Effects of Shenmai injection on the values of CO, SV, and EF in patients undergoing off-pump coronary artery bypass graft: A randomized, clinical trial.

BACKGROUND: To explore the effects of Shenmai (SM) injection on the values of cardiac output (CO), stroke volume (SV), and the ejection fraction (EF) in patients treated with off-pump coronary artery bypass graft (OPCABG). METHODS: Forty patients undergoing OPCABG were randomly divided into SM group (n = 20) and the 5% glucose (G) group (n = 20). The control liquids were injected from the beginning of the operation to the start of coronary artery bypass graft (CABG). The values of CO, SV, and EF before induction (t1), at the beginning of operation (t2), 30 minutes after the start of operation (t3), at the beginning of coronary artery bypass graft (t4), at the end of coronary artery bypass graft (CABG) (t5), and at the end of operation (t6) were recorded. RESULTS: The values of CO, SV, and EF in the patients of SM group at t3 to t6 were found to be significantly higher than those at t1 (P < .05). The values of CO, SV, and EF in the patients of G group were found to be increased at t5 and t6 (P < .05). At t3 and t4, the values of CO, SV, and EF in SM group were significantly higher than those in the G group (P < .05). CONCLUSION: In patients with OPCABG, the infusion of SM injection can effectively increase the values of CO, SV, and EF and increase the safety of anesthesia management.

Bleeding risk of dietary supplements: A hidden nightmare for cardiac surgeons.

We report a 55-year-old man who underwent off-pump bypass surgery and had diffuse oozing and bruising postoperatively. His hematological profile had been normal preoperatively and he had been off antiplatelets for a week prior to surgery. Postoperatively, a detailed talk revealed that he had been on dietary supplements containing fish oil and garlic - both of which are known to affect platelet function. It behooves the surgeon and anesthetist to screen all patients preoperatively for the possibility of intake of any dietary supplements taken by the patient.

Effect of Prewarming during Induction of Anesthesia on Microvascular Reactivity in Patients Undergoing Off-Pump Coronary Artery Bypass Surgery: A Randomized Clinical Trial.

BACKGROUND: General anesthesia may induce inadvertent hypothermia and this may be related to perioperative cardiovascular complications. Microvascular reactivity, measured by the recovery slope during a vascular occlusion test, is decreased during surgery and is also related to postoperative clinical outcomes. We hypothesized that microvascular changes during surgery may be related to intraoperative hypothermia. To evaluate this, we conducted a randomized study in patients undergoing off-pump coronary artery bypass surgery, in which the effect of prewarming on microvascular reactivity was evaluated. METHODS: Patients scheduled for off-pump coronary artery bypass surgery were screened. Enrolled patients were randomized to the prewarming group to receive forced-air warming during induction of anesthesia or to the control group. Measurement of core and skin temperatures and vascular occlusion test were conducted before anesthesia induction, 1, 2, and 3 h after induction, and at the end of surgery. RESULTS: In total, 40 patients were enrolled and finished the study (n = 20 in the prewarming group and n = 20 in the control group). During the first 3 h of anesthesia, core temperature was higher in the prewarming group than the control group (p < 0.001). The number of patients developing hypothermia was lower in the prewarming group than the control group (4/20 vs. 13/20, p = 0.004). However, tissue oxygen saturation and changes in recovery slope following a vascular occlusion test at 3 h after anesthesia induction did not differ between the groups. There was no difference in clinical outcome, including perioperative transfusion, wound infection, or hospital stay, between the groups. CONCLUSIONS: Prewarming during induction of anesthesia decreased intraoperative hypothermia, but did not reduce the deterioration in microvascular reactivity in patients undergoing off-pump coronary artery bypass surgery. TRIAL REGISTRATION: ClinicalTrials.gov NCT02186210.

Ten year experience of using a novel metabolic protocol in 'off pump' coronary artery bypass revascularization.

PURPOSE: Assessment of both short- and long-term outcomes in patients undergoing off-pump coronary artery bypass using a perioperative metabolic protocol. METHODS: A total of 975 of 995 adult patients underwent coronary artery bypass 'off-pump' from 1997 through 2006. Patients presenting in cardiogenic shock were excluded from this assessment. A perioperative metabolic protocol, which included the implementation of allopurinol, insulin supplementation, magnesium sulfate, supplemental corticosteroids, milrinone, norepinephrine (prn), aspirin, clopidogrel, statins and ß-blockers, was used in these patients. RESULTS: The mean age at the time of surgery was 70.5 years and the average number of bypass grafts was 4 per procedure; 18% (n = 176) of the cases had a preoperative intra-aortic balloon pump inserted for hemodynamic instability, tight left main coronary artery stenosis or angina. The 30-day mortality was 1.8% versus a Society of Thoracic Surgeons (STS) predicted mortality of 4.8%. Left main coronary artery disease was present in 38% (n = 371) of the patients. No strokes occurred intra-operatively and the postoperative incidence of stroke was 0.9% (n = 9). Incidence of renal failure requiring dialysis was 0.8% (n = 8). There was a single sternal infection. Mean follow up was 65 months with a survival rate of 90% (n = 955). Re-intervention, which commonly involved PTCA ± stent placement or re-do coronary artery bypass grafting (CABG), was 4% at 1 year and 11.6% (n = 113) during the 65-month follow-up period. CONCLUSIONS: Off-pump coronary artery bypass coupled with this novel metabolic protocol was associated with a low operative mortality and acceptable perioperative morbidities, including patients with left main coronary artery disease. These benefits are apparent at both short- and medium-term follow up.

Drug, devices, technologies, and techniques for blood management in minimally invasive and conventional cardiothoracic surgery: a consensus statement from the International Society for Minimally Invasive Cardiothoracic Surgery (ISMICS) 2011.

OBJECTIVE: The objectives of this consensus conference were to evaluate the evidence for the efficacy and safety of perioperative drugs, technologies, and techniques in reducing allogeneic blood transfusion for adults undergoing cardiac surgery and to develop evidence-based recommendations for comprehensive perioperative blood management in cardiac surgery, with emphasis on minimally invasive cardiac surgery. METHODS: The consensus panel short-listed the potential topics for review from a comprehensive list of potential drugs, devices, technologies, and techniques. The process of short-listing was based on the need to prioritize and focus on the areas of highest importance to surgeons, anesthesiologists, perfusionists, hematologists, and allied health care involved in the management of patients who undergo cardiac surgery whether through the conventional or minimally invasive approach. MEDLINE, Cochrane Library, and Embase databases were searched from their date of inception to May 2011, and supplemental hand searches were also performed. Detailed methodology and search strategies are outlined in each of the subsequently published systematic reviews. In general, all relevant synonyms for drugs (antifibrinolytic, aprotinin, [Latin Small Letter Open E]-aminocaproic acid, tranexamic acid [TA], desmopressin, anticoagulants, heparin, antiplatelets, anti-Xa agents, adenosine diphosphate inhibitors, acetylsalicylic acid [ASA], factor VIIa [FVIIa]), technologies (cell salvage, miniaturized cardiopulmonary bypass (CPB) circuits, biocompatible circuits, ultrafiltration), and techniques (transfusion thresholds, minimally invasive cardiac or aortic surgery) were searched and combined with terms for blood, red blood cells, fresh-frozen plasma, platelets, transfusion, and allogeneic exposure. The American Heart Association/American College of Cardiology system was used to label the level of evidence and class of each recommendation. RESULTS AND RECOMMENDATIONS: Database search identified more than 6900 articles, with 4423 full-text randomized controlled trials assessed for eligibility, and the final 125 systematic reviews and meta-analyses were used in the consensus conference. The results of the consensus conference, including the evidence-based statements and the recommendations, are outlined in the text, with references given for the relevant evidence that formed the basis for the statements and recommendations. RECOMMENDATIONS FOR ANTIFIBRINOLYTICS: The lysine analogs ?-aminocaproic acid (Amicar) and tranexamic acid (TA) reduce exposure to allogeneic blood inpatients undergoing on-pump cardiac surgery. These agents are recommended to be used routinely as part of a blood conservation strategy especially in patients at risk of undergoing onpump cardiac surgery (Class I, Level A). It is important not to exceed maximum TA total dosages (50Y100mg/kg) because of potential neurotoxicity in the elderly and open-heart procedures (Class IIb, Level C). Aprotinin is not recommended in adult cardiac surgery until further studies on its safety profile have been performed (Class III, Level A). RECOMMENDATIONS FOR TA IN OFF-PUMP CORONARY ARTERY BYPASS: Tranexamic acid may be recommended as part of a blood conservation strategy in high risk patients undergoing off-pump coronary artery bypass (OPCAB) surgery (Class I, Level A).Tranexamic acid dosing in OPCAB surgery needs further study particularly with regard to possible neurotoxicity such as seizures.In addition, the benefit-risk ratio in OPCAB needs further eludication because of the lower inherent risk for bleeding in this group (Class IIb, Level C). RECOMMENDATIONS FOR DDAVP: DDAVP can be considered for prophylaxis in coronary artery bypass grafting (CABG) surgery, in particular, for patients onASA within 7 days or prolonged CPB more than 140 minutes (Class IIa, Level A). Caution should be used with the DDAVP infusion rate to avoid significant systemic hypotension (Class I, Level A). RECOMMENDATIONS FOR TOPICAL HEMOSTATICS: The routine use of topical antifibrinolytics in cardiac surgery isnot recommended (Class IIa, Level A). Topical fibrin sealants may be considered in clinical situations where conventional approaches of surgical and medical improvement of hemostasis are not effective, that is, with bleeding problems more local than generalized, bearing in mind the blackbox warning of bovine thrombin by the US Food and Drug Administration (Class IIb, Level C).Recommendations for FVIIa:Prophylactic use of FVIIa cannot be recommended because of a significant increase in the risk of thromboembolic events and stroke (Class IIa, Level A).Factor VIIa may be considered in clinical situations where conventional approaches of surgical and pharmacologic hemostasis have failed and uncontrollable hemorrhage poses a high risk of severe and life-threatening outcomes (Class IIb, Level B). RECOMMENDATIONS FOR ERYTHROPOIETIN PLUS IRON: It is reasonable to administer erythropoietin preoperatively to increase red blood cell mass in patients who are anemic or refuse blood products (such as for Jehovah's Witness faith) or who are likely to have postoperative anemia (Class IIa, Level A). RECOMMENDATIONS FOR ANTIPLATELETS BEFORE CARDIAC SURGERY: Acetylsalicylic acid may be continued until surgery (Class IIa,Level B) For stable elective CABG procedures with no drug-elutingstent, stop clopidogrel 5 days before surgery (Class I, Level A).h For stable elective CABG procedures with drug-eluting stents less than 1 year old, consider continuing clopidogrel or heparin as abridge to surgery (Class IIb, Level C).h Direct-acting P2Y12 receptor antagonists may be a better alternative than clopidogrel in acute coronary syndrome patients undergoing CABG surgery (Class IIa, Level B). RECOMMENDATIONS FOR ANTIPLATELETS AFTER CARDIAC SURGERY: In stable CABG surgery (nonYacute coronary syndrome patients), the routine use of postoperative clopidogrel with ASAis not warranted (Class IIb, Level B). RECOMMENDATIONS FOR ACUTE NORMOVOLEMIC HEMODILUTION: Acute normovolemic hemodilution can be considered in selected patients with adequate preoperative hemoglobin to reduce post-CPB bleeding (Class IIa, Level A).The routine use of acute normovolemic hemodilution is not recommended (Class IIb, Level B). RECOMMENDATIONS FOR RETROGRADE AUTOLOGOUS PRIMING: Retrograde autologous priming is recommended as a blood conservation modality to reduce allogeneic blood transfusion for onpump cardiac surgery (Class I, Level A). RECOMMENDATIONS FOR CELL SALVAGE: Routine use of cell salvage is recommended in operations where an increased blood loss is expected (Class 1, Level A). Cell salvage should be used throughout the entire operation and not merely as a replacement for CPB cardiotomy suction (Class IIa, Level A). RECOMMENDATIONS: BIOCOMPATIBLE CPB CIRCUITS: The routine use of biocompatible coated CPB circuitry may be considered as part of a multimodal blood conservation program. However, the heterogeneity of surface-modified products, anticoagulation management, and CPB technique does not significantly impact surgical blood loss and transfusion needs (Class IIb,Level A). RECOMMENDATIONS FOR MINIATURIZED EXTRACORPOREAL CARDIOPULMONARY CIRCUIT VERSUS CONVENTIONAL EXTRACORPOREAL CARDIOPULMONARY CIRCUIT: Miniaturized extracorporeal cardiopulmonary circuit can be considered as a blood conservation technique to reduce allogeneic blood exposure (Class IIa, Level A); however, issues related to heparinization management and biocompatible coatings remain to be clarified. RECOMMENDATIONS FOR ULTRAFILTRATION (CONTINUOUS OR MODIFIED):h Ultrafiltration may be considered for blood conservation (Class IIb, Level A); however, the impact on clinically relevant outcomes remains unknown. RECOMMENDATIONS FOR PLATELET PLASMAPHERESIS:It is reasonable to recommend platelet plasmapheresis for blood management in cardiac surgery (Class IIa, Level A), although the impact on clinically relevant outcomes remains unknown. RECOMMENDATIONS FOR POINT-OF-CARE MONITORING:The evidence is too premature to recommend point-of-caretechnology for routine use because its use has not been shown to impact clinical outcome (Class IIb, Level A). RECOMMENDATIONS FOR SURGICAL TECHNIQUES FOR OPCAB, MINIMALLY INVASIVE STERNOTOMY FOR AORTIC VALVE SURGERY, MINIMALLY INVASIVE STERNOTOMY FOR MITRAL VALVE SURGERY, AND TRANSCATHETHER AORTIC VALVE IMPLANTATION: Although these minimally invasive procedures are not primarily selected for the purpose of blood management, the reduced allogeneic blood exposure should be considered in the balance of benefits and risks when selecting the appropriate surgery for patients.

Minimally invasive coronary artery bypass grafting via a small thoracotomy versus off-pump: a case-matched study.

OBJECTIVE: The minimally invasive coronary artery bypass grafting (MICS CABG) operation performed via a small thoracotomy has not previously been examined in a direct comparison to sternotomy off-pump coronary artery bypass grafting (OPCAB). METHODS: We matched, according to age, gender, left ventricular function, and median number of distal anastomoses, 150 patients who underwent MICS CABG via small left thoracotomy, and 150 patients who received sternotomy OPCAB. All operations were performed by the same surgeon. RESULTS: There was no perioperative mortality (0/300). In the MICS CABG group, pump assistance was used in 28/150 (19%) patients, and conversion to sternotomy occurred in 10/150 (6.7%) patients. In the OPCAB group, conversion to on-pump occurred in 3/150 (2.0%) patients. There were four (2.7%) reoperations for bleeding and one (0.7%) for anastomotic revision in each group. The median hospital length of stay was 5 days for MICS CABG (average 5.4), and 6 days for OPCAB (average 7.2) (P=0.02). New-onset atrial fibrillation occurred in 35 (23%) MICS CABG patients and in 42 (28%) OPCAB patients (P=0.3). No wound infection occurred with MICS CABG versus six (4.0%) with OPCAB (P=0.03). A self-limiting left pleural effusion developed in 22 (15%) MICS CABG patients and in six (4.0%) OPCAB patients (P=0.002). The median time to return to full physical activity was 12 days in MICS CABG patients versus >5 weeks in OPCAB patients (P<0.001). CONCLUSIONS: MICS CABG is a valuable alternative for patients in need of multivessel CABG. The operation appears at least as safe as OPCAB, and associated with shorter hospital length of stay, less wound infections, and faster postoperative recovery than OPCAB.

Major factors of homologous blood transfusion in valvular heart operation with intraoperative autologous blood predonation in cases with difficulty in preoperative predonation.

Intraoperative autologous blood predonation is reported to be useful for the prevention of homologous blood transfusion in cardiac operations, especially in on-pump coronary artery bypass grafting (CABG). However, CABG is now performed more often off-pump than on-pump. We analyzed the major factors of homologous blood transfusion in 25 consecutive cases of valvular heart operation with intraoperative autologous blood predonation except those with preoperative autologous blood donation. Homologous blood was not transfused in 18 cases, but was in 7 cases only after cardiopulmonary bypass (CPB). The homologous transfusion was not correlated with body weight, CPB dilution or duration, or preoperative hematocrit level, but was found to correlate with age (r2=0.289, p=0.0413), bleeding output (r2=0.197, p=0.0485), and predonation blood volume (r2=0.436, p=0.0152). In conclusion, suitable intraoperative predonation may reduce the necessity for homologous blood transfusion in valvular heart operations.

[Effect of instrumental blood reinfusion on clinical parameters and morphology of erythrocytes during aortocoronary bypass grafting].

Erythrocytic morphological changes were studied in 48 patients with coronary heart disease (CHD) at the stages of coronary artery bypass grafting, in whom intraoperative continuous apparatus (CATS, Fresenius, Germany) reinfusion of lost autoblood was used. The patients with CHD were found to have a significant erythrocytic morphological transformation with the oxygen status compensated by the preserved nonpathological forms of erythrocytes. Intraoperatively stable tissue oxygen delivery and rapid blood loss compensation during coronary artery bypass grafting could be provided by continuous reinfusion of lost autoblood that contained valuable erythrocytes after apparatus elimination of disrupted and degenerative forms.

Reduction of postoperative hypothermia with a new warming device: a prospective randomized study in off-pump coronary artery surgery.

Hypothermia has been used for decades in cardiac surgery to limit the ischemic insult to the heart. With the diffusion of off-pump coronary artery surgery, the practice of arresting and cooling the heart has been abandoned. At University of Miami Miller School of Medicine, we tested a new warming device by performing a prospective study in which 50 patients were randomized to either the use of the Kimberly-Clark warming system or to standard methods of control of body temperature. The two groups were compared in terms of core body temperature (CBT), intra- and postoperative blood loss, blood products transfusions, extubation time, intensive care unit (ICU) and hospital length of stay and incidence of infections. Five patients in the control group and 0 patients in the study group dropped their CBT below 35 degrees C during the operation (P<0.01). Total blood loss, measured in terms of cell-saver and chest tube drainage, was 27 % and 14 % less for the study group (P<0.01). Hospital length of stay was 1.2 day less in the study group (P<0.01). The Kimberly-Clark Patient Warming System allowed for better control of core body temperature during off pump coronary artery bypass surgery compared to traditional techniques. This translated in less intra and postoperative blood loss and shorter hospital length of stay. Other advantages, such as decreased blood-products transfusions, decreased incidence of infections, decreased ICU length of stay and overall reduction of costs might be evident on larger study groups.

Comparison of economic and patient outcomes with minimally invasive versus traditional off-pump coronary artery bypass grafting techniques.

BACKGROUND: Minimally invasive coronary artery bypass grafting (miniCABG) decreases in-hospital morbidity versus traditional sternotomy CABG. We performed a prospective cohort study (NCT00481806) to assess the impact of miniCABG on costs and metrics that influence quality of life after hospital discharge. METHODS: One hundred consecutive miniCABG cases performed using internal mammary artery (IMA) grafting +/- coronary stenting were compared with a matched group of 100 sternotomy CABG patients using IMA and saphenous veins, both treating equivalent number of target coronaries (2.7 vs. 2.9), off-pump. We compared perioperative costs, time to return to work/normal activity, and risk of major adverse cardiac/cerebrovascular events (MACCE) at 1 year: myocardial infarction (elevated troponin or EKG changes), target vessel occlusion (CT angiography at 1 year), stroke, or death. RESULTS: For miniCABG, robotic instruments and stents increased intraoperative costs; postoperative costs were decreased from significantly less intubation time (4.80 +/- 6.35 vs. 12.24 +/- 6.24 hours), hospital stay (3.77 +/- 1.51 vs. 6.38 +/- 2.23 days), and transfusion (0.16 +/- 0.37 vs. 1.37 +/- 1.35 U) leading to no significant differences in total costs. Undergoing miniCABG independently predicted earlier return to work after adjusting for confounders (t = -2.15; P = 0.04), whereas sternotomy CABG increased MACCE (HR, 3.9; 95% CI, 1.4-7.6), largely from lower target-vessel patency. CONCLUSIONS: MiniCABG shortens patient recovery time, minimizes MACCE risk at 1 year, and showed superior quality and outcome metrics versus standard-of-care CABG. These findings occurred without increasing costs and with superior target vessel graft patency.

Anatomical pitfalls during encircling cryoablation of the left atrium for atrial fibrillation therapy in the pig.

We previously published encircling endocardial cryo-isolation of the pulmonary vein (PV) region. This study documented mechanisms of isolation failure using CARTO mapping. Cryo-isolation used a modified Surgifrost introduced via a Universal Cardiac Introducer on the left atrial appendage. Of five pigs, two had incomplete isolation and repeat mapping: Activation was over Bachmann's bundle (BB) in one and the coronary sinus (CS) in the other. Repeat cryoablation failed to eliminate gaps. Histologically, the BB gap had nonlesioned sub-epicardial fibres and thick fat covering the cryolesioned BB: fat protecting the epicardium from cryoablation. The inferior gap had a large CS, and a thick myocardium bridging the isthmus: myocardial thickness and CS thermal sink preventing transmural cryolesions. CARTO mapping localized gaps. Although the CS is known to cause failure, its protective mechanism is not well documented. The BB gap is novel. These findings have important clinical implications for isolation of the PV region.

Efficacy of cell saver in reducing homologous blood transfusions during OPCAB surgery: a prospective randomized trial.

Despite the refinements in surgical technique, rates of homologous blood transfusion (HBT) in cardiac surgery remain high. The adverse effects of blood transfusion are well documented. Retransfusion of shed mediastinal blood reduces the requirement for HBTs during conventional coronary artery bypass grafting. However, some studies have found that autotransfusion leads to bleeding diathesis and paradoxical increase in blood transfusions. Through this prospective randomized trial, we have studied the safety and efficacy of this modality in patients undergoing off-pump coronary artery bypass grafting (OPCAB). Fifty patients enrolled in the study and 49 fulfilled the study criteria. They were randomly divided into group C (cell saver) and group N (non-cell saver). Whereas the cell saver group received processed shed autologous blood and homologous blood if necessary, the non-saver group was transfused homologous blood only. The threshold for transfusion was haemoglobin of 9 g dL(-1) in both the groups. The cell saver group required significantly less number of HBTs (1.6 +/- 1.2 vs. 2.4 +/- 1.3 units). The incidence of re-exploration was zero in both the groups. The mean mediastinal drainage in both the groups was not significantly different (355 +/- 196 vs. 316 +/- 119.8 mL). The number of patients requiring any blood transfusion however was very high. All the patients in the non-saver group and 20 (83%) of the patients in the saver group received homologous blood. During OPCAB surgery, the use of cell saver reduced the requirement for HBT. Its use is not associated with any clinically significant bleeding diathesis.

[Successful off-pump coronary artery bypass for a patient with aplastic anemia].

We report a 61-year-old man with aplastic anemia who underwent successful off-pump coronary artery bypass (OPCAB) after being admitted for angina pectoris. Coronary angiography showed severe stenosis of the left main coronary artery. Preoperative WBC was 2,200/microl, neutrophil 704/microl, Hb 8.1g/dl, and PLT 16,000/microl. We conducted OPCAB on double vessels using left internal thoracic and radial artery grafts. Thirty units of platelets were transfused intraoperatively with little perioperaive hemorrhage. Because of high grade fever, we injected 150 microg granulocyte colony-stimulating factor (G-CSF) every 3 days postoperatively to prevent major infection. The combination of appropriate perioperative management and OPCAB yielded an effective result for a patient with severe hematological disorders causing pancytopenia.

En bloc exclusion of the pulmonary vein region in the pig using off pump, beating, intra-cardiac surgery: a pilot study of minimally invasive surgery for atrial fibrillation.

BACKGROUND: Off-pump, closed, beating heart, minimally-invasive surgery in patients with lone atrial fibrillation (AF) must be effective to become the preferred alternative to catheter ablation. Because of the inherent anatomical limitations of the epicardial access, we explored the feasibility of an intracardiac approach. METHODS: We report an acute study of en bloc, cryo-exclusion of the pulmonary vein region in 7 pigs. The left atrial appendage (LAA) was approached via a left thoracotomy. Electrodes were attached to the posterior wall of the left atrium (LPA) and right atrial appendage (RAA) for pacing and electrophysiological monitoring. A modified Surgifrost probe was introduced via the LAA and positioned using transesophageal (TEE) and intracardiac (ICE) echocardiographic guidance to generate encircling cryolesions (3 minutes, -105 degrees C) of the pulmonary vein region. RESULTS: A complete two-way block was achieved in 6 pigs and an incomplete block in 1. The excluded segment had very slow idiosyncratic rhythm or was electrically silent. In all pigs before isolation, sustained AF was inducible with the most rapid rhythms and fractionated electrograms recorded from the LA. While sustained AF was induced before exclusion, it was not after isolation in either the exclude or non-excluded segments. All tissue samples taken along the encircling cryolesions had transmural cryolesions on pathological examination. CONCLUSIONS: We conclude that off-pump, closed heart, beating, intracardiac AF surgery is feasible, reliable and can duplicate the accuracy and precision of the open-heart approach. However, further developments are needed to make this novel approach an alternative to current approaches for catheter ablation.

Creatine phosphate administration preserves myocardial function in a model of off-pump coronary revascularization.

AIM: Off pump coronary artery bypass grafting (OPCAB) involves, and is occasionally impaired by obligatory regional myocardial ischemia, particularly with the use of proximal coronary in-flow occlusion techniques. Intracoronary shunts do not guarantee absence of distal ischemia given their small inner diameter and the presence of proximal coronary stenosis. Additional adjunctive measures to provide short-term myocardial protection may facilitate OPCAB. High-energy phosphate supplementation with creatine phosphate prior to ischemia may attenuate ischemic dysfunction. METHODS: In a rodent model of a transient coronary occlusion and myocardial ischemia, 36 animals underwent preischemic intravenous infusion of either creatine phosphate or saline, 10 minutes of proximal left anterior descending (LAD) occlusion, and 10 minutes of reperfusion. Rats underwent continuous intracavitary pressure monitoring and cellular ATP levels were quantified using a luciferin/luciferase bioluminescence assay. RESULTS: Within 2 minutes of ischemia onset, creatine phosphate animals exhibited statistically significant greater preservation of myocardial function compared to controls, an augmentation which persisted throughout the duration of ischemia and subsequent reperfusion. Furthermore, significantly greater cellular ATP levels were observed among creatine phosphate treated animals (344+/-55 nMol/g tissue, n=5) compared to control animals (160+/-9 nMol/g tissue, n=5)(p=0.014). CONCLUSIONS: A strategy of intravenous high-energy phosphate administration successfully prevented ischemic ventricular dysfunction in a rodent model of OPCAB.