Form Of Mechanical Circulatory Support Research Articles

Intraaortic Balloon Pump Counterpulsation, Part I: History, Technical Aspects, Physiologic Effects, Contraindications, Medical Applications/Outcomes.

Intraaortic balloon pump counterpulsation is the most common form of mechanical circulatory support used in patients with myocardial ischemia and cardiogenic shock. The physiologic principles of counterpulsation include diastolic augmentation of aortic pressure and systolic reduction of left ventricular afterload, resulting in hemodynamic benefits through increased coronary perfusion pressure and improved myocardial oxygen balance in patients with myocardial ischemia. Major trials have failed to conclusively demonstrate improvements in morbidity and mortality with counterpulsation therapy for patients with acute myocardial infarction (MI), cardiogenic shock, and/or severe coronary artery disease undergoing revascularization therapy, and the debate over its applications continues. Part I of this review focuses on the history of the development of counterpulsation, technical considerations, and complications associated with its use, its physiologic effects, and evidence for its use in myocardial ischemia and cardiogenic shock.

Simulation training on bedside veno-arterial extracorporeal membrane oxygenation decannulation.

Veno-arterial extracorporeal membrane oxygenation is a form of mechanical circulatory support for patients with refractory decompensated heart failure. Blood is drawn from a large vein and pumped back to a large artery, usually a femoral artery through large bore catheters. When the heart recovers, the extracorporeal membrane oxygenation support can be terminated and the catheters are decannulated. The bleeding at the venous side can be controlled by prolonged compression; however, the arteriotomy wound needs to be repaired. Conventionally, the arteriotomy wounds require open vascular repair in the operating theater. The novel application of percutaneous vascular closure devices, which have been commonly used in vascular operations and percutaneous structural heart interventions, could be applied for closure of arteriotomy wounds at the bedside after extracorporeal membrane oxygenation support. The post-close ProGlide (Abbott Vascular) technique was shown to be safe and could potentially save time and manpower. The wounds are much smaller as compared with the conventional open repair and potentially, the chance of wound infection can be reduced. However, the success of percutaneous bedside closure requires careful prior planning and technique training. Backup plans with vascular surgeons' standby are essential in case of failure of closure. Staffs in the extracorporeal membrane oxygenation centers need to be familiar with the preparation, the procedure as well as the device application technique for successful percutaneous closure. The long learning curve and the limited case load mean that such skills are best trained by simulation scenarios. This article described how this new technique and the team logistics can be trained by simulation.

Highlights From the Circulation Family of Journals.

Highlights From the Circulation Family of Journals.

Current Role of the Total Artificial Heart in the Management of Advanced Heart Failure.

The total artificial heart (TAH) is a form of mechanical circulatory support that involves resection of the native ventricles followed by placement of a device that can restore total pulmonary and systemic flow. Given the increasing burden of congestive heart failure and cardiovascular disease, the number of people in need of cardiac replacement therapy will continue to grow. Despite aggressive efforts to expand the donor pool, the number of heart transplants in the United States (US) has plateaued at less than 3000 per year. In addition, there is increasing recognition of the long-term complications of current generation left ventricular assist devices such as progressive aortic insufficiency, complications related to blood trauma, and both early and delayed right ventricular failure. These factors may serve to expand the role of the TAH in the treatment of patients with end-stage heart failure particularly if new generation devices are developed that are durable, have an improved safety profile, and are totally implantable. PURPOSE OF REVIEW: To review the role and current evidence of the use of the TAH in the management of advanced heart failure and discuss development of recent TAHs that may have an impact on the field in the near future. RECENT FINDINGS: Many patients that receive a heart transplant are bridged with a mechanical support device, most commonly a left ventricular assist device (LVAD). However, there is a small subset of patients with profound biventricular (BV) failure or structural abnormalities that preclude LVAD placement, who will require support with a biventricular assist device (BiVAD) or TAH. There are numerous studies showing the efficacy of the TAH in bridging to transplantation. Also, recent studies have shown equal rates of bridging to transplantation between patients receiving a TAH compared to a BiVAD. However, BiVAD support has a higher incidence of stroke in addition to complications related to the native heart such as arrhythmias and valve dysfunction. Currently, there are multiple new generation artificial hearts in both preclinical development and in clinical trials for both bridge to transplant and destination therapy. TAH have been shown to be effective for circulatory support in select patients with end-stage heart failure. Current LVADs are associated with significant long-term complications related to retention of the native heart and pump design. Many of these complications may be addressed by the increased use of cardiac replacement therapy, i.e., total artificial hearts. Multiple generations of both pulsatile and advanced design continuous flow TAH are under development which have the potential to expand the role of TAHs.

Initial United Kingdom experience with the syncardia total artificial heart

Introduction The SynCardia Total Artificial Heart (TAH) is a form of mechanical circulatory support where the patient's native ventricles and valves are explanted and replaced by a pneumatically powered artificial heart (1). Implantation is indicated in patients with irreversible biventricular cardiac failure (2). We have recently initiated a TAH program at Harefield Hospital for the UK patient population. The aim of this study is to review our initial experience in terms of success rate of bridging patients to transplantation and post cardiac transplant outcomes. Methods We analysed data from all patients who received a TAH from July 2014 until April 2019 at our institution to quantify the rate of successful bridging to transplantation and the subsequent post cardiac transplant outcomes. Results 22patients (males, n = 14; mean age 39 ± 17) received TAH implants due to severe, irrecoverable biventricular failure. Aetiologies were dilated (n = 11, 50%), ischaemic (n = 6, 27%) and valvular (n = 3, 13%) cardiomyopathies. 12 patients (55%) were on veno-arterial extra corporeal membrane oxygen support with mean duration of 8.3 ± 8.6 days prior to TAH implantation. Mean duration on TAH support was 95 ± 114 days. 7 patients (32%) suffered stroke, 8 (36%) required surgical exploration for bleeding and 7 (32%) developed sepsis. 9 patients (40%) were successfully bridged to and received a heart transplant, another 3 patients are on the waiting list. 6 patients (27%) are still living: 3 post heart transplantation and 3 remain on the waiting list for a heart transplant. Discussion We have successfully introduced The TAH program in the UK as an important and unique intervention for a high risk patient population with biventricular heart failure who are not candidates for left ventricular assist device. Despite high rate of perioperative and early mortality and postoperative complications TAH implantation provides a realistic alternative for these otherwise futile cases.

Hemodynamic Effects of Mechanical Circulatory Support Devices in Ventricular Septal Defect

Ventricular septal defect (VSD) is a lethal complication of acute myocardial infarction (AMI) and is often associated with cardiogenic shock. The optimal form of percutaneous mechanical circulatory support (MCS) for AMI-VSD is unknown. We used a previously validated cardiovascular model to simulate AMI-VSD with parameters adjusted to replicate average hemodynamics reported in the literature, including a pulmonary-to-systemic blood flow ratio of 3.0. We then predicted effects of different types of percutaneous MCS (including intra-aortic balloon pumping, Impella, TandemHeart, and extracorporeal membrane oxygenation) on pressures and flows throughout the cardiovascular system. The simulation replicated all major hemodynamic parameters reported in the literature with AMI-VSD. Inotropes and vasopressors worsened left-to-right shunting, whereas vasodilators decreased shunting at the expense of worsening hypotension. All MCS devices increased forward blood flow and arterial pressure but other effects varied among devices. Impella 5.0 provided the greatest degree of pulmonary capillary wedge pressure reductions and decreased left-to-right shunting. Extracorporeal membrane oxygenation worsened pulmonary capillary wedge pressure and shunting, which could be improved by adding Impella or passive left ventricular vent. Pulmonary-to-systemic blood flow ratio could not be reduced below 2.0, and pulmonary flows remained high with all forms of MCS. Although no form of percutaneous MCS normalized hemodynamics in AMI-VSD, pulmonary capillary wedge pressure and shunting were worsened by extracorporeal membrane oxygenation and improved by Impella. Accordingly, based on hemodynamics alone, Impella provides the optimal form of support in AMI-VSD. However, other factors, including team experience, device availability, potential for tissue ingestion, and clinical characteristics, need to be considered when choosing a percutaneous MCS device for AMI-VSD.

Left Ventricular Unloading During Extracorporeal Membrane Oxygenation in Patients With Cardiogenic Shock

BackgroundVenoarterial extracorporeal membrane oxygenation (VA-ECMO) is a widely used form of mechanical circulatory support in patients with refractory cardiogenic shock. A common drawback of this modality is a resultant increase in left ventricular afterload. ObjectivesThe purpose of this meta-analysis was to examine the efficacy and safety of left ventricular unloading strategies during VA-ECMO in adult patients with cardiogenic shock. MethodsThe authors performed a systematic search of studies examining left ventricular unloading during VA-ECMO in Medline, EMBASE, and the Cochrane library. The primary outcome was all-cause mortality. Secondary outcomes included limb ischemia, bleeding, need for renal replacement therapy, multiorgan failure, stroke or transient ischemic attack, and hemolysis. ResultsOf 2,221 publications identified, 17 observational studies met the inclusion criteria. In total, outcomes in 3,997 patients were included with 1,696 (42%) receiving a concomitant left ventricular unloading strategy while on VA-ECMO (intra-aortic balloon pump 91.7%, percutaneous ventricular assist device 5.5%, pulmonary vein or transseptal left atrial cannulation 2.8%). There were 2,412 deaths (60%) in the total cohort. Mortality was lower in patients with (54%) versus without (65%) left ventricular unloading while on VA-ECMO (risk ratio: 0.79; 95% confidence interval: 0.72 to 0.87; p < 0.00001). Hemolysis was higher in patients who underwent VA-ECMO with left ventricular unloading. Otherwise, secondary outcomes were not demonstrably different in patients treated with VA-ECMO with versus without left ventricular unloading. ConclusionsIn observational studies, left ventricular unloading was associated with decreased mortality in adult patients with cardiogenic shock treated with VA-ECMO. In the absence of prospective randomized data, left ventricular unloading may be considered for appropriately selected patients undergoing VA-ECMO support.

Extracorporeal Cardiopulmonary Resuscitation (ECPR): Initiation and Surgical Technique in the Pediatric Population

Surgical outcomes in the field of congenital heart surgery have dramatically improved over the last several decades. This success has led to sicker and more complex children presenting for major corrective surgery. Extracorporeal cardiopulmonary resuscitation (ECPR) in form of mechanical circulatory support that has become an integral service of most congenital heart programs; the concept of ECPR is essentially the rapid and effective initiation of extracorporeal membrane oxygenation (ECMO), usually at the bedside and often on an infant who has just undergone repair of a complex congenital heart defect. The financial resources and personnel that must be dedicated to an ECPR program exceed those of routine ECMO programs and must be justified relative to the surgical complexity that a particular institution chooses to offer its patients. With the appropriate dedication of resources and personnel, ECPR has been shown to improve postoperative survival as compared to outcomes when this service is not available.

Extracorporeal membrane oxygenation (ECMO) for heart failure in children: a review of current practice

Abstract Mechanical circulatory support (MCS) is a valuable treatment modality for a small proportion of children with heart failure who are refractory to conventional medical management. Advances in MCS technology, particularly in recent times with the advent of ventricular assist devices (VADs) has made it possible to offer life support for this diverse population. ECMO has historically been used to provide temporary support for children with heart failure either as a bridge to recovery and occasionally as a bridge to heart transplantation, particularly in the pre-VAD era. In contemporary practice, ECMO may be used in refractory end-stage heart failure with end-organ dysfunction as a bridge to decision regarding transplant candidacy or as a bridge to a durable MCS device pending recovery of other end-organ dysfunction. The management of a child supported on ECMO is complex and requires multidisciplinary expertise. Ensuring optimal conditions for myocardial rest and recovery whilst mitigating for complications remains challenging. Cumulative experience has shown that although survival has improved there are a growing number of ECMO survivors in need of long-term follow-up. In this review, we will focus on children with systolic heart failure requiring ECMO as a form of MCS given the established role of VADs in paediatric heart failure.

Prognostic Value of Electrocardiography in Patients With Fulminant Myocarditis Supported by Percutaneous Venoarterial Extracorporeal Membrane Oxygenation - Analysis From the CHANGE PUMP Study.

Fulminant myocarditis (FM) presents various abnormal findings on ECG, the prognostic impact of which has not been not fully elucidated. The aim of this study was therefore to clarify the prognostic value of ECG data in FM patients supported by venoarterial extracorporeal membrane oxygenation (VA-ECMO).Methods and Results:In this multicenter chart review, we investigated 99 patients with FM supported by VA-ECMO. The final cohort consisted of 87 patients (mean age, 52±16 years; female, 42%) after 12 patients who required conversion to other forms of mechanical circulatory support were excluded. The median LVEF was 14.5%. At the time of VA-ECMO initiation, 38 patients (44%) had arrhythmias including atrial fibrillation (6%), complete atrioventricular block (CAVB; 17%), and ventricular tachycardia or fibrillation (VT/VF; 15%). Of the 49 patients with sinus rhythm (SR), 26 had QRS duration ≥120 ms (wide QRS). On logistic regression analysis, wide QRS predicted in-hospital death in patients with SR (OR, 3.6; 95% CI: 1.07-13.61, P=0.04). Compared with SR with narrow QRS (QRS duration <120 ms), CAVB and VT/VF had a higher risk of in-hospital death (CAVB: OR, 7.20; 95% CI: 1.78-34.15, P=0.005; VT/VF: OR, 8.10; 95% CI: 1.86-42.31, P=0.005). In patients with FM, CAVB and VT/VF carried a higher risk of in-hospital death. Wide QRS also predicted a higher risk of in-hospital death in patients with SR.

Clinical pharmacology considerations for children supported with ventricular assist devices.

The ventricular assist device is being increasingly used as a "bridge-to-transplant" option in children with heart failure who have failed medical management. Care for this medically complex population must be optimised, including through concomitant pharmacotherapy. Pharmacokinetic/pharmacodynamic alterations affecting pharmacotherapy are increasingly discovered in children supported with extracorporeal membrane oxygenation, another form of mechanical circulatory support. Similarities between extracorporeal membrane oxygenation and ventricular assist devices support the hypothesis that similar alterations may exist in ventricular assist device-supported patients. We conducted a literature review to assess the current data available on pharmacokinetics/pharmacodynamics in children with ventricular assist devices. We found two adult and no paediatric pharmacokinetic/pharmacodynamic studies in ventricular assist device-supported patients. While mechanisms may be partially extrapolated from children supported with extracorporeal membrane oxygenation, dedicated investigation of the paediatric ventricular assist device population is crucial given the inherent differences between the two forms of mechanical circulatory support, and pathophysiology that is unique to these patients. Commonly used drugs such as anticoagulants and antibiotics have narrow therapeutic windows with devastating consequences if under-dosed or over-dosed. Clinical studies are urgently needed to improve outcomes and maximise the potential of ventricular assist devices in this vulnerable population.

Heparin-induced thrombocytopenia complicating extracorporeal membrane oxygenation support in pediatric patients: review of the literature and alternative anticoagulants.

Heparin-induced thrombocytopenia (HIT) is a prothrombotic, immune-mediated complication of unfractionated heparin (UFH) and low molecular weight heparin therapy. HIT is characterized by moderate thrombocytopenia 5-10 days after initial heparin exposure, detection of platelet-activating anti-platelet factor 4/heparin antibodies and an increased risk of venous and arterial thrombosis. Extracorporeal membrane oxygenation (ECMO) is a form of mechanical circulatory support used in critically ill patients with respiratory or cardiac failure. Systemic anticoagulation is used to alleviate the thrombotic complications that may occur when blood is exposed to artificial surfaces within the ECMO circuit. Therefore, when HIT complicates patients on ECMO support, it is associated with a high thrombotic morbidity and mortality. The following article reviews the current knowledge in pediatric HIT, especially in ECMO patients, and the alternative anticoagulation options in the presence of HIT.

Ovine Leukocyte Microparticles Generated by the CentriMag Ventricular Assist Device In Vitro.

Ventricular assist devices (VADs) are a life-saving form of mechanical circulatory support in heart failure patients. However, VADs have not yet reached their full potential due to the associated side effects (thrombosis, bleeding, infection) related to the activation and damage of blood cells and proteins caused by mechanical stress and foreign materials. Studies of the effects of VADs on leukocytes are limited, yet leukocyte activation and damage including microparticle generation can influence both thrombosis and infection rates. Therefore, the aim was to develop a multicolor flow cytometry assessment of leukocyte microparticles (LMPs) using ovine blood and the CentriMag VAD as a model for shear stress. Ovine blood was pumped for 6 h in the CentriMag and regular samples analyzed for hemolysis, complete blood counts and LMP by flow cytometry during three different pump operating conditions (low flow, standard, high speed). The high speed condition caused significant increases in plasma-free hemoglobin; decreases in total leukocytes, granulocytes, monocytes, and platelets; increases in CD45+ LMPs as well as two novel LMP populations: CD11bbright /HLA-DR- and CD11bdull /HLA-DR+ , both of which were CD14- /CD21- . CD11bbright /HLA-DR- LMPs appeared to respond to an increase in shear magnitude whereas the CD11bdull /HLA-DR+ LMPs significantly increased in all pumping conditions. We propose that these two populations are released from granulocytes and T cells, respectively, but further research is needed to better characterize these two populations.

Early Prediction Model for Successful Bridge to Recovery in Patients With Fulminant Myocarditis Supported With Percutaneous Venoarterial Extracorporeal Membrane Oxygenation - Insights From the CHANGE PUMP Study.

Cardiac recovery and prevention of end-organ damage are the cornerstones of establishing successful bridge to recovery (BTR) in patients with fulminant myocarditis (FM) supported with percutaneous venoarterial extracorporeal membrane oxygenation (VA-ECMO). However, the timing and method of successful BTR prediction still remain unclear. We aimed to develop a prediction model for successful BTR in patients with FM supported with percutaneous VA-ECMO.Methods and Results:This was a retrospective multicenter chart review enrolling 99 patients (52±16 years; female, 42%) with FM treated with percutaneous VA-ECMO. The S-group comprised patients who experienced percutaneous VA-ECMO decannulation and subsequent discharge (n=46), and the F-group comprised patients who either died in hospital or required conversion to other forms of mechanical circulatory support (n=53). At VA-ECMO initiation (0-h), the S-group had significantly higher left ventricular ejection fraction (LVEF) and lower aspartate aminotransferase (AST) concentration than the F-group. At 48 h, the LVEF, increase in the LVEF, and reduction of AST from 0-h were identified as independent predictors in the S-group. Finally, we developed an S-group prediction model comprising these 3 variables (area under the curve, 0.844; 95% confidence interval, 0.745-0.944). We developed a model for use 48 h after VA-ECMO initiation to predict successful BTR in patients with FM.

Impact of a Monoplane Hemodynamic TEE (hTEE) Monitoring Device on Decision Making in a Heterogeneous Hemodynamically Unstable Intensive Care Unit Population: A Prospective, Observational Study

This prospective observational study was undertaken to evaluate the utility of a miniature transesophageal echocardiography probe (ImaCor hemodynamic [hTEE]) in the management of hemodynamically unstable intensive care unit patients with and without various forms of mechanical circulatory support. A prospective observational study. A single tertiary care cardiothoracic and surgical intensive care unit. Fifty-three cardiothoracic and surgical intensive care unit patients undergoing miniature transesophageal echocardiography examinations. All patients had hemodynamic instability as defined by necessity of mechanical circulatory support (MCS) devices or vasoactive medications. From April 2012 to February 2014, 53 hemodynamically unstable intensive care unit patients received an examination with the miniature transesophageal echocardiography probe when deemed necessary by the intensivist for rapid and/or ongoing transesophageal echocardiographic examinations. Twenty-eight of the examinations were performed in patients with MCS devices (53%). The remainder of examinations (n = 25, 47%) were performed in patients after other cardiothoracic surgery or noncardiac surgery with cardiac complications. The measured endpoint was determination of usefulness of management guidance due to the miniature transesophageal echocardiographic examination as assessed by the intensivist caring for the patient. The incidence of hTEE imaging provoking a change in management also was recorded. Overall, of the 53 examinations, 77% (n = 41) provided useful information to the management. Of the 25 examinations in patients without MCS, 92% (n = 23) of the examinations were useful in guiding management. Among the 28 examinations in patients with MCS devices, 64% (n = 18) of examinations were useful in guiding management (odds ratio = 0.156; 95% confidence interval, 0.015-0.899; p = 0.022). Eight of the 53 examinations (15%) were deemed to have "poor image quality" by the echocardiographer. Age, sex, and body mass index did not significantly affect the usefulness of the hTEE examinations. Examination of a heterogeneous hemodynamically unstable intensive care population with a miniature transesophageal echocardiography probe provided useful information beyond standard intensive care unit monitoring data, which influenced post-hTEE medical decision making. The examinations were more useful in patients without MCS devices than in those with MCS. Of the patients with MCS, patients with durable ventricular assist devices had the lowest rate of useful examinations.

Severe respiratory failure and traumatic brain injuries: What do we know?

Extracorporeal membrane oxygenation (ECMO) is a form of mechanical circulatory support that can be lifesaving in people with potentially reversible heart or lung injuries. ECMO is nearly always used urgently, when all other treatment options for cardiopulmonary injury have failed and high mortality is otherwise expected. Standard ECMO treatment involves venous drainage from the femoral vein or left atrium with artificial extra-circulatory oxygen exchange. Return to the body is through the same veins (veno-venous) or arterial system via the femoral artery or ascending aorta (veno-arterial). Compared with cardiopulmonary bypass circuit, ECMO is transportable, smaller, closed to the atmosphere, and can treat a patient for several days to weeks. Neurological consequences of severe respiratory failure and its different management strategies in adults are likely common but uncharacterized and poorly described in the reviewed literature. Development of severe respiratory failure (SRF) occurs in 20–25% of patients with isolated severe traumatic brain injury (TBI) and is associated with a threefold increase in mortality, or patients remaining in a vegetative state.1 It has been attributed mostly to aspiration, infection, neurogenic pulmonary edema, and release of pro-inflammatory mediators into the systemic circulation causing ultrastructural damage in type II pneumocyte.2 This decreases the pulmonary tolerance of subsequent mechanical stress due to mechanical ventilation. Actually, some data suggest that the main feature of ALI/ARDS in brain-injured patients is the presence of a poor oxygenation (reduced PaO2/FiO2 ratio) accompanied by a moderate increase in the elastance of the respiratory system even though these patients had a normal chest X-ray. Ventilatory support for such patients could be difficult with a lot of challenges to keep optimal oxygenation and acceptable level of blood carbon dioxide. It involves the application of positive end-expiratory pressure (PEEP) to recruit collapsed alveoli, improve arterial oxygenation, and reduce elastance of the respiratory system. Although improving oxygenation is a key factor for optimizing O2 delivery to the brain, clinical studies provide contradictory information on the use of PEEP in patients with acute lung injury (ALI) complicating severe brain injury. Furthermore, we tend to use higher tidal volumes in patients with acute brain injury because mild hypocapnia is a key factor in the clinical management of raised intracranial pressure, which is a frequent abnormality in such patients;3,4 this would be an injurious ventilator strategy and may present a further relevant inflammatory stimulus. Moreover, it has been shown that the use of high tidal volumes for the first 48 h after ICU admission is associated with the development of ventilator-induced lung injury.4 In addition, one of the recognized methods in improving oxygenation in SRF patients is the use of prone position, because it improves the lung mechanics and augments oxygenation. Studies have demonstrated that patients with unstable intracranial pressure (ICP) have higher ICP in the horizontal position sideways. Therefore, the recommended position for this patient cohort is a 30-degree head-up tilt combined with a straight head position.4 Furthermore, TBI patients who require ECMO support for their SRF will need full anticoagulation, as the circuit poses considerable derangement in the hemostatic system with increased platelet consumption and a higher risk of intracranial bleeding. There have been several reports of ECMO without anticoagulation therapy, but so far with no evidence or good literature to support this notion.5 Although some controversy and difficulties exist, it seems that multiorgan clinical approach instead of single-organ approach represents the optimal way in clinical management of patients with ALI/SRF and TBI.

Monitoring and complications during neonatal/pediatric ECMO run

Extracorporeal membrane oxygenation (ECMO) is a commonly used form of mechanical circulatory support in children with congenital or acquired heart disease, and cardiac failure refractory to conventional medical treatments.1 The cardiac output is partially or completely provided by the ECMO machine. To assess how much support is needed at any given time, a constant balance of oxygen delivery and oxygen consumption is required. Permanent monitoring of flow, hemoglobin, arterial, and mixed venous saturations are key elements to provide the needed understanding and continuous guidance of body requirements, aiming at controlling and maintaining optimal management of the ECMO patient. Although ECMO is lifesaving in many circumstances, it bares challenges and certain risks of complications. Despite bioline-coated circuits, anticoagulation is required. Measurement of activated clotting time (ACT) and activated partial thromboplastin time (APTT) are both used to guide anticoagulation, but it is unclear which method is the best, and constant monitoring of the hemoglobin level allows the early detection of internal and external bleeding.2 For children, sedation and analgesia, most often in combination with paralysis, is unavoidable for a smooth ECMO run. On the other hand, with such treatment on board, it is almost impossible to assess the neurological status of the patient on ECMO. Different monitoring tools, such as cerebral near infrared spectroscopy (NIRS) and serial brain ultrasound studies, are used to estimate brain integrity and function, but further research is needed to show which methods are the most practical and useful to achieve a favorable outcome.3 Nutrition in critically ill children is known to be crucial but debated how to achieve as the gut perfusion can be impaired and therefore the risk of necrotizing enterocolitis (NEC) is increased. It is discussed if somatic perfusion by NIRS monitoring can help to avoid NEC.4 The kidney function is often impaired in these critically ill children and careful monitoring of kidney function and urine output leads the decision when to start which type of renal replacement therapy for renal clearance and/or fluid removal. Techniques available include peritoneal dialysis or continuous renal replacement therapy (CRRT) incorporated with the ECMO circuit. Medication dosing is under discussion in many centers as the circulatory volume is higher than normal. Adjustment of medication dosing could consequently be of great importance. Close monitoring of medications where toxic levels can be reached is crucial to avoid further damage to the patient's organ functions.

Gastrointestinal Symptoms from Left Ventricular Assist Device External Compression of the Gastric Lumen

Left ventricular assist device (LVAD) implantation is an increasingly prevalent form of mechanical circulatory support as a bridge to heart transplant and as destination therapy. While bleeding remains the most recognized gastrointestinal (GI) adverse event, there have been reports on other complications due to GI tract luminal compression from the device. A 74-year-old man with end-stage ischemic cardiomyopathy underwent LVAD implantation with a Heartmate IITM (Thoratec, Pleasanton, CA, USA) as destination therapy, three years prior to his hospital admission for melena (Figure 1). On review of symptoms, the patient had been endorsing early satiety, intermittent nausea and non-specific abdominal discomfort since LVAD implantation. Esophagogastroduodenoscopy (EGD) and colonoscopy prior to LVAD placement had been unremarkable. EGD revealed moderate external compression of the anterior gastric wall from the LVAD pump and outflow tract with luminal narrowing in the antrum (Figure 2). This was associated with some mild resistance to the maneuvering of the endoscope across the pylorus and into the duodenum. A bleeding angioectasia was found in the second portion of the duodenum and treated. The patient recovered without further episodes of GI bleeding and hemoglobin remained stable.Figure 1Figure 2Figure 3Apart from its increased association with bleeding, the effects of LVAD implantation on the GI system have not been clearly defined. In this case, we speculate that the patient's symptoms of early satiety and nausea coincided with LVAD implantation in the setting of endoscopic evidence of gastric luminal compression and distortion from the device. Overall, while bleeding may be the most commonly encountered GI manifestation in LVAD patients, other potential complications, including luminal compression from the device, should be recognized given the increasing use of these devices.

The Registry of the International Society for Heart and Lung Transplantation: Nineteenth Pediatric Heart Transplantation Report—2016; Focus Theme: Primary Diagnostic Indications for Transplant

The Registry of the International Society for Heart and Lung Transplantation: Nineteenth Pediatric Heart Transplantation Report—2016; Focus Theme: Primary Diagnostic Indications for Transplant

Hemodynamic Transesophageal Echocardiography-Guided Venous-Arterial Extracorporeal Membrane Oxygenation Support in a Case of Giant Cell Myocarditis.

Giant cell myocarditis (GCM) is a rare and commonly fatal form of fulminant myocarditis. During the acute phase, while immunosuppressive therapy is initiated, venoarterial extracorporeal membrane oxygenation (VA-ECMO) support is commonly used as a bridge to heart transplantation or recovery. Until recently, conventional transesophageal echocardiography and transthoracic echocardiography were the tools available for hemodynamic assessment of patients on this form of mechanical circulatory support. Nevertheless, both techniques have their limitations. We present a case of a 54-year-old man diagnosed with GCM requiring VA-ECMO support that was monitored under a novel miniaturized transesophageal echocardiography (hTEE) probe recently approved for 72 hours of continuous hemodynamic monitoring. Our case highlights the value of this novel, flexible, and disposable device for hemodynamic monitoring, accurate therapy guidance, and potential VA-ECMO weaning process of patients with this form of severe myocarditis.