Percutaneous Left Ventricular Support Research Articles

Echocardiographic image monitoring during Impella use: our experience

Abstract Funding Acknowledgements None. Introduction Impella CP is a type of percutaneous left ventricular (LV) mechanical circulatory support located inside LV and placed through the aortic valve. There is little information about the incidence of valvular complications related to its use or other complications assessable by echocardiography. Purpose To determine the existence of complications assessable by echocardiography in patients treated with Impella CP in our centre. Methods Retrospective analysis of patients treated with Impella CP in 2020 and 2021 in our centre. Baseline clinical characteristics were studied and pre- and post-procedure echocardiograms of these patients were reviewed. Results A total of 32 echocardiograms were analysed in 16 patients with a mean age of 70 years. Clinical and echocardiographic features are described in table 1. After device removal, the presence or degree of aortic regurgitation did not change in the patients, including 2 patients who had moderate aortic regurgitation pre-implantation. However, on echocardiograms after device removal, intraventricular thrombus was detected in 2 patients, who also had severe LV systolic dysfunction and who had the longest duration in days of implantation (6 and 7 days). The mean number of days of implantation was 1.68 days. Conclusion Echocardiography is a useful tool for the management and detection of complications during the time of support with Impella CP, such as valve dysfunction and the presence of intraventricular thrombus. In our centre, the use of Impella is not related to the onset or worsening of aortic valve pathology.

Escalation strategies, management, and outcomes of acute myocardial infarction-cardiogenic shock patients receiving percutaneous left ventricular support.

There are limited national-level data on the contemporary practices of mechanical circulatory support (MCS) use in acute myocardial infarction-cardiogenic shock (AMI-CS). We utilized the Healthcare Cost and Utilization Project-National/Nationwide Inpatient Sampledata (2005-2017) to identify adult admissions (>18 years) with AMI-CS. MCS devices were classified as intra-aortic balloon pump (IABP), percutaneous left ventricular assist devices (pLVAD), or extracorporeal membrane oxygenation (ECMO). We evaluated trends in the initial device used (IABP alone, pLVAD alone or ≥2 MCS devices), device escalation, bridging to durable LVAD/heart transplantation, and predictors of in-hospital mortality and device escalation. Among 327,283 AMI-CS admissions, 131,435 (40.2%) had an MCS device placed with available information on timing of placement. IABP, pLVAD, and ≥2 MCS devices were used as initial device in 120,928 (92.0%), 8202 (6.2%), and 2305 (1.7%) admissions, respectively. Most admissions were maintained on the initial MCS device with 1%-1.5% being escalated (IABP to pLVAD/ECMO, pLVAD to ECMO). Urban, medium, and large-sized hospitals and acute multiorgan failure were significant independent predictors of MCS escalation. In admissions receiving MCS, escalation of MCS device was associated with higher in-hospital mortality (adjusted odds ratio:1.56, 95% confidence interval:1.38-1.75; p < 0.001). Admissions receiving durable LVAD/heart transplantation increased over time in those initiated on pLVAD and ≥2 MCS devices, resulting in lower in-hospital mortality. In this 13-year study, escalation of MCS in AMI-CS was associated with higher in-hospital mortality suggestive of higher acuity of illness. The increase in number of durable LVAD/heart transplantations alludes to the role of MCS as successful bridge strategies.

Utilization of the percutaneous left ventricular support as bridge to heart transplantation across the United States: In-depth UNOS database analysis

Intra-aortic balloon pump (IABP) and Impella device utilization as a bridge to heart transplantation (HTx) have risen exponentially. We aimed to explore the influence of device selection on HTx outcomes, considering regional practice variation. A retrospective longitudinal study was performed on a United Network for Organ Sharing (UNOS) registry dataset. We included adult patients listed for HTx between Oct 2018 and April 2022 as status 2, as justified by requiring IABP or Impella support. The primary endpoint was successful bridging to HTx as status 2. Of 32,806 HTx during the study period, 4,178 met inclusion criteria (Impella n = 650, IABP n = 3,528). Waitlist mortality increased from a nadir of 16 (in 2019) to a peak of 36 (in 2022) per thousand status 2 listed patients. Impella annual use increased from 8% in 2019 to 19% in 2021. Compared to IABP, Impella patients demonstrated higher medical acuity and lower success rate of transplantation as status 2 (92.1% vs. 88.9 %, P < 0.001). The IABP: Impella utilization ratio varied widely between regions, ranging from 1.77 to 21.31, with high Impella use in Southern and Western states. However, this difference was not justified by medical acuity, regional transplant volume, or waitlist time and did not correlate with waitlist mortality. The shift in utilizing Impella as opposed to IABP did not improve waitlist outcomes. Our results suggest that clinical practice patterns beyond mere device selection determine successful bridging to HTx. There is a critical need for objective evidence to guide tMCS utilization and a paradigm shift in the UNOS allocation system to achieve equitable HTx practice across the United States.

Impact of hemodynamic support in high-risk VT ablation procedures

Abstract Funding Acknowledgements Type of funding sources: None. Introduction It is an ongoing debate whether VT ablation is better performed in SR or during VT. During SR patients are in stable conditions, however, VT mechanisms can only be visualized during VT. Hemodynamic stability during VT is critical and is shorter in patients with structural heart disease and severely reduced left ventricular ejection fraction (LVEF). In unstable VT with need for cardioversion, the risk of map anatomy shifts is increased, but a precise anatomical reconstruction is crucial for successful ablation. Considering hemodynamic support during VT ablation, handling must be easy and as little disruptive to the ablation procedure as possible. Percutaneous left ventricular support systems with appropriate access size seem to be the most suitable, but are limited in their support capacity. The aim of this study was to evaluate, whether a hemodynamic support of a maximum of 3,5 L/min is sufficient to ensure hemodynamic stability even in faster VT. Methods The study enrolled patients with a history of one or more sustaining VTs and severely reduced LVEF. Procedure was performed under deep sedation. Transseptal and transaortal access was prepared to access the LV. In epicardial cases an additional subxiphoidal access was used. Impella CP with SmartAssist was introduced via the opposite groin. Hemodynamic support was started immediately after placement. VTs were induced via programmed RV and burst pacing. VT was mapped and ablated with the Carto 3 Mapping system. The need to frequently adjust pump setting, duration of hemodynamic stability during VT, identification of VT mechanism and ablation success were evaluated. Results 8 patients with a total of 21 VTs have been mapped, analyzed and ablated. 4/8 patients received epi-/endocardial ablation. With hemodynamic support, all VTs could be mapped under stable conditions (CLmedian VT = 360ms). 87,5% could be terminated during catheter ablation, in 50% no VT was reinducible after ablation. The median time for Impella placement was 20min. The Smart Assist Mode enabled an easy handling without the necessity of manual adjustments during the course of the case. The Impella could be explanted at the end of the procedure in 7 out of 8 cases. Femoral closure was done with either Proglide or AngioSeal closure device. Post procedural, one patient developed a segmental stenosis of the A. femoralis superficialis, most likely due to the Proglide device. This case was treated conservatively and recovered after a few months. Conclusion Hemodynamic support of a maximum of 3,5L/min provides adequate and effective support for mapping of sustained VTs. No manual adjustment was required and patients could in general be weaned directly at the end of the procedure. Broader benefits of this concept need to be evaluated in further studies.

(750) Determinants of Successful Bridging to Heart Transplantation on Temporary Percutaneous Left Ventricular Support - An Insight Using Artificial Intelligence

(750) Determinants of Successful Bridging to Heart Transplantation on Temporary Percutaneous Left Ventricular Support - An Insight Using Artificial Intelligence

Abstract 15122: Escalation Strategies, Management, and Outcomes of Acute Myocardial Infarction-Cardiogenic Shock Patients Receiving Percutaneous Left Ventricular Support

Introduction: Despite well-established device selection algorithms, there remain wide variations in mechanical circulatory support (MCS) device utilization in patients with cardiogenic shock complicating acute myocardial infarction (AMI-CS). Further, there are limited national-level data on the contemporary practices of MCS device use. Methods: To evaluate national utilization patterns of MCS devices, we identified adult admissions (&gt;18 years) with AMI-CS from the HCUP-NIS data (2005-2017). Use of MCS devices including intraaortic balloon pump (IABP), percutaneous left ventricular assist devices (pLVAD) (Impella/Tandem Heart), and extracorporeal membrane oxygenation (ECMO) during hospitalization was identified. We evaluated trends in the initial MCS device used (IABP alone, pLVAD alone, or ≥2 MCS devices), device escalation, bridging to durable LVAD/heart transplantation, and predictors of in-hospital mortality and device escalation. Results: Among a total of 327,283 AMI-CS admissions in this 13-year period, 132,146 (40.2%) had an MCS device with information on timing of placement. IABP, pLVAD, ≥2 MCS, and ECMO devices were used as initial device in 120,928 (92.0%), 8,202 (6.2%), 2,305 (1.7%), and 711 (0.1%) admissions, respectively. Most admissions were maintained on initiated MCS device with 1-1.5% being escalated (IABP to pLVAD/ECMO, pLVAD to ECMO). The median time to escalation across all devices categories was 2 (IQR 1-4) days. Urban, medium, and large-sized hospitals, and acute multiorgan failure were significant independent predictors of MCS escalation. In admissions receiving MCS, escalation of MCS device was associated with higher in-hospital mortality (adjusted OR 1.56, 95% CI 1.38-1.75; p &lt;0.001). Admissions receiving durable LVAD/heart transplantation increased over time in those initiated on pLVAD and ≥2 MCS devices resulting in lower in-hospital mortality. Conclusions: In this 13-year study, escalation from initial MCS device was associated with higher in-hospital mortality suggestive of higher acuity of illness. However, the observed increase in number of durable LVADs or heart transplantations may be an indication of the utility of these MCS devices as successful bridge therapies.

Percutaneous coronary intervention combining rotational atherectomy and intravascular lithotripsy in two vessels with edge restenosis assisted by percutaneous left ventricular pump support.

Percutaneous coronary intervention combining rotational atherectomy and intravascular lithotripsy in two vessels with edge restenosis assisted by percutaneous left ventricular pump support.

Outcomes with Impella in Cardiogenic Shock

Background The Impella (ABIOMED, Danvers, MA) is a temporary left ventricular support device, intended for short-term cardiac support for percutaneous procedures and cardiac shock. The Impella device is available in several sizes capable of producing different flows. It is FDA approved for up to 6 days of support. The device can provide significantly higher blood flow than an intra-aortic balloon pump and can be implanted percutaneously. We sought to describe potential complications and outcomes associated with extended Impella use for cardiogenic shock. Methods We retrospectively evaluated patients who underwent implantation of either the Impella CP (Impella 3.5) or Impella 5.0 from September 1, 2017 to September 1, 2019 at our institution. Hemolysis was defined as plasma free hemoglobin level > 50 mg/dL, a lactate dehydrogenase (LDH) level > 500 units/L, and bilirubin increase > 1 mg/dL. Results 58 patients underwent percutaneous insertion of an Impella device, with the indication of cardiogenic shock in 32 patients (55%). In these 32 patients, only one had an Impella 2.5 device, 21 had an Impella CP (66%), and 10 (31%) had an Impella 5.0. The average age at time of implantation was 55 ± 17 years, and 25 patients were male (78%). Ejection fraction was 17 ± 11.7%. The average duration of Impella support was 5.5 days (1, 16 days). Complications included hematoma at the time of insertion (3 patients), leg ischemia (2 patients), improper positioning (7 patients), acute renal failure (28 patients), and hemolysis (20 patients). Hemolysis developed in 12 patients (57%) with the Impella CP and in 8 patients (80%) with the Impella 5.0, with an average LDH of 1452 units/L. 8 patients were transitioned to veno-arterial (VA) extracorporeal membrane oxygenation (ECMO), with the Impella utilized for left ventricular venting. 9 patients (28%) eventually underwent durable left ventricular assist device (LVAD) implantation on average 7 ± 6.1 days after Impella, and two patients underwent heart transplantation, both 9 days following Impella insertion. 23 patients (72%) did not survive past the initial hospitalization. Conclusion The Impella is a percutaneous temporary left ventricular support device used to provide additional cardiac output in patients with cardiogenic shock. Serious complications can occur with extended support, including hemolysis, acute renal failure, and high mortality. Of our 28 patients who received an Impella, 11 were able to be successfully bridged to either LVAD or heart transplantation with the Impella.

Ischemic Stroke and Intracranial Hemorrhages during Percutaneous Left Ventricular Assist Device Cardiac Support

Mechanical circulatory support systems for cardiogenic shock and heart failure are associated with ischemic strokes and intracranial hemorrhages. Impella is a percutaneously placed, ventricular assist device for short-term cardiac support. We aimed to study the prevalence of acute neurologic complications during short-term support with Impella. We reviewed prospectively collected data of 79 consecutive persons implanted with Impella at a single, tertiary center between October 2010 to July 2018. Acute neurological events (ANE) were defined as ischemic strokes or intracranial hemorrhages, including intracerebral hemorrhage, subdural hematomas and subarachnoid hemorrhages. Among those with ANE, specific causes of ischemic and hemorrhagic events were collected and discussed. Of 79 persons with Impella with median 8 days of support (range 1-33 days), 6 (7.5%) developed ANE at a median of 5 days from implant (range 1-8 days). There were 3 ischemic strokes, 2 intracerebral hemorrhages, and 1subdural hematoma. Hemorrhagic events were attributed to anticoagulant use and thrombocytopenia at the time of the events. Two ischemic strokes were attributed to inadequate anticoagulation with one case of pump thrombosis diagnosed at time of ischemic stroke. Only 2 of the 6 patients survived the acute cardiogenic shock period to achieve heart transplantation. In-hospital ischemic strokes and intracranial hemorrhages are common during the short-term cardiac support period with Impella. Antithrombotic intensity, duration of device support time, and thrombocytopenia might contribute to the incidence of these events.

Sex-related disparities in obstructive coronary artery disease, percutaneous coronary intervention, and mortality in adults with cardiac arrest

ObjectivesDespite numerous advances in the delivery of resuscitative care, cardiac arrest (CA) continues to be associated with high morbidity and mortality. We sought to examine the association between sex and presence of obstructive coronary artery disease (CAD), percutaneous coronary intervention (PCI), and mortality in adults with CA. MethodsThe study population included 208 consecutive patients hospitalized with CA who underwent resuscitation and subsequent coronary angiogram at an academic tertiary medical center. The primary outcome of interest was presence of obstructive CAD, defined as >1 coronary artery with >70% stenosis or >1 coronary bypass graft with >70% stenosis. ResultsOf the study population, 150 patients (72%) were men and 58 (28%) were women. Women had a trend toward lower rates of obstructive CAD (69% vs 80%, p = 0.09) and lower rates of multivessel CAD compared to their male counterparts, but no significant difference in rates of PCI (62% vs 53%, p = 0.26). While rates of therapeutic hypothermia and vasopressor requirement were similar in men and women, women were less likely to require percutaneous left ventricular support. In-hospital mortality rates were similar in men and women (23% vs 21%, p = 0.68). In multivariate analysis, sex was not independently associated with obstructive CAD or mortality. ConclusionsIn this observational contemporary study of adults with CA undergoing coronary angiogram, although women had a trend toward lower rates of obstructive CAD, no significant difference in rates of PCI and in-hospital mortality were noted between men and women.

(131) - Association Between the Use of Invasive Hemodynamic Monitoring and Outcomes with Percutaneous Left Ventricular Support: A Call for Standardization?

(131) - Association Between the Use of Invasive Hemodynamic Monitoring and Outcomes with Percutaneous Left Ventricular Support: A Call for Standardization?

CRT-200.40 Impact of Left Ventricular Support Device on Surgically Rejected Patients Undergoing Unprotected Left Main Percutaneous Coronary Intervention

In patients undergoing high risk percutaneous coronary intervention (PCI) a percutaneous left ventricular support device is often used, especially in unprotected left main (ULM) disease. For these patients, we sought to determine if there is an impact of device support use on short and long term

PREDICTORS OF 30-DAY MORTALITY AND OUTCOMES IN PATIENTS WHO RECEIVE PERCUTANEOUS LEFT-VENTRICULAR SUPPORT WITH AN IMPELLA ASSIST DEVICE

Cardiogenic shock (CGS) is associated with increased mortality despite advancements in treatment options. The purpose of this study was to determine the predictors of 30-day mortality and outcomes in consequtive CGS patients of multiple etiologies who received percutaneous left ventricular support with an Impella device (Abiomed Inc, Boston, Mass). This single-center registry retrospectively included 41 patients (58.5+16.4 years; 68.2% male) with CGS receiving Impella left ventricular assist device for temporary circulatory support implanted at the Peter Munk Cardiac Centre in Toronto, Ontario. The demographic characteristics are shown in table 1. The primary end-point was mortality at 30 days. Secondary endpoints included change in plasma lactate levels, early major adverse cardiac and cerebrovascular events and device-related complications. Successful implantation of Impella was performed in all patients. Thirty day mortality was 48.8% in the study population. Following implantation of the Impella, lactate levels decreased from 3.9+3.7 mmol/L to 1.8+2.06 mmol/L at 48 hours. Major bleeding at access site requiring blood transfusion occurred in 4 (9.8%) patients, and hemolysis occurred in 1 patient. Lactate level >3.8 mmol/L at admission was identified as a predictor of 30-day mortality on multivariate analysis (figure 1). In this study, we describe ‘real-world’ clinical outcomes following the use of temporary mechanical circulatory support with the Impella device in CGS. In this patient cohort, baseline lactate levels predicted 30-day mortality, and insertion of the Impella resulted in significant lactate reduction at 48-hours. This finding suggests that very early insertion of this device may significantly improve outcomes, a finding that should be evaluated in prospective clinical trials.View Large Image Figure ViewerDownload (PPT)

TCT-204 Predictors of 30-day mortality and outcomes in patients who receive percutaneous left-ventricular support with an Impella assist device

Cardiogenic shock (CGS) is associated with increased mortality despite advancements in treatment. Although CGS complicates around 10% of acute myocardial infarction, it accounts for almost 90% of mortality in this patient sub-group. The purpose of this study was to determine the predictors of 30-day

CRT-162 Impella® and Tandem Heart® for Circulatory Support in Refractory Cardiogenic Shock

Previous studies demonstrate that in patients with cardiogenic shock the Impella® (Abiomed, Danvers, MA) and Tandem Heart® (CardiacAssist, Pittsburg, PA) percutaneous left ventricular hemodynamic support devices improve cardiac index, systemic blood pressure and mixed venous oxygen saturation.

Feasibility and efficacy of the 2.5 L and 3.8 L impella percutaneous left ventricular support device during high‐risk, percutaneous coronary intervention in patients with severe aortic stenosis

Assessment of the feasibility and outcomes of the 2.5 L and 3.8 L Impella cardiac pump in patients with severe aortic stenosis (AS) and left ventricular impairment undergoing percutaneous revascularization (PCI) with or without balloon aortic valvuloplasty (BAV). We reviewed the clinical and procedural findings from a consecutive series of unselected patients with severe AS who underwent PCI during Impella support. In addition, we describe novel "balloon-assist" techniques that allowed implantation of Impella into the left ventricle (LV) when initial unassisted attempts failed. Five patients with severe AS were identified (four males, age 78.2 years, aortic valve area (AVA) 0.6 cm(2) , left ventricular ejection fraction (LVEF) 24 ± 5%, mean Society of Thoracic Surgeons (STS) mortality 11% (range 3-17%)). The Impella catheter traversed the aortic valve (AV) unassisted in only one patient, with four cases requiring balloon-assist techniques. All patients underwent planned revascularisation; mean procedure time 177 min (range 135-252 min), mean number of stents 3.4 (range 1-8), with three patients requiring rotational atherectomy. All procedures were well tolerated, with absence of arrhythmia, hypotension, pulmonary edema, stroke, or myocardial infarction. One patient died 48 hr post-PCI of multi-organ failure. The four remaining patients were well at 30 days. Implantation of the 2.5 and 3.8 L Impella appears feasible in patients with severe AS and left ventricle (LV) impairment. A balloon-assist technique may be used to facilitate device implantation when initial unassisted attempts fail. Improved hemodynamic stability may enhance the tolerability of lengthy and complex procedures.

Letter by Maini Regarding Article, “Percutaneous Left-Ventricular Support With the Impella-2.5-Assist Device in Acute Cardiogenic Shock: Results of the Impella-EUROSHOCK-Registry”

In their article, Lauten et al1 describe very eloquently the continued dismal prognosis of patients presenting with cardiogenic shock,2 despite tremendous strides that have been made in the field of cardiovascular medicine. The patients included in the registry met the diagnosis of cardiogenic shock as per the standard definitions from the SHOCK trial and underwent standard of care treatment, including high-dose vasopressors and intra-aortic balloon pump support if considered necessary, and the decision to institute Impella LP 2.5 …

Response to Letter Regarding Article, “Percutaneous Left-Ventricular Support With the Impella-2.5-Assist Device in Acute Cardiogenic Shock Results of the Impella-EUROSHOCK-Registry”

In their article, Lauten et al1 describe very eloquently the continued dismal prognosis of patients presenting with cardiogenic shock,2 despite tremendous strides that have been made in the field of cardiovascular medicine. The patients included in the registry met the diagnosis of cardiogenic shock as per the standard definitions from the SHOCK trial and underwent standard of care treatment, including high-dose vasopressors and intra-aortic balloon pump support if considered necessary, and the decision to institute Impella LP 2.5 …

Percutaneous Left-Ventricular Support With the Impella-2.5–Assist Device in Acute Cardiogenic Shock

Background— Acute cardiogenic shock after myocardial infarction is associated with high in-hospital mortality attributable to persisting low-cardiac output. The Impella–EUROSHOCK-registry evaluates the safety and efficacy of the Impella-2.5–percutaneous left-ventricular assist device in patients with cardiogenic shock after acute myocardial infarction. Methods and Results— This multicenter registry retrospectively included 120 patients (63.6±12.2 years; 81.7% male) with cardiogenic shock from acute myocardial infarction receiving temporary circulatory support with the Impella-2.5–percutaneous left-ventricular assist device. The primary end point evaluated mortality at 30 days. The secondary end point analyzed the change of plasma lactate after the institution of hemodynamic support, and the rate of early major adverse cardiac and cerebrovascular events as well as long-term survival. Thirty-day mortality was 64.2% in the study population. After Impella-2.5–percutaneous left-ventricular assist device implantation, lactate levels decreased from 5.8±5.0 mmol/L to 4.7±5.4 mmol/L ( P =0.28) and 2.5±2.6 mmol/L ( P =0.023) at 24 and 48 hours, respectively. Early major adverse cardiac and cerebrovascular events were reported in 18 (15%) patients. Major bleeding at the vascular access site, hemolysis, and pericardial tamponade occurred in 34 (28.6%), 9 (7.5%), and 2 (1.7%) patients, respectively. The parameters of age &gt;65 and lactate level &gt;3.8 mmol/L at admission were identified as predictors of 30-day mortality. After 317±526 days of follow-up, survival was 28.3%. Conclusions— In patients with acute cardiogenic shock from acute myocardial infarction, Impella 2.5–treatment is feasible and results in a reduction of lactate levels, suggesting improved organ perfusion. However, 30-day mortality remains high in these patients. This likely reflects the last-resort character of Impella-2.5–application in selected patients with a poor hemodynamic profile and a greater imminent risk of death. Carefully conducted randomized controlled trials are necessary to evaluate the efficacy of Impella-2.5–support in this high-risk patient group.

Temporary Percutaneous Left Ventricular Support for Ablation of Untolerated Ventricular Tachycardias

Catheter ablation is increasingly recognized as an important option for the treatment of ventricular tachycardia (VT) in the serious clinical settings of frequent implantable cardioverter defibrillator shocks, and arrhythmia storms, in a variety of structural heart diseases.1 The high incidence of VTs that are not hemodynamically tolerated forces challenges to the traditional approaches of using activation and entrainment mapping to localize the ablation target area, in favor of a strategy of substrate modification that can be performed during sinus rhythm. In some patients, however, a clear target cannot be detected during sinus rhythm; this frequently occurs in some forms of nonischemic cardiomyopathies. More recently, interest is growing in the possibility of making VT tolerable through cardiopulmonary support. Article see p 1202 In this issue of Circulation: Arrythmia and Electrophysiology , Ostadal et al2 provide experimental data on the different capabilities offered by 3 commercially available support systems. It should be kept in mind, however, that these systems are Food and Drug Administration–approved only to support temporary high-risk situations. The data offered in this study are limited in that they provide only information related to systemic arterial pressure in healthy animals and do not allow any evaluation of the different levels of perfusion attained at individual critical organs, ie, brain or kidney. The study does, however, offer a comparative evaluation of the performances of these different systems and offers the opportunity to discuss advantages and limitation of their use. Percutaneous left ventricular assist devices (pLVAD) are increasingly used in few high-volume and skilled centers around the world in an attempt to achieve hemodynamic support during previously nontolerated ventricular arrhythmias to allow use of electrophysiological maneuvers to identify the critical isthmus of the circuit where an effective ablation will produce a permanent interruption of the VT. It is hoped that …