Release Of Aortic Cross-clamp Research Articles

Coronary Artery Bypass Grafting for Refractory Ventricular fibrillation after the Release of the Aortic Cross-Clamp in Patients Undergoing Aortic Valve Replacement: A Case Report

Background: Ventricular fibrillation (VF) is a known complication after the release of the aortic cross-clamp (ACC) during cardiopulmonary bypass (CPB) surgery. Various factors contribute to persistent refractory VF, making its management challenging. This case report describes the successful treatment of postoperative refractory VF by coronary artery bypass grafting (CABG) in a patient undergoing aortic valve replacement (AVR) with ACC release. Case Presentation: A 52-year-old woman with a history of hypertension and ischemic cerebral infarction presented with symptoms of chest tightness, dyspnoea and palpitations. She underwent a modified maze procedure of radiofrequency ablation, mitral repair, left atrial appendage closure and mechanical AVR under a CPB procedure. Following the ACC release, the patient experienced recurrent VF that was unresponsive to standard interventions such as lidocaine, amiodarone and direct current shocks. The suspicion of right coronary artery (RCA) insufficiency led to the decision to perform CABG using the great saphenous vein. After the CABG procedure, the patient's heart rhythm gradually returned to sinus rhythm, and she had an uneventful recovery. Discussion and Conclusions: Refractory VF after the ACC release can pose diagnostic and treatment challenges. In this case, RCA insufficiency was suspected as the cause of refractory VF. The absence of blood flow in the proximal RCA and the presence of distal blood return during cardiac surface exploration supported this suspicion. Coronary artery bypass grafting using the great saphenous vein successfully restored normal sinus rhythm, confirming the diagnosis. This case emphasises the importance of considering coronary artery stenosis or occlusion as a potential cause of refractory VF after the ACC release during CPB, with CABG serving as a viable alternative treatment.

Del Nido versus hematic cardioplegia in minimally invasive aortic valve surgery.

The quality of a myocardial protection of a single-dose del Nido cardioplegia versus multiple dose blood-based cardioplegia on myocardial injury, outcomes and operative times in patients undergoing minimally invasive aortic valve replacement is basically unreported. Preoperative and post-operative data, as well as technical details from isolated minimally invasive aortic valve replacements, performed using single-dose or multiple-dose cardioplegia were prospectively collected and retrospectively analysed. A total of 110 patients undergoing minimally invasive valve replacements at our institution composed two groups: 55 patients in the blood cardioplegia group (BloCa) and 55 in the del Nido group (DeNiCa). The two-matched groups were comparable in terms of preoperative variables. In the DeNiCa group, there was a statistically significant less need for cardiac defibrillation after aortic cross-clamp release (p < 0.001). Moreover, the BloCa group received intraoperatively more blood transfusions (p = 0.001) and more insulin administration for higher glucose levels (p < 0.001). The BloCa group showed higher intraoperative lactate levels (p = 0.01). Need for post-operative inotropic and vasoactive support, Creatine Kinase-MB levels after 6 and 12 h, onset of post-operative atrial fibrillation and length of stay were similar. No deaths occurred in neither groups. Single-dose del Nido cardioplegia in the setting of minimally invasive aortic surgery seems to offer adequate myocardial protection, comparable to multiple dose hematic cardioplegia. It has been documented a lower peri-operative need of defibrillation after cross-clamp release, lactate- and glucose peak values, as well as less blood transfusions compared to blood cardioplegic strategy.

Patterns of cytokine release and association with new onset of post-cardiac surgery atrial fibrillation.

Postoperative Atrial Fibrillation (POAF) is a common complication of cardiac surgery, associated with increased mortality, stroke risk, cardiac failure and prolonged hospital stay. Our study aimed to assess the patterns of release of systemic cytokines in patients with and without POAF. A post-hoc analysis of the Remote Ischemic Preconditioning (RIPC) trial, including 121 patients (93 males and 28 females, mean age of 68 years old) who underwent isolated coronary artery bypass grafting (CABG) and aortic valve replacement (AVR). Mixed-effect models were used to analyze patterns of release of cytokines in POAF and non-AF patients. A logistic regression model was used to assess the effect of peak cytokine concentration (6 h after the aortic cross-clamp release) alongside other clinical predictors on the development of POAF. We found no significant difference in the patterns of release of IL-6 (p = 0.52), IL-10 (p = 0.39), IL-8 (p = 0.20) and TNF-α (p = 0.55) between POAF and non-AF patients. Also, we found no significant predictive value in peak concentrations of IL-6 (p = 0.2), IL-8 (p = >0.9), IL-10 (p = >0.9) and Tumour Necrosis Factor Alpha (TNF-α)(p = 0.6), however age and aortic cross-clamp time were significant predictors of POAF development across all models. Our study suggests no significant association exists between cytokine release patterns and the development of POAF. Age and Aortic Cross-clamp time were found to be significant predictors of POAF.

The Effect of Prophylactic Intravenous Amiodarone Administration on Reperfusion Ventricular Fibrillation in Patients With Left Ventricular Hypertrophy Undergoing Cardiopulmonary Bypass Surgery: Protocol for a Randomized Double-Blind Clinical Trial

Ventricular fibrillation (VF) is a common arrhythmia that occurs after the release of aortic cross-clamp (ACC) in patients undergoing cardiopulmonary bypass (CPB) surgery. Repeated defibrillation and long duration of VF could increase myocardial injuries. In patients with left ventricular hypertrophy (LVH), VF is easier to occur and more difficult to be terminated. Amiodarone, known as class III antiarrhythmic agent, has the prominent properties of converting VF and restoring the sinus rhythm. Before ACC release, administration of amiodarone has been confirmed useful to reduce occurrence of VF. However, few studies are focused on the effect of amiodarone before ACC release on reducing VF in patients with LVH. This study aimed at determining the efficacy of prophylactic intravenous amiodarone administration on reperfusion VF after release of ACC in patients with LVH undergoing CPB surgery. This will be a prospective, randomized, double-blind, placebo-controlled trial. The trial will enroll 54 patients with LVH aged 18-75 years who will undergo CPB surgery. All eligible participants will be randomly allocated to either the amiodarone or placebo group by using the block randomization in a 1:1 ratio. The primary end point will be the incidence rate of VF 30 minutes after ACC release and be assessed using the Fisher exact test. All data will be analyzed in accordance with the intention-to-treat principle. The study began in August 2022, and the data collection will take place for the next 2 academic years. As of this writing, 21 participants have already been recruited for the study. With this trial, we are hoping to demonstrate that prophylactic infusion of amiodarone before ACC release could reduce the occurrence of reperfusion VF in patients with LVH. ClinicalTrials.gov ChiCTR2000035057; https://www.chictr.org.cn/showprojen.aspx?proj=57145. DERR1-10.2196/40115.

Comparison of Amiodarone with Combined Doses of Magnesium Sulphate and Lidocaine for Prevention of Ventricular Fibrillation Following Coronary Clamp Release During Coronary Artery Bypass Graft Surgery

Objective: To compare the effects of amiodarone with effects of combined doses of magnesium sulphate and lidocaine for prevention of ventricular fibrillation following coronary clamp release during (coronary artery bypass grafting) CABG.&#x0D; Study Design: Comparative cross sectional study.&#x0D; Place and Duration of Study: Army Cardiac Centre, Lahore Pakistan, from Jun 2021 to Dec 2021.&#x0D; Methodology: One hundred patients who reported at Army Cardiac Centre Lahore, Pakistan for coronary artery bypass grafting surgery, were involved in comparative study. Patients satisfying the inclusion criteria were allocated into the LM(Lidocaine Magnesium) and A (Amiodarone) groups. Following aortic cross clamp release, the incidence of ventricular fibrillation (VF) and other arrhythmias was calculated in first 30 minutes and up to 24 hours later. The ionotropic agent used was epinephrine at a rate of 0.05 to 0.1 micrograms/kg/minute. Within 15 minutes of anesthetic induction and 15 minutes after the CPB pump was removed, hemodynamic parameters were assessed and recorded.&#x0D; Results: Arrhythmias within 30 minutes and up to 24 hours after aortic cross clamp ACC release in A and LM group were compared. The difference between two groups, having arrhythmias and no arrhythmias was statistically insignificant (p≥0.050) except VF up to 24 hours after ACC release. The highest voltage for defibrillation was used in Group-A n=20 (40.0%) and n=27 (54.0%) in L.M group, (p=0.004). The average electrical defibrillations in group-A was less than that of group L.M,(p=0.000). While, the use of ionotropic agent was almost equal in both the groups, (p=0.975).&#x0D; Conclusion: Overall, the amiodarone group had a decreased incidence of VF when the ACC was released, while the difference was not statistically significant.

Plasma Exosome Hemoglobin Released During Surgery Is Associated With Cardiac Injury in Animal Model

BackgroundPatients with valvular heart disease require cardiopulmonary bypass and cardiac arrest. Here, we test the hypothesis that exosomal hemoglobin formed during cardiopulmonary bypass mediates acute cardiac injury in humans and in an animal model system. MethodsPlasma exosomes were collected from arterial blood at baseline and 30 minutes after aortic cross-clamp release in 20 patients with primary mitral regurgitation and 7 with aortic stenosis. These exosomes were injected into Sprague-Dawley rats and studied at multiple times up to 30 days. Tissue was examined by hematoxylin and eosin stain, immunohistochemistry, transmission electron microscopy, and brain natriuretic peptide. ResultsTroponin I levels increased from 36 ± 88 ng/L to 3622 ± 3054 ng/L and correlated with exosome hemoglobin content (Spearman r = 0.7136, < .0001, n = 24). Injection of exosomes isolated 30 minutes after cross-clamp release into Sprague-Dawley rats resulted in cardiomyocyte myofibrillar loss at 3 days. Transmission electron microscopy demonstrated accumulation of electron dense particles of ferritin within cardiomyocytes, in the interstitial space, and within exosomes. At 21 days after injection, there was myofibrillar and myosin breakdown, interstitial fibrosis, elevated brain natriuretic peptide, and left ventricle diastolic dysfunction measured by echocardiography/Doppler. Pericardial fluid exosomal hemoglobin content is fourfold higher than simultaneous plasma exosome hemoglobin, suggesting a cardiac source of exosomal hemoglobin. ConclusionsRed blood cell and cardiac–derived exosomal hemoglobin may be involved in myocardial injury during cardiopulmonary bypass in patients with valvular heart disease.

Tropisetron Preconditioning Decreases Myocardial Biomarkers in Patients Undergoing Heart Valve Replacement Surgery

BackgroundCardioplegic arrest during the heart valve replacement surgery frequently leads to myocardial damage. Tropisetron (TRP) has been demonstrated to reduce myocardial ischemia-reperfusion injury and inflammation in animals. We examined the efficacy of TRP in lowering myocardial biomarkers in patients undergoing heart valve replacement surgery.MethodsA total of seventy-five patients, scheduled for elective heart valve replacement surgery, were randomly chosen to receive either 10 ml of normal saline or 10 mg/10 ml of TRP immediately after anesthesia induction. Blood samples for the measurement of cardiac troponin I (cTnI), creatine kinase (CK-MB), lactate dehydrogenase (LDH), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-10 (IL-10) were taken before anesthesia, as well as 4, 12, and 24 h after aortic cross-clamp release to evaluate myocardial injury using two-way ANOVA for repeated measurements. The study was registered at www.chictr.org.cn (number, ChiCTR-1800018681).ResultsTreatment with TRP decreased the increment of cTnI (Fgroup = 4.911, p = 0.030; Ftime = 55.356, p = 0.001; Fgroup × time = 5.340, p = 0.002) at 12 and 24 h; of CK-MB (Fgroup = 6.552, p = 0.013; Ftime = 49.276, p = 0.001; Fgroup × time = 7.627, p = 0.003) at 4, 12, and 24 h; of TNF-α (Fgroup = 4.153, p = 0.046; Ftime = 28.244, p = 0.002; Fgroup × time = 4.692, p = 0.006) at 4 and 12 h; and of LDH (Fgroup = 4.275, p = 0.043; Ftime = 63.225, p = 0.001; Fgroup × time = 2.501, p = 0.083) at 24 h after the release of the aortic cross-clamp. It increased IL-10 (Fgroup = 5.958, p = 0.018; Ftime = 31.226, p = 0.002; Fgroup × time = 1.464, p = 0.236) at 12 h after the release of the aortic cross-clamp. Multiple linear regression analysis showed that cardiopulmonary bypass (CPB) time was a risk factor, and that TRP treatment was a protective factor for postoperative cTNI change (β = 4.449, 95% CI [0.97–7.92], p = 0.013 for CPB time; and β = −381, 95% CI [−613.4 to −148.5], p = 0.002 for TRP treatment).ConclusionsTropisetron had cardioprotective and anti-inflammatory effects in patients undergoing heart valve replacement surgery with cardioplegic arrest. The addition of TRP and reduction of CPB time should be considered for myocardial protection in heart valve replacement surgery.Clinical Trial Registration[www.chictr.org.cn/index.aspx], identifier [ChiCTR1800018681].

Plasmalyte-A Based del Nido Cardioplegia Versus Plain Ringer Based del Nido Cardioplegia: Double-Blind Randomized Trial.

Background: In this prospective randomized controlled trial, we compared the standard del Nido cardioplegia solution (SDN) with the modified del Nido cardioplegia solution (MDN) in which the base solution was the plain Ringer solution. Methods: A total of 80 patients aged < 12 years undergoing intracardiac repair of Tetralogy of Fallot were randomized into SDN (n = 39) or MDN (n = 41) groups. The primary outcome was a change in cardiac index (CI). Secondary outcomes were ventricular arrhythmias after the release of aortic-cross clamp, postoperative inotropic score (IS), time to peripheral rewarming, duration of mechanical ventilation, intensive care unit (ICU) length of stay, and hospital length of stay, and electron microscopic differences between the 2 groups. Cardiac Troponin-I, inflammatory markers tumor necrosis factor-α (TNF-α), and interleukin-L (IL-6) were measured. Results: Applying the noninferiority confidence interval approach, the difference between the changes in CI between the 2 groups was -0.093 L/min/m2 (95% CI: -0.46-0.27 L/min/m2) which was within the noninferiority threshold of -0.5 indicating that CI was similar in both SDN and MDN. Ventricular arrhythmias postclamp release (P = .91), IS (P = .09), duration of mechanical ventilation (P = .27), ICU length of stay (P = .50), hospital length of stay (P = .57), IL-6 (P = .19), TNF-α (P = .17), Troponin-I (P = .15), electron microscopy changes (P > .05) were not different between groups. Conclusion: MDN was shown to be noninferior to the SDN cardioplegia in terms of preservation of cardiac index. In addition, other metrics indicative of myocardial protection were similar between groups. In developing nations where SDN is not available or is expensive, MDN cardioplegia is an acceptable alternative.

Minimal invasive extracorporeal circulation preserves coagulation integrity.

Coagulopathy after cardiac surgery is a serious multifactorial complication that results in postoperative bleeding requiring transfusion of red blood cells and procoagulant products. Use of cardiopulmonary bypass represents the major contributing factor affecting coagulation. We sought to prospectively investigate the effect of contemporary minimal invasive extracorporeal circulation (MiECC) on coagulation parameters using point-of-care (POC) rotational thromboelastometry and the relation to postoperative bleeding. Patients undergoing elective cardiac surgery on MiECC were prospectively recruited. Anticoagulation strategy was based on individualized heparin management and heparin level-guided protamine titration. Rotational thromboelastometry testing was performed before induction of anesthesia and after aortic cross-clamp release. A strict POC-guided transfusion protocol was implemented. The primary endpoint was the assessment of viscoelastic properties of the coagulating blood at the end of surgery compared to preoperative values and the relation to postoperative bleeding and 24-hour transfusion requirements. Fifty patients were included in the study with a significant proportion having complex surgery. Thirteen patients (26%) required blood transfusion (mean rate: 0.5 ± 1 units per patient), 5/50 (10%) received coagulation factors while no patient received fresh frozen plasma, platelets or fibrinogen. Thromboelastometry analysis showed that the major derangement was CT EXTEM > 100 seconds in 28/50 (56%) and A10 EXTEM < 40 mm in one (2%) patient without clinical significance. Platelet function was preserved throughout surgery. A10-FIBTEM was found predictive of postoperative bleeding at 12 hours. MiECC preserves clot quality throughout surgery acting in both key determinants of clot strength; fibrinogen and platelets. This is clinically translated into minimal postoperative bleeding and restricted use of blood products and coagulation factors.

Safety and Effectiveness of Del Nido Cardioplegia in Comparison to Blood-Based St. Thomas Cardioplegia in Congenital Heart Surgeries: A Prospective Randomized Controlled Study.

To compare the safety and effectiveness of del Nido cardioplegia with blood-based St Thomas Hospital (BSTH) cardioplegia in myocardial protection in congenital heart surgery. It is a prospective, open-labeled, randomized controlled study conducted at National Heart Institute, Kuala Lumpur from July 2018 to July 2019. All patients with simple and complex congenital heart diseases (CHD) with good left ventricular function (left ventricular ejection fraction [LVEF] >50%) were included while those with LVEF <50% were excluded. A total of 100 patients were randomized into two groups of 50 each receiving either del Nido or BSTH cardioplegia. Primary end points were the spontaneous return of activity following aortic cross-clamp release and ventricular function between two groups. Secondary end point was myocardial injury as assessed by troponin T levels. Cardiopulmonary bypass and aortic cross-clamp time, return of spontaneous cardiac activity following the aortic cross-clamp release, the duration of mechanical ventilation, and intensive care unit stay were comparable between two groups. Statistically significant difference was seen in the amount and number of cardioplegia doses delivered (P < .001). The hemodilution was significantly less in the del Nido complex CHD group compared to BSTH cardioplegia (P = .001) but no difference in blood usage (P = .36). The myocardial injury was lesser (lower troponin T release) with del Nido compared to BSTH cardioplegia (P = .6). Our study showed that both del Nido and BSTH cardioplegia are comparable in terms of myocardial protection. However, single, less frequent, and lesser volume of del Nido cardioplegia makes it more suitable for complex repair.

Bilateral Remote Ischaemic Conditioning in Children (BRICC) trial: protocol for a two-centre, double-blind, randomised controlled trial in young children undergoing cardiac surgery

IntroductionMyocardial protection against ischaemic-reperfusion injury is a key determinant of heart function and outcome following cardiac surgery in children. However, with current strategies, myocardial injury occurs routinely following aortic cross-clamping,...

Labetalol Infusion Attenuates Paradoxical Hypertension and Decreases Plasma Renin Activity After Repair of Coarctation of the Aorta in Children

Paradoxical hypertension after repair of coarctation of the aorta in children is associated with the release of catecholamines and activation of the renin-angiotensin system. The objective of the present study was to describe the effects of labetalol infusion on blood pressure, plasma catecholamine levels, and plasma renin activity in a series of children undergoing repair of coarctation of the aorta. Prospective, observational cohort study. Tertiary children's hospital with university affiliation. The study was comprised of 15 consecutive children older than 1 year undergoing repair of coarctation of the aorta. Intravenous infusion of labetalol, up to 20 µg/kg/min, was administered when patients became hypertensive after release of the aortic cross-clamp. Supplementation with nitroprusside was allowed as needed. Blood pressure was maintained below baseline values throughout the labetalol infusion. Plasma norepinephrine increased from 160 ± 81 pg/mL (preoperative) to 657 ± 268 pg/mL (6 h after release of aortic cross-clamp). Plasma renin activity decreased from 16.6 ± 9.7 ng/kg/h (at cross-clamp release) to 2.2 ± 2.2 ng/kg/h (6 h after cross-clamp release). Nitroprusside was added for 12 patients, at a highest mean dose of 2.4 ± 2.5 μg/kg/min. Labetalol inhibited activation of the renin-angiotensin system and helped control paradoxical hypertension after coarctation repair in children.

Prophylactic Effect of Amiodarone Infusion on Reperfusion Ventricular Fibrillation After Release of Aortic Cross-Clamp in Patients with Left Ventricular Hypertrophy Undergoing Aortic Valve Replacement: ARandomized Controlled Trial

To investigate whether prophylactic amiodarone infusion prevents ventricular fibrillation after aortic cross-clamp release and attenuates cytokine production in patients with left ventricular hypertrophy undergoing cardiac surgery. Prospective, randomized controlled trial. A public hospital. The study comprised 68 patients undergoing aortic valve replacement for severe aortic stenosis. Patients were randomly assigned to receive a 150mg bolus then 30mg/h continuous infusion of amiodarone (amiodarone group) or a 1 mg/kg bolus then 1 mg/kg/h continuous infusion of lidocaine (lidocaine group). The primary outcome was the ventricular fibrillation incidence rate after aortic cross-clamp release. Secondary outcomes included perioperative serum interleukin-6 and tumor necrosis factor-alpha levels. The ventricular fibrillation incidence rate was significantly lower in the amiodarone than in the lidocaine group (20.6% v 50%, relative risk 0.41; 95% confidence interval [CI] 0.20-0.86; p = 0.021). Interleukin-6 levels 1hour after aortic cross-clamp release and at intensive care unit admission were significantly lower in the amiodarone than in the lidocaine group (geometric mean [95% CI] 117.4pg/mL [87.1-158.4] v 339.5pg/mL [210.6-547.2]; p < 0.01 and 211.1pg/mL [162.8-73.6] v 434.1pg/mL [293.7-641.5]; p < 0.01, respectively). Tumor necrosis factor-alpha levels 1hour after aortic cross-clamp release were significantly lower in the amiodarone than in the lidocaine group (geometric mean [95% CI] 1.624pg/mL [1.359-1.940] v 2.283pg/mL [1.910-2.731]; p = 0.02). Amiodarone prevented reperfusion ventricular fibrillation in patients with left ventricular hypertrophy undergoing aortic valve replacement to a greater extent than did lidocaine. Furthermore, amiodarone inhibited postoperative interleukin-6 and tumor necrosis factor-alpha production.

Comparing the Effect of Lidocaine - Magnesium Sulfate Combination with Amiodarone - Magnesium Sulfate Combination in Preventing Ventricular Fibrillation After Aortic Artery Cross-clamp Removal During Coronary Artery Bypass Graft Surgery

Abstract Background: The prevalence of ventricular fibrillation after removal of the aortic cross-clamp in patients undergoing coronary artery bypass surgery is about 74%-96% cross-clamp. Defibrillation shock and different types of agents are used to treat ventricular fibrillation (VF). Objectives: This study was aimed to compare the effects of combining lidocaine lidocaine + magnesium sulfate sulfate with amiodarone + magnesium sulfate sulfate in the prevention of reperfusion-induced ventricular fibrillation. Methods: This randomized, double-blinded clinical study included 74 ASA class II and III patients undergoing coronary artery bypass grafting (CABG) in a university-affiliated hospital, Bandar Abbas, Iran, in the years 2015-2016. Patients were divided into two groups based on a random sample table of block. Both groups received magnesium sulfate through the cardiopulmonary cardiopulmonary bypass pump. lidocaine 2% (100 mg) and amiodarone (300 mg) were injected respectively to group lidocaine + magnesium sulfate (LM) and group amiodarone + magnesium sulfate (AM) patients before aortic cross-clamp release. The incidences of arrhythmias were recorded within 30 minutes after release of the aortic sross-clamp (ACC). Additionally, the defibrillation shocks (frequency and level of joules delivered), amount of inotrope agent, and the hemodynamic and arterial blood gas parameters were recorded up to 24 hours post-operatively. Results: There was no significant difference between the two groups in terms of demographic characteristics, ejection fraction, and ASA class. The prevalence of ventricular fibrillation (VF) and atrial fibrillation (Af) 30 minutes after ACC release were 46.7% and 53.3% (P = 0.240) vs. 33.3% and 66.7% (P > 0.999); while, up to 24 hours post-operatively were 60% and 20.0% vs. 0.0% and 0.0% in groups LM and AM respectively. The number of defibrillations in the lidocaine + magnesium sulfate group was significantly higher 57.9% vs. 25% in groups LM and AM respectively (P = 0.004). Conclusions: The use of amiodarone + magnesium sulfate reduces the number of defibrillation following the release of the Aortic cross-clamp compared with lidocaine + magnesium sulfate. © 2018, Author(s).

EFFECT OF AMIODARONE IN PREVENTION OF ATRIAL FIBRILLATION IMMEDIATELY AFTER RELEASE OF AORTIC CROSS-CLAMP

Objective: The objective of this study is to determine the efficacy of a bolus dose of amiodarone administered by the way of cardiopulmonary bypass pump before releasing of aortic cross-clamp (ACC) in the prevention of atrial fibrillation.Methods: In this prospective study, 22 non-diabetic patients were randomly assigned in a double-blind fashion to either amiodarone or placebo group. In amiodarone group injection amiodarone 3 mg/kg in 10 ml normal saline (amiodarone group, Group A, n=10) and in control group (control group, Group P, n=12), the same volume of normal saline was administered 3 min before the release of ACC. Initial rhythm after the release of ACC was noted.Results: The major rhythm after the release of ACC was ventricular arrhythmia in control group (n=5, 40%), whereas in amiodarone group, it is normal sinus rhythm (n=7, 63%). Only the need of cardioversion/defibrillation and the amount of energy needed was less in the amiodarone group but not reached statistical significance level. There was a trend toward a higher ventricular rate in control group compared to amiodarone group, but it never reached statistical significance level (114±46 vs. 97±29, p=0.3). One patient in amiodarone group required temporary pacemaker for sustained atrioventricular block with heart rate of &lt;50 beats/min and continued on temporary pacemaker for 48 h.

Efficacy of amiodarone and lidocaine for preventing ventricular fibrillation after aortic cross-clamp release in open heart surgery: a meta-analysis of randomized controlled trials.

The relative preventative efficacy of amiodarone and lidocaine for ventricular fibrillation (VF) after release of an aortic cross-clamp (ACC) during open heart surgery has not been determined. This meta-analysis was designed to systematically evaluate the influence of amiodarone, lidocaine, or placebo on the incidence of VF after ACC. Prospective randomized controlled trials (RCTs) that compared the VF-preventative effects of amiodarone with lidocaine, or amiodarone or lidocaine with placebo were included. PubMed, EMBASE, and the Cochrane Library were searched for relevant RCTs. Fixed or randomized effect models were applied according to the heterogeneity of the data from the selected studies. We included eight RCTs in the analysis. Pooled results suggested that the preventative effects of amiodarone and lidocaine were comparable (relative risk (RR)=1.12, 95% confidence interval (CI): 0.70 to 1.80, P=0.63), but both were superior to the placebo (amiodarone, RR=0.71, 95% CI: 0.51 to 1.00, P=0.05; lidocaine, RR=0.63, 95% CI: 0.46 to 0.88, P=0.006). The percentage of patients requiring electric defibrillation counter shocks (DCSs) did not differ significantly among patients administered amiodarone (RR=0.21, 95% CI: 0.04 to 1.19, P=0.08), lidocaine (RR=2.44, 95% CI: 0.13 to 44.02, P=0.55), or the placebo (RR=0.56, 95% CI: 0.25 to 1.25, P=0.16). Amiodarone and lidocaine are comparably effective in preventing VF after ACC, but the percentage of patients who subsequently require DCSs does not differ among those administered amiodarone, lidocaine, or placebo.

Abstract 12438: Intraoperative Magnesium Reduces Postoperative Arrhythmias in Congenital Heart Surgery Is the Effect Arrhythmia-Specific and Dose-Dependent?

Introduction: Magnesium (MG) has been used to decrease the incidence of postoperative junctional ectopic tachycardia (PO JET); its efficacy on other arrhythmias (A) is less known. We tested the hypotheses that the effect of MG on PO A may be: 1) arrhythmia-specific and 2) dose-dependent. Methods: 1871 out of a total of 2208 congenital heart surgeries (CHS), performed from 2005 to 2013, were reviewed based on selection criteria. 750 cases did not receive MG, 338 cases received 25 mg/kg MG (25 Mg) and 783 cases received 50 mg/kg MG (50 Mg) after aortic cross clamp release. All procedures were classified according to Aristotle Score (1 to 4). The incidence of 5 PO A categories was recorded: JET, accelerated junctional rhythm (AJR), atrial tachycardia (AT), ventricular tachycardia (VT) and 2°and 3° heart block (HB). Pearson chi-square test and logistic model analyses were used to evaluate the effect of MG on arrhythmia. BSA, Aristotle score, cardiopulmonary bypass, aortic cross-clamp and surgery times were controlled in logistic models. Results: 1) PO JET was reduced with MG use (0 Mg 15.3%; Mg 7.2%; p&lt;0.001), but without evidence of a difference by dose (25 Mg 7.1%: 50 Mg 7.3%). 2) AJR was reduced with MG use (0 Mg 4.3%: 25 Mg 2.4%: 50 Mg 2.2%, NS between doses). 3) AT was reduced with MG use (0 Mg 9.1%: 25 Mg 3.6 %: 50 Mg 4.0%, NS between doses). 4) VT was reduced in low dose (0 Mg 5.1%: 25 Mg 2.7%; p =0.02), but not at the higher dose (50 Mg 5.5%). 5) PO HB did not differ by Mg use (0 Mg 4.8 %: 25 Mg 3.3 %: 50 Mg 2.6 %). The reduction of PO JET was significantly greater with increasing surgical complexity. Effect of MG was independent of Aristotle score in other A- categories. Conclusion: In agreement with prior clinical trial results, MG use was preventive of PO arrhythmia; however its effect appeared to be arrhythmia-specific. The occurrence of PO JET, AJR, and AT was reduced with Mg use. The effect of MG on PO VT appeared inversely dose dependent with no effect at higher dose and MG appeared to have no impact on PO HB. In general, higher doses of MG did not enhance PO arrhythmia suppression, but might be proarrhythmic (VT) in patients undergoing CHS. Our results suggest that an intraoperative MG dosage of 25 mg/kg may be optimal.

Sufficient myocardial protection of del Nido cardioplegia regardless of ventricular mass and myocardial ischemic time in adult cardiac surgical patients

Del Nido (DN) cardioplegic solution (CPS) has been widely used during pediatric cardiac surgery. However, its use in the field of adult cardiac surgery is not popular yet. We evaluated efficacy of DN cardioplegia in adult cardiac surgical patients. Fifty-three adult patients (mean age, 54±16 years) who underwent cardiovascular surgery using DN cardioplegia were enrolled. Myocardial troponin I (TnI) level up to three days after surgery and early clinical outcomes were evaluated. Propensity score matching was performed to compare these results with those after surgery using blood cardioplegia (BC). DN cardioplegia was infused with an initial dose of 1,126±221 mL, and an additional 500 mL was reinfused in 15 patients 91 minutes after initial infusion. After release of aortic cross clamp (ACC), spontaneous defibrillation was achieved in 94.3% (50/53). The peak TnI level after surgery was 9.8 ng/mL (range, 2.0-90.2 ng/mL). Linear regression models demonstrated that neither left ventricular mass (LVM) nor ACC time was associated with increased level of peak TnI (P=0.928 and 0.595, respectively). Early mortality occurred in one patient (1.9%). Postoperative complications included atrial fibrillation (n=18, 34.0%), acute kidney injury (n=4, 7.5%), low cardiac output syndrome (n=1, 1.9%), and respiratory complications (n=1, 1.9%). Propensity score matching extracted 39 pairs. Spontaneous defibrillation was achieved more frequently in the DN than BC groups (37/39 vs. 12/39, P<0.001). Peak level and serial changes of TnI were not statistically different between the two groups (P=0.085 and 0.959, respectively). There were also no significant differences in early mortality and postoperative complication rates between the two groups. DN cardioplegia is as effective as BC for adult patients in terms of myocardial protection and early clinical outcomes.

Effect of intravenous lidocaine on the transcerebral inflammatory response during cardiac surgery: a randomized-controlled trial.

Postoperative cognitive dysfunction (POCD) occurs frequently after cardiac surgery. The pathophysiology of POCD remains elusive, but previous work showed that intravenous lidocaine may be protective against POCD, possibly by modulating cerebral inflammation. We hypothesized that intravenous lidocaine would attenuate the cerebral inflammatory response to cardiopulmonary bypass (CPB) by reducing the transcerebral activation gradients of platelets, leukocytes, and/or platelet-leukocyte conjugates. We studied 202 patients undergoing cardiac surgery with CPB in this prospective randomized double-blinded placebo-controlled trial. Subjects were randomized to receive either intravenous lidocaine (bolus + 48-hr infusion) or placebo (identical infusion volume and duration). Paired jugular venous and radial arterial blood samples were drawn at several time points and analyzed by fluorescence-activated cell sorting to identify activated platelets and platelet-leukocyte conjugates. Transcerebral activation gradients were calculated by subtracting arterial values from venous values and were compared between groups using repeated measures regression models with covariate adjustment for age, sex, surgery type, and CPB duration. Beginning after aortic cross-clamp release and peaking ten minutes after the termination of CPB, the mean (SD) transcerebral activation gradient of platelet-monocyte conjugates decreased in lidocaine-treated vs placebo-treated patients [-1.84 (11.47) mean linear fluorescence intensity (MLFI) vs 1.46 (13.88) MLFI, respectively; mean difference, -4.08 MLFI; 95% confidence interval, -7.86 to -0.29; P = 0.03). No difference was seen at any time point for activated platelets or for platelet-neutrophil conjugates. While lidocaine did not affect the systemic or transcerebral activation of platelets or leukocytes, we did observe a reduction in the transcerebral activation of platelet-monocyte conjugates after aortic cross-clamp release. This may be a manifestation of reduced cerebral inflammation during cardiopulmonary bypass in response to treatment with lidocaine. This trial was registered at ClinicalTrials.gov (NCT00938964).

Aortic cross-clamping phase of cardiopulmonary bypass is related to decreased microvascular reactivity after short-term ischaemia of the thenar muscle both under intravenous and volatile anaesthesia: a randomized trial.

The purpose of the present study was to assess, by near-infrared spectroscopy with an INVOS oximeter during the vascular occlusion test (VOT), the influence of cardiopulmonary bypass (CPB) on tissue saturation in the thenar muscle. The secondary aim was to compare the effects of propofol and sevoflurane anaesthesia on tissue saturation. This was a prospective, randomized, open-label study. Sixty cardiac surgery patients received either propofol or sevoflurane anaesthesia. Three-minute VOT was performed at the following time points: 30 min after anaesthesia induction, directly after sternotomy, 20 and 40 min after aortic cross-clamping, 20 min after aortic cross-clamp removal and 45 min after weaning of cardiopulmonary bypass. Group and time effects on tissue saturation were analysed with RM-ANOVA and the post hoc Tukey test. In both groups at baseline, the lowest and the highest tissue saturation and the rate of saturation recovery during the reperfusion phase of the vascular occlusion test were lower during aortic cross-clamping in comparison to the values before CPB. Lower nadir tissue saturation during ischaemia was observed under propofol in comparison to sevoflurane anaesthesia (P = 0.018). This study demonstrated that the aortic cross-clamping phase of CPB cardiac surgery is associated with lower values of tissue saturation and a decreased rate of saturation recovery under both propofol and sevoflurane anaesthesia. Aortic cross-clamp release is followed by accelerated tissue desaturation during VOT. Propofol anaesthesia for CPB cardiac surgery results in greater reduction of nadir tissue saturation during the ischaemic phase of VOT in comparison to that of sevoflurane. NCT02593448.