Administration Of Cardioplegia Research Articles

Comparative analysis of del Nido cardioplegia versus blood cardioplegia in isolate coronary artery bypass grafting

BackgroundThis study examined the efficacy of del Nido cardioplegia compared with traditional blood cardioplegia in adult cardiac surgery for isolated coronary artery bypass grafting by evaluating the early postoperative outcomes.MethodsA total of 119 patients who underwent isolated conventional coronary artery bypass grafting were enrolled and divided into two groups (del Nido cardioplegia group [n = 36] and blood cardioplegia group [n = 50]) based on the type of cardioplegia used. This study compared the preoperative characteristics, intraoperative data, and early postoperative outcomes. Further subgroup analyses were conducted for high-risk patient groups.ResultsThe 30-day mortality and morbidity rates were not significantly different between groups. The del Nido cardioplegia group exhibited advantageous myocardial protection outcomes, demonstrated by a significantly smaller rise in Troponin I levels post-surgery (2.8 [-0.4; 4.2] vs. 4.5 [2.9; 7.4] ng/mL, p = 0.004) and fewer defibrillation attempts during weaning off of cardiopulmonary bypass (0.0 ± 0.2 vs. 0.4 ± 1.1 times, p = 0.011) when compared to the blood cardioplegia group. Additionally, the del Nido group achieved a reduction in surgery duration, as evidenced by the reduced aortic cross-clamping time (64.0 [55.5; 75.5] vs. 77.5 [65.0; 91.0] min, p = 0.001) and total operative time (287.5 [270.0; 305.0] vs. 315.0 [285.0; 365.0] min, p = 0.008). Subgroup analyses consistently demonstrated that the del Nido cardioplegia group had a significantly smaller postoperative increase in Troponin I levels across all subgroups (p < 0.05).Conclusionsdel Nido cardioplegia provided myocardial protection and favorable early postoperative outcomes compared to blood cardioplegia, making it a viable option for conventional coronary artery bypass grafting. Establishing a consensus on the protocol for Del Nido cardioplegia administration in adult surgeries is needed.

New approach to the mitral valve through the left anterior minithoracotomy for combined valve and coronary surgical procedures

ObjectiveWe have developed a new technique for accessing the mitral valve through the left anterior minithoracotomy. This approach has been used in patients requiring both mitral valve surgery and coronary artery bypass grafting. MethodsFrom October 2020 to September 2022, we performed 24 concomitant mitral valve procedures and coronary artery bypass grafting through the left anterior minithoracotomy. The average age of the patients was 65.5 years, and the mean left ventricular ejection fraction was 44.5%. Computed tomography angiography was routinely performed preoperatively. The surgical technique included a left anterior minithoracotomy in the fourth intercostal space, peripheral cardiopulmonary bypass, aortic crossclamping using a transthoracic clamp through the additional port in the left second intercostal space, the administration of cold blood cardioplegia, a right atrial transseptal approach to the mitral valve, and special surgical exposure maneuvers. These maneuvers were designed to displace the heart into the left pleural space by pulling the inferior vena cava tape and the ascending aorta tape to the left. Conventional mitral valve surgical techniques were used. The mitral valve repair or replacement was performed after the distal anastomoses to the right and circumflex coronary system were completed. Subsequently, after the mitral valve procedure, coronary anastomosis to the left anterior descending artery was performed. ResultsThe mitral valve was effectively visualized, and a planned procedure was successfully completed in all patients. There was no need for conversion to a sternotomy. mitral valve repair was performed in 22 patients (91.7%), and mitral valve replacement was performed in 2 patients (8.3%). Conventional surgical instruments were used in 10 cases (41%), and long-shafted instruments were used in 14 cases (59%). A knot-pusher was required in 9 cases (37.5%). A computed tomography distance from the skin level to the mitral valve posterior annulus of more than 14 cm was identified as a technical difficulty marker, necessitating the use of long-shafted instruments. Concomitant complete revascularization was achieved in all cases. The mean number of distal anastomoses was 2.54 ± 0.7 (1; 4). Total operation time was 341 ± 41 (285; 420) minutes, cardiopulmonary bypass time was 231 ± 38 (172; 316) minutes, and the crossclamp time was 127 ± 23 (80; 169) minutes. Patients had a mean intensive care unit stay of 1.87 ± 0.69 (1; 4) days, and their total hospital stay averaged 6.54 ± 1.86 (4; 10) days. There were no reoperations due to bleeding, no occurrences of strokes, and no other major complications. There were no instances of hospital mortality or mortality within 30 days after the procedures. ConclusionsMitral valve repair or replacement through the left anterior thoracotomy and transseptal approach is a valuable and effective technique that can be used for concomitant procedures performed through a single minithoracotomy incision in selected patients.

Blood cardioplegia may be better than crystalloid cardioplegia during cardiac surgery for infective endocarditis

Abstract Background Cardioplegia is an indispensable element in cardiac surgery for left sided infective endocarditis (IE). Crystalloid cardiolegia (CC) as a single or dual-dose is more attractive in complicated IE surgery than repeated, every 15-20 min, administration of blood cardioplegia (BC). Recently, blood cardioplegia was shown to reduce the systemic inflammatory response to cardiopulmonary (CPB) compared to crystalloid cardioplegia. As the systemic inflammatory response after surgery for IE endocarditis is more exaggerated than in non-IE valve surgery, it is important to investigate impact of the two solutions on outcome after IE surgery. Methods We retrospectively analyzed data of all patients (n=581) with endocarditis who underwent cardiac valve surgery at our institution between January 2007 and March 2018. The primary endpoint was 30-day mortality, secondary endpointwas the length of intensive care unit (ICU) stay. Nearest neighbor propensity matching with a caliper of 0.01 was performed to adjust for differences in basal characteristics between patients who received Calafiore BC vs Bretschneider CC. Results Patients who received CC were older (67 vs 63, p&amp;lt;0.01) had greater incidence of large vegetations (42.7% vs 32.3%, p&amp;lt;0.01), prosthetic valve endocarditis (30.8% vs 17.3%, p&amp;lt;0.01) and mitral valve endocarditis (54.6 vs 43.6 p&amp;lt;0.01). Logistic regression in the raw data revealed a higher mortality rate and longer LOS in ICU for the patients who received CC. After matching, CC was still associated with higher 30-day mortality (24.4% vs 15.9%, p=0.01) and longer ICU-stay (median: 6, IQR: 9 vs median: 3, IQR: 6, p&amp;lt;0.01). Conclusions Administration of blood cardioplegia during cardiac surgery for infective endocarditis may be associated with lower 30-day mortality and shorter ICU-stay compared to using crystalloid solution.

Twenty-Four Hour Normothermic Ex Vivo Heart Perfusion With Hemofiltration In an Adult Porcine Model

Historically, cardiac transplantation relied on cold static storage at 5 °C for ex vivo myocardial preservation. Currently, machine perfusion is the standard of care at many transplant centers. These storage methods are limited to 12 hours. We sought to evaluate the efficacy of hemofiltration and filtrate replacement in adult porcine hearts using normothermic heart perfusion (NEVHP) for 24 hours. We performed 24-hour NEVHP on 5 consecutive hearts. After anesthetic induction, sternotomy, cardioplegia administration, explantation, and back-table instrumentation, NEVHP was initiated in beating, unloaded mode. After 1 hour, plasma exchange was performed, and hemofiltration was initiated. Heart function parameters and arterial blood gasses were obtained hourly. All hearts (n=5) were viable at the 24-hour mark. The average left ventricular systolic pressure at the beginning of the prep was 36.6 ± 7.9 mm Hg compared with 27 ± 5.5 mm Hg at the end. Coronary resistance at the beginning of prep was 0.79 ± 0.10 mm Hg/L/min and 0.93 ± 0.28 mm Hg/L/min at the end. Glucose levels averaged 223 ± 13.9 mg/dL, and the lactate average at the termination of prep was 2.6 ± 0.3 mmol/L. We successfully perfused adult porcine hearts at normothermic temperatures for 24 hours with results comparable to our pediatric porcine heart model. The next step in our research is NEVHP evaluation in a working mode using left atrial perfusion.

Management of a rare isolated left main coronary artery ostial stenosis in a young patient: a case report

BackgroundIsolated congenital ostial stenosis of the left coronary artery (LCA) is extremely rare, and available literature is limited. Long-term treatment success is key in the choice of treatment strategy due to the mostly young age of the patients. Here, we present a clinical case and shed light on the surgical treatment strategies including their pitfalls.Case presentationWe describe a 20-year-old male who presented to the emergency department with recurrent typical angina pectoris symptoms (CCS class II). Computed tomography and coronary angiography revealed isolated ostial stenosis of the LCA, with prominent collaterals from the right coronary artery. The patient was operated on and intra-operative findings showed a severely narrowed LCA ostium that appeared to be fibrotic, and to originate from a similarly fibrotic left coronary sinus of the aortic root. The LCA was excised from the left coronary sinus, and trimmed until the coronary artery lumen appeared macroscopically normal. The fibrotic left coronary sinus was resected and replaced with a bovine pericardial patch, into which the coronary artery was re-inserted. During weaning from cardiopulmonary bypass, we faced a diminished left ventricular function. We attributed this to insufficient myocardial protection. Isolated antegrade cardioplegia had been used, which, for technical reasons, had to be administered separately to the right and left coronary artery after aortotomy. In the setting of huge collaterals from the right to the left coronary artery, a steal-effect likely occurred. After prolonged reperfusion, the left ventricular function recovered, and the further post-operative course was unremarkable.ConclusionsFor the surgical treatment of congenital ostial stenosis of the LCA, both ostium reconstruction and coronary artery bypass grafting have been described. The advantage of ostium reconstruction as chosen here is to create a physiological flow and supply situation to the affected myocardial areas. Furthermore, in case of other downstream events, such as the development of coronary artery disease, all further therapeutic options are preserved.Special attention should be paid to the administration of cardioplegia in these patients. Combined ante and retrograde cardioplegia administration probably would have achieved more extensive myocardial protection in our case.

Postoperative sodium concentrations after cardiac surgery using histidine- tryptophan-ketoglutarate cardioplegia and cardiopulmonary bypass – a retrospective study

Introduction: Histidine-tryptophan-ketoglutarate (HTK) cardioplegia is used to induce cardiac arrest during cardiopulmonary bypass (CPB) in cardiac surgery. HTK cardioplegia is hyponatremic (15 mmol/L) and slightly hyperosmolar (310 mOsm/kg) and can induce hyponatremia when it enters systemic circulation. The purpose of this study is to investigate the effect of HTK cardioplegia, cannulation strategy and intraoperative correction of sodium levels on postoperative sodium concentration. Secondly, the effect of the sodium concentrations on postoperative agitation is evaluated. Methods: Patients who underwent cardiac surgery using CPB and HTK cardioplegia were included in this retrospective study. Sodium concentrations of arterial blood gases (ABG) and laboratory blood samples were analyzed at multiple points in time. It was recorded if the perfusionist corrected intraoperative hyponatremia with hypertonic saline or sodium bicarbonate 8.4%. Characteristics of the patients, intraoperative data and the patient’s Richmond Agitation-Sedation Scale (RASS) score were collected. Results: The median sodium concentration on ABG [IQR] decreased from 139 mmol/L [138-140] to 125.5 mmol/L [122-130] (p &lt; 0.001) after the administration of HTK cardioplegia. The median sodium concentration after the administration of HTK cardioplegia was significantly lower in the group with single cannulation than with double cannulation (123 mmol/L [121-125] vs. 130 mmol/L [128-133]; p&lt;0.001). The median sodium concentration increased to 134 mmol/L [133-136] (p=0.007) at T6. There was no significant difference in postoperative sodium concentration between patients who received correction intraoperatively and those who did not, or between patients who had agitation and those who had not. Conclusions: The administration of HTK cardioplegia induced acute hyponatremia during cardiac surgery mainly in patients with single venous cannulation. Postoperatively, a normalization of sodium concentrations can be observed. No difference in postoperative sodium concentration was observed with or without intraoperative correction of sodium. Intraoperative correction of hyponatremia shows no benefit or harm on postoperative sodium concentrations. Hyponatremia could be avoided or at least diminished by using double venous cannulation.

CARD16: Prolonged Normothermic Ex Vivo Heart Perfusion with Hemofiltration in Resting and Intermittent Working-heart Models

Introduction: Cold static storage (5C) or normothermic (37C) ex vivo heart perfusion (NEVHP) in the beating but resting mode (Langendorff) successfully preserves hearts for transplantation for up to 6 hours. Previous attempts to prolong the preservation period increases morbidity and mortality following transplantation. In addition, the 6-hour limit imposes geographic restrictions for recipients, prevents optimal organ assessment, and reduces the number of hearts available for transplantation. We have successfully maintained 10 consecutive pediatric hearts (60±8.8 g) for 24 hours using NEVHP with hemofiltration in the beating, resting-heart mode. Although this prolonged NEVHP model was successful, cardiac function could not be comprehensively assessed in the beating, resting-heart mode. We sought to expand our prolonged NEVHP model to include intermittent left atrial (LA) perfusion that would allow cardiac assessment in the working-heart mode. Methods: We performed 24-hour NEVHP on 5 consecutive hearts (276 ±22.6 g). Following anesthetic induction, sternotomy, cardioplegia administration, explantation, and back-table instrumentation, NEVHP was initiated in beating, resting mode. After 1 hour the circuit was transitioned to LA perfusion working-heart mode for 30 minutes, baseline working-heart parameters were documented (Figure 1) and perfusion was returned to beating, resting-heart mode. Intermittent LA perfusion with working-heart assessment was performed every 4-6 hours. Final working-heart measurements were obtained at 24 hours. Results: All hearts survived 24 hours and all maintained working-heart parameters statistically identical to baseline. Mean LA pressure was 8.2±7.5 mmHg, peak left ventricle (LV) pressure was 33.9±8.7 mmHg, mean LV pressure was 12.0±13.7 mmHg, peak aortic pressure was 35.6±7.8 mmHg, mean aortic pressure was 22.8±7.7 mmHg, coronary resistance 0.15±0.05 mmHg/L/min, and lactate levels were 2.7±0.6 mmol/L. Conclusions: We have successfully developed and validated a porcine NEVHP model for assessment of cardiac function in the working-heart mode using intermittent LA perfusion. While intermittent LA perfusion is an important step toward comprehensive ex vivo assessment of donor heart function, proof of cardiac preservation following prolonged NEVHP still requires successful transplantation and complete assessment in the recipient. We plan to perform this as our next step toward prolonged ex vivo heart preservation. Techniques and cannula for intermittent LA perfusion in the pediatric model will also be developed.

CARD17: 24 hr Normothermic Ex Vivo Heart Perfusion in Adult Porcine Hearts with Hemofiltration

Introduction: Currently, to successfully transplant a heart, cardiac preservation relies on cold static storage at 5C for up to 6 hours. If hearts are stored at this temperature for a longer duration, their function after transplantation is compromised, increasing post-transplant morbidity and mortality. This time restriction negatively impacts the availability of donor hearts and limits distance and transportation options, optimal cross-matching, and organ assessment, all of which facilitate successful transplantation. Previous studies from our group have demonstrated that: 1) Plasma cross circulation at 1 L/hr from a living paracorporeal sheep allowed for safe normothermic ex vivo heart perfusion (NEVHP) for 3 days, 2) NEVHP for 24 hours is feasible with plasma exchange without a paracorporeal animal, 3) 24-hour NEVHP is also feasible with the addition of hemofiltration (22 kDa filter) and filtration replacement. All studies with up to 24hr of NEVHP were performed using piglet hearts (60±8.8 g) The experiments described in this study were designed to evaluate the efficacy of hemofiltration and filtrate replacement in adult porcine hearts. Methods: We performed 24-hour NEVHP on 5 consecutive hearts (mean weight 263±15.5 g). Following anesthetic induction, sternotomy, cardioplegia administration, explantation, and back-table instrumentation, NEVHP was initiated in beating, resting mode. After 1 hour plasma exchange was performed and hemofiltration was initiated. Heart function parameters and arterial blood gasses were obtained hourly and at termination of prep all hearts were removed from circuit and stored in formalin. Results: All hearts (n=5) were viable at the 24-hour mark. Aortic blood flow was adjusted to maintain coronary artery blood flow at 0.7 mL/min/g. Average LV systolic pressure at the beginning of the prep was 36.6±7.9 mmHg compared to 27±5.5 mmHg at the end. Coronary resistance at the beginning of prep was 0.79±0.10 mmHg/L/min and at the end of prep was 0.93±0.28 mmHg/L/min. Glucose levels averaged 223±13.9 mg/dL and the lactate average at the termination of prep was 2.6±0.3 mmol/L. Conclusions: We successfully perfused adult porcine hearts at normothermic temperatures for 24 hours with results comparable to our pediatric porcine heart model. The next steps in our research are NEVHP evaluation in a working mode using left atrial perfusion, extension of NEVHP preservation beyond 24 hours, and verification of functional status of the ex vivo heart by transplantation after 24 hours on our circuit.

P62: A Unique case of Transcatheter aortic valve replacement dislodgement in the presence of a durable left ventricular assist device

Background: Transcatheter aortic valve replacement [TAVR] for severe pure aortic insufficiency [AI] in the presence of a durable left ventricular assist device [LVAD] is fraught with challenges. We report an interesting case of TAVR valve dislodgement by the LVAD that was treated with redeployment of another TAVR valve, and redo surgery for extraction of the intraventricular TAVR valve. Methods and Results: A 46-year-old man presented to our unit in cardiogenic shock [CS] and severe pulmonary hypertension [PH] of 72/45mmHg. He underwent placement of an Impella 5.5 [Abiomed, Danvers, MA] as a bridging strategy to treat his CS and PH while transplant candidacy was being assessed. However, he remained pulmonary hypertensive with a trans-pulmonary gradient 26mmHg and pulmonary vascular resistance 5.3 wood units, despite 14 days of impella 5.5 therapy combined with aggressive management with milrinone 0.25 mcg/kg/min and bumetanide infusion 1mg/hr. He therefore underwent implantation of heart mate 3 [HM3] LVAD [Abbott Laboratories, Chicago, IL] by a limited left thoracotomy in the 5th intercostal space and upper ‘inverse-T’ hemi-sternotomy into the fourth intercostal space. His postoperative course was complicated by requirement for 31mm percutaneous Protek Duo [LivaNova, London, UK] Right VAD [RVAD] for 32 days, and gastrointestinal bleeding requiring cessation of heparin therapy, which prompted formation of thrombus in the left coronary cusp of the aortic valve. Organization of this thrombus and consequent retraction of the left coronary leaflet led to severe AI and consequent CS, requiring inotropic support and discussion on optimal management strategy. He underwent TAVR with a 29mm Edwards Sapien 3 valve [Edwards Lifesciences, Irvine, CA] with 20% over-sizing, which got dislodged and migrated into the LV. Another 29mm Edwards Sapien 3 TAVR valve was successfully deployed. The patient was then placed on cardiopulmonary bypass via the femoral vessels, and the left thoracotomy was reopened. The LVAD was temporarily stopped, and the latch mechanism on the HM3 was opened. The HM3 was removed from the sewing cuff, and the TAVR valve was ‘fished-out’ from the cavity of the LV. The HM3 was reinserted and restarted after thorough de-airing through the outflow graft. The incisions were closed in a standard manner and the patient was discharged home on the 20th postoperative day. Conclusions: TAVR for severe AI in the presence of a durable LVAD is fraught with challenges due to the constant suction action of the LVAD, and the absence of calcium in the native annulus to anchor the prosthesis. Our case highlights the feasibility of extricating a dislodged TAVR valve through simple redo-surgery. With this approach, we managed to avoid a more conventional redo procedure involving administration of cardioplegia for a surgical AVR or for extricating the prosthesis, with its inherent risk of right ventricular failure requiring RVAD. Figure showing dislodged TAVR on the left and redeployment on the right

PO-02-202 CORONARY SINUS PRESSURE FOLLOWING RETROGRADE CARDIOPLEGIA PREDICTS POSTOPERATIVE ATRIAL FIBRILLATION

Coronary sinus cannulation and occlusion are routinely performed during cardiac surgery for administration of retrograde cardioplegia. Under these circumstances, coronary sinus occlusion pressure closely parallels left ventricular end-diastolic pressure, and thus serves as a surrogate for left atrial pressure. Left ventricular diastolic dysfunction has been identified as an important predictor of post-operative atrial fibrillation (POAF). In the setting of impaired left ventricular compliance, left atrial pressure is highly sensitive to very small volume shifts, thereby stretching the left atrium and increasing pulmonary veins arrhythmogenic activity. We hypothesized that elevation of coronary sinus occlusion pressure during cardiac surgery is indicative of increased left atrial pressure and thus may predict the occurrence of POAF. Consecutive patients (n=91, age 65 ± 11yrs) underwent cardiac surgery with retrograde cardioplegia. Patients with a history of atrial fibrillation were excluded. Baseline mean coronary sinus occlusion pressure was obtained following cannulation of the coronary sinus for administration of retrograde cardioplegia before initiation of bypass. The mean coronary sinus occlusion pressure was measured again during bypass as well as immediately after removal of the aortic cross clamp. Clinical outcomes and post-operative complications were collected until hospital discharge. Baseline clinical and procedural characteristics were compared among patients who developed POAF and those who did not. Eleven of the 91 patients (12%) developed POAF. In patients who developed POAF, post-bypass cardiac index was lower (2.4±0.3 vs 2.9±1.1 L/min/m2, p =0.004) and post-bypass coronary sinus occlusion pressure was higher compared to those who did not (16.5±9.5 vs 9.0±6.0 mm Hg, p = 0.036). Post-bypass coronary sinus occlusion pressure was independently predictive of POAF after adjusting for post-bypass cardiac index [OR 1.2 (95% CI 1.1-1.3), p=0.003]. Post-bypass coronary sinus occlusion pressure is significantly higher in patients who develop POAF, reflecting the development of post-bypass impaired relaxation and increased left atrial pressure. Given the ubiquitous use of coronary sinus occlusion during bypass procedures and the ease of measurement of post-bypass coronary sinus occlusion pressure, this may be a valuable and inexpensive tool for POAF risk stratification.

A novel versatile concept of cardioplegia delivery in cardiac surgery: The ReverseTWO cardioplegia circuit system.

Nowadays, the necessity of having a cardioplegia circuit capable of being adapted in order to administer different types of cardioplegia is strategically fundamental, both for the perfusionist and for the cardiac surgeon. This allows to avoid cutting tubes, guarantees sterility and, most of all, limits the number of cardioplegia circuits for the different strategies of cardiac arrest. The novel "ReverseTWO cardioplegia circuit system" is the development of the precedent "Reverse system" where mainly the 4:1 and crystalloid cardioplegia were used, It has the advantage of allowing immediate change of cardioplegia set-up versus four types of cardioplegia technique, when the strategy is unexpectedly changed before the beginning of cardiopulmonary bypass (CPB), is safe and enables the perfusionist to use one single custom pack of cardioplegia. Two pediatric roller pumps are usually used in our centre for cardioplegia administration; they have a standardized calibration (the leading with ¼ inch and the follower with 1/8 inch) and the circuit consequently has two different tube diameters for the two different pumps. The presence in the circuit of two different shunts coupled with two different coloured clamps allows the immediate set-up for different cardioplegia administration techniques utilizing a colour-coding mechanism The aim of this manuscript is to present the new ReverseTWO Circuit. This novel system allows to administer four different cardioplegic solutions (4:1, 1:4, crystalloid, ematic) based on multiple tubes, which can be selectively clamped, identified through a color-coding method. The specificity of this circuit is the great versatility, which leads to numerous advantages, such as reduced risk of perfusion accident and reduced costs related not only to the purchase of different cardioplegia kits but also to the storage. https://youtu.be/ovJBE4ok2Ds.

105 A CASE OF RARE ATYPICAL ATRIAL STRUCTURE

Abstract A 27-year-old woman, without previous cardiological history, was admitted at our emergency department in the clinical context of an acute pericarditis. Echocardiography documented mild pericardial effusion (8 mm) without any sign of hemodynamic impact. The patient was then admitted at our Cardiology Unit. During the hospitalization a complete transthoracic echocardiogram showed a normal biventricular morphology and function, normal valvular function and found an anechoic structure on the postero-lateral left atrial wall (1.75×1.5 cm). To better characterize this accidental finding, a transesophageal echocardiography was performed unmasking a dilated coronary sinus with anomalous course. A subsequent cardiac computed tomography was performed showing anomalous systemic venous return with the persistency of the left superior vena cava draining into the coronary sinus. No other congenital anomalies were found. PLSVC is present in approximatively 0.5% of individuals in the general population and is the most frequent congenital malformation of the thoracic venous return. In about 90% coexists with the right superior vena cava and co-occur in almost 40% of patients with other congenital heart abnormalities such as atrial septal defect, aortic coarctation, bicuspid aortic valve, tetralogy of Fallot, transposition of the great vessels, anomalous connections of the pulmonary veins, dextroversion and cor triatatum. Patients usually are asymptomatic. Nevertheless, this congenital malformation may cause chest discomfort, cardiac arrhythmias, thromboembolic events, decreased exercise tolerance and syncope. Moreover, the correct identification of this condition has important clinical implications. In fact, it is a relative contraindication to the administration of retrograde cardioplegia during cardiac surgery. Furthermore, the placement of central venous-access line, pulmonary artery catheterization or the implantation of pacemaker/resynchronization leads could be difficult or can result in incorrect positioning. In these cases, it is recommended to access to the right heart through the right subclavian vein instead the left one. Legend: *: Anomalous course of coronary sinus; LA: Left Atrium; LV: Left Ventricle; Ao: Aorta; RA: Right Atrium; R-SVC: Right superior vena cava; L-SVC: Left superior vena cava; LSPV: Left superior pulmonary vein.

Variations in Electrolytes Level After Del-Nido Cardioplegia Administration in Patients Undergoing Congenital Heart Defects Surgery

Objective: To evaluate the variation (increase or decrease) in Electrolytes level after del-nido cardioplegia administration in patients undergoing on pump congenital heart defect surgery.&#x0D; Study Design: The design used in this study was descriptive cross-sectional.&#x0D; Place and Duration of Study: The study was carried out at Pediatric Cardiac Surgery Department of Armed Forces Institute of Cardiology in Rawalpindi, Pakistan from Oct 2021 to Dec 2021.&#x0D; Methodology: Patients undergoing congenital heart surgery were the subject of interest in this study. The sample size was 147.Non-probability consecutive sampling technique was used. Patients undergoing on pump Congenital Heart Surgery, patients with age &lt; 30 years, patients of both gender were included in our study. Patients with surgery of multiple stages (abdominal surgery, palliative surgery), Emergency patients, Chronic renal failure patients, Re-do operations were excluded from our study.&#x0D; Results: Sample size was 147 with anticipated percentage 10.7% having 78(53.1%) males and 69(46.9%) females who underwent congenital cardiac surgery. Statistical test was applied and results are significant. There was significant difference in the means of electrolyte levels after administration of Del-Nido Cardioplegia (p-value &lt;0.05).&#x0D; Conclusion: Our study concluded that after Del-Nido Cardioplegia administration, imbalance in electrolytes levels (Sodium,Potassium, and Calcium) occur which causes hyperkalemia, hypernatremia and hypercalcemia. Prolonged cardiopulmonary bypass time and cross clamp time are risk factors for increased del-nido cardioplegia administration.

Novel Portable Hypothermic Cardiac Preservation Device Extends Cardiac Viability and Function Beyond the Standard of Care Using Isolated Porcine Hearts

<h3>Purpose</h3> The standard of care: cold static storage (CSS), limits the time a heart can be preserved to 4-6 hours. Machine perfusion preservation has been shown to improve organ viability. However, current machine perfusion technology is complex and requires the use of blood or blood products. The purpose of this study was to test the efficacy of a portable hypothermic oxygenated and acellular perfusion machine device, in preserving cardiac viability and function in comparison to CSS for 4 hours at different perfusion times using an isolated heart porcine model. <h3>Methods</h3> Isolated porcine hearts (N=17) were recovered under anesthesia and by inducing cardiac arrest through cardioplegia administration. Experimental hearts were perfused using a novel cardiac preservation device with an acellular perfusate at 4-8°C for 4 hours(n=3), 8 hours(n=4), and 24 hours(n=3). In addition, 3 hearts were perfused for 2 hours and then kept inside the perfusor at 4-8°C for an additional 4 hours without perfusion (extended mode), to determine efficacy during inoperable conditions. Controls (n=4) were hearts kept in CSS for 4 hours. Hourly flow, pressure, temperature, and blood gas measurements were taken from perfused hearts. After preservation, the hearts were placed in a Langendorff for functional recovery determined by +/- dP/dT and maximum pressure. Biopsy samples were taken before and at the end of either preservation method for histological and gene expression analyses. <h3>Results</h3> Control hearts weight gain (%) was -3.4 ± 4.9 and perfused hearts was 1.52 ± 7.6. Venous and arterial lactate concentrations were less than 2.5 mmol/L across all experiments. Perfused hearts at 4 hours, 8 hours, and extended mode had significantly increased contractility (p<0.05) than CSS demonstrated by +dP/dT and peak pressure. Gene expression showed a significant reduction (p<0.005) of inflammation (IL-6, IL-8, TNFα) and cell death markers (p53,cTnI) in perfused hearts compared to control hearts. Furthermore, histological assessment confirmed greater myocardium damage in CSS hearts. <h3>Conclusion</h3> This novel cardiac preservation device enhances cardiac viability and function compared to CSS. Furthermore, it allows for 4 hours of CSS after 2 hours of perfusion in case of cessation of perfusion. Animal transplant studies will be conducted to verify these results.

Heart Transplantation from Donation After Circulatory Death Donors: An Update on the Australian Experience

<h3>Purpose</h3> With an expanding end-stage heart failure population the demand for donor hearts is increasing. Donation after circulatory death (DCD) is a pathway that could help address this; we explore the impact of DCD over the last 8-years on our unit and compare our early vs contemporary outcomes. <h3>Methods</h3> All DCD heart transplants at our unit were included. Inclusion criteria for DCD donors are: normal transthoracic echo, age <55yrs & nil previous cardiac history. DCD heart retrievals are subject to varying functional (when systolic blood pressure drops <90mmHg) and asystolic warm ischemic times (aWIT) prior to administration of cardioplegia - this warrants an assessment of viability through visual inspection and monitoring of lactate levels. Donor hearts are cannulated onto an ex-vivo normothermic machine perfusion device where 1.2-1.5L of donor blood is circulated in a Langendorff fashion. <h3>Results</h3> Since 2014 we have performed 69 DCD heart transplants. Since 2020, DCD donors account for 32% of our heart transplant activity (32/100). Overall 1yr & 5yr survival for DCD vs BD donor heart transplant recipients was not significantly different (p=0.27). In the early experience, 12/34 patients (35.3%) required immediate post-operative ECMO or mechanical support. Recent recipients have a significantly lower rate with 3/35 (8.57%) requiring ECMO/mechanical support post-transplant (p=0.009). Mean DCD donor & recipient age was 32.6yrs(+/-10.5yrs) & 53.6yrs(+/-12.7yrs) respectively. Mean donor aWIT was 12.3mins (+/-2.8mins). Recipients of donors with an aWIT >15mins had significantly higher post-transplant ECMO/mechanical support requirement compared to those with an aWIT <=15mins (66.17% vs 17.46%, p=0.0177, OR 9.455). Median hospital length of stay was 17.5days (11-27.5days). <h3>Conclusion</h3> DCD donors can contribute to heart transplantation activity with survival comparable to BD pathways. Donor hearts subject to an aWIT >15mins are more likely to require post-operative ECMO/mechanical support.

Minimally invasive and robotic approaches to mitral valve surgery: Transthoracic aortic crossclamping is optimal

Minimally invasive and robotic approaches to mitral valve surgery: Transthoracic aortic crossclamping is optimal

Editorial comment to the manuscript "Minimal invasive approach of post-MI ventricular septal defect repair and coronary artery revascularization via left anterior minithoracotomy".

Authors are to be congratulated for their successful minimally invasive treatment of the infarction VSD via left anterior minithoracotomy, coupled with LIMA grafting to the LAD. It should be stressed that authors encountered an “optimal” infarction VSD, in an obvious subacute stage, with haemodynamic stabilization after 3 days of drug treatment. Such a stabilization period is hardly possible in an acute infarction VSD, which quickly progresses to a profound heart failure without surgical closure.1 But readers should credit the authors with a remarkable surgical dexterity, first for their dealing with the cannulation, administration of cardioplegia, and controlling pulmonary venous return when working only from the small anterior thoracotomy; and for their decision to harvest LIMA through the anterior thoracotomy. This approach makes LIMA harvesting much simpler2 and is used by many surgeons in minimally invasive off-pump CABG.

Strategies to Improve Survival from Surgery for Heart Valve Implantation in Sheep.

Sheep are a commonly used and validated model for cardiovascular research and, more specifically, for heart valve research. Implanting a heart valve on the arrested heart in sheep is complex and is often complicated by difficulties in restarting the heart, causing significant on-table mortality. Therefore, optimal cardioprotective management during heart valve implantation in sheep is essential. However, little is known about successful cardioprotective management techniques in sheep. This article reports our experience in the cardioprotective management of 20 female sheep that underwent surgical aortic valve replacement with a stented tissue-engineered heart valve prosthesis. During this series of experiments, we modified our cardioprotection protocol to improve survival. We emphasize the importance of total body hypothermia and external cooling of the heart. Furthermore, we recommend repeated cardioplegia administration at 20 min intervals during surgery, with the final dosage of cardioplegia given immediately before the de-clamping of the aorta. To reduce the number of defibrillator shocks during a state of ventricular fibrillation (VF), we have learned to restart the heart by reclamping the aorta, administering cardioplegia until cardiac arrest, and de-clamping the aorta thereafter. Despite these encouraging results, more research is needed to finalize a protocol for this procedure.

COMPARISON OF THE EFFECT OF ANTEGRADE AND ANTEGRADE/RETROGRADE CARDIOPLEGIA ON THE OUTCOME OF CORONARY ARTERY BYPASS GRAFT SURGERY FOR SEVERE CORONARY ARTERY DISEASE

Objective: To compare the early outcome of Coronary Artery Bypass Graft surgery using a combination of antegrade and retrograde cardipoplegia with that utilizing antegrade cardioplegia alone in triple vessel coronary artery disease.&#x0D; Study Design: Comparative cross-sectional study.&#x0D; Place and Duration of Study: Department of Adult Cardiac Surgery of Armed Forces Institute of Cardiology and National Institute of Heart Diseases, Rawalpindi, from Sep 2013 to Apr 2019.&#x0D; Methodology: A total of 160 patients with triple vessel coronary artery disease who underwent CABG surgery for 90% or greater stenos is in at least one major vessel in each of the three territories, namely the left anterior descending, the circumflex and the right coronary artery were investigated retrospectively. These were divided into 2 equal groups on the basis of the technique of administration of cardioplegia: in group-1 only ante grade blood cardioplegia was administered for myocardial protection and group-2 was given ante grade and retrograde cardiolplegia. Clinical outcomes like peri-operative mortality and morbidity were recorded, and serum creatine kinase MB, lactate, and mixed venous oxygen saturation levels were monitored. Two dimensional echocardiogram was performed on the 6th post-operative day and follow-up visits were planned 1 week and 4 weeksafter discharge from hospital.&#x0D; Results: There were 2 (2.5%) early deaths in group-1 and no peri-operative mortality in group-2. Five patients in group-1 (6.25%) and 2 (2.5%) in group-2 had non-fatal peri-operative myocardial infarction. However, significant differences included increased incidence of intra-operative ventricular dysrythmias, higher CK-MB levels at 24 hours after surgery, and increased requirement of intra-aortic balloon pump and inotropic support in Group-1.&#x0D; Conclusion: We conclude from this study that the combined delivery of ante grade and retrograde cardioplegia during CABG surgery for triple vessel coronary artery disease provides better myocardial protection and hence better outcome than antegrade cardioplegia alone.Keywords: , , ,

Myocardial oxygen consumption during histidine-tryptophan-ketoglutarate cardioplegia in young human hearts.

Energy demand and supply need to be balanced to preserve myocardial function during paediatric cardiac surgery. After a latent aerobic period, cardiac cells try to maintain energy production by anaerobic metabolism and by extracting oxygen from the given cardioplegic solution. Myocardial oxygen consumption (MVO2) changes gradually during the administration of cardioplegia. MVO2 was measured during cardioplegic perfusion in patients younger than 6 months of age (group N: neonates; group I: infants), with a body weight less than 10 kg. Histidine-tryptophan-ketoglutarate crystalloid solution was used for myocardial protection and was administered during a 5-min interval. To measure pO2 values during cardioplegic arrest, a sample of the cardioplegic fluid was taken from the inflow line before infusion. Three fluid samples were taken from the coronary venous effluent 1, 3 and 5 min after the onset of cardioplegia administration. MVO2 was calculated using the Fick principle. The mean age of group N was 0.2 ± 0.09 versus 4.5 ± 1.1 months in group I. The mean weight was 3.1 ± 0.2 versus 5.7 ± 1.6 kg, respectively. MVO2 decreased similarly in both groups (min 1: 0.16 ± 0.07 vs 0.36 ± 0.1 ml/min; min 3: 0.08 ± 0.04 vs 0.17 ± 0.09 ml/min; min 5: 0.05 ± 0.04 vs 0.07 ± 0.05 ml/min). We studied MVO2 alterations after aortic cross-clamping and during delivery of cardioplegia in neonates and infants undergoing cardiac surgery. Extended cardioplegic perfusion significantly reduces energy turnover in hearts because the balance procedures are both volume- and above all time-dependent. A reduction in MVO2 indicates the necessity of a prolonged cardioplegic perfusion time to achieve optimized myocardial protection.