rate was 100% (47/47). Overall, graft flow was 55 ± 36 ml/min on IABP and 53 ± 36 ml/min off IABP (p = 0.37). The pulsatility index was 4.1 ± 2.1 on IABP and 2.7 ± 1.5 off IABP (p < 0.001). There was no significant difference in graft flow between on and off IABP for aortocoronary bypass or in situ grafts. Graft flow was 57 ± 36 ml/min on IABP and 55 ± 37 ml/min off IABP (p = 0.41) in in situ grafts and 52 ± 34 ml/min on IABP and 49 ± 35 off IABP (p = 0.41) in aortocoronary grafts. Graft flow on IABP was more than 5 ml/min greater in 28 (37%) bypass grafts, and more than 5 ml/min lower in 20 (26%) bypass grafts. CONCLUSION: In contrast to previous reports for conventional CABG, graft flow after OPCAB was not necessarily increased by IABP, regardless of elevated diastolic arterial pressure. It is suggested that preserved autoregulation of coronary flow contributes to a lower impact on the heart and early functional recovery, and consequently, greater perioperative safety of OPCAB.

Comparison of early haemodynamics of 19-mm aortic valve bioprostheses in patients with a small aortic annulus.

OBJECTIVES: A potential problem in aortic valve replacement (AVR) for patients with a small aortic annulus is prosthesis-patient mismatch (PPM). Although larger size prostheses have been well studied, the haemodynamics of 19-mm bioprostheses has been reported in only a small number of patients. The Trifecta valve is a novel bioprosthesis and its unique design is conceived to increase effective orifice area (EOA) and prevent PPM. This study aims at comparing the early haemodynamics of the new Trifecta valve with that of other conventional 19-mm valves. METHODS: We retrospectively evaluated 128 consecutive patients who underwent AVR with 19-mm bioprosthesis (39 Trifecta valve, 67 Magna Ease valve and 22 Mosaic Ultra valve) at Saitama International Medical Center between April 2012 and December 2014. Haemodynamics was evaluated by transthoracic echocardiography at 1 month after discharge and at 1-year follow-up. RESULTS: The average body surface area of all patients was 1.37 m(2). There was no difference in postoperative clinical outcomes between the three groups. Among the three groups, the mean pressure gradient (MPG) was the smallest (10.6 ± 4.3 mmHg, P < 0.001) and the EOA was the largest (1.63 ± 0.36 cm(2), P < 0.001) in the Trifecta group at 1 month after discharge. In the Trifecta group, PPM was not observed (P < 0.001), the MPG was the smallest (12.8 ± 3.6 mmHg, P < 0.001) and the EOA was the largest (1.50 ± 0.30 cm(2), P < 0.001) at the 1-year follow-up. CONCLUSIONS: The new 19-mm Trifecta valve showed favourable early haemodynamics compared with the conventional valves and may be useful for preventing PPM in patients with a small aortic annulus.

[Surgery for Ventricular Tachycardia Arising from Left Ventricular Aneurysm in a Patient with Dilated Cardiomyopathy；Report of a Case].

A left ventricular aneurysm (LVA) generally results from myocardial infarction, but rarely LVA can be associated with dilated cardiomyopathy (DCM). We herein report a surgical case of malignant ventricular tachycardia (VT) in a patient with LVA associated with DCM. A 57-year-old woman was diagnosed with DCM and LVA when she 1st presented with sustained VT. She had anti-arrhythmic medical therapy and implantable cardiac defibrillator. Subsequently, she presented with recurrent monomorophic VT arising from the LVA. Because anti-arrhythmic medical therapy and endocardial ablation were not effective, the patient was performed left ventricular aneurysmectomy and encircling endocardial cryoablation and could achive good arrhythmic control and clinical outcome.

Sivelestat reduces myocardial ischemia and reperfusion injury in rat hearts even when administered after onset of myocardial ischemia.

Sivelestat, a neutrophil elastase inhibitor, has been shown to attenuate pulmonary injury during ischemia and reperfusion by improving microcirculation and may be effective as a cardioprotective agent. Isolated rat hearts were Langendorff-perfused (constant pressure, 75 mmHg) with oxygenated Krebs-Henseleit bicarbonate buffer (KHB). The optimal sivelestat concentration at 19 micromol/l was revealed because left ventricular developed pressure (LVDP) recovery in 19 micromol/l sivelestat was highest among 0.19, 1.9, 19, 190, and 1900 micromol/l sivelestat (26+/-10, 33+/-7, 56+/-5*, 35+/-2, and 15+/-5%, respectively; *P<0.01). In order to examine the optimal administration timing, sivelestat was administered at pre- and post-ischemic phases. LVDP recovery and troponin-T were observed in pre-, post-ischemic sivelestat groups and control. After 60 min-reperfusion, LVDP recoveries were 42+/-10*, 45+/-19*, and 14+/-5%, respectively (*P<0.01 compared to control), and troponin-T values were 4+/-1, 2+/-1**, and 8+/-2, respectively (**P<0.05 compared to control). Acetylcholine-induced increase in coronary flow was also investigated to examine the sivelestat's cardioprotective mechanism. Ischemia-reperfusion (I/R) impaired the acetylcholine-induced increase in coronary flow (maximal changes: sham, 125+/-11%; I/R, 98+/-3; P<0.01) and this impairment was attenuated by sivelestat-perfusion at reperfusion (maximal change: 112+/-7%; P<0.05 vs. I/R). Sivelestat attenuates coronary endothelial ischemia-reperfusion injury and improves myocardial protection even when administered at the reperfusion period. This suggests a role for sivelestat in the preservation of coronary endothelial function enhancing myocardial protection.

Intraoperative verification of conduction block in atrial fibrillation surgery.

BACKGROUND: Atrial tachycardia is a troublesome and medically refractory complication after surgery for atrial fibrillation. Incomplete surgical ablation during atrial fibrillation surgery can result in residual conduction over the lesions and postoperative atrial tachycardia. Intraoperative verification of conduction block would detect incomplete ablation lesions and direct repeat ablations to prevent postoperative atrial tachycardia. METHODS: The incidence of postoperative atrial tachycardia was examined in 218 patients who underwent atrial fibrillation surgery between November of 1994 and October of 2007. No conduction block across any ablation lesions was confirmed intraoperatively in the first 128 patients (group C). Isolation of each pulmonary vein was verified by intraoperative pulmonary vein pacing in the following 72 patients (group PV). In the recent 18 consecutive patients, conduction block in the coronary sinus, in addition to pulmonary vein isolation, was confirmed by intraoperative coronary sinus pacing (group PV/CS). Postoperative atrial tachycardia was characterized by electroanatomic mapping. RESULTS: The incidence of postoperative atrial tachycardia in groups C and PV was 7% and 1%, respectively (P = .0985). No patients exhibited any postoperative atrial tachycardia in group PV/CS. The postoperative electroanatomic mapping revealed that the mechanisms of the atrial tachycardia were macro-reentry through incomplete coronary sinus and mitral valve ablation lesions (n = 9), and focal activation in the coronary sinus (n = 1). Intraoperative verification of conduction block directed the repeat ablation lesions to the pulmonary veins. CONCLUSION: The majority of postoperative atrial tachycardia was associated with an incomplete coronary sinus ablation. Intraoperative verification of conduction block may be helpful to prevent the occurrence of postoperative atrial tachycardia.