The high WBC group (Table 5) had a longer length of in- tensive care unit (ICU, P = 0.046) and a trend toward longer total hospital stay (P = 0.064). There was more postoperative renal failure requiring dialysis in the high WBC group (P = 0.014), but no difference in subsequent permanent dialy- sis (P = 0.611). Postoperatively (Table 5), the higher WBC was more likely to experience right heart failure (13.4% vs 5.8%, P = 0.006), and need for a right ventricularassistdevice (RVAD) (11.0% vs 4.4%, P = 0.008). Patients experiencing postop RVF had a higher preop WBC (11.3 + 5.7 vs 8.7 + 3.1) and CRP (5.6 + 4.4 vs 3.3 + 4.7) levels. For those
A ventricularassistdevice (VAD) is effective for treatment of systolic end-stage heart failure, and can support the patient’s blood circulation until heart transplantation [1–8]. In fact, patients’ 1-year survival rates were three times higher when a VAD was used compared to drug therapies alone [6–8]. Despite the advantages of VADs, they are not widely implemented because of their high cost and risk of critical failure [6–9]. Malfunc- tions and inappropriate control of VADs can seriously damage organs and vessels; there- fore, the outflow of VADs must be monitored to detect device failure or changes in the patient’s physiology [10–15].
Background and purpose: It is unknown what the optimal anticoagulant level is to prevent thromboembolic stroke in patients with left ventricularassistdevice (LVAD) support. We aimed to evaluate the relation between coagulation status and the occurrence of thromboembolic stroke in HeartMate-II LVAD assisted patients. Methods: Thirty-eight consecutive patients with a HeartMate-II LVAD were included. Coagulation status was classified according to INR and aPTT ratio at: 1) the moment of first thromboembolic stroke; and 2) during the two weeks preceding the first thromboembolic stroke to assess long-term coagulation status. In patients without stroke, coagulation status was determined just before heart transplant, VAD explantation or death, whichever came first, and at two weeks preceding these surrogate endpoints. Based on coagulation status, patients were divided in two groups: Group I (reference group) was defined as INR below 2 and aPTT ratio below 1.5; Group II (adequate anticoagulation) as INR above 2 or aPTT ratio above 1.5. Logistic regression analysis was performed to assess the odds ratio for developing stroke for patients with adequate anticoagulation compared to the reference Group. Results: Thromboembolic stroke occurred in six (16 %) patients, none within 2 weeks after LVAD implantation. Considering coagulation status at the time of event, patients in coagulation Group II had no decreased risk for thromboembolic stroke (OR 0.78; 95 % CI 0.12 – 5.0). Results for coagulation status 2 weeks prior of event could not be calculated as all six strokes occurred in Group II.
Advanced heart failure patients are increasingly being treated with left ventricularassistdevice placement; however, definitive evaluation of both left and right ventricular function is required due to the increased mortality rate associated with right heart failure after LVAD placement. Our results suggest that FPRNA only has a moderate correlation with RVEF calculated using cardiac MRI. Furthermore, echocardiographic parame- ters of RV function including TAPSE and FAC demon- strated a fair and moderate agreement, respectively, compared to cardiac MRI suggesting a possible substi- tute for FPRNA. With the increasing need for identifica- tion of patients at risk for right heart failure, further studies are warranted to find a more accurate estimate of RVEF. Since this study and prior studies comparing radionuclide or echocardiographic RV function analysis to cardiac MRI-derived RVEFs produced at best a
analysis of the associated degree of ventricular recovery during left ventricularassistdevice (LVAD) support. An assumption was made there is a linear relationship between ventricular recovery degree and the pump electric current pulsatility index (PI). The experimental study was carried out using the ViVitro Pulse Duplicator System with Sputnik 1 LVAD connected. Cardiac output (CO) and cardiac power output (CPO) were used as a measure of ventricular recovery degree. Different heart rates (HR) (59, 73, 86 bpm) and pump speeds (7600–8400 rpm in 200 rpm steps) were investigated. Ventricular stroke volumes in the range of 30–80 ml for each heart rate at certain pump speed were used. The obtained relationships of CO and CPO vs. PI was linear as the coefficients of determination for each regression curve were more than 0.8. CO vs. PI: R 2 =0.9218; 0.9271; 0.9172 and CPO vs. PI: R 2 =0.8517; 0.841; 0.8244 for HR=59 bpm;
There are only a few reports on the use of assist de- vices in the setting of post partum cardiomyopathy. In cases where LVAD acts as bridge to recovery, it will help maintaining the patient alive, allowing the myocar- dium to recover. Recovery of the left ventricle function in this case is due mainly to recovery of the underlying disease, nevertheless there is now compelling evidence, that near complete unloading of the left ventricle with the use of a left ventricularassistdevice is associated with structural reverse remodeling that can be accompanied by functional improvement [18-23]. Sufficient recovery of left ventricular function, allowing LVAD explantation, however, is rare and is mainly feasible in patients suffer- ing from acute myocarditis or post partum cardiomyopa- thy (PPM) . Explantation in this case can be consid- ered if the following criteria are met while the left ven- tricular assistdevice is off for 15 minutes: 1—Echocar- diographic criteria [18,23]: a left ventricular end diastolic diameter of less than 60 mm, a left ventricular end-sys-
The left ventricularassistdevice was originally designed to be surgically implanted as a bridge to transplantation for patients with chronic end-stage heart failure. On the basis of the REMATCH trial, the US Food and Drug Administration and the US Centers for Medicare & Medicaid Services approved permanent implantation of the left ventricularassistdevice as a destination therapy in Medicare beneficiaries who are not candidates for heart transplantation. The use of the left ventricularassistdevice as a destination therapy raises certain ethical challenges. Left ventricularassist devices can prolong the survival of average recipients compared with optimal medical management of chronic end-stage heart failure. However, the overall quality of life can be adversely affected in some recipients because of serious infections, neurologic complications, and device malfunction. Left ventricularassist devices alter end-of-life trajectories. The caregivers of recipients may experience significant burden (e.g., poor physical health, depression, anxiety, and posttraumatic stress disorder) from destination therapy with left ventricularassist devices. There are also social and financial ramifications for recipients and their families. We advocate early utilization of a palliative care approach and outline prerequisite conditions so that consenting for the use of a left ventricularassistdevice as a destination therapy is a well informed process. These conditions include: (1) direct participation of a multidisciplinary care team, including palliative care specialists, (2) a concise plan of care for anticipated device-related complications, (3) careful surveillance and counseling for caregiver burden, (4) advance-care planning for anticipated end-of-life trajectories and timing of device deactivation, and (5) a plan to address the long-term financial burden on patients, families, and caregivers. Short-term mechanical circulatory devices (e.g. percutaneous cardiopulmonary bypass, percutaneous ventricularassist devices, etc.) can be initiated in emergency situations as a bridge to permanent implantation of ventricularassist devices in chronic end-stage heart failure. In the absence of first-person (patient) consent, presumed consent or surrogate consent should be used cautiously for the initiation of short-term mechanical circulatory devices in emergency situations as a bridge to permanent implantation of left ventricularassist devices. Future clinical studies of destination therapy with left ventricularassist devices should include measures of recipients' quality of end-of-life care and caregivers' burden.
The two-dimensional cavitating flow phenomena due to the valve closure in a ventricularassistdevice were computa- tionally studied. This is a simplification of three-dimensional viscous effects in a ventricular valve. Both laminar flow and turbulent flow were computed and compared with each other. For computations, a dynamic mesh strategy to cope with the movement of the valve was developed. The simulation of cavitation was conducted with a model which took considerations of the first-order effect of the formation and transport of vapor bubbles, the turbulent fluctuations of pressure and velocity, and the magnitude of non-condensable gases. The turbulent flow was computed by using the k- model. The results show that the local turbulence is one of the vital effects on the development of the cavitating flow. The maximum velocity at the moments of valve closure was significantly reduced in the turbulent flow modeling. Tur- bulence also reduces the jet intensity at the valve closure and, hence, the cavitating region on the valve. Furthermore, the results show that the turbulent flow model has a better capability for prediction of cavitation duration.
Background: The Masimo Pronto-7 W calculates hemoglobin (Hb) values using the pulsoximetry technique and a variety of mathematical algorithms analyzing the pulse waveform. Although this system has demonstrated a high level of accuracy in average patients, the performance might be altered in special patient populations. Regarding patients with left ventricular cardiac failure, a rotary blood pump generates a constant, continuous, non-pulsatile flow to improve effective cardiac output. Due to this alteration in both, blood flow and arterial blood pressure we hypothesized a reduced accuracy of the Masimo Pronto-7 W to detect Hb in patients with left ventricular cardiac failure. To test our hypothesis, we evaluated the Pronto-7 W SpHb system in outpatients after continuous-flow-left ventricularassistdevice (cf-LVAD) implantation (HeartMate II, Thoratec).
that damage the heart muscle; one example is coronary artery disease (CAD) wherein arteries are blocked or severely narrowed causing decreased blood flow to the heart muscle and which may lead to myocardial infarction. Infections, alcohol or drug abuse also can cause damage the muscle of the heart. Although heart transplantation remains the most successful long-term treatment for late stage heart failure, the limited number of donors in most regions of the world restricts its widespread adoption. Due to such limitation, VentricularAssist Devices (VAD) have become a promising alternative treatment . It has become an established Abstract: One treatment modality for heart failure is to employ a mechanical heart assistdevice to increase blood flow to peripheral organs. There are various kinds of axial and centrifugal type mechanical pumps available for implantation depending on patient condition. Axial pumps are smaller in size comparatively, although centrifugal pumps have the advantages of lower rotational speed as well as better maintaining any native blood flow pulsatility. This work presents the results of the numerical study of the centrifugal blood pump configured as a Left VentricularAssistDevice (LVAD). The pump design utilized standard industrial centrifugal pump design principles but applied to smaller sized blood pumps. Flow characteristics are modelled using 3-dimensional steady state models operating at design speed of 2000 rpm using Newtonian blood properties for the fluid. Two design parameters of the pump are studied, the impeller blade height and tip clearance resulting in nine model variants. Analysis includes the hydrodynamic performance of the pump and the flow characteristics in the pump. A haemolysis prediction model quantifying red blood cell stress from exposure time and shear stress was used for quantitative predictions of haemolysis within the blood pump. Blood damage estimation was calculated along each path-line and averaged to a single value. By using a ranked selection method, the model with the 15 mm blade height and 800 µm tip clearance was selected as the preferred configuration with Haemolysis Index of 0.01 mmHg, efficiency of 58% at 104 mmHg outlet pressure.
After an atrial switch operation (Mustard or Senning op- eration) for correction of transposition of the great arteries (TGA) or in patients with congenitally corrected TGA (CCTGA), discordant atrioventricular and ventriculoarter- ial connections are both present. Owing to this double discordance, a reconnection of the heart vessels is neces- sary to allow for proper blood circulation. This can be done with the Mustard or Senning procedure, which will help prevent cyanosis. Patients who undergo such arterial switch procedures are surviving to adulthood, but they often develop RV heart failure a few decades later. Implantation of ventricularassistdevice (VAD) is a useful
Left ventricularassistdevice (LVAD) therapy is an established treatment option for select patients with advanced heart failure. Advances in technology and patient management have resulted in improved post-implant outcomes. Consequently, more patients with LVADs are presenting for evaluation and care of non-car- diac surgical disease. However, there is a paucity of literature regarding the optimal perioperative and surgical management of such patients. We present the case of a 71-year-old male with a HeartMate II (Thoratec Corporation, Pleasanton, CA) LVAD, who underwent a laparoscopic left nephroureterectomy for an upper uri- nary tract transitional cell carcinoma. His perioperative course was uneventful due to the multidisciplinary efforts of cardiac surgery, cardiac anesthesia, nephrology and urology. To our knowledge, this is the first reported case of a laparoscopic nephroureterectomy in a patient with a HeartMate II LVAD.
thrombotic events in left ventricularassistdevice patients as a transition to oral anticoagulants but carries the risk of heparin-induced thrombocytopenia. Limited data is available for the treatment of heparin-induced thrombocytopenia in this patient population. We report an evaluation of 8 left ventricularassistdevice patients with suspected or confirmed HIT started on fondaparinux at the time of heparin-induced platelet-factor-4 antibody positivity. Methods: Adult patients were reported if they were heparin-induced platelet antibody positive, tested via enzyme-linked immunusorbent assay, post-operative after left-ventricularassistdevice, and were initiated on fondaparinux at the time of heparin-induced platelet antibody positivity. Waiver of informed consent was granted from the institutional review board. Baseline demographics, clinical course of HIT, safety and efficacy variables were collected.
Abstract: This study deals with an osteopathic approach used for a patient with left-ventricularassistdevice (L-VAD) affected by left brachialgia. Clinical examination revealed the presence of thoracic outlet syndrome and pectoralis minor syndrome, with compression of the left proximal ulnar nerve, related to the surgical sternotomy performed. The osteopathic techniques used can be classified as indirect and direct, addressed to the pectoralis minor and the first left rib, respectively. To our knowledge, this is the first text in literature with an osteopathic treatment in a patient with L-VAD.
EXPERIENCE OF SHORT-TERM VENTRICULARASSISTDEVICE SUPPORT Although participants had been determined and striving towards discharge from hospital, there was also a sense of loss and grieving as their outpatient appointments became less frequent and there was more emphasis on the new heart or LVAD working for itself. There was a fine line between those who were still attending the hospital regularly, that this was a chore, compared to those who were moving towards six monthly reviews. The hospital and staff became like friends and family for many of the participants. The participant (Daisy) who was three years post discharge felt that she had moved on from that period of her life and the sense of loss was not as great. From this position, participants reflected on the changes they had noticed in themselves and that others had noticed in them since the ST-VAD and future plans.
Results: In patients with PVCs or normal heartbeats, CPC controlled by a VAD reduced the cardiac load by 20 and 40%, respectively. When the HR was greater for other reasons, such as sinus tachycardia, simultaneous ejection from the heart and VAD was observed; however, the cardiac load was not increased by rapid cardiac contractions resulting from decreased left ventricle volume. These data suggest that the PLL algo- rithm reduces the cardiac load and maintains consistent hemodynamic changes. Keywords: Windkessel model, Pulsatile ventricularassistdevice, Counter-pulsation control, Phase-locked loop, Arrhythmia
Treatment of ischemic stroke for a patient on left ventricularassistdevice (LVAD) by neurointerventional means is rare and many anesthesia providers are unfamiliar with both LVAD and neurointerventional protocols. Examples of this include: 1) filling for continuous-flow LVAD depend on preload and the flow is inversely related to afterload; as mean arterial pressure (MAP) increases above 80 to 90 mm Hg, flow decreases; 2) there may be no palpable pulse in patients with continuous flow LVADs; 3) pulse oximetry may not work when pump flow is high and native myocardial function is minimal; 4) increasing MAP above 80 mm Hg potentially will maintain ischemic brain tissue—the penumbra—until flow is restored. This latter example creates a paradoxical management goal: increasing the mean arterial pressure (MAP) above 80 mm Hg while maintaining ischemic brain tissue, may decrease flow to the LVAD. Finally, there is controversy regarding which type of anesthesia is most efficacious for neuro interventional procedures. We describe three patients on LVAD suffering ischemic stroke requiring anesthesia for embolectomy and angioplasty during neuro- interventional radiology procedures.
Ongoing limitations in donor heart supply and improve- ments in ventricularassistdevice (VAD) technology have led to increased utilization of VADs as a bridge to transplantation [1-5]. Decreasing mortality and cost of VAD usage in the post-REMATCH era suggest improve- ments in care and resource utilization for patients requir- ing mechanical circulatory support . The impact of prior VAD implantation on heart transplant outcomes has been assessed extensively but uncertainty persists on how the BTT pathway affects transplant outcomes and how this pathway can be optimized for greatest net benefit to the heart transplant population and to the healthcare
All patients who underwent implantation of a CF-LVAD from July 2010 to July 2015 (n = 139) at the University of Pennsylvania were retrospectively reviewed. After initial data accrual, all patient identifiers were removed from the database. The University of Pennsylvania Institutional Review Board (IRB 7) approved this study for investigation. Device selection was based on patient characteristics and surgeons’ preference. Patients were initially not anti-coagulated on post-operative day zero. On post- operative day one, the patients were started on a hep- arin drip with a goal partial thromboplastin time of 45–50 s. Ultimately, all patients were anticoagulated with 325 mg of aspirin and Coumadin to a target International Normalized Ratio (INR) of 2.0–3.0. No addi- tional anti-platelet agents were used in either cohort.