Clinical Predictors and Outcomes After Left Ventricular Assist Device Implantation and Tracheostomy.

BACKGROUND: Postoperative respiratory failure is a major complication that affects up to 10% of patients who undergo cardiac surgery and has a high in-hospital mortality rate. Few studies have investigated whether patients who require tracheostomy for postoperative respiratory failure after continuous-flow left ventricular assist device (CF-LVAD) implantation have worse survival outcomes than patients who do not. OBJECTIVE: To identify risk factors for respiratory failure necessitating tracheostomy in CF-LVAD recipients and to compare survival outcomes between those who did and did not require tracheostomy. METHODS: Consecutive patients who underwent primary CF-LVAD placement at a single institution between August 1, 2002, and December 31, 2019, were retrospectively reviewed. Propensity score matching accounted for baseline differences between the tracheostomy and nontracheostomy groups. Multivariate logistic regression was used to identify tracheostomy risk factors and 90-day survival; Kaplan-Meier analysis was used to assess midterm survival. RESULTS: During the study period, 664 patients received a CF-LVAD; 106 (16.0%) underwent tracheostomy for respiratory failure. Propensity score matching produced 103 matched tracheostomy-nontracheostomy pairs. Patients who underwent tracheostomy were older (mean [SD] age, 57.9 [12.3] vs 54.6 [13.9] years; P = .02) and more likely to need preoperative mechanical circulatory support (61.3% vs 47.8%; P = .01) and preoperative intubation (27.4% vs 8.8%; P < .001); serum creatinine was higher in the tracheostomy group (mean [SD], 1.7 [1.0] vs 1.4 [0.6] mg/dL; P < .001), correlating with tracheostomy need (odds ratio, 1.76; 95% CI, 1.21-2.56; P = .003). Both before and after propensity matching, 30-day, 60-day, 90-day, and 1-year survival were worse in patients who underwent tracheostomy. Median follow-up was 0.8 years (range, 0.0-11.2 years). Three-year Kaplan-Meier survival was significantly worse for the tracheostomy group before (22.0% vs 61.0%; P < .001) and after (22.4% vs 48.3%; P < .001) matching. CONCLUSION: Given the substantially increased probability of death in patients who develop respiratory failure and need tracheostomy, those at high risk for respiratory failure should be carefully considered for CF-LVAD implantation. Comprehensive management to decrease respiratory failure before and after surgery is critical.

The Evolution of Durable, Implantable Axial-Flow Rotary Blood Pumps.

Left ventricular assist devices (LVADs) are increasingly used to treat patients with end-stage heart failure. Implantable LVADs were initially developed in the 1960s and 1970s. Because of technological constraints, early LVADs had limited durability (eg, membrane or valve failure) and poor biocompatibility (eg, driveline infections and high rates of hemolysis caused by high shear rates). As the technology has improved over the past 50 years, contemporary rotary LVADs have become smaller, more durable, and less likely to result in infection. A better understanding of hemodynamics and end-organ perfusion also has driven research into the enhanced functionality of rotary LVADs. This paper reviews from a historical perspective some of the most influential axial-flow rotary blood pumps to date, from benchtop conception to clinical implementation. The history of mechanical circulatory support devices includes improvements related to the mechanical, anatomical, and physiologic aspects of these devices. In addition, areas for further improvement are discussed, as are important future directions-such as the development of miniature and partial-support LVADs, which are less invasive because of their compact size. The ongoing development and optimization of these pumps may increase long-term LVAD use and promote early intervention in the treatment of patients with heart failure.

Ex situ heart perfusion for optimization of pediatric donor organ utilization: Attitudes and perceptions.

BACKGROUND: Children with heart failure have the highest mortality while awaiting transplantation. Ex situ heart perfusion (ESHP), a method for continuous perfusion of the donor heart, has the potential to improve access to transplant by increasing travel distance between donor and recipient. An adult ESHP device is currently available, but as of yet there is no pediatric device. The aim of this study was to evaluate current knowledge of ESHP among pediatric heart transplant practitioners, define potential barriers, and identify uses of this novel technology. METHODS: An electronic survey was developed to assess perspectives of international pediatric heart transplant stakeholders (n = 68) on ESHP. Select questions were analyzed to evaluate for associations between groups of respondents and patterns of response. RESULTS: Most respondents were familiar but <10% had clinically utilized ESHP. There was optimism that ESHP could decrease waitlist mortality. Respondents were concerned about potential device malfunction and lack of long-term outcomes. There were no differences found in terms of ESHP familiarity among age groups, practitioner center volume, country of work, or discipline. CONCLUSIONS: ESHP has the potential to expand the pediatric heart donor pool and decrease waitlist mortality. More education on outcomes and risks/benefits is needed in order to promote widespread adoption.

Clinical and Economic Evaluation of Impella Treatment for Fulminant Myocarditis　- A Preliminary Retrospective Cohort Study in Japan.

BACKGROUND: Fulminant myocarditis (FM) is rare but has an extremely poor prognosis. Impella, a catheter-based heart pump, is a new therapeutic strategy, but reports regarding its health economics are lacking.Methods and Results: This retrospective cohort study compared Impella treatment (Group I) with existing treatments (Group E) using medical data collected from October 2017 to September 2021, with a 1-year analysis period. Cost-effectiveness indices were life-years (LY; effect index) and medical fee amount (cost index). Results were validated using probabilistic sensitivity analysis. The incremental cost-effectiveness ratio (ICER) was calculated using quality-adjusted LY (QALY) and medical costs. Each group included 7 patients, and more than half (57.1%) received combined Impella plus extracorporeal membrane oxygenation. There was no significant difference between Groups I and E in 1-year mortality rates (28.6% vs. 57.1%, respectively) or LY (mean [±SD] 163.1±128.3 vs. 107.8±127.3 days, respectively), but mortality risk was significantly lower in Group I than Group E (95% confidence interval 0.02-0.96; P<0.05). Compared with Group E, Group I had higher total costs (9,270,597±4,121,875 vs. 6,397,466±3,801,364 JPY/year; P=0.20) and higher cost-effectiveness (32,443,987±14,742,966 vs. 92,637,756±98,225,604 JPY/LY; P=0.74), which was confirmed in the sensitivity analysis. ICER probability distribution showed 23.2% and 51.5% reductions below 5 million and 10 million JPY/QALY, respectively. CONCLUSIONS: Impella treatment is more cost-effective than conventional FM treatments. Large-scale studies are needed to validate the added effects and increasing costs.

Risk factors and predictive analysis of hyperkalemia after heart transplantation / 器官移植

Objective To analyze clinical prognosis, risk factors and predictive indexes of hyperkalemia in recipients after heart transplantation. Methods Clinical data of 158 recipients were retrospectively analyzed. According to the serum potassium levels within postoperative 1-year follow-up, all recipients were divided into the normal serum potassium level group (n=83), hyperkalemia group (n=43) and severe hyperkalemia group (n=32). The incidence and prognosis of hyperkalemia after heart transplantation were summarized. The risk factors and predictive indexes of hyperkalemia after heart transplantation were identified. Results The incidence of hyperkalemia and severe hyperkalemia within postoperative 1 year was 47.5%(75/158) and 20.3%(32/158), respectively. In the severe hyperkalemia group, the fatality was 16%(5/32), higher than 8%(7/83) in the normal serum potassium level group and 7%(3/43) in the hyperkalemia group. The mean serum creatinine (Scr) within 6 months before heart transplantation, the final total bilirubin level before heart transplantation, postoperative hemodialysis time, the Scr level and N-terminal pro-brain natriuretic peptide level at postoperative 1 d were the independent risk factors for hyperkalemia following heart transplantation (all P < 0.05). The mean Scr level within 6 months before heart transplantation, postoperative hemodialysis time, and Scr levels at postoperative 1 and 7 d could be used to predict postoperative severe hyperkalemia. Conclusions The recipients with severe hyperkalemia after heart transplantation obtain poor prognosis. The mean Scr level within 6 months before heart transplantation, the final total bilirubin level before heart transplantation, postoperative hemodialysis time, and the Scr level and N-terminal pro-brain natriuretic peptide level at postoperative 1 d are the independent risk factors for hyperkalemia after heart transplantation. Perioperative Scr level and postoperative hemodialysis time may be used to predict the incidence of severe hyperkalemia within 1 year after heart transplantation.

An ex vivo comparison of partial thromboplastin time and activated clotting time for heparin anticoagulation in an ovine model.

BACKGROUND: Sheep are a primary model of mechanical circulatory support (MCS) with heparin anticoagulation therapy frequently being monitored by activated clotting time (ACT) due to ease and cost. In patients undergoing long-term heparin therapy, other anticoagulation monitoring strategies, such as activated partial thromboplastin time (aPTT), have proven to be more reliable indicators for the adequacy of anticoagulation, frequently determined by heparin concentration. As there is a paucity of similar studies in sheep, we sought to investigate the correlation between heparin concentration and ACT and aPTT using whole sheep blood in an ex vivo model. METHODS: Fresh whole blood was serially drawn from an adult female Dorset-hybrid sheep and aliquots were placed into tubes containing heparin saline solutions with concentrations ranging from 0 to 7.81 U heparin per mL of whole blood. ACT and aPTT values were measured on each of the samples. The experiment was performed four times with the same animal. A simple linear regression was performed to determine correlation, and subgroup analysis was performed on low versus high heparin concentrations typically seen in human patients on long-term MCS, such as extracorporeal membrane oxygenation (ECMO), versus cardiopulmonary bypass, respectively. RESULTS: aPTT measurements versus the heparin concentration had an R2  = 0.7295. ACT measurements versus the heparin concentration had a R2  = 0.4628. aPTT measurements versus the ACT measurements had a R2  = 0.2974. The strength of the correlation between aPTT and heparin concentration increased at low heparin concentrations (R2  = 0.8392). CONCLUSION: aPTT had a more reliable correlation to heparin concentration and thus anticoagulation level than ACT. This was particularly true at lower heparin concentrations, similar to ranges seen for patients on ECMO. The correlation between aPTT and ACT values was poor. Further in vivo studies should be performed to confirm our results.

Angiotensin receptor neprilysin inhibitor use in patients with left ventricular assist devices: A single-center experience.

Though left ventricular assist devices (LVADs) are an increasingly common therapy for ACC/AHA Stage D heart failure, the optimal medical therapy for patients with LVADs is not known. We sought to evaluate the safety and efficacy of angiotensin receptor neprilysin inhibitor (ARNi) therapy in our single center LVAD patient experience. We evaluated patients implanted with LVADs at Columbia University Irving Medical Center between August 2010 and May 2019, and who were treated with an ARNi for at least 3 months. Thirty patients met this criteria. Eighteen (60%) patients transitioned to an ARNi from an angiotensin-converting enzyme inhibitor (ACEi) or angiotensin receptor blocker (ARB), while all were on a beta blocker (BB) at the time of ARNi initiation. The primary outcome, NT-proBNP levels at time of initiation and 3 and 6 month follow up, significantly decreased from a median of 1265 pg/mL at initiation to 750 pg/mL at 3 months and 764 pg/mL at 6 months (p = 0.01). No significant change was seen in serum creatinine, BUN, or potassium levels.

Neutrophil dysfunction due to continuous mechanical shear exposure in mechanically assisted circulation in vitro.

OBJECTIVE: Leukocytes play an important role in the body's immune system. The aim of this study was to assess alterations in neutrophil phenotype and function in pump-assisted circulation in vitro. METHODS: Human blood was circulated for four hours in three circulatory flow loops with a CentriMag blood pump operated at a flow of 4.5 L/min at three rotational speeds (2100, 2800, and 4000 rpm), against three pressure heads (75, 150, and 350 mm Hg), respectively. Blood samples were collected hourly for analyses of neutrophil activation state (Mac-1, CD62L, CD162), neutrophil reactive oxygen species (ROS) production, apoptosis, and neutrophil phagocytosis. RESULTS: Activated neutrophils indicated by both Mac-1 expression and decreased surface expression of CD62L and CD162 receptors increased with time in three loops. The highest level of neutrophil activation was observed in the loop with the highest rotational speed. Platelet-neutrophil aggregates (PNAs) progressively increased in two loops with lower rotational speeds. PNAs peaked at one hour after circulation and decreased subsequently in the loop with the highest rotational speed. Neutrophil ROS production dramatically increased at one hour after circulation and decreased subsequently in all three loops with similar levels and trends. Apoptotic neutrophils increased with time in all three loops. Neutrophil phagocytosis capacity in three loops initially elevated at one hour after circulation and decreased subsequently. Apoptosis and altered phagocytosis were dependent on rotational speed. CONCLUSIONS: Our study revealed that the pump-assisted circulation induced neutrophil activation, apoptosis, and functional impairment. The alterations were strongly associated with pump operating condition and duration.

The contribution of cardiac and extracardiac factors to NT-proBNP concentrations in patients with advanced heart failure before and after left ventricular assist device implantation.

The clinical significance of N-terminal pro-brain natriuretic peptide (NT-proBNP) in patients undergoing left ventricular assist device (LVAD) implantation is not fully explored. NT-proBNP concentrations are influenced by body composition, renal function and intracardiac pressures; dynamic measures pre- and post-LVAD implantation. We sought to identify the individual contribution of cardiac and extracardiac factors to NT-proBNP concentrations in advanced heart failure patients before and after LVAD implantation. We retrospectively collected data from 63 patients implanted with a LVAD with NT -proBNP measurements (2006-2019). Hemodynamic measurements were obtained through right heart catheterization (RHC). Univariable linear regression and multivariable stepwise regression models were used to analyze variables associated with NT-proBNP concentrations in the pre- and post-LVAD setting. Paired t-test was performed on a subpopulation of 13 patients with complete data. We found significant differences in all extracardiac (BMI, creatinine, eGFR) and all invasive hemodynamic measurements pre-LVAD compared to post-LVAD. NT-proBNP decreased by 83 %, in the subpopulation of 13 patients: 736 pmol/L [IQR 498-1330] to 126 pmol/L [IQR 74.8-241.7]. In multivariable analysis, only creatinine remained significantly associated with NT-proBNP before LVAD implant (p = 0.016), whereas pulmonary capillary wedge pressure (PCWP) was the only independent variable associated with NT-proBNP after LVAD implant (p < 0.0001). Creatinine and PCWP were the only independent factors associated with NT-proBNP concentrations before and after LVAD implantation, respectively. Invasive hemodynamic measurements were more closely associated with NT-proBNP concentration after LVAD than extracardiac factors and reversely pre-LVAD, suggesting that NT-proBNP serves as a useful biomarker of cardiac conditions post-LVAD implantation.

Left atrial assist device function at various heart rates using a mock circulation loop.

We are developing a new left atrial assist device (LAAD) for patients who have heart failure with preserved ejection fraction (HFpEF). This study aimed to assess the hemodynamic effects of the LAAD under both normal heart conditions and various diastolic heart failure (DHF) conditions using a mock circulatory loop. A continuous-flow pump that simulates LAAD, was placed between the left atrial (LA) reservoir and a pneumatic ventricle that simulated a native left ventricle on a pulsatile mock loop. Normal heart (NH) and mild, moderate, and severe DHF conditions were simulated by adjusting the diastolic drive pressures of the pneumatic ventricle. With the LAAD running at 3200 rpm, data were collected at 60, 80, and 120 bpm of the pneumatic ventricle. Cardiac output (CO), mean aortic pressure (AoP), and mean LA pressure (LAP) were compared to evaluate the LAAD performance. With LAAD support, the CO and AoP rose to a sufficient level at all heart rates and DHF conditions (CO; 3.4-3.8 L/min, AoP; 90-105 mm Hg). Each difference in the CO and the AoP among various heart rates was minuscule compared with non-pump support. The LAP decreased from 21-23 to 17-19 mm Hg in all DHF conditions (difference not significant). Furthermore, hemodynamic parameters improved for all DHF conditions, independent of heart rate. The LAAD can provide adequate flow to maintain the circulation status at various heart rates in an in vitro mock circulatory loop.

Value of Hemodynamic Monitoring in Patients With Cardiogenic Shock Undergoing Mechanical Circulatory Support.

The recent widespread availability and use of mechanical circulatory support is transforming the management and outcomes of cardiogenic shock (CS). Clinical decision-making regarding the optimization of therapies for patients with CS can be guided effectively by hemodynamic monitoring with a pulmonary artery catheter (PAC). Because several studies regarding the benefit of PACs are ambiguous, the use of PACs is variable among clinicians treating patients with CS. More notable is that PAC use has not been studied as part of a randomized, controlled trial in patients with CS with or without mechanical circulatory support. Standardized approaches to hemodynamic monitoring in these patients can improve decision-making and outcomes. In this review, we summarize the hemodynamics of CS and mechanical circulatory support with PAC-derived measurements, and provide a compelling rationale for the use of PAC monitoring in patients with CS receiving mechanical circulatory support.

Use of a Virtual Mock Loop model to evaluate a new left ventricular assist device for transapical insertion.

We are developing a novel type of miniaturized left ventricular assist device that is configured for transapical insertion. The aim of this study was to assess the performance and function of a new pump by using a Virtual Mock Loop system for device characterization and mapping. The results, such as pressure-flow performance curves, from pump testing in a physical mock circulatory loop were used to analyze its function as a left ventricular assist device. The Virtual Mock Loop system was programmed to mimic the normal heart condition, systolic heart failure, diastolic heart failure, and both systolic and diastolic heart failure, and to provide hemodynamic pressure values before and after the activation of several left ventricular assist device pump speeds (12,000, 14,000, and 16,000 r/min). With pump support, systemic flow and mean aortic pressure increased, and mean left atrial pressure and pulmonary artery pressure decreased for all heart conditions. Regarding high pump-speed support, the systemic flow, aortic pressure, left atrial pressure, and pulmonary artery pressure returned to the level of the normal heart condition. Based on the test results from the Virtual Mock Loop system, the new left ventricular assist device for transapical insertion may be able to ease the symptoms of patients with various types of heart failure. The Virtual Mock Loop system could be helpful to assess pump performance before in vitro bench testing.

Development of a circulatory mock loop for biventricular device testing with various heart conditions.

This study aimed to evaluate a newly designed circulatory mock loop intended to model cardiac and circulatory hemodynamics for mechanical circulatory support device testing. The mock loop was built with dedicated ports suitable for attaching assist devices in various configurations. This biventricular mock loop uses two pneumatic pumps (Abiomed AB5000™, Danvers, MA, USA) driven by a dual-output driver (Thoratec Model 2600, Pleasanton, CA, USA). The drive pressures can be individually modified to simulate a healthy heart and left and/or right heart failure conditions, and variable compliance and fluid volume allow for additional customization. The loop output for a healthy heart was tested at 4.2 L/min with left and right atrial pressures of 1 and 5 mm Hg, respectively; a mean aortic pressure of 93 mm Hg; and pulmonary artery pressure of 17 mm Hg. Under conditions of left heart failure, these values were reduced to 2.1 L/min output, left atrial pressure = 28 mm Hg, right atrial pressure = 3 mm Hg, aortic pressure = 58 mm Hg, and pulmonary artery pressure = 35 mm Hg. Right heart failure resulted in the reverse balance: left atrial pressure = 0 mm Hg, right atrial pressure = 30 mm Hg, aortic pressure = 100 mm Hg, and pulmonary artery pressure = 13 mm Hg with a flow of 3.9 L/min. For biventricular heart failure, flow was decreased to 1.6 L/min, left atrial pressure = 13 mm Hg, right atrial pressure = 13 mm Hg, aortic pressure = 52 mm Hg, and pulmonary artery pressure = 18 mm Hg. This mock loop could become a reliable bench tool to simulate a range of heart failure conditions.

Implante de un dispositivo de asistencia ventricular izquierda definitivo y circulación asistida en cuidados intensivos como terapia puente. Cuidados enfermeros: caso clínico / Permanent left ventricular assistance internal device implantation and assisted circulation in intensive care as bridge therapy. Nursing care: case report

A lo largo de los últimos años la implantación de Dispositivos de Asistencia Ventricular (DAV) está tomando un papel más relevante en el tratamiento de la Insuficiencia Cardíaca (IC). El uso de los DAV también está cambiando hacia la Terapia Definitiva (TD), conformándose como alternativa clara al trasplante cardíaco. La implantación de un DAV, en ocasiones, requiere previamente tratamiento emergente con otros dispositivos de Asistencia Circulatoria Mecánica (ACM) como Circulación Extracorpórea con Membrana de Oxigenación (ECMO) o Asistencia Ventricular paracorpórea Izquierda o Derecha. Por tanto, es necesario el ingreso en Unidades de Cuidados Intensivos (UCI) especializadas en estas terapias hasta la estabilización del paciente y toma de la decisión correcta. Se expone un caso clínico reciente de una persona que requiere asistencia inicial con ECMO V-A emergente en el hospital de origen y su traslado al centro de referencia para posterior asistencia biventricular paracorpórea e implantación definitiva de un DAVI (Dispositivo de Asistencia Ventricular Izquierda). Se exponen la secuencia de decisiones, complicaciones y el plan de cuidados de enfermería inicial en UCI con taxonomía NANDA. Es el primer implante de un DAVI, realizado en nuestro hospital. En él ha intervenido un enorme equipo multidisciplinar.

Over the past few years, the Ventricular Assist Devices (VADs) implementation is taking a relevant role in the Heart Failure (HF) treatment. VADs ́s use is also shifting towards Definitive Therapy (TD), being a clear alternative to heart transplantation. The implantation of a VAD, sometimes, requires a previous emergent treatment with other Mechanical Circulatory Assistance (ACM) devices such as Extracorporeal Circulation with Oxygenation Membrane (ECMO) or Left or Right Paracorporeal Ventricular Assistance. So is necessary of a mobile team for emergency assistance with ECMO and transfer to Intensive Care Units (ICU) which is specialized in these therapies until the patient stabilizes and doctors takes the right decision. A recent clinical case of a patient is exposed. This person required assistance with emergent ECMO V-A (Venous-Arterial) in the hospital of origin and his transfer to the reference center for subsequent biventricular paracorporeal assistance and to the definitive implantation of LVAD (Left Ventricular Assist Device). The sequence of decisions, complications and the initial nursing care plan at ICU with NANDA taxonomy, are presented here. This is the first implant of a LVAD in our hospital. A huge multidisciplinary team has been involved in the project.

Impella-Induced Incessant Ventricular Tachycardia.

Background: The Impella 2.5 and Impella Cardiac Power (CP) devices (ABIOMED) are used to provide mechanical circulatory support for high-risk percutaneous coronary interventions or cardiogenic shock as a bridge to recovery or destination therapy. The Impella device has shown both efficacy and safety in patients presenting with cardiogenic shock. Performing clinical and hemodynamic assessments of patients presenting with cardiogenic shock is an important step to determine if mechanical circulatory support with an Impella device is indicated. Case Report: A 62-year-old male presented with cardiogenic shock requiring Impella device support. Two days later, the patient developed incessant ventricular tachycardia. Transthoracic echocardiography showed that the Impella device had migrated out of the ventricular cavity. Once the position of the Impella device was adjusted, ventricular tachycardia immediately resolved. Conclusion: Our case emphasizes the importance of using imaging modalities such as transthoracic echocardiography to ensure correct positioning of an Impella device in the left ventricle to avoid complications.

Fulminant myocarditis due to the influenza B virus in adults: Report of two cases and literature review / Miocarditis fulminante en adultos por el virus de la influenza B: reporte de dos casos y revisión de la literatura

La miocarditis es una enfermedad inflamatoria del miocardio. Las infecciones virales son la causa más común, aunque también puede deberse a reacciones de hipersensibilidad y de etiología autoinmunitaria, entre otras. El espectro clínico de la enfermedad es variado y comprende desde un curso asintomático, seguido de dolor torácico, arritmias y falla cardiaca aguda, hasta un cuadro fulminante. El término 'fulminante' se refiere al desarrollo de un shock cardiogénico con necesidad de soporte vasopresor e inotrópico o dispositivos de asistencia circulatoria, ya sea oxigenación por membrana extracorpórea o balón de contrapulsación intraaórtico. Cerca del 10 % de los casos de falla cardiaca por miocarditis corresponde a miocarditis fulminante. La miocarditis por influenza se considera una condición infrecuente; no obstante, su incidencia ha aumentado desde el 2009 a raíz de la pandemia de influenza por el virus AH1N1. Por su parte, la miocarditis por influenza de tipo B sigue siendo una condición infrecuente. Se describen aquí dos casos confirmados de miocarditis fulminante por el virus de la influenza B atendidos en un centro cardiovascular, que requirieron dispositivos de asistencia circulatoria mecánica.

Myocarditis is an inflammatory disease of the myocardium. Viral infections are the most common cause, although it can also be due to hypersensitivity reactions and autoimmune etiology, among other causes. The clinical spectrum of the disease is varied, from an asymptomatic course, followed by chest pain, arrhythmias, and acute heart failure, to a fulminant episode. The term fulminant refers to the development of cardiogenic shock with a need for vasopressor support and inotropic or assisted circulation devices either extracorporeal membrane oxygenation (ECMO) or intra-aortic counterpulsation balloon. About 10% of cases of heart failure due to myocarditis correspond to fulminant myocarditis. Influenza myocarditis has been considered an infrequent condition. However, its incidence has increased since 2009 as a result of the AH1N1 pandemic; otherwise, myocarditis due to the Influenza type B virus remains an infrequent entity. We describe the experience in a cardiovascular center of two confirmed cases of fulminant myocarditis due to influenza B that required circulatory assistance devices.

Miocarditis fulminante en adultos por el virus de la influenza B: reporte de dos casos y revisión de la literatura / Fulminant myocarditis due to the influenza B virus in adults: Report of two cases and literature review

Resumen La miocarditis es una enfermedad inflamatoria del miocardio. Las infecciones virales son la causa más común, aunque también puede deberse a reacciones de hipersensibilidad y de etiología autoinmunitaria, entre otras. El espectro clínico de la enfermedad es variado y comprende desde un curso asintomático, seguido de dolor torácico, arritmias y falla cardiaca aguda, hasta un cuadro fulminante. El término 'fulminante' se refiere al desarrollo de un shock cardiogénico con necesidad de soporte vasopresor e inotrópico o dispositivos de asistencia circulatoria, ya sea oxigenación por membrana extracorpórea o balón de contrapulsación intraaórtico. Cerca del 10 % de los casos de falla cardiaca por miocarditis corresponde a miocarditis fulminante. La miocarditis por influenza se considera una condición infrecuente; no obstante, su incidencia ha aumentado desde el 2009 a raíz de la pandemia de influenza por el virus AH1N1. Por su parte, la miocarditis por influenza de tipo B sigue siendo una condición infrecuente. Se describen aquí dos casos confirmados de miocarditis fulminante por el virus de la influenza B atendidos en un centro cardiovascular, que requirieron dispositivos de asistencia circulatoria mecánica.

Abstract Myocarditis is an inflammatory disease of the myocardium. Viral infections are the most common cause, although it can also be due to hypersensitivity reactions and autoimmune etiology, among other causes. The clinical spectrum of the disease is varied, from an asymptomatic course, followed by chest pain, arrhythmias, and acute heart failure, to a fulminant episode. The term fulminant refers to the development of cardiogenic shock with a need for vasopressor support and inotropic or assisted circulation devices either extracorporeal membrane oxygenation (ECMO) or intra-aortic counterpulsation balloon. About 10% of cases of heart failure due to myocarditis correspond to fulminant myocarditis. Influenza myocarditis has been considered an infrequent condition. However, its incidence has increased since 2009 as a result of the AH1N1 pandemic; otherwise, myocarditis due to the Influenza type B virus remains an infrequent entity. We describe the experience in a cardiovascular center of two confirmed cases of fulminant myocarditis due to influenza B that required circulatory assistance devices.

Can venous cannula design influence venous return and negative pressure with a minimally invasive extracorporeal circulation?

INTRODUCTION: Recent advances to make cardiopulmonary bypass more physiological include the use of kinetic-assisted venous drainage but without a venous reservoir. Despite manipulation of intravascular volume and patient positioning, arterial flow is frequently reduced. Negative venous line pressures can be generated, which may elicit gaseous microemboli. We investigated the influence of venous cannula design on venous return and negative venous line pressures. METHODS: In a single-centre, single-surgeon, prospective, randomized, double-blind trial, 48 patients undergoing isolated coronary artery, aortic valve or combined coronary artery and aortic valve surgery, with a minimally invasive circuit, were randomized to a conventional two-stage (2S) or three-stage venous cannula (3S), or to a three-stage venous cannula with additional 'fenestrated' ridges (F3S). Blood flow, venous line pressures and gaseous microemboli number and size were measured. RESULTS: The pump flow achieved was the same between groups, but in each case fell below the target range of 2.2-2.4 L min-1 m-2. The three-stage cannula recorded significantly lower negative pressure than the other cannulae. The total count and volume of gaseous emboli detected with the F3S cannulae was very high in some cases, with wide heterogeneity. DISCUSSION: The low negative pressures recorded with three-stage cannula, despite having a larger drainage orifice area, suggest that negative pressure may be more influenced by lumen diameter and vena cava collapse rather than drainage hole size. The additional fenestrations resulted in flow characteristics and negative pressures similar to the larger two-stage cannula but are associated with generation of gaseous microemboli.