Overview of the Interatrial Septum: Review of Cardiac Nomenclature for Transseptal Puncture.

Transseptal puncture is an increasingly common procedure undertaken to gain access to the left side of the heart during structural heart disease interventions. Precision guidance during this procedure is paramount to ensure success and patient safety. As such, multimodality imaging, such as echocardiography, fluoroscopy, and fusion imaging, is routinely used to guide safe transseptal puncture. Despite the use of multimodal imaging, there is currently no uniform nomenclature of cardiac anatomy between the various imaging modes and proceduralists, and echocardiographers tend to use imaging modality-specific terminology when communicating among the various imaging modes. This variability in nomenclature among imaging modes stems from differing anatomic descriptions of cardiac anatomy. Given the required level of precision in performing transseptal puncture, a clearer understanding of the basis of cardiac anatomic nomenclature is required by both echocardiographers as well as proceduralists; enhanced understanding can help facilitate communication across specialties and possibly improve communication and safety. In this review, the authors highlight the variation in cardiac anatomy nomenclature among various imaging modes.

Curriculum for Subspecialty Anesthesia Training in Adult Structural Heart Disease Imaging: A Single-Center Experience.

Intraprocedural transesophageal echocardiography imaging is an integral part of percutaneous structural heart disease (SHD) interventions. The rapid growth in the number, scope, and complexity of SHD interventions has outpaced the efforts to develop training and proficiency standards in periprocedural imaging. At the Beth Israel Deaconess Medical Center in Boston, Massachusetts, the authors have developed a 6-month duration fellowship in interventional echocardiography for SHD to address this issue. The purpose of this fellowship is to train cardiac anesthesiologists to address the unique challenges of interventional echocardiography. In this paper, the authors describe the rationale for and specific features of this training program. Their fellowship curriculum follows a multimodal integrative approach to training in SHD imaging, which includes simulation sessions, online modules, deliberate practice in the clinical setting, and interdisciplinary team-based training. In the next several years, there will be an increased need for echocardiographers who are proficient in intraprocedural SHD imaging. In this article, the authors describe their experience with a competency-based curriculum for subspecialty anesthesia training in SHD imaging.

Multifactorial risk index for prediction of intraoperative blood transfusion in endovascular aneurysm repair.

BACKGROUND: In some institutions, the current blood ordering practice does not discriminate minimally invasive endovascular aneurysm repair (EVAR) from open procedures, with consequent increasing costs and likelihood of blood product wastage for EVARs. This limitation in practice can possibly be addressed with the development of a reliable prediction model for transfusion risk in EVAR patients. We used the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database to create a model for prediction of intraoperative blood transfusion occurrence in patients undergoing EVAR. Afterward, we tested our predictive model on the Vascular Study Group of New England (VSGNE) database. METHODS: We used the ACS NSQIP database for patients who underwent EVAR from 2011 to 2013 (N = 4709) as our derivation set for identifying a risk index for predicting intraoperative blood transfusion. We then developed a clinical risk score and validated this model using patients who underwent EVAR from 2003 to 2014 in the VSGNE database (N = 4478). RESULTS: The transfusion rates were 8.4% and 6.1% for the ACS NSQIP (derivation set) and VSGNE (validation) databases, respectively. Hemoglobin concentration, American Society of Anesthesiologists class, age, and aneurysm diameter predicted blood transfusion in the derivation set. When it was applied on the validation set, our risk index demonstrated good discrimination in both the derivation and validation set (C statistic = 0.73 and 0.70, respectively) and calibration using the Hosmer-Lemeshow test (P = .27 and 0.31) for both data sets. CONCLUSIONS: We developed and validated a risk index for predicting the likelihood of intraoperative blood transfusion in EVAR patients. Implementation of this index may facilitate the blood management strategies specific for EVAR.

Summative Objective Structured Clinical Examination Assessment at the End of Anesthesia Residency for Perioperative Ultrasound.

While standardized examinations and data from simulators and phantom models can assess knowledge and manual skills for ultrasound, an Objective Structured Clinical Examination (OSCE) could assess workflow understanding. We recruited 8 experts to develop an OSCE to assess workflow understanding in perioperative ultrasound. The experts used a binary grading system to score 19 graduating anesthesia residents at 6 stations. Overall average performance was 86.2%, and 3 stations had an acceptable internal reliability (Kuder-Richardson formula 20 coefficient >0.5). After refinement, this OSCE can be combined with standardized examinations and data from simulators and phantom models to assess proficiency in ultrasound.

Assessment of Perioperative Ultrasound Workflow Understanding: A Consensus.

OBJECTIVES: Understanding of the workflow of perioperative ultrasound (US) examination is an integral component of proficiency. Workflow consists of the practical steps prior to executing an US examination (eg, equipment operation). Whereas other proficiency components (ie, cognitive knowledge and manual dexterity) can be tested, workflow understanding is difficult to define and assess due to its contextual and institution-specific nature. The objective was to define the workflow components of specific perioperative US applications using an iterative process to reach a consensus opinion. DESIGN: Expert consensus, survey study. SETTING: Tertiary university hospital. PARTICIPANTS: This study sought expert consensus among a focus group of 9 members of an anesthesia department with experience in perioperative US. Afterward, 257 anesthesia faculty members from 133 academic centers across the United States were surveyed. INTERVENTIONS: A preliminary list of tasks was designed to establish the expectations of workflow understanding by an anesthesiology resident prior to clinical exposure to perioperative US. This list was modified by a focus group through an iterative process. Afterwards, a survey was sent to faculty members nationwide, and Likert scale ratings for each task were obtained and reviewed during a second round. MEASUREMENTS AND MAIN RESULTS: Consensus among members of the focus group was reached after 2 iterations. 72 participants responded to the nationwide survey (28%), and consensus was reached after the second round (Cronbach's α = 0.99, ICC = 0.99) on a final list of 46 workflow-related tasks. CONCLUSIONS: Specific components of perioperative US workflow were identified. Evaluation of workflow understanding may be combined with cognitive knowledge and manual dexterity testing for assessing proficiency in perioperative US.

Heterogeneity in the Structure of the Left Ventricular Outflow Tract: A 3-Dimensional Transesophageal Echocardiographic Study.

BACKGROUND: The left ventricular outflow tract (LVOT) is a composite of adjoining structures; therefore, a circular or elliptical shape at one point may not represent its entire structure. The purpose of this study was to evaluate the presence of heterogeneity in the LVOT. METHODS: Patients with normal valvular and ventricular function undergoing elective coronary revascularization surgery were included in the study. Intraoperative R-wave gated 3-dimensional (3D) transesophageal echocardiographic imaging of the LVOT was performed at end-systole, with the midesophageal long axis as the reference view. Acquired data were analyzed with the Philips Q-Lab software with multiplanar reformatting in the sagittal (minor axis), transverse (major axis), and coronal (cross-sectional area by planimetry) views of the LVOT. These measurements were made on the left ventricular side or proximal LVOT, aortic side, or distal LVOT and mid-LVOT. RESULTS: Fifty patients were included in the study. The LVOT minor (sagittal) axis dimension did not differ across the mid-LVOT, proximal LVOT, and distal LVOT (P = .11). The major axis diameter of LVOT differed among the 3 regions of the LVOT (P < .001). A difference in major axis diameter was observed between the proximal and the distal LVOT (median difference of 0.39 cm; Bonferroni-adjusted 95% confidence interval [CI] of the difference = 0.31-0.48 cm; Bonferroni-adjusted P < .001). Planimetry of the LVOT area differed significantly (P < .001) between the regions analyzed, and we found a difference between the distal and the proximal LVOT (median difference = 0.65 cm, Bonferroni-adjusted 95% CI of the difference = 0.44-0.88 cm, Bonferroni-adjusted P < .001). The LVOT area calculated from minor axis diameter differed significantly from the area obtained by planimetry (P < .001). CONCLUSIONS: There was heterogeneity in the major axis diameter and cross-sectional area for the different regions of the LVOT. The distal LVOT (aortic side) was more circular, whereas the proximal LVOT (left ventricular side) was more elliptical in shape. This change in shape from circular to elliptical was accounted for by a difference in the major axis diameter from proximal to distal LVOT and a relatively similar minor axis diameter. Although the clinical significance of this finding is unknown, the assumption of a uniform structure of LVOT is incorrect. Three-dimensional imaging may be useful for assessing the LVOT shape and size at a specific region of interest.

Hemodynamic Testing of Patient-Specific Mitral Valves Using a Pulse Duplicator: A Clinical Application of Three-Dimensional Printing.

OBJECTIVE: To evaluate the feasibility of obtaining hemodynamic metrics of echocardiographically derived 3-dimensional printed mitral valve models deployed in a pulse-duplicator chamber. DESIGN: Exploratory study. SETTING: Tertiary-care university hospital. PARTICIPANTS: Percutaneous MitraClip procedure patient. INTERVENTIONS: Three-dimensional R-wave gated, full-volume transesophageal echocardiography images were obtained after deployment of the MitraClip device. A high-quality diastolic frame of the mitral valve was segmented using Mimics Innovation Suite and merged with a flange. The data were exported as a stereolithography (.stl) file, and a rigid 3-dimensional model was printed using a MakerBot Replicator 2 printer. A flexible silicone cast then was created and deployed in the pulse-duplicator chamber filled with a blood-mimicking fluid. MEASUREMENTS AND MAIN RESULTS: The authors were able to obtain continuous-wave Doppler tracings of the valve inflow with a transesophageal echocardiography transducer. They also were able to generate diastolic ventricular and atrial pressure tracings. Pressure half-time and mitral valve area were computed from these measurements. CONCLUSION: This pulse duplicator shows promising applications in hemodynamic testing of patient-specific anatomy. Future modifications to the system may allow for visualization and data collection of gradients across the aortic valve.

Manual Skill Acquisition During Transesophageal Echocardiography Simulator Training of Cardiology Fellows: A Kinematic Assessment.

OBJECTIVE: To investigate whether a transesophageal echocardiography (TEE) simulator with motion analysis can be used to impart proficiency in TEE in an integrated curriculum-based model. DESIGN: A prospective cohort study. SETTING: A tertiary-care university hospital. PARTICIPANTS: TEE-naïve cardiology fellows. INTERVENTIONS: Participants underwent an 8-session multimodal TEE training program. Manual skills were assessed at the end of sessions 2 and 8 using motion analysis of the TEE simulator's probe. At the end of the course, participants performed an intraoperative TEE; their examinations were video captured, and a blinded investigator evaluated the total time and image transitions needed for each view. Results are reported as mean±standard deviation, or median (interquartile range) where appropriate. MEASUREMENTS AND MAIN RESULTS: Eleven fellows completed the knowledge and kinematic portions of the study. Five participants were excluded from the evaluation in the clinical setting because of interim exposure to TEE or having participated in a TEE rotation after the training course. An increase of 12.95% in post-test knowledge scores was observed. From the start to the end of the course, there was a significant reduction (p<0.001 for all) in the number of probe. During clinical performance evaluation, trainees were able to obtain all the required echocardiographic views unassisted but required a longer time and had more probe transitions when compared with an expert. CONCLUSION: A curriculum-based approach to TEE training for cardiology fellows can be complemented with kinematic analyses to objectify acquisition of manual skills during simulator-based training.

Cardiac output calculation and three-dimensional echocardiography.

OBJECTIVE: To compare the determination of stroke volume (SV) and cardiac output (CO) using 2-dimensional (2D) versus 3-dimensional (3D) transesophageal echocardiography (TEE). DESIGN: Prospective observational study. SETTING: Tertiary care university hospital. PARTICIPANTS: 35 patients without structural valve abnormalities undergoing isolated coronary artery bypass grafting. INTERVENTIONS: Left ventricular outflow tract (LVOT) diameter determined with 2D TEE was used to estimate LVOT cross-sectional area (CSALVOT). LVOT area was measured directly with 3D TEE by planimetry on an en face view. SV and CO were calculated for both methods using the continuity equation. MEASUREMENTS AND MAIN RESULTS: The area of the LVOT differed significantly between methods, being significantly larger in the 3D method (3.57±0.70 cm(2)v 3.98±0.93 cm(2)) . This resulted in a 10% lower CO with the 2D method of LVOT area estimation. CONCLUSIONS: LVOT area is underestimated with the single- axis 2D method when compared with 3D planimetered area. This results in a CO that is approximately 10% lower with the 2D method.

Dynamism of the mitral annulus: a spatial and temporal analysis.

OBJECTIVE: In this study, the authors sought to investigate the extent and timing of changes in mitral annular area during the cardiac cycle. Particularly, the authors assessed whether these changes were limited to the posterior part of the annulus or were more global in nature. DESIGN: Prospective, observational study SETTING: Tertiary care university hospital PARTICIPANTS: Twenty three patients undergoing non-valvular cardiac surgery and 3 patients undergoing vascular procedures. INTERVENTIONS: Intraoperative 3-dimensional transesophageal echocardiographic data obtained from patients with normal mitral valves undergoing non-valvular cardiac surgery were analyzed geometrically. Annular areas and diameters were measured during various stages of the cardiac cycle. Intertrigonal distance also was measured using 3D data. MEASUREMENTS AND MAIN RESULTS: Both anterior and posterior portions of the mitral annulus demonstrated dynamism throughout the cardiac cycle. The expansion phase ranged from mid-systole to early-diastole, whereas mid-diastole to early-systole was characterized by an annular contraction phase. Area changes were contributed equally by anterior and posterior parts of the annulus. Annular dimensions increased in accordance with mitral annular area (p<0.05). Echocardiographically-identified intertrigonal distance showed the least delta change. CONCLUSIONS: Both the anterior and posterior parts of the annulus contribute to changes in mitral annular area, which undergoes discrete expansion and contraction phases that extend into both systole and diastole. Compared to other annular dimensions, the echocardiographically-identified intertrigonal distance does not change significantly during the cardiac cycle.

A Shocking Discovery: Electrostatic Discharge-Induced Pump Failure in an Implantable Left Ventricular Assist Device.

Despite advancements in left ventricular assist device (LVAD) technology, numerous complications continue to be associated with these devices. The interactions between LVADs and other electronic devices and the effects of electrostatic discharge (ESD) are not well established. This study reports a rare case of ESD causing pump malfunction in an implantable LVAD.