Mechanical life support algorithm for emergency management of patient receiving extracorporeal membrane oxygenation.

BACKGROUND: There are limited practical advanced life support algorithms to aid teams in the management of cardiac arrest in patients on extracorporeal membrane oxygenation (ECMO). METHODS: In our specialist tertiary referral centre we developed, by iteration, a novel resuscitation algorithm for ECMO emergencies which we validated through simulation and assessment of our multi-disciplinary team. A Mechanical Life Support course was established to provide theoretical and practical education combined with simulation to consolidate knowledge and confidence in algorithm use. We assessed these measures using confidence scoring, a key performance indicator (the time taken to resolve gas line disconnection) and a multiple choice question (MCQ) examination. RESULTS: Following this intervention the median confidence scores increased from 2 (Interquartile range IQR 2, 3) to 4 (IQR 4, 4) out of maximum 5 (n = 53, p < 0.0001). Theoretical knowledge assessed by median MCQ score increased from 8 (6, 9) to 9 (7, 10) out of maximum 11 (n = 53, p0.0001). The use of the ECMO algorithm reduced the time taken by teams in a simulated emergency to identify a gas line disconnection and resolve the problem from median 128 s (65, 180) to 44 s (31, 59) (n = 36, p 0.001) and by a mean of 81.5 s (CI 34, 116, p = 0.001). CONCLUSIONS: We present an evidence based practical ECMO resuscitation algorithm that provides guidance to clinical teams responding to cardiac arrest in ECMO patients covering both patient and ECMO troubleshooting.

Bleeding and thrombotic complications and their impact on mortality in patients supported with left ventricular assist device for cardiogenic shock.

INTRODUCTION: Thrombosis and bleeding are major complications in patients supported with left ventricular assist devices (LVADs). We aimed to assess the incidence of bleeding and thrombosis in patients supported with a HeartWare left ventricular assist device (HVAD), their predictive factors and their impact on mortality. METHODS: A single centre retrospective observational study of patients supported with HVAD over 5 years from January 2015 to October 2020. RESULTS: A total 139 patients (median age 52.5, 72.1% male) were included for analysis. The probability of 1-year survival was 73.1%. Advanced age (>60 years) and EuroSCORE II score (>20%) were independently associated with reduced survival. Major bleeding and thrombosis occurred in 46.8% and 35.3% respectively. Secondary mechanical circulatory support (MCS) increased likelihood of experiencing major bleeding (HR: 2.76, 95%1.65-4.62, p < 0.0001) whilst patients receiving aspirin were protected from bleeding and thrombosis (HR: 0.34 95% CI 0.19-0.58, p < 0.001). Pre-operative anaemia (HR: 3.02, 95% CI: 1.6-5.7, p = 0.014) and use of a secondary MCS device (HR: 2.78, 95% CI: 1.2-6.3, p = 0.001) were associated with an increased risk of thrombosis. Patients with any major bleeding (with or without thrombosis) had a 7.68-fold (95% CI 3.5-16.8) increased risk of death compared to those without. In contrast, 'thrombosis only' patients had 4.23-fold (95% CI 1.8-10.2) increased risk of death compared to those without thrombosis. The risk of mortality was increased in patients with any thrombosis and the risk of death was highest in patients with major bleeding and thrombosis (HR: 16.49 [95% CI 7.7-35.3]). CONCLUSIONS: Major bleeding and thrombosis significantly increase the 1-year mortality. Optimal perioperative haemostasis and anticoagulation remains crucial in patients supported with HVAD.

Algorithms to guide ambulance clinicians in the management of emergencies in patients with implanted rotary left ventricular assist devices.

Advances in left ventricular assist device (LVAD) therapy have resulted in increasing numbers of adult LVAD recipients in the community. However, device failure, stroke, bleeding, LVAD thrombosis and systemic infection can be life-threatening emergencies. Currently, four LVAD systems are implanted in six UK transplant centres, each of which provides device-specific information to local emergency services. This has resulted in inconsistent availability and content of information with the risks of delayed or inappropriate decision-making. In order to improve patient safety, a consortium of UK healthcare professionals with expertise in LVADs developed universally applicable prehospital emergency algorithms. Guidance was framed as closely as possible on the standard ABCDE approach to the assessment of critically ill patients.

Investigation of the Characteristics of HeartWare HVAD and Thoratec HeartMate II Under Steady and Pulsatile Flow Conditions.

The aim of this study was to elucidate the dynamic characteristics of the Thoratec HeartMate II (HMII) and the HeartWare HVAD (HVAD) left ventricular assist devices (LVADs) under clinically representative in vitro operating conditions. The performance of the two LVADs were compared in a normothermic, human blood-filled mock circulation model under conditions of steady (nonpulsatile) flow and under simulated physiologic conditions. These experiments were repeated using 5% dextrose in order to determine its suitability as a blood analog. Under steady flow conditions, for the HMII, approximately linear inverse LVAD differential pressure (H) versus flow (Q) relationships were observed with good correspondence between the results of blood and 5% dextrose under all conditions except at a pump speed of 9000 rpm. For the HVAD, the corresponding relationships were inverse curvilinear and with good correspondence between the blood-derived and 5% dextrose-derived relationships in the flow rate range of 2-6 L/min and at pump speeds up to 3000 rpm. Under pulsatile operating conditions, for each LVAD operating at a particular pump speed, an counterclockwise loop was inscribed in the HQ domain during a simulated cardiac cycle (HQ loop); this showed that there was a variable phase relationship between LVAD differential pressure and LVAD flow. For both the HMII and HVAD, increasing pump speed was associated with a right-hand and upward shift of the HQ loop and simulation of impairment of left ventricular function was associated with a decrease in loop area. During clinical use, not only does the pressure differential across the LVAD and its flow rate vary continuously, but their phase relationship is variable. This behavior is inadequately described by the widely accepted representation of a plot of pressure differential versus flow derived under steady conditions. We conclude that the dynamic HQ loop is a more meaningful representation of clinical operating conditions than the widely accepted steady flow HQ curve.

Ex vivo heart perfusion after cardiocirculatory death; a porcine model.

BACKGROUND: Donation after cardiocirculatory death (DCD) has lead to an increase in organ availability. However, because of medical, logistic, and ethical issues, the use of hearts from DCD donors for transplantation is not generally considered to be feasible. In this study, we investigated the feasibility of ex vivo resuscitation and assessment of the porcine heart after circulatory death using the organ care system (OCS). METHODS: Cardiocirculatory death was induced in five pigs by cessation of mechanical ventilation. No heparin was administered. The agonal time (AT) was calculated as the time between a reduction of blood pressure <50 mm Hg or a fall in saturation beneath 70% and the cessation of electrical activity. After a further 15 min of warm ischemia, hearts were procured and implanted into the OCS, mimicking the actual clinical scenario for other organs. Thus, procured grafts were assessed ex vivo over a period of 4 h. RESULTS: Four hearts were successfully resuscitated on the system (AT 8, 15, 20, and 34 min) Three grafts had excellent visual contractility and lactate trends and were considered to be transplantable. One graft (AT 34 min) had an increased lactate and abnormal contractility being unsuitable for transplantation. One heart with 48-min AT could not be resuscitated. CONCLUSIONS: Our data show that hearts from nonheparinized DCD porcine donors can be successfully resuscitated using the OCS in a scenario, which closely simulates clinical conditions.

First experience with the Synergy Micro-Pump in patients in INTERMACS class 1-2 as a bridge to transplantation: pushing the limits?

The Synergy Micro-pump is the smallest implantable left ventricular assist device (LVAD) and provides partial flow support up to 4.25 L/min. It was shown that early intervention with this device can provide substantial benefits to patients with severe heart failure not yet sick enough for a full-support LVAD. However, as it can be inserted via small incisions with no need for sternotomy or cardiopulmonary bypass, it might be beneficial for selected high-risk patients. The aim of this study was to evaluate the efficacy of the Synergy Micro-pump in patients in INTERMACS class 1-2. From February 2012 to August 2013, 13 patients with severe heart failure were supported with the Synergy Pocket Micro-pump. Patients were divided into two groups according to INTERMACS class: the high-risk group (INTERMACS class 1-2) and the low-risk group (INTERMACS class 3-4). There were seven patients in INTERMACS class 1-2 and six in INTERMACS class 3-4. Patient demographics, perioperative characteristics, and postoperative outcomes were compared. There were no statistically significant differences in patient demographics, and mean support time was 108 ± 114 days in the high-risk group and 238 ± 198 days in the low-risk group. Also, there were no significant differences in perioperative characteristics or in the rate of postoperative adverse events. The overall survival was comparable between the two groups (one late death in each group, log-rank P = 0.608). Two patients from the high-risk group were upgraded to a full-support LVAD (P = 0.462) after 65 ± 84.9 days of mean support. One patient from the high-risk group and two patients from the low-risk group were successfully transplanted (P = 0.559). The use of the Synergy Micro-pump in INTERMACS 1-2 patients is feasible and is associated with similar postoperative outcome as in patients in INTERMACS 3-4. Carefully selected patients with severe heart failure could benefit due to the small size of the pump; however, further studies and medium-term follow-up are required.

Use of left ventricular assist device for cardiomyopathy associated with arthrogryposis multiplex congenita.

Arthrogryposis multiplex congenita (AMC) is characterized by contractions of multiple joints present at birth. AMC is rarely associated with cardiomyopathy. We present a case of a young man with dilated cardiomyopathy associated with AMC admitted with rapidly deteriorating severe heart failure who was offered left ventricular assist device as a bridge to transplant.

British societies guideline on the management of emergencies in implantable left ventricular assist device recipients in transplant centres.

An implantable left ventricular assist device (LVAD) is indicated as a bridge to transplantation or recovery in the United Kingdom (UK). The mechanism of action of the LVAD results in a unique state of haemodynamic stability with diminished arterial pulsatility. The clinical assessment of an LVAD recipient can be challenging because non-invasive blood pressure, pulse and oxygen saturation measurements may be hard to obtain. As a result of this unusual situation and complex interplay between the device and the native circulation, resuscitation of LVAD recipients requires bespoke guidelines. Through collaboration with key UK stakeholders, we assessed the current evidence base and developed guidelines for the recognition of clinical deterioration, inadequate circulation and time-critical interventions. Such guidelines, intended for use in transplant centres, are designed to be deployed by those providing immediate care of LVAD patients under conditions of precipitous clinical deterioration. In summary, the Joint British Societies and Transplant Centres LVAD Working Group present the UK guideline on management of emergencies in implantable LVAD recipients for use in advanced heart failure centres. These recommendations have been made with a UK resuscitation focus but are widely applicable to professionals regularly managing patients with implantable LVADs.

Mechanical life support algorithm for the emergency management of patients with left-sided Impella.

We sought to remedy the limited guidance that is available to support the resuscitation of patients with the Impella Cardiac Power (CP) and 5.0 devices during episodes of cardiac arrest or life-threatening events that can result in haemodynamic decompensation. In a specialist tertiary referral centre we developed, by iteration, a novel resuscitation algorithm for Impella emergencies, which we validated through simulation and assessment by our multi- disciplinary team. A mechanical life support course was established to provide theoretical and practical education, combined with simulation to consolidate knowledge and confidence in algorithm use. We assessed these measures using confidence scoring, a key performance indicator (the time taken to resolve a suction event) and a multiple-choice question (MCQ) examination. Following this intervention, median confidence score increased from 2 (interquartile range [IQR] 2 to 3) to 4 (IQR 4 to 4) out of a maximum of 5 (n=53, p<0.0001). Theoretical knowledge of the Impella, as assessed by median MCQ score, increased from 12 (IQR 10 to 13) to 13 (12 to 14) out of a maximum of 17 (p<0.0001). The use of a bespoke Impella resuscitation algorithm reduced the mean time taken to identify and resolve a suction event by 53 seconds (95% confidence interval 36 to 99, p=0.0003). In conclusion, we present an evidence-based resuscitation algorithm that provides both technical and medical guidance to clinicians responding to life-threatening events in Impella recipients.

A novel intrapericardial pulsatile device for individualized, biventricular circulatory support without direct blood contact.

OBJECTIVE: Due to severely limited donor heart availability, durable mechanical circulatory support remains the only treatment option for many patients with end-stage heart failure. However, treatment complexity persists due to its univentricular support modality and continuous contact with blood. We investigated the function and safety of reBEAT (AdjuCor GmbH), a novel, minimal invasive mechanical circulatory support device that completely avoids blood contact and provides pulsatile, biventricular support. METHODS: For each animal tested, an accurately sized cardiac implant was manufactured from computed tomography scan analyses. The implant consists of a cardiac sleeve with three inflatable cushions, 6 epicardial electrodes and driveline connecting to an electro-pneumatic, extracorporeal portable driver. Continuous epicardial electrocardiogram signal analysis allows for systolic and diastolic synchronization of biventricular mechanical support. In 7 pigs (weight, 50-80 kg), data were analyzed acutely (under beta-blockade, n = 5) and in a 30-day long-term survival model (n = 2). Acquisition of intracardiac pressures and aortic and pulmonary flow data were used to determine left ventricle and right ventricle stroke work and stroke volume, respectively. RESULTS: Each implant was successfully positioned around the ventricles. Automatic algorithm electrocardiogram signal annotations resulted in precise, real-time mechanical support synchronization with each cardiac cycle. Consequently, progressive improvements in cardiac hemodynamic parameters in acute animals were achieved. Long-term survival demonstrated safe device integration, and clear and stable electrocardiogram signal detection over time. CONCLUSIONS: The present study demonstrates biventricular cardiac support with reBEAT. Various demonstrated features are essential for realistic translation into the clinical setting, including safe implantation, anatomical fit, safe device-tissue integration, and real-time electrocardiogram synchronized mechanical support, result in effective device function and long-term safety.

Reversal of severe heart failure with a continuous-flow left ventricular assist device and pharmacological therapy: a prospective study.

BACKGROUND: We have previously shown that a specific combination of drug therapy and left ventricular assist device unloading results in significant myocardial recovery, sufficient to allow pump removal, in two thirds of patients with dilated cardiomyopathy receiving a Heartmate I pulsatile device. However, this protocol has not been used with nonpulsatile devices. METHODS AND RESULTS: We report the results of a prospective study of 20 patients who received a combination of angiotensin-converting enzymes, ß-blockers, angiotensin II inhibitors, and aldosterone antagonists followed by the ß2-agonist clenbuterol and were regularly tested (echocardiograms, exercise tests, catheterizations) with the pump at low speed. Before left ventricular assist device insertion, patient age was 35.2 ± 12.6 years (16 male patients), patients were on 2.0 ± 0.9 inotropes, 7 (35) had an intra-aortic balloon pump, 2 were hemofiltered, 2 were ventilated, 3 had a prior Levitronix device, and 1 had extracorporeal membrane oxygenation. Cardiac index was 1.39 ± 0.43 L · min⁻¹ · m⁻², pulmonary capillary wedge pressure was 31.5 ± 5.7 mm Hg, and heart failure history was 3.4 ± 3.5 years. One patient was lost to follow-up and died after 240 days of support. Of the remaining 19 patients, 12 (63.2) were explanted after 286 ± 97 days. Eight had symptomatic heart failure for ≤6 months and 4 for >6 months (48 to 132 months). Before explantation, at low flow for 15 minutes, ejection fraction was 70 ± 7, left ventricular end-diastolic diameter was 48.6 ± 5.7 mm, left ventricular end-systolic diameter was 32.3 ± 5.7 mm, mV(O2) was 21.6 ± 4 mL · kg⁻¹ · min⁻¹, pulmonary capillary wedge pressure was 5.9 ± 4.6 mm Hg, and cardiac index was 3.6 ± 0.6 L · min⁻¹ · m⁻². Estimated survival without heart failure recurrence was 83.3 at 1 and 3 years. After a 430.7 ± 337.1-day follow-up, surviving explants had an ejection fraction of 58.1 ± 13.8, left ventricular end-diastolic diameter of 59.0 ± 9.3 mm, left ventricular end-systolic diameter of 42.0 ± 10.7 mm, and mV(O2) of 22.6 ± 5.3 mL · kg⁻¹ · min⁻¹. CONCLUSIONS: Reversal of end-stage heart failure secondary to nonischemic cardiomyopathy can be achieved in a substantial proportion of patients with nonpulsatile flow through the use of a combination of mechanical and pharmacological therapy.

Mechanical life support algorithm developed by simulation for inpatient emergency management of recipients of implantable left ventricular assist devices.

Background: Published guidance concerning emergency management of left ventricular assist device (LVAD) recipients is both limited and lacking in consensus which increases the risk of delayed and/or inappropriate actions. Methods: In our specialist tertiary referral centre we developed, by iteration, a novel in-hospital resuscitation algorithm for LVAD emergencies which we validated through simulation and assessment of our multi-disciplinary team. A Mechanical Life Support course was established to provide theoretical and practical education combined with simulation to consolidate knowledge and confidence in algorithm use. We assessed these measures using confidence scoring, a key performance indicator (the time taken to restart LVAD function) and a multiple-choice question (MCQ) examination. Results: The mean baseline staff confidence score in management of LVAD emergencies was 2.4 ± 1.2 out of a maximum of 5 (n = 29). After training with simulation, mean confidence score increased to 3.5 ± 0.8 (n = 13).Clinical personnel who were provided with the novel resuscitation algorithm were able to reduce time taken to restart LVAD function from a mean value of 49 ± 8.2 seconds (pre-training) to 20.4 ± 5 seconds (post-training) (n = 42, p < 0.0001).The Mechanical Life Support course increased mean confidence from 2.5 ± 1.2 to 4 ± 0.6 (n = 44, p < 0.0001) and mean MCQ score from 18.7 ± 3.4 to 22.8 ± 2.6, out of a maximum of 28 (n = 44, p < 0.0001). Conclusion: We present a simplified LVAD Advanced Life Support algorithm to aid the crucial first minutes of resuscitation where basic interventions are likely to be critical in assuring good patient outcomes.

Adult human heart slices are a multicellular system suitable for electrophysiological and pharmacological studies.

Electrophysiological and pharmacological data from the human heart are limited due to the absence of simple but representative experimental model systems of human myocardium. The aim of this study was to establish and characterise adult human myocardial slices from small patients' heart biopsies as a simple, reproducible and relevant preparation suitable for the study of human cardiac tissue at the multicellular level. Vibratome-cut myocardial slices were prepared from left ventricular biopsies obtained from end-stage heart failure patients undergoing heart transplant or ventricular assist device implantation, and from hearts of normal dogs. Multiple slices were prepared from each biopsy. Regular contractility was observed at a range of stimulation frequencies (0.1-2 Hz), and stable electrical activity, monitored using multi-electrode arrays (MEA), was maintained for at least 8 h from slice preparation. ATP/ADP and phosphocreatine/creatine ratios were comparable to intact organ values, and morphology and gap junction distribution were representative of native myocardium. MEA recordings showed that field potential duration (FPD) and conduction velocity (CV) in human and dog slices were similar to the values previously reported for papillary muscles, ventricular wedges and whole hearts. Longitudinal CV was significantly faster than transversal CV, with an anisotropic ratio of 3:1 for human and 2.3:1 for dog slices. Importantly, slices responded to the application of E-4031, chromanol and 4-aminopyridine, three potassium channel blockers known to affect action potential duration, with an increase in FPD. We conclude that viable myocardial slices with preserved structural, biochemical and electrophysiological properties can be prepared from adult human and canine heart biopsies and offer a novel preparation suitable for the study of heart failure and drug screening.

Left ventricular assist device and drug therapy for the reversal of heart failure.

BACKGROUND: In patients with severe heart failure, prolonged unloading of the myocardium with the use of a left ventricular assist device has been reported to lead to myocardial recovery in small numbers of patients for varying periods of time. Increasing the frequency and durability of myocardial recovery could reduce or postpone the need for subsequent heart transplantation. METHODS: We enrolled 15 patients with severe heart failure due to nonischemic cardiomyopathy and with no histologic evidence of active myocarditis. All had markedly reduced cardiac output and were receiving inotropes. The patients underwent implantation of left ventricular assist devices and were treated with lisinopril, carvedilol, spironolactone, and losartan to enhance reverse remodeling. Once regression of left ventricular enlargement had been achieved, the beta2-adrenergic-receptor agonist clenbuterol was administered to prevent myocardial atrophy. RESULTS: Eleven of the 15 patients had sufficient myocardial recovery to undergo explantation of the left ventricular assist device a mean (+/-SD) of 320+/-186 days after implantation of the device. One patient died of intractable arrhythmias 24 hours after explantation; another died of carcinoma of the lung 27 months after explantation. The cumulative rate of freedom from recurrent heart failure among the surviving patients was 100% and 88.9% 1 and 4 years after explantation, respectively. The quality of life as assessed by the Minnesota Living with Heart Failure Questionnaire score at 3 years was nearly normal. Fifty-nine months after explantation, the mean left ventricular ejection fraction was 64+/-12%, the mean left ventricular end-diastolic diameter was 59.4+/-12.1 mm, the mean left ventricular end-systolic diameter was 42.5+/-13.2 mm, and the mean maximal oxygen uptake with exercise was 26.3+/-6.0 ml per kilogram of body weight per minute. CONCLUSIONS: In this single-center study, we found that sustained reversal of severe heart failure secondary to nonischemic cardiomyopathy could be achieved in selected patients with the use of a left ventricular assist device and a specific pharmacologic regimen.

Percutaneous Impella CP exchange with preservation of transfemoral access.

In patients with cardiogenic shock, the global use of percutaneous mechanical circulatory support using the Impella CP device has increased with early data suggesting potential benefits over conservative management. In the current case report we describe a simple technique facilitating percutaneous Impella CP or RP exchange with preservation of transfemoral access, which does not require the use of a 0.035' wire. This technique allows for percutaneous sealing of the 14F arteriotomy using new closure devices avoiding the traditional cut-down.

Full-Support LVAD Implantation in a C-Pulse Heart Assist System Recipient with Deteriorating Chronic Heart Failure: Is It Feasible and Safe?

Heart failure is a progressive disease with limited treatment options. The C-Pulse Heart Assist System (Eden Prairie, MN) is an extravascular, diastolic counterpulsation circulatory support device for patients with refractory NHYA Class III/ambulatory class IV heart failure. It comprises a balloon-cuff which is implanted around the ascending aorta that is synchronised to inflate during ventricular diastole. The system eliminates the need for systemic anticoagulation and significantly reduces the risk of bleeding and overcomes the problem of device thrombosis. However, clinical efficacy is dependent on maintenance of residual myocardial function. We describe a case of a patient who presented with ischemic cardiomyopathy in end-stage heart failure and received the C-Pulse System. Due to deterioration in cardiac function, the system had to be upgraded to a full-support left ventricular assist device (LVAD) after 4 months. However, the aorta ascendens was short and the outflow graft of the HeartWare LVAD had to be anastomosed to the cuff balloon region of the aorta. Our experience showed in this case that the inflatable cuff action did not compromise the structural integrity of the aortic wall.

A UK Single Centre Retrospective Analysis of the Relationship between Haemodynamic Changes and Outcome in Patients Undergoing Prolonged Left Ventricular Assist Device Support.

PURPOSE: Despite their efficacy, LVADs remain associated with serious complications. The relationship between haemodynamic changes during support and outcome remains inadequately characterised. This association was investigated in LVAD recipients undergoing prolonged support. METHODS: Forty patients receiving LVAD therapy for >2 years were reviewed retrospectively (mean support duration was 38.62 ± 15.28). Pre- and on-LVAD haemodynamic data were assessed in three groups: (1) those receiving ongoing support (n = 24); (2) those who underwent cardiac transplantation (n = 4); (3) those who died during support (n = 12). RESULTS: For group 1 and 2, LVAD support achieved a decrease in mean PAP, mean PCWP, TPG, and PVR and an increase in thermodilution blood flow (TBF) with significance at ≤5% level. For group 3, there were non-significant changes in TPG and PVR at the 5% level but for mean PAP, mean PCWP, and TBF the changes were similar to Groups 1 and 2 with significance at ≤5% level. Aggregated data from all three groups showed a 58% increase in TBF on LVAD support. CONCLUSION: Highly significant and favourable haemodynamic changes were found. However, group 3 did not undergo decrease in TPG and PVR possibly because of suboptimal LVAD flow, right heart dysfunction and unavoidable prolongation of support.

Simple and non-invasive techniques to evaluate the function of CircuLite Synergy.

OBJECTIVES: The Synergy CircuLite micropump is a novel partial-support miniature left ventricular assist device that propels 2-3 l/min blood from the left atrium into the right subclavian artery. The ability of currently available investigative modalities to confirm Synergy pump malfunction is limited. The Synergy speed fluctuates periodically (at 10-s intervals) from the baseline to a transient decrease followed by a transient increase (alternating speed algorithm, ASA) with the purpose of changing the blood flow behaviour, thereby reducing thrombogenicity. The aim of this study was to develop a simple non-invasive monitoring technique to assess pump function based on the detection of the ASA in the peripheral microcirculation. METHODS: Between February 2012 and July 2013, 10 patients with advanced chronic heart failure underwent Synergy implantation at our institution. The pump function was assessed by echocardiography and invasive monitoring according to standard protocols; additionally, the pump speed and power consumption were monitored. During the pump function assessment, the pulse oximeter waveform was recorded from the index fingers of the left and right hand with simultaneous pump auscultation using a stethoscope positioned on the pump (right infra-clavicular pocket). RESULTS: The pulse oximeter waveform was readily detectable from the right and left hand of all study patients. If the Synergy function was normal, there was a significant difference in the morphology of the pulse oximeter waveform from each hand: the ASA algorithm produced a more pronounced variation (giant wave) in the trace from the right hand than from the left. The giant waves invariably coincided with the sound variation associated with the ASA algorithms, which were detected regularly at 10-s intervals. CONCLUSIONS: We describe a simple, readily applicable, inexpensive, non-invasive technique that allows evaluation of Synergy pump function and may have diagnostic utility under conditions of suspected pump thrombus/malfunction. This technique is readily applicable from the early post-implant period throughout support and allows clinical personnel to verify blood flow variation through the Synergy, thereby providing a novel method of assessing device function.

Central extracorporeal life support with left ventricular decompression for the treatment of refractory cardiogenic shock and lung failure.

BACKGROUND: The purpose of this prospective study was to evaluate the effects and functional outcome of central extracorporeal life support (ECLS) with left ventricular decompression for the treatment of refractory cardiogenic shock and lung failure. METHODS: Between August 2010 and August 2013, 12 consecutive patients (2 female) with a mean age of 31.6 ± 15.1 years received central ECLS with left ventricular decompression for the treatment of refractory cardiogenic shock and lung failure. Underlying disease was acute cardiac decompensation due to dilated cardiomyopathy (n = 3, 25%), coronary artery disease with acute myocardial infarction (AMI) (n = 3, 25%), and acute myocarditis (n = 6, 50%). We routinely implemented ECLS by cannulating the ascending aorta, right atrium and inserting a left ventricular decompression cannula vent via the right superior pulmonary vein. RESULTS: All patients were successfully bridged to either recovery (n = 3, 25%), long-term biventricular support (n = 6, 50%) or cardiac transplantation (n = 3, 25%). Seven patients (58.3%) were discharged after a mean hospital stay of 42 ± 11.9 days. The overall survival from ECLS implantation to the end of the study was 58.3%. The cumulative ICU stay was 23.1 ± 9.6 days. The length of support was 8.0 ± 4.3 days (range 3-17 days). CONCLUSIONS: We strongly recommend left ventricular decompression in refractory cardiogenic shock and lung failure to avoid pulmonary edema, left heart distension and facilitate myocardial recovery.