Current status and progress of implantable left ventricular assist devices / 中国胸心血管外科临床杂志

@#Implantable left ventricular assist device (LVAD) has become an essential treatment for end-stage heart failure, and its effect has been continuously improved. In the world, magnetic levitation LVAD has become mainstream and is increasingly used as a destination treatment. China has also entered the era of ventricular assist device. The continuous improvement of the ventricular assist device will further improve the treatment effect. This article reviews the current situation and development trend of LVAD treatment in China and abroad.

A prospective multicenter clinical trial study of a domestic HeartCon third-generation magnetic and hydrodynamic levitation LVAD for the treatment of 50 cases of end-stage heart failure / 中华胸心血管外科杂志

Objective:To analyze and evaluate the safety and efficacy of a Chinese domestically manufactured Heart Con-type implantable third-generation magnetic and hydrodynamic levitation left ventricular assist device(LVAD) for the treatment of end-stage heart failure(ESHF), by reporting the results of eleven-center clinical trial on 50 cases.Methods:This study was a multicenter clinical trial, designed by means of prospective, multicenter and single-group target value. 50 subjects with ESHF were competitively enrolled and treated with HeartCon as the LVAD in eleven centers. The primary efficacy measure was survival, defined as either the subjects experiencing the transition to heart transplantation(HT) or myocardial recovery assisted by the device within 90 days, or as successfully assisted by the LVAD for full 90 days after implantation. The target survival rate was 60%, other observations included implantation success rate, mortality, pump failure needing replacement or emergency heart transplantation.Results:All enrolled 50 patients received LVAD implantation successfully, 46 survived with the pump for 90 days, 1 patient transitioned to heart transplantation, and 3 patients experienced pump thrombosis, within which 2 patients underwent pump replacement and continued to live with the pump for 90 days, and the other one received emergency heart transplantation. There were no dropout subjects. The survival rate at full 90 days after HeartCon implantation was 100%. The survival rates with pump in the full set analysis and the protocol set analysis were 96.00% and 95.92% respectively, which were higher than the target value of 60%. The differences were both statistically significant( P<0.05). Conclusion:The results of the multicenter clinical trial with the largest sample size in China using domestically manufactured third-generation LVAD has demonstrated that, HeartCon is a safe and effective LVAD to treat ESHF patients.

Pharmacotherapy of patients with left ventricular assist devices / 中国临床药理学与治疗学

Left ventricular assist devices (LVAD) are increasingly used in patients with end-stage heart failure. Devices significantly affect patient physiology, leading to unique complications and different drug treatment strategies. The pharmacist is an integral part of a multidisciplinary team and has the responsibility to help patients use their medicines safely and appropriately. It is important to anticipate common postoperative complications and prepare appropriate treatments for them. This article reviews the current guidelines and research literature on the management of pharmacotherapy in patients with LVAD, integrates clinical research practice, summarizes the medication relevant experience and presents a review.

Effects of Left Ventricular Assist and Aortic Graft Angle on Aortic Valve: A Hemodynamic Study / 医用生物力学

Objective To investigate the effect of left ventricular assist device (LVAD) and aortic graft angle on hemodynamics of aortic valve. Methods Three models of aorta and aortic valve with 45°, 60° and 90° anastomosis angles between LVAD and aorta were constructed, and an in vitro pulsating table was built for in vitro experiments. Using particle image velocimetry (PIV) system, three moments in the cardiac cycle ( T1 systolic peak, T rapid closure, T3 diastolic peak), were selected to study the hemodynamic state of aortic valve. Results Velocity vector, vorticity and viscous shear stress were used to evaluate the effect of LVAD anastomosis angle on hemodynamics of aortic valve. During the period of rapid valve closure, with the increase of graft angle, the blood flow velocity near the valve wall, the average vorticity and the maximum viscous shear stress all increased. Conclusions When the graft angle is lower, the impact velocity of blood on the valve is smaller, and the shear force on the valve decreases, so that the valve is in a better hemodynamic environment. This study provides references for the selection of anastomotic angles in clinical operations.

Current status and progress of left ventricular assist device for end-stage heart failure / 中国胸心血管外科临床杂志

@#Although heart transplantation remains to be the optimal treatment for advanced heart failure, its use has been largely limited due to shortage of available donor organs. Over the past two decades, left ventricular assist device (LVAD) has been significantly modified in size, durability and hemocompatibility. In addition to the bridge to transplantation, LVAD has become an attractive alternative to heart transplantation for end-stage heart failure as destination therapy for unsuitable candidates. Although the performance of LVAD has been improving greatly in recent years, there are still great challenges in the management of device complications and low quality of life after implantation. This review will summarize the types of LVAD, indications for implantation, postoperative management and adverse events.

Short-term effect of HeartCon left ventricular assist device on the treatment of 20 adult patients with end-stage heart failure / 中华危重病急救医学

Objective:To investigate and evaluate the efficacy of HeartCon left ventricular assist device (LVAD) in the treatment of adult patients with end-stage heart failure (ESHF).Methods:A prospective and observational study was conducted. Patients with ESHF who underwent LVAD implantation in the department of cardiac surgery of Teda International Cardiovascular Hospital from September 2020 to August 2021 were selected. The left ventricular end-diastolic diameter (LVEDD), left ventricular ejection fraction (LVEF), New York Heart Association (NYHA) classification, N-terminal pro-B type natriuretic peptide (NT-proBNP), and six minute walk distance (6MWD) before operation and 90 days after operation were compared. The incidence of equipment failures and major adverse events within 90 days after operation were recorded.Results:A total of 20 patients with ESHF were included, with 15 males and 5 females. Patients' age ranged from 20 to 67 years old, with an average of (50.2±13.6) years old. The range of body weight was 49.8-106.1 kg, with an average of (67.9±15.5) kg, and the body surface area (BSA) was from 1.49 to 2.32 m 2, with an average of (17.6±0.22) m 2. The operation process of all the patients were successful. The length of hospital stay ranged from 33 to 90 days, and the average was 56.0 (42.8, 75.0) days. Complications within 90 days after operation as follows, 2 cases with pericardial tamponade (10%), 1 case with cerebral hemorrhage (5%), 1 case with mediastinum infection (5%), 3 cases with acute renal injury (AKI, 15%), 5 cases with gastrointestinal bleeding (25%). There were no mechanical failure of LVAD and hemolysis events, right ventricular failure (RVF), cerebral infarction and death occurred. Compared with preoperative, the LVEDD significantly decreased (mm: 67.50±13.98 vs. 77.40±9.73), LVEF significantly increased (%: 34.80±9.76 vs. 22.70±5.62), NT-proBNP significantly decreased (ng/L: 2 028.65±1 752.05 vs. 4 796.45±4 355.40), 6MWD significantly increased (m: 385.20±144.12 vs. 85.81±63.50) at 90 days after operation, and the differences were statistically significant (all P < 0.05). 18 cases (90%) of the 20 patients reached NYHA classification Ⅰ and 2 cases (10%) reached NYHA classification Ⅱ, which were significantly improved compared with those before surgery (all patients' NYHA classification were Ⅳ before surgery). Conclusion:HeartCon LVAD can effectively improve the life quality of patients with ESHF, which has been proved safe and effective in clinical trials, but its long-term effects and complications need further observation and study.

Flow Estimation Method of Centrifugal Left Ventricular Assist Device Based on Motor Parameters / 医用生物力学

Objective To study CH-VAD blood pump developed by CH Biomedical Inc., a method for estimating the real-time flow of blood pump was established by using the voltage, current, speed, duty cycle, and fluid viscosity as the input data. Methods The blood pump system was disassembled into two modules, the motor and the centrifugal pump. Firstly, the output torque of the motor was calculated according to the voltage, current, speed and duty cycle of the motor, then the relationship between flow and torque at different speeds and viscosities was tested through experiments, and a fitting model was established based on the experimental data. Results The fit goodness of Pump 1 and Pump 2 reached 0.982 6 and 0.982 9,respectively. The fitting parameters were used for verification. When the viscosity changed, the root mean square error for the estimated flow of Pump 1 and Pump 2 was 0.260 and 0.274 L/min, respectively. The fitting parameters and estimated results of the two blood pumps were in good agreement. The flow estimation method could follow the actual flow waveform in real time, and the accuracy of the estimated average flow was not affected by the pulsation. Conclusions The flow estimation method proposed in this paper is suitable for CH-VAD blood pumps. It can accurately estimate the flow of blood pumps in the range of speed 1 600-3 600 r/min, flow 0.4-8 L/min, viscosity 1.2-5 mPa·s, and can follow the flow waveform well under pulsating conditions.

Role of transesophageal echocardiography in the intraoperative monitoring of left ventricular assist device implantation / 中华超声影像学杂志

Objective:To evaluate the clinical value of intraoperative transesophageal echocardiography (TEE) in monitoring left ventricular assist device (LVAD) implantation.Methods:Between March 2019 and November 2021, 23 consecutive patients from TEDA International Cardiovascular Hospital, including 21 cases with dilated cardiomyopathy, 1 case with myocardial noncompaction and 1 case with ischemic cardiomyopathy, underwent HeartCon blood pump, a type of third generation LVAD implantation for severe heart failure. TEE was preformed in all cases before and after cardiopulmonary bypass. The dimensions of left-sided and right-sided cardiac chamber, ventricular function, de-airing, interventricular septal position, inlet cannulae position and the function of device were observed and recorded during LVAD implantation. Paired t test was used for statistical analysis of left-sided and right-sided heart parameters in pre- and post-operative measurements. Results:The left heart was dilated significantly and coexistent with right heart enlargement in some degree before LVAD implantation in total 23 cases. More than moderate mitral regurgitation (MR) in 16 cases and less than moderate MR in 7 cases were present. Mild or trace aortic regurgitation (AR) existed in 13 cases. More than moderate tricuspid regurgitation (TR) in 4 cases and less than moderate TR in 16 cases were observed. Left atrial appendage thrombosis was detected in 2 cases. After LVAD implantation, TEE revealed that the left ventricular end-diastolic diameter reduced significantly (42 mm/m 2 vs 32.8 mm/m 2, P<0.05) and left ventricular ejection fraction increased accordingly (22.2% vs 34.0%, P<0.05). There were no significant differences in right ventricular diameter and fractional area change between pre- and post-operative findings(all P>0.05). The ratio of left ventricular inner diameter to right ventricular inner diameter (2.09 vs 1.69, P<0.05) decreased in total 23 cases after LVAD implantation.Interventricular septal position became neutral position instead of pre-oprative rightward position. The severity of MR decreased in varying degrees in total 23 cases after LVAD implantation. All patients underwent tricuspid valvuloplasty with residual mild regurgitation in 8 cases. Conclusions:HeartCon blood pump can effectively unload the left ventricle with sufficient cardiac output in patients with severe congestive heart failure. TEE plays a major role in the clinical decision making during LVAD implantation, which can evaluate pre-operative cardiac abnormalities, intra-operative air embolism, inlet cannulae position, cannulas patency and cardiac function, especially blood volume status and the balance between double ventricles, which is critical for optimal functioning of the device.

Study on the synchronization of biventricular beats with the control mode of left ventricular assist device / 生物医学工程学杂志

Right ventricular (RV) failure has become a deadly complication of left ventricular assist device (LVAD) implantation, for which desynchrony in bi-ventricular pulse resulting from a LVAD is among the important factor. This paper investigated how different control modes affect the synchronization of pulse between LV (left ventricular) and RV by numerical method. The numerical results showed that the systolic duration between LV and RV did not significantly differ at baseline (LVAD off and cannula clamped) (48.52%

Early outcomes of heart transplantation in critical patients: single center experience of Fuwai Hospital / 器官移植

Objective To analyze the early outcomes of heart transplantation in critical patients and its significance in donor allocation decision. Methods Clinical data of 449 recipients undergoing heart transplantation were retrospectively analyzed. According to preoperative status, all patients were divided into the critical status group (n=64) and general status group (n=385). The incidence of critical status was summarized. Clinical data of recipients were statistically compared between two groups. Postoperative survival and causes of death in recipients between two groups were analyzed. Perioperative results of critical recipients undergoing different mechanical circulation support as a bridge to heart transplantation were compared. Results Critical patients accounted for 14.3% of the total number of transplant recipients. The proportion of critical patients gradually increased in recent 5 years. Compared with the general status group, the recipients in critical status group had a lower proportion of smoking history, a higher proportion of cardiac surgery history, a higher serum level of creatinine, and a higher proportion of primary diseases of heart failure before heart transplantation(all P≤0.01). The proportion of undergoing mechanical circulation support was higher, the incidence of complications was higher, the stay time in intensive care unit (ICU) was longer and the in-hospital fatality was higher after heart transplantation in the critical status group (all P≤0.01). The 1-year survival rate of recipients in critical status group was significantly lower than that in general status group (83% vs. 95%, P < 0.01). The fatality of recipients due to infection and multiple organ failure in critical status group was higher than that in general status group. Among 64 critical recipients, 1 recipient received ventilator alone, and 63 recipients underwent mechanical circulation support devices as a bridge to heart transplantation. Among them, intra-aortic balloon pump (IABP) alone was applied in 49 cases (77%), 8 cases (13%) of extracorporeal membrane oxygenation (ECMO) combined with IABP, 4 cases (6%) of ECMO alone, and 2 cases (3%) of left ventricular assist device (LVAD) alone. Critical patients who received preoperative ECMO and ECMO combined with IABP bridging to heart transplantation have a higher proportion of postoperative complications, a longer ICU stay time, a longer mechanical ventilation time, and a higher proportion of hospital deaths. Conclusions The overall prognosis of critical patients undergoing heart transplantation is relatively poor. Effective preoperative management may reverse the high-risk status of critical patients in a certain extent. The limited quantity of donor heart should be allocated to the most urgent patients who can obtain the greatest benefit from heart transplantation.

Value of transthoracic echocardiography to monitor and evaluate aortic insufficiency after implantation of left ventricular assist device / 中国胸心血管外科临床杂志

@#Objective    To explore the value of transthoracic echocardiography (TTE) to monitor and evaluate aortic insufficiency (AI) within one year after the implantation of the left ventricular assist device (LVAD). Methods    We retrospectively collected and analyzed the TTE data of 12 patients who received LVAD implantation from 2018 to 2020 in our hospital. All patients were males, with an average age of 43.3±8.6 years. We analyzed temporal changes in the aortic annulus (AA), aortic sinus (AoS), ascending aorta (AAo), the severity of AI and the opening of aortic valve before operation and 1 month, 3 months, 6 months and 12 months after LVAD implantation. Results    All 12 patients survived within 1 year after LVAD implantation. One patient was bridged to heart transplantation 6 months after implantation, and two patients did not receive TTE after 3 and 6 months. Compared to pre-implantation, AoS increased at 1 month after implantation (31.58±5.09 mm vs. 33.83±4.69 mm). The inner diameters of AA, AoS and AAo increased at 3, 6 and 12 months after LVAD implantation compared to pre-implantation (P<0.05), but all were within the normal range except for one patient whose AoS slightly increased before operation. After LVAD pump speed was adjusted, the opening of aortic  valve improved. The severity of AI increased at 6 and 12 months after LVAD implantation compared to pre-implantation, and increased at 12 months compared to 6 months after LVAD implantation (P<0.05). Conclusion    TTE can evaluate aortic regurgitation before and after LVAD implantation and monitor the optimization and adjustment of LVAD pump function, which has a positive impact on the prognosis after LVAD implantation.

Empleo preoperatorio de azul de metileno pre-implante de dispositivos de asistencia ventricular izquierda / Preoperative utilization of methylene blue previously to implant of left ventricular assist device

Introducción. El objetivo del presente estudio fue analizar el empleo preoperatorio de azul de metileno (AM) como prevención del desarrollo de síndrome vasopléjico en pacientes bajo implante de dispositivos de asistencia ventricular izquierda (DAVI), considerando: porcentaje de pacientes que desarrollan vasoplejía, requerimiento de vasopresores, morbimortalidad postoperatoria y seguridad del empleo del fármaco. Métodos. Fueron incluidos pacientes sometidos al implante de DAVI de flujo continuo (HeartMate II o HeartWare) entre enero de 2009 y enero de 2014. Los pacientes fueron aleatorizados a AM en dosis de 1,5 mg/Kg, previamente a la circulación extracorpórea, seguido por una infusión de 0,5 mg/Kg/hora del mismo. Se definió síndrome vasopléjico en base a hipotensión arterial con presión capilar pulmonar baja, índice cardíaco normal o elevado, resistencias sistémicas descendidas y requerimiento vasopresor. Un valor de P<0,05 se consideró significativo. Resultados. En el lapso del estudio fueron incluidos 64 pacientes, 33 de los cuales recibieron AM (dosis promedio 3,5 mg/kg) y 31 pacientes representaron el grupo control. Veinte (31,1%) pacientes desarrollaron vasoplejía, 6 (18,2%) pacientes en el grupo AM frente a 14 (45,2%) del grupo control (P=0,01; OR 0,27 con IC de 0,08-0,84). El requerimiento de vasopresores resulto, asimismo, inferior en los pretratados, 23 (69,7%) pacientes versus 30 (96,8%) pacientes (P=0,004; OR 0,07; IC 0,003-0,522). La mortalidad postoperatoria resulto de 13 (20,3%) pacientes, 4 (12,1%) de ellos en el grupo AM frente a 9 (29%) del grupo control (P=0,06; OR 0,35; IC 0,106-1,117). En todos los pacientes tratados con AM se evidenció el cambio de coloración de la orina. Cinco (7,8%) pacientes presentaron hipertensión arterial, requiriendo vasodilatadores endovenosos, 3 (9,1%) pacientes en el grupo AM frente a 2 (6,4%) en el grupo control (valor de P=0,3). Conclusiones. El empleo preoperatorio de AM se asoció con la reducción del desarrollo de síndrome vasopléjico, así como del requerimiento vasopresor. Se observó una reducción de complicaciones postoperatorias y una tendencia a menor mortalidad. Un número mayor de pacientes requiere ser valorado para comprobar la utilidad de esta estrategia

Introduction. The objective of this study was to analyze preoperative utilization of methylene blue (MB) for preventing development of vasoplegic syndrome in patients underwent left ventricle assist device (LVAD) implant considering: percentage of patients developing vasoplegia, vasopresor requirement, perioperative morbidity and mortality and safety associated with MB s use. Methods. There were admitted patients underwent an implant of a LVAD of continuous flow (HeartMate II or HeartWare) from January 2009 to January 2014. Patients were randomized to MB, 1.5 mg/Kg one hour before extracorporeal circulation followed for 0.5 mg/kg/hour or placebo (control group). It was defined vasoplegia by: arterial hypotension, low capillary pulmonary pressure, normal or elevated cardiac index, descended systemic vascular resistances and vasopresor requirement. A P<0.05 was considered significant. Results. There were included 64 patients, 33 of them were randomized to MB (average dose 3.5 mg/Kg) and 31 patients represented control group. Twenty (31.1%) patients developed vasoplegia, 6 (18.2%) patients from MB s group versus 14 (45.2%) patients from control group (P=0.01, OR 0.27, IC de 0.08-0.84). Vasopressor requirement was lower in those receiving MB 23 (69.7%) patients versus 30 (96.8%) patients (P=0.004, OR 0.07, IC 0.003- 0.522). Postoperative mortality was 13 (20.3%) patients, 4 (12.1%) of them receiving MB versus 9 (29%) patients from control group (P=0.06, OR 0.35 IC 0.106-1.117). In all treated patients it was evident a change in urine s color and also five (7.8%) patients developed arterial hypertension, requiring vasodilators 3 (9.1%) patients from MB s group versus 2 (6.4%) from control (valor de P=0.3). Conclusions. The preoperative use of MB was associated with reduction of vasoplegia and a lower vasopresor requirements. It was also observed reduction of postoperative complications and a trend to reduced mortality. A superior number of patients needs to be evaluated for proving the value of this strategy

Introdução. O objetivo deste estudo foi analisar a utilização pré-operatória do azul de metileno (AM) para prevenir o desenvolvimento da síndrome vasoplégica em pacientes submetidos a implante de dispositivo de assistência ventricular esquerda (DAVE), considerando: porcentagem de pacientes em desenvolvimento de vasoplegia, necessidade de vasopresor, morbidade e mortalidade e segurança perioperatórias associado ao uso do AM. Métodos. Foram admitidos pacientes submetidos a um implante de uma DAVE de fluxo contínuo (HeartMate II ou HeartWare) de janeiro de 2009 a janeiro de 2014. Os pacientes foram randomizados para AM, 1,5 mg/kg uma hora antes da circulação extracorpórea, seguidos por 0,5 mg/kg/hora ou placebo (grupo controle). Foi definida vasoplegia por: hipotensão arterial, pressão pulmonar capilar baixa, índice cardíaco normal ou elevado, resistências vasculares sistêmicas descendentes e necessidade de vasopresor. Um P<0,05 foi considerado significativo. Resultados. Foram incluídos 64 pacientes, 33 deles foram randomizados para MB (dose média de 3,5 mg / kg) e 31 pacientes representaram o grupo controle. Vinte (31,1%) pacientes desenvolveram vasoplegia, 6 (18,2%) pacientes do grupo AM versus 14 (45,2%) pacientes do grupo controle (P=0,01; OR 0,27; IC de 0,08-0,84). A necessidade de vasopressores foi menor nos pacientes que receberam AM 23 (69,7%) versus 30 (96,8%) pacientes (P=0,004; OR 0,07; IC 0,003-0,522). A mortalidade pós-operatória foi de 13 (20,3%) pacientes, 4 (12,1%) deles recebendo AM versus 9 (29%) pacientes do grupo controle (P=0,06; OR 0,35; IC 0,106-1,117). Em todos os pacientes tratados, foi evidente uma alteração na cor da urina e também cinco (7,8%) pacientes desenvolveram hipertensão arterial, exigindo vasodilatadores 3 (9,1%) pacientes do grupo AM versus 2 (6,4%) do controle (valor de P=0,3). Conclusões. O uso pré-operatório de AM foi associado à redução da vasoplegia e menor necessidade de vasopresor. Também foi observada redução das complicações pós-operatórias e tendência à redução da mortalidade. Um número superior de pacientes precisa ser avaliado para provar o valor dessa estratégia

Study on sensorless suction detection method based on the intrinsic parameter of rotary left ventricular assist devices / 生物医学工程学杂志

The rotary left ventricular assist device (LVAD) has been an effective option for end-stage heart failure. However, while clinically using the LVAD, patients are often at significant risk for ventricular collapse, called suction, mainly due to higher LVAD speeds required for adequate cardiac output. Some proposed suction detection algorithms required the external implantation of sensors, which were not reliable in long-term use due to baseline drift and short lifespan. Therefore, this study presents a new suction detection system only using the LVAD intrinsic blood pump parameter (pump speed) without using any external sensor. Three feature indices are derived from the pump speed and considered as the inputs to four different classifiers to classify the pumping states as no suction or suction. The results using a combined human circulatory system and LVAD model show that the proposed method can detect ventricular suction effectively, demonstrating that it has high classification accuracy, stability, and robustness. The proposed suction detection system could be an important part in the LVAD for detecting and avoiding suction, while at the same time making the LVAD meet the cardiac output demand for the patients. It could also provide theoretical basis and technology support for designing and optimizing the control system of the LVAD.

Hemodynamic Analysis on Meglev Left Ventricular Assist Device of a New Generation / 医用生物力学

Objective To reduce the thrombosis probability and hemolysis risk of the meglev left ventricular assist device (LVAD), so as to increase the efficiency of blood supply. Methods The influences of the pump outlet diameter, exit angle, fillet size between the outlet and the inner wall of the pump, as well as gap between the rotor and the shell on internal flow field of the pump were studied by using the computational fluid dynamics (CFD) method, so as to optimize the internal structure and improve the hydrodynamic performance of the pump. Results Compared with pump of the previous generation, the maximum wall shear stress (WSS) of the pump inner wall, the maximum WSS of the pump rotor, the area with WSS >200 Pa were reduced by 23.6%, 47.4%, 76.2%, respectively, while the outlet flow was increased by 14.4%. Conclusions For the meglev LVAD of the new generation, its internal blood flow tended to be smooth, and the hemodynamic performance of blood flow was improved comprehensively. The research findings provide references for optimization design of the meglev LVAD and related experimental researches in the future.

Temporary Right Ventricular Assist Device Insertion via Left Thoracotomy after Left Ventricular Assist Device Implantation / 대한흉부외과학회지

Right heart failure is a relatively common complication after left ventricular assist device (LVAD) implantation. Severe right heart failure can be managed by temporary right ventricular assist device (RVAD) implantation. However, trans-sternal RVAD insertion requires a subsequent third sternotomy for cannula removal. Herein, we present a case of RVAD insertion via a left anterior mini-thoracotomy after LVAD implantation in a patient with alcohol-induced cardiomyopathy.

Looking inside the third generation left ventricular assist device using color doppler transesophageal echocardiography

HeartWare is a third-generation continuous flow left ventricular assist device (LVAD) and generates centrifugal pattern of blood flow. In the perioperative setting, interrogating the HeartWare devices is very difficult due to the interference of the Doppler by the impeller frequency and generation of the waterfall artifact. We present a case where using color Doppler a view “inside“ the impeller can be seen which corresponds to the centrifugal flow of blood. With time, these images can be looked into in pathological states such as pump thrombosis, to come to a more meaningful conclusion regarding the flow of blood within the centrifugal chamber. Newer technologies are constantly evolving to give us more meaningful insights into the flow of blood within the heart chambers. We believe similar technologies can be applied to see the flow of blood inside the LVAD devices.

Advances in mechanical circulatory support therapy for fulminant myocarditis in children / 国际儿科学杂志

Fulminant myocarditis in children often has a transient viral prodrome,which is characterized by acute onset and lack of specificity in the early stage.It is prone to deteriorate in serious cardiac pump dysfunction and arrhythmia,which may lead to cardiogenic shock and even sudden cardiac death.Some patients are given the pharmacologic treatment of large doses of inotropes,corticosteroids,intravenous immunoglobulin,antiarrhythmic agents as well as other therapies such as mechanical ventilation,temporary pacemaker,but the circulatory failure still can not be improved,leading to irreversible heart damage and life-threatening.It has been reported that timely mechanical circulatory support for critically ill children can effectively promote the recovery of cardiac pump function,reduce mortality and improve prognosis.Mechanical circulatory assist devices mainly inclucle extracorporeal membrane oxygenation(ECMO),intra aortic balloon pump (IABP),left ventricular assist device (LVAD) or double ventricular assist device(Bi-VAD).In view of the limited understanding of the technology in the field of pediatrics in our country,this has not been used extensively.This article reviews the progress of FM treatment in children with mechanical circulatory support.

Short term left ventricular assistive device use in postoperative pediatric patients with congenital heart disease / 中华胸心血管外科杂志

Objective To discuss the methods and experience of using short term left ventricular assist devices (LVADs) in patients after congenital heart disease(CHD) corrective surgery.Methods This study included 17 postoperative cases using short term LVAD support.The device used was a Maquet Rotaflow system, and the clinical patient data was collected and eval-uated retrospectively.Results The 17 patients were divided into two groups by the clinical outcome as follows: 6 cases in the early death group(Group D) and 11 cases in the survival group(Group S).The pre-support time[(9.00 ±9.95)h vs. (23.83 ±13.23)h, P＝0.042]and the lactate level values[(4.01 ±2.15)mmol/L vs.(9.30 ±4.90)mmol/L, P＝0.045] were significantly lower and more favorable in Group S.Patients in Group S also received a longer support time than patients in Group D.Conclusion Using the Maquet Rotaflow system is generally safe and efficient, when used as a short term LVAD in postoperative pediatric patients.The selection of patients, the timing of support, and reasonable management were the keys to patient survival.

Systematic Left Ventricular Assist Device Implant Eligibility with Non-Invasive Assessment: The SIENA Protocol

In patients with end-stage left ventricular (LV) heart failure who receive LV assist device (LVAD) implantation, right ventricular (RV) failure represents a possible critical complication that heavily affects morbidity and mortality. Several clinical, laboratory, hemodynamic, and echocardiographic variables have been found to be associated with RV failure occurrence after surgery. Different models and risk scores have been proposed, with poor results. No accordance has ever been reached about RV pre-operative evaluation, and time has come to introduce a standardized systematic protocol for LVAD suitability assessment according to RV function. We analyzed imaging parameters associated with LVAD implantation-related RV failure, in order to identify the minimum number for pre-operative reliable prediction of post-operative RV failure. A few echocardiographic parameters have been identified as the most reliable, or promising, and reproducible tools in this field: free-wall RV longitudinal strain, RV fractional area change, RV sphericity index, and RV ejection fraction with 3D-echocardiography. We propose the Systematic LVAD Implant Eligibility with Non-invasive Assessment protocol–the SIENA protocol–as a new and simple way of pre-operative evaluation of patients candidates to LVAD implantation.

Perioperative management of patients with left ventricular assist devices undergoing noncardiac surgery.

Aim: The aim of this study was to describe our institutional experience, primarily with general anesthesiologists consulting with cardiac anesthesiologists, caring for left ventricular assist device (LVAD) patients undergoing noncardiac surgery. Materials and Methods: This is a retrospective review of the population of patients with LVADs at a single institution undergoing noncardiac procedures between 2009 and 2014. Demographic, perioperative, and procedural data collected included the type of procedure performed, anesthetic technique, vasopressor requirements, invasive monitors used, anesthesia provider type, blood product management, need for postoperative intubation, postoperative disposition and length of stay, and perioperative complications including mortality. Statistical Analysis: Descriptive statistics for categorical variables are presented as frequency distributions and percentages. Continuous variables are expressed as mean ± standard deviation and range when applicable. Results: During the study, 31 patients with LVADs underwent a total of 74 procedures. Each patient underwent an average of 2.4 procedures. Of the total number of procedures, 48 (65%) were upper or lower endoscopies. Considering all procedures, 81% were performed under monitored anesthesia care (MAC). Perioperative care was provided by faculty outside of the division of cardiac anesthesia in 62% of procedures. Invasive blood pressure monitoring was used in 27 (36%) procedures, and a central line, peripherally inserted central catheter or midline was in place preoperatively and used intraoperatively for 38 (51%) procedures. Vasopressors were not required in the majority (65; 88%) of procedures. There was one inhospital mortality secondary to multiorgan failure; 97% of patients survived to discharge after their procedure. Conclusion: At our institution, LVAD patients undergoing noncardiac procedures most frequently require endoscopy. These procedures can frequently be done safely under MAC, with or without consultation by a cardiac anesthesiologist.