Protamine titration to optimize heparin antagonization after cardiopulmonary bypass.

OBJECTIVES: To optimize protamine titration for heparin antagonization after weaning from cardiopulmonary bypass (CPB). DESIGN: A prospective, observational trial. SETTING: Single-center, non-university teaching hospital. PARTICIPANTS: Forty patients presenting for elective on-pump coronary artery bypass grafting with or without single valve surgery. INTERVENTIONS: At the end of CPB, the residual amount of heparin in the patient was estimated using a Bull-curve. The total protamine dose was calculated as 1 unit of protamine for 1 unit of heparin. Protamine was administered as 5 aliquots containing 20% of the total protamine dose each, with 2-min intervals. MEASUREMENTS AND MAIN RESULTS: Activated Clotting Time (ACT) values were measured 2 min after administration of each aliquot. ROTEM(®)-analysis was performed after the full dose of protamine had been administered. After 60% of the total protamine dose had been administered, ACT values were normalized in 86.5% of patients. After the complete dose of protamine had been administered, 61.1% of patients displayed signs of protamine overdose on ROTEM(®)-analysis. CONCLUSIONS: In patients who present for on-pump coronary artery bypass grafting with or without single valve surgery, a 0.6-to-1 ratio of protamine-to-heparin to antagonize heparin may be sufficient and beneficial for patients.

Assessing Left Ventricular Early Diastolic Velocities With Tissue Doppler and Speckle Tracking by Transesophageal and Transthoracic Echocardiography.

BACKGROUND: Assessing diastolic dysfunction is essential and should be part of every routine echocardiography examination. However, clinicians routinely observe lower mitral annular velocities by transesophageal echocardiography (TEE) under anesthesia than described by awake transthoracic echocardiography (TTE). It would be important to know whether this difference persists under constant loading conditions. We hypothesized that mean early diastolic mitral annular velocity, measured by tissue Doppler imaging (TDI, JOURNAL/asag/04.03/00000539-202105000-00029/inline-graphic1/v/2021-04-15T211206Z/r/image-tiff) would be different in the midesophageal 4-chamber (ME 4Ch) than in the apical 4-chamber (AP 4Ch) view under unchanged or constant loading conditions. Secondarily we examined (1) JOURNAL/asag/04.03/00000539-202105000-00029/inline-graphic2/v/2021-04-15T211206Z/r/image-tiff in an alternative transesophageal view with presumed superior Doppler beam alignment, the deep transgastric view (DTG), compared to those in the AP 4Ch, and (2) early diastolic speckle tracking-based strain rate (JOURNAL/asag/04.03/00000539-202105000-00029/inline-graphic3/v/2021-04-15T211206Z/r/image-tiff), in the ME 4Ch and in the AP 4Ch. METHODS: Twenty-five consecutive adult patients undergoing on-pump cardiac surgery from February 2017 to July 2017 were included. Both TTE and TEE measurements were obtained under anesthesia in a randomized order in the AP 4Ch, ME 4Ch, and DTG views. Within-patient average values were compared by paired t tests with a Bonferroni adjustment. Box plots, correlation, and agreement by Bland-Altman were examined for all 3 comparisons. A second echocardiographer independently acquired and analyzed images; images were reanalyzed after 4 weeks. Image quality and reproducibility were also reported. RESULTS: Averaged JOURNAL/asag/04.03/00000539-202105000-00029/inline-graphic4/v/2021-04-15T211206Z/r/image-tiff measurements were lower in the ME 4Ch than in the AP 4Ch (6.6 ± 1.7 cm/s vs 7.0 ± 1.5 cm, P = .028; within-patient difference mean ± standard deviation: 0.6 ± 1.2 cm/s). An alternative TEE view for JOURNAL/asag/04.03/00000539-202105000-00029/inline-graphic5/v/2021-04-15T211206Z/r/image-tiff, the DTG, also exhibited lower mean values (6.0 ± 1.6 cm/s, P = .006; within-patient difference mean ± standard deviation: 1.1 ± 1.8 cm/s). JOURNAL/asag/04.03/00000539-202105000-00029/inline-graphic6/v/2021-04-15T211206Z/r/image-tiff strain rate showed a low degree of bias, but greater variability (ME 4Ch: 0.87 ± 0.32%/s vs AP 4Ch: 0.73 ± 0.18%/s, P = .078; within-patient difference mean ± standard deviation: -0.1 ± 0.2%/s). CONCLUSIONS: This study confirms that TEE modestly underestimates JOURNAL/asag/04.03/00000539-202105000-00029/inline-graphic7/v/2021-04-15T211206Z/r/image-tiff but not to a clinically relevant extent. While JOURNAL/asag/04.03/00000539-202105000-00029/inline-graphic8/v/2021-04-15T211206Z/r/image-tiff in the DTG is not a promising alternative, the future role for speckle tracking-based early diastolic strain rate is unknown.

Current Anesthetic Care of Patients Undergoing Transcatheter Aortic Valve Replacement in Europe: Results of an Online Survey.

OBJECTIVES: Transcatheter aortic valve replacement (TAVR) has become an alternative treatment for patients with symptomatic aortic stenosis not eligible for surgical valve replacement due to a high periprocedural risk or comorbidities. However, there are several areas of debate concerning the pre-, intra- and post-procedural management. The standards and management for these topics may vary widely among different institutions and countries in Europe. DESIGN: Structured web-based, anonymized, voluntary survey. SETTING: Distribution of the survey via email among members of the European Association of Cardiothoracic Anaesthesiology working in European centers performing TAVR between September and December 2018. PARTICIPANTS: Physicians. MEASUREMENTS AND MAIN RESULTS: The survey consisted of 25 questions, including inquiries regarding number of TAVR procedures, technical aspects of TAVR, medical specialities present, preoperative evaluation of TAVR candidates, anesthesia regimen, as well as postoperative management. Seventy members participated in the survey. Reporting members mostly performed 151-to-300 TAVR procedures per year. In 90% of the responses, a cardiologist, cardiac surgeon, cardiothoracic anesthesiologist, and perfusionist always were available. Sixty-six percent of the members had a national curriculum for cardiothoracic anesthesia. Among 60% of responders, the decision for TAVR was made preoperatively by an interdisciplinary heart team with a cardiothoracic anesthesiologist, yet in 5 countries an anesthesiologist was not part of the decision-making. General anesthesia was employed in 40% of the responses, monitored anesthesia care in 44%, local anesthesia in 23%, and in 49% all techniques were offered to the patients. In cases of general anesthesia, endotracheal intubation almost always was performed (91%). It was stated that norepinephrine was the vasopressor of choice (63% of centers). Transesophageal echocardiography guiding, whether performed by an anesthesiologist or cardiologist, was used only ≤30%. Postprocedurally, patients were transferred to an intensive care unit by 51.43% of the respondents with a reported nurse-to-patient ratio of 1:2 or 1:3, to a post-anesthesia care unit by 27.14%, to a postoperative recovery room by 11.43%, and to a peripheral ward by 10%. CONCLUSION: The results indicated that requirements and quality indicators (eg, periprocedural anesthetic management, involvement of the anesthesiologist in the heart team, etc) for TAVR procedures as published within the European guideline are largely, yet still not fully implemented in daily routine. In addition, anesthetic TAVR management also is performed heterogeneously throughout Europe.

The evolving role of the modern perfusionist: insights from transesophageal echocardiography.

Transesophageal echocardiography is a relatively non-invasive, mobile, safe imaging technique that is ideal for providing real-time information on cardiac anatomy and function during heart surgery. The technology has evolved from two-dimensional to real-time three-dimensional imaging during cardiac procedures, which has significantly benefited preoperative planning, intraoperative guidance, evaluation, and postoperative follow-up. Transesophageal echocardiography may serve the clinical perfusionist by providing imaging guidance for identifying potential problems before cardiopulmonary bypass, guiding the proper placement of cannulas, monitoring cardiac performance on cardiopulmonary bypass, and providing useful feedback during weaning from cardiopulmonary bypass. Although the perfusionist should be able to understand all echocardiographic images and measurements in depth, perfusion-related echocardiographic information can or should be used to optimize the clinical practice of the modern perfusionist. Vice versa, whenever the perfusionist suspects a problem, the surgical team including the sonographer should verify this "clinical treat" by echocardiography whenever possible.

Right Ventricular Systolic Assessment by Transesophageal Versus Transthoracic Echocardiography: Displacement, Velocity, and Myocardial Deformation.

OBJECTIVE: First, to compare tricuspid annular displacement and velocity in transthoracic and transesophageal echocardiography (TTE, TEE) using conventional angle-dependent technologies. Second, to evaluate both alternative TEE views as well as an alternative technology (speckle tracking) for overcoming proposed differences in TTE and TEE. DESIGN: Prospective, comparative, cross-over study with a randomized order of image acquisition. SETTING: University hospital. PARTICIPANTS: Adults undergoing cardiac surgery. INTERVENTIONS: Postinduction standardized image acquisition and analysis in TTE and TEE by 2 echocardiographers. MEASUREMENTS AND MAIN RESULTS: The authors measured tricuspid annular plane systolic excursion (TAPSE) by M-mode and velocity by tissue Doppler (S') in the apical 4-chamber TTE view and midesophageal 4-chamber TEE view (AP4C, ME4C). They then examined (1) the same measurements in alternative TEE views with proposed better ultrasound angulation; and (2) speckle tracking-based endpoints (TAPSE by speckle tracking, strain, and strain rate). Data were available in 24 of 25 patients. Conventional TAPSE by M-mode and velocity by tissue Doppler (TDI) were underestimated in the ME4C compared with the AP4C reference (mean ± standard deviation: TAPSE: 13.1 ± 3.8 mm v 17.3 ± 4.0 mm; S': 6.7 ± 2.1 cm/s v 9.1 ± 2.2 cm/s; both p < 0.001). Neither a modified deep transgastric view (TAPSE 14.5 ± 4.7 mm, p = 0.017; S' 6.8 ± 1.8 cm/s, p < 0.001) nor a transgastric right ventricular inflow view (TAPSE 12.3 ± 4.0 mm, p = 0.001; S' 6.0 ± 1.3 cm/s, p < 0.001) was similar to the AP4C. Speckle tracking TAPSE was unbiased but with high variability (mean bias = -0.3 mm, 95% limits of agreement = -9.1 to 8.4); strain and strain rate were higher in TEE than for TTE (-17.7 ± 3.6 v -12.6 ± 2.1, p < 0.001; -1.0 ± 0.2/s v -0.7 ± 0.1/s, p < 0.001). CONCLUSIONS: Right ventricular displacement, velocity, and myocardial deformation measured by TEE versus TTE are different. Neither alternative transesophageal echocardiography views nor speckle tracking-based deformation is promising; TAPSE by speckle tracking is unbiased but imprecise.

Rapid, Single-View Speckle-Tracking-Based Method for Examining Left Ventricular Systolic and Diastolic Function in Point of Care Ultrasound.

OBJECTIVES: A rapid, reliable quantitative assessment of left ventricular systolic and diastolic function is important for patient treatment in urgent and dynamic settings. Quantification of annular velocities based on a single 2-dimensional image loop, rather than on Doppler velocities, could be useful in point-of-care or focused cardiac ultrasound. We hypothesized that novel speckle-tracking-based mitral annular velocities would correlate with reference standard tissue Doppler imaging (TDI) velocities in a focused cardiac ultrasound-esque setting. METHODS: Two echocardiographers each performed transthoracic echocardiographic measurements before and after induction of anesthesia in supine patients undergoing cardiac surgery. Speckle-tracking echocardiography (STE)-based systolic (S'STE ) and diastolic (E'STE and A'STE ) velocities were compared to TDI and global longitudinal strain/strain rate. We also compared mitral annular displacement by speckle tracking with M-mode imaging. RESULTS: Twenty-five patients were included and examined in both preinduction and postinduction states. Speckle-tracking-based velocities correlated with TDI measurements in both states (S', r = 0.73 and 0.76; E', r = 0.87 and 0.65; and A', r = 0.65 and 0.73), showing a mean bias of 25% to 30% of the reference standard measurement. The correlation of S'STE with strain and the strain rate (S-wave) and E'STE with the strain rate (E-wave) was good in awake, spontaneously breathing patients but was less strong in the ventilated state. Similarly, displacement by speckle tracking correlated with M-mode measurements in both states (r = 0.91 and 0.84). Measurements required medians of 31 and 34 seconds; reproducibility was acceptable for S'STE and E'STE . CONCLUSIONS: Speckle-tracking-based mitral annular velocities and displacement correlate well with conventional measures as well as with deformation imaging. They may be clinically useful in rapidly assessing both systolic and diastolic function from a single 2-dimensional image loop.

Point-of-care ultrasound in pregnancy: gastric, airway, neuraxial, cardiorespiratory.

PURPOSE OF REVIEW: This review focuses on the use of point-of-care ultrasound (PoCUS) in the obstetric context for airway management and assessment of aspiration risk, the placement of neuraxial blocks and the diagnosis and follow-up of cardiorespiratory dysfunction. RECENT FINDINGS: Gastric ultrasound is a useful aspiration risk assessment tool in pregnant patients. Total gastric fluid assessment models and specific cut-offs between high-risk and low-risk stomachs are presented. Airway assessment is useful to detect specific changes in pregnancy and to guide airway management. Handheld ultrasound devices with automated neuraxial landmark detection capabilities could facilitate needle placement in the future. Lung and cardiac ultrasonography is useful in the management of preeclampsia, pulmonary arterial hypertension and peripartum cardiomyopathy. SUMMARY: Owing to its noninvasiveness, ease of accessibility and lack of exposure to radiation, PoCUS plays an increasing and essential role in aspiration risk assessment, airway management, neuraxial anaesthesia and cardiorespiratory diagnosis and decision-making during pregnancy.

Use of Levosimendan in Intensive Care Unit Settings: An Opinion Paper.

Levosimendan is an inodilator that promotes cardiac contractility primarily through calcium sensitization of cardiac troponin C and vasodilatation via opening of adenosine triphosphate-sensitive potassium (KATP) channels in vascular smooth muscle cells; the drug also exerts organ-protective effects through a similar effect on mitochondrial KATP channels. This pharmacological profile identifies levosimendan as a drug that may have applications in a wide range of critical illness situations encountered in intensive care unit medicine: hemodynamic support in cardiogenic or septic shock; weaning from mechanical ventilation or from extracorporeal membrane oxygenation; and in the context of cardiorenal syndrome. This review, authored by experts from 9 European countries (Austria, Belgium, Czech republic, Finland, France, Germany, Italy, Sweden, and Switzerland), examines the clinical and experimental data for levosimendan in these situations and concludes that, in most instances, the evidence is encouraging, which is not the case with other cardioactive and vasoactive drugs routinely used in the intensive care unit. The size of the available studies is, however, limited and the data are in need of verification in larger controlled trials. Some proposals are offered for the aims and designs of these additional studies.

A Novel Speckle-Tracking Based Method for Quantifying Tricuspid Annular Velocities in TEE.

OBJECTIVES: A novel speckle-tracking-based option for measuring tricuspid annular velocities in the midesophageal 4-chamber view (ME4C) was compared with velocities measured by tissue Doppler in the apical-4 chamber view (AP4C). Because this method was based on a modified speckle-tracking-based measurement of tricuspid annular plane systolic excursion (TAPSE), the authors also compared TAPSE by speckle tracking in the ME4C with TAPSE by M-mode in the AP4C. The authors hypothesized that velocities measured by speckle tracking in transesophageal echocardiography (TEE) would be similar, correlate, and agree with those measured by tissue Doppler in transthoracic echocardiography (TTE). DESIGN: Prospective diagnostic study with randomization of the order of post-induction echocardiography views by TTE (AP4C) and TEE (ME4C). Images were both acquired and analyzed by 2 echocardiographers independently. The primary outcome was S'; secondary outcomes were E', A', and TAPSE. SETTING: Single university hospital. PARTICIPANTS: Consecutive adult patients undergoing cardiac surgery (mainly coronary artery bypass grafting). INTERVENTIONS: None. MAIN RESULTS: Complete data was available in 24 of 25 patients. For the primary outcome, S' measured by speckle tracking in the ME4C correlated and agreed with S' measured by tissue Doppler in the AP4C (S'STE = 0.87STDI + 0.60, p < 0.001, r = 0.78; mean bias -0.6 cm/s, 95% limits of agreement (LoA) -3.5 to 2.4 cm/s). Similarly results were found for E', but not A' (E'STE = 0.69E'TDI + 2.37, p < 0.001, r = 0.71; mean bias 0.1 cm/s, 95%LoA -2.5 to 2.8cm/s; A'STE = 0.15A'TDI + 11.17, p = 0.629). TAPSE measurements by the authors' modified speckle-tracking-based technique were similar to TAPSE by M-mode (18.2 ± 5.5 mm and 17.1 ± 3.9 mm, respectively). CONCLUSIONS: Tricuspid annular velocities (S'STE, E'STE) determined by speckle tracking in TEE seem to be promising surrogates for velocities measured in TTE. This may be important for perioperative assessment of the right ventricle.

Differences in Two- and Three-Dimensional Assessment of the Mitral Valve by Novices and Experts, Illustrated Using Anterior Mitral Valve Leaflet Length.

OBJECTIVES: In this measurement validation study, the authors evaluated agreement between 2-dimensional (2D) and three-dimensional (3D) transesophageal echocardiography (TEE), measuring anterior mitral valve leaflet length by both novice and experienced echocardiographers. DESIGN: This was a retrospective, observational study. SETTING: Single university hospital. PARTICIPANTS: Analyses on datasets from 44 patients. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Fifty datasets from 44 patients with mitral regurgitation were analyzed by 4 observers (2 novices, 2 experts). All observers measured the anterior mitral valve leaflet length from end-systolic 2D TEE images from the midesophageal longitudinal axis view and 3D software-augmented TEE images. The overall mean anterior mitral valve leaflet length was significantly shorter with 3D versus 2D TEE measurements (24.6 ± 4.5 mm v 26.2 ± 5.3 mm; p < 0.001), with novices measuring shorter leaflets than experts for both techniques (p < 0.001 and p = 0.005, respectively). Bland-Altman plots of 3D and 2D TEE measurements showed mean biases (95% limits of agreement) of -1.6 mm (-9.0 to 5.9 mm), -1.8 mm (-9.6 to 6.0 mm), and -1.3 mm (-8.4 to 5.7 mm) for all observers, novices, and experts, respectively. For 2D measurements, interobserver reliability was very strong among experts and strong among novices (Pearson's r = 0.83 v 0.66; p = 0.055). For 3D measurements, interobserver reliability was strong in experts and moderate in novices (Pearson's r = 0.69 v 0.51; p = 0.168). CONCLUSION: For both novices and experts, 3D TEE measurements of the anterior mitral valve leaflet were significantly shorter than 2D measurements. Interobserver reliability was lowest for novices making 3D TEE measurements, indicating that reliable, quantitative evaluation of 3D TEE may require a greater amount of practice.

Quality evaluation of the emergency program of three contemporary cell-washing machines.

This study evaluates the efficiency of emergency programs used by three contemporary cell washers. Both time necessary to process a given amount of blood and quality of the processed blood are investigated. The Fresenius Kabi Smart, Haemonetics Elite and LivaNova Xtra were validated using bovine blood, with a starting hematocrit of 13% or 21%. For all devices, the pre-programmed emergency program was used. The total volume processed in the 13% hematocrit group was 358 ± 68 mL for Fresenius, 375 ± 308 mL for Haemonetics and 497 ± 87 mL for LivaNova. In the 21% hematocrit group, the volumes were 533 ± 60 mL, 713 ± 142 mL and 798 ± 96 mL, respectively, showing a statistical difference between the Fresenius and LivaNova (p = 0.02). In the 13% hematocrit group, the Fresenius processed 45 ± 15 mL blood/min, the Haemonetics 62 ± 8 mL blood/min and the LivaNova 66 ± 1.5 mL blood/min. The difference between the Fresenius and LivaNova was statistically significant (p = 0.04). In the 21% hematocrit group, the processing speed was 69 ± 4 mL blood/min, 62 ± 8 mL blood/min and 77 ± 5 mL blood/min for the Fresenius, LivaNova and Haemonetics, respectively (p = 0.25). No major differences in the elimination of potassium, albumin and total protein or in hemolytic index were observed. No major differences were observed between discontinuous and continuous systems with respect to processing speed and wash quality with a starting hematocrit of 21%. Minor differences in processing speed were observed with a starting hematocrit of 13%.

Use of Levosimendan in Cardiac Surgery: An Update After the LEVO-CTS, CHEETAH, and LICORN Trials in the Light of Clinical Practice.

Levosimendan is a calcium sensitizer and adenosine triphosphate-dependent potassium channel opener, which exerts sustained hemodynamic, symptomatic, and organ-protective effects. It is registered for the treatment of acute heart failure, and when inotropic support is considered appropriate. In the past 15 years, levosimendan has been widely used in clinical practice and has also been tested in clinical trials to stabilize at-risk patients undergoing cardiac surgery. Recently, 3 randomized, placebo-controlled, multicenter studies (LICORN, CHEETAH, and LEVO-CTS) have been published reporting on the perioperative use of levosimendan in patients with compromised cardiac ventricular function. Taken together, many smaller trials conducted in the past suggested beneficial outcomes with levosimendan in perioperative settings. By contrast, the latest 3 studies were neutral or inconclusive. To understand the reasons for such dissimilarity, a group of experts from Austria, Belgium, Finland, France, Germany, Italy, Switzerland, and Russia, including investigators from the 3 most recent studies, met to discuss the study results in the light of both the previous literature and current clinical practice. Despite the fact that the null hypothesis could not be ruled out in the recent multicenter trials, we conclude that levosimendan can still be viewed as a safe and effective inodilator in cardiac surgery.

Assessment of Cerebral Autoregulation Patterns with Near-infrared Spectroscopy during Pharmacological-induced Pressure Changes.

BACKGROUND: Previous work has demonstrated paradoxical increases in cerebral oxygen saturation (ScO2) as blood pressure decreases and paradoxical decreases in ScO2 as blood pressure increases. It has been suggested that these paradoxical responses indicate a functional cerebral autoregulation mechanism. Accordingly, the authors hypothesized that if this suggestion is correct, paradoxical responses will occur exclusively in patients with intact cerebral autoregulation. METHODS: Thirty-four patients undergoing elective cardiac surgery were included. Cerebral autoregulation was assessed with the near-infrared spectroscopy-derived cerebral oximetry index (COx), computed by calculating the Spearman correlation coefficient between mean arterial pressure and ScO2. COx less than 0.30 was previously defined as functional autoregulation. During cardiopulmonary bypass, 20% change in blood pressure was accomplished with the use of nitroprusside for decreasing pressure and phenylephrine for increasing pressure. Effects on COx were assessed. Data were analyzed using two-way ANOVA, Kruskal-Wallis test, and Wilcoxon and Mann-Whitney U test. RESULTS: Sixty-five percent of patients had a baseline COx less than 0.30, indicating functional baseline autoregulation. In 50% of these patients (n = 10), COx became highly negative after vasoactive drug administration (from -0.04 [-0.25 to 0.16] to -0.63 [-0.83 to -0.26] after administration of phenylephrine, and from -0.05 [-0.19 to 0.17] to -0.55 [-0.94 to -0.35] after administration of nitroprusside). A negative COx implies a decrease in ScO2 with increase in pressure and, conversely, an increase in ScO2 with decrease in pressure. CONCLUSIONS: In this study, paradoxical changes in ScO2 after pharmacological-induced pressure changes occurred exclusively in patients with intact cerebral autoregulation, corroborating the hypothesis that these paradoxical responses might be attributable to a functional cerebral autoregulation.

A pathophysiological approach towards right ventricular function and failure.

The scope of this review is to provide a pathophysiological summary of perioperative right ventricular function and failure. In recent decades, the importance of right ventricular function in the perioperative period has been established. However, much of our current knowledge on the management of this clinical entity is based on extrapolation of results from left ventricular research, although biventricular physiology is known to be markedly different in many aspects. Here, on the basis of a thorough literature search, we review theoretical as well as practical aspects of perioperative right ventricular failure. After underlining the importance of this topic, we review basic right ventricular anatomy and physiology, with an emphasis on the role of ventricular interaction. Next, potential causes of perioperative right ventricular failure are discussed. The emphasis of this review is on the perioperative anaesthetic considerations, ranging from preoperative assessment through intraoperative monitoring to specific contemporary therapeutic options of perioperative right ventricular failure.

Pressure-Volume Loops for Reviewing Right Ventricular Physiology and Failure in the Context of Left Ventricular Assist Device Implantation.

Right ventricular (RV) function is complex as a number of determinants beyond preload, inotropy and afterload play a fundamental role. In particular, arterial elastance (Ea), ventriculo-arterial coupling (VAC), and (systolic) ventricular interdependence play a vital role for the right ventricle. Understanding and actively visualizing these interactions in the failing RV as well as in the altered hemodynamic and morphological situation of left ventricular assist device (LVAD) implantation may aid clinicians in their understanding of RV dysfunction and failure. While, admittedly, hard data is scarce and invasive pressure-volume loop measurements will not become routine in cardiac surgery, we hope that clinicians will benefit from the comprehensive, simulation-based review of RV pathology. In particular, the aim of this article is to first, address and clarify the pathophysiologic hemodynamic factors that lead to RV dysfunction and then, second, expand upon this basis examining the changes occurring by LVAD implantation. This is illustrated using Harvi software which shows elastance, ventricular arterial coupling, and ventricular interdependence by simultaneously showing pressure volume loops of the right and left ventricle.

Noninvasive neurological monitoring to enhance pLVAD-assisted ventricular tachycardia ablation - a Mini review.

For critically ill patients, hemodynamic fluctuations can be life-threatening; this is particularly true for patients experiencing cardiac comorbidities. Patients may suffer from problems with heart contractility and rate, vascular tone, and intravascular volume, resulting in hemodynamic instability. Unsurprisingly, hemodynamic support provides a crucial and specific benefit during percutaneous ablation of ventricular tachycardia (VT). Mapping, understanding, and treating the arrhythmia during sustained VT without hemodynamic support is often infeasible due to patient hemodynamic collapse. Substrate mapping in sinus rhythm can be successful for VT ablation, but there are limitations to this approach. Patients with nonischemic cardiomyopathy may present for ablation without exhibiting useful endocardial and/or epicardial substrate-based ablation targets, either due to diffuse extent or a lack of identifiable substrate. This leaves activation mapping during ongoing VT as the only viable diagnostic strategy. By enhancing cardiac output, percutaneous left ventricular assist devices (pLVAD) may facilitate conditions for mapping that would otherwise be incompatible with survival. However, the optimal mean arterial pressure to maintain end-organ perfusion in presence of nonpulsatile flow remains unknown. Near infrared oxygenation monitoring during pLVAD support provides assessment of critical end-organ perfusion during VT, enabling successful mapping and ablation with the continual assurance of adequate brain oxygenation. This focused review provides practical use case scenarios for such an approach, which aims to allow mapping and ablation of ongoing VT while drastically reducing the risk of ischemic brain injury.