2D Echocardiographic Evaluation of Right Ventricular Function Correlates With 3D Volumetric Models in Cardiac Surgery Patients.

OBJECTIVES: The early diagnosis and treatment of right ventricular (RV) dysfunction are of critical importance in cardiac surgery patients and impact clinical outcome. Two-dimensional (2D) transesophageal echocardiography (TEE) can be used to evaluate RV function using surrogate parameters due to complex RV geometry. The aim of this study was to evaluate whether the commonly used visual evaluation of RV function and size using 2D TEE correlated with the calculated three-dimensional (3D) volumetric models of RV function. DESIGN AND SETTING: Retrospective study, single center, University Hospital. PARTICIPANTS AND INTERVENTION: Seventy complete datasets were studied consisting of 2D 4-chamber view loops (2-3 beats) and the corresponding 4-chamber view 3D full-volume loop of the right ventricle. RV function and RV size of the 2D loops then were assessed retrospectively purely qualitatively individually by 4 clinician echocardiographers certified in perioperative TEE. Corresponding 3D volumetric models calculating RV ejection fraction and RV end-diastolic volumes then were established and compared with the 2D assessments. MEASUREMENTS AND MAIN RESULTS: 2D assessment of RV function correlated with 3D volumetric calculations (Spearman's rho -0.5; p<0.0001). No correlation could be established between 2D estimates of RV size and actual 3D volumetric end-diastolic volumes (Spearman's rho 0.15; p = 0.25). CONCLUSION: The 2D assessment of right ventricular function based on visual estimation as frequently used in clinical practice appeared to be a reliable method of RV functional evaluation. However, 2D assessment of RV size seemed unreliable and should be used with caution.

Echocardiography for Less-Invasive Implantation of Left Ventricular Assist Devices.

New surgical techniques aim for less-invasive implantation of left ventricular assist devices (LVADs) via small surgical incision sites. Echocardiography plays an important role during patient selection and guidance of the procedure. The surgical incision site can be identified preoperatively by transthoracic echocardiography. Intraoperative identification of left ventricular apex, de-airing, and monitoring heart function is performed by transesophageal echocardiography. This article highlights special echocardiographic considerations during less-invasive LVAD implantation surgeries.

Safety of transesophageal echocardiography during extracorporeal life support.

INTRODUCTION:: Use of extracorporeal life support (ECLS) has significantly increased in critically ill patients refractory to medical management. ECLS requires systemic anticoagulation to avoid thromboembolic complications and superimposed coagulopathies are common. Transesophageal echocardiography (TEE) is frequently employed to assess cannula position and cardiac function during extracorporeal therapy. The goal of this study was to assess whether TEE probe insertion and removal in systemically anticoagulated ECLS patients was safe compared to patients without ECLS and normal coagulation studies. METHODS:: Eighty-seven separate TEE examinations in 53 adult ECLS patients were analyzed. Detailed complication profiles were logged for each patient from initiation through discontinuation of ECLS. Routine coagulation testing was recorded within two hours prior to the TEE exams. Controls consisted of age- and gender-matched patients undergoing perioperative TEE without ECLS and normal coagulation (N=87). RESULTS:: Overall TEE-associated morbidity in ECLS patients was 2.3% and consisted of minor oropharyngeal bleeding (2/87 TEE exams) exclusively. The patients presenting with oropharyngeal bleeding received heparin for anticoagulation and had two or more abnormal coagulation studies at the time of TEE. Seventy-nine percent of ECLS patients received intravenous heparin infusions, 6.8% argatroban and 3.4% epoprostenol. Ten-point-eight percent of patients were not anticoagulated at the time of TEE because of pre-existing bleeding complications and/or deranged plasmatic coagulation profiles. No major complications (e.g., esophageal perforation, gastrointestinal bleeding, accidental extubation) were recorded in either group. CONCLUSIONS:: TEE remained safe in critically ill patients under ECLS, despite systemic anticoagulation, during probe insertion, manipulation and removal. TEE-related complications pertained solely to oropharyngeal bleeding amenable to conservative management.

One-year clinical outcome after ablation with a novel multipolar irrigated ablation catheter for treatment of atrial fibrillation: potential implications for clinical use.

AIMS: Pulmonary vein isolation (PVI) is an established therapy for atrial fibrillation (AF). However, PVI remains a time-consuming procedure. A novel multipolar irrigated radiofrequency (RF) ablation catheter (nMARQ™) is aiming to improve PVI. We investigated the influence on procedural parameters and assessed clinical outcomes after PVI using this novel catheter. METHODS AND RESULTS: Fifty-eight consecutive patients with paroxysmal AF were equally allocated (n = 29/group) to PVI treatment with (i) the novel multipolar ablation catheter (nMARQ™) and (ii) a standard single-tip ablation catheter (SAC). Study endpoints included procedure time, fluoroscopy time, radiation dose, RF time, number of energy applications, and clinical outcome defined as freedom from AF after a single procedure. Successful PVI was confirmed by a separate circular, multipolar mapping catheter in all patients treated with the nMARQ™. Pulmonary vein isolation was achieved in 100% in the SAC group. In the nMARQ™ group, PVI was suggested in all patients. However, confirmatory mapping revealed persistent pulmonary vein (PV) conduction in 19 out of 29 nMARQ™ patients. These patients underwent further ablation, which still failed to achieve PVI in 5 of the 29 nMARQ™ patients, mainly due to significant temperature rise in the oesophagus and device-related limitations reaching the right inferior PV. Mean fluoroscopy time (31 ± 12 vs. 23 ± 10 min, P < 0.05) and (132 ± 37 vs. 109 ± 30 min, P < 0.05) were longer in nMARQ™ vs. SAC patients. Radiofrequency time was shorter in nMARQ™ vs. SAC group (21 ± 9 vs. 35 ± 12 min, P < 0.001). Radiation dose and the number of energy applications did not differ between both groups. Clinical outcome analysis revealed no significant differences (nMARQ™: 72 vs. SAC: 72%) after a mean follow-up of 373 ± 278 days. CONCLUSION: The use of the nMARQ™ catheter is associated with important device-related limitations to achieve successful PVI. However, clinical outcomes were equivalent in nMARQ™- and SAC-treated patients.

Tricuspid annular plane systolic excursion (TAPSE) predicts poor outcome in patients undergoing acute pulmonary embolectomy.

INTRODUCTION: Right ventricular failure remains a major cause of mortality during acute pulmonary embolism. Right ventricular function can be assessed with transesophageal echocardiography. However, due to the complex right ventricular anatomy, only a few echocardiographic parameters are reliable and easily obtainable intraoperatively. Tricuspid annular plane systolic excursion is a validated parameter of global right ventricular function. METHODS: Data from 81 patients with acute pulmonary embolus undergoing pulmonary embolectomy were evaluated. Transesophageal echocardiography derived parameters of right ventricular function were obtained and compared to tricuspid annular plane systolic excursion measurements. Patients were then divided into two groups (TAPSE < 18 mm and ≥18 mm). RESULTS: The patient population consisted of 46 males and 35 females, mean age 61.0 ± 12.9 years. Patients in the TAPSE <18 mm group had significantly larger diastolic (p=0.0015) and systolic (p=0.0031) right ventricular diameters, lower right ventricular fractional area change  (p=0.0065) and greater degrees of tricuspid regurgitation (p=0.0001) compared to patients with TAPSE ≥18 mm. In addition, all patients who needed intraoperative cardiopulmonary resuscitation (11/81) or died intraoperatively (8/81) belonged to the TAPSE <18 mm group. Logistic regression analysis confirmed TAPSE <18 mm as an independent risk factor for intraoperative cardiopulmonary resuscitation and death. CONCLUSIONS: Transesophageal echocardiography derived TAPSE is easily obtainable and correlates well with other standardized parameters of right ventricular function. TAPSE <18 mm is an independent predictor of intraoperative cardiopulmonary resuscitation and death in patients undergoing emergent pulmonary embolectomy.

Influence of intraaortic balloon pump counterpulsation on transesophageal echocardiography derived determinants of diastolic function.

INTRODUCTION: Intraaortic balloon pump counterpulsation (IABP) is often used in patients with acute coronary syndrome for its favourable effects on left ventricular (LV) systolic function and coronary perfusion. However, the effects of IABP on LV diastolic function have not been comprehensively investigated. Acute diastolic dysfunction has been linked to increased morbidity and mortality. The aim of this study was to examine the influence of IABP on LV diastolic dysfunction using standard TEE derived parameters. METHODS: Intraoperative TEE was performed in 10 patients (mean age 65 ± 11 yrs) undergoing urgent coronary artery bypass graft surgery (CABG), who had received an IABP preoperatively. TEE derived measures of diastolic dysfunction included early to late transmitral Doppler inflow velocity ratio (E/A), deceleration time (Dt), pulmonary venous systolic to diastolic Doppler velocity ratio (S/D), transmitral propagation velocity (Vp), and the ratio of early to late mitral annular tissue Doppler velocities (e'/a'). Statistical analyses included the Wilcoxon Sign-Rank test, and a p<0.05 was considered significant. RESULTS: Transmitral inflow E/A ratios increased significantly from 0.86 to 1.07 (p < 0.05), while Dt decreased significantly from 218 to 180 ms (p < 0.05) with the use of IABP. Significant increases in Vp (34 cm/s to 43 cm/s; p < 0.05), and e'/a' (0.58 to 0.71; p < 0.05) suggested a favourable influence of intraaortic counterpulsation on diastolic function. CONCLUSION: The use of perioperative IABP significantly improves TEE derived parameters of diastolic function consistent with a favourable impact on LV relaxation in cardiac surgery patients undergoing CABG.

Noteworthy articles in 2014 for cardiothoracic anesthesiologists.

In 2014, cardiothoracic anesthesiology again generated high-quality scientific work published in highly regarded journals. Our specialty continues to make significant strides in the creation and implementation of protocols to improve outcomes in our patients, which undoubtedly contribute to a safer hospital environment for patients and employees alike. Another theme that stirred a lot of interest in the past year is the search for patient-centered treatment plans. Even though we are still some time away from truly personalized medicine, our specialty starts to ask and answer exciting questions: Would we treat patient A any different from patient B if their genetic profiles were easily accessible? Could individualized treatment choices influence our patients' immediate and long-term outcomes? For this review, we selected a sample of relevant contributions to the field of cardiothoracic anesthesiology in 2014 with potential impact on our clinical routine.

Echocardiographic evaluation of mitral inflow hemodynamics after asymmetric double-orifice repair.

BACKGROUND: A comprehensive transesophageal echocardiographic (TEE) examination is essential for the evaluation of a mitral valve (MV) repair. The edge-to-edge MV repair (i.e., Alfieri stitch) can pose a unique challenge in assessing iatrogenic mitral stenosis, especially when an asymmetric double-orifice is created. The reliability of the simplified Bernoulli equation for evaluating transvalvular pressure gradients across an asymmetric Alfieri MV repair remains controversial. We sought to evaluate the reliability of this principle further by comparing TEE-acquired pressure gradients across each orifice in patients undergoing asymmetric, double-orifice repair. METHODS: Routinely collected intraoperative, 2-dimensional and 3-dimensional TEE datasets acquired from 15 patients undergoing double-orifice MV repair were retrospectively reviewed and analyzed. Planimetered anterior lateral (AL) and posterior medial (PM) orifice areas were acquired from 3-dimensional TEE full volume datasets, by cropping the image to develop a short-axis view at the narrowest diastolic orifice cross-sectional area at the MV leaflet tips. Transmitral Doppler flow velocity values were measured through the AL and PM orifices. Peak and mean pressure gradients were calculated from the simplified Bernoulli equation at both orifices and were compared to each respective orifice for each patient. RESULTS: The mean difference between the AL and PM orifice areas for each patient was statistically significant (0.72 ± 0.40 cm(2), P < 0.0001). The mean differences between the AL and PM parameters were also significant for peak velocity: 0.15 m/s, SD: 0.08, P < 0.0001; peak pressure gradients: 1.76 mm Hg, SD: 1.42, P < 0.0001; and mean pressure gradient: 1.04 mm Hg, SD: 0.93, P < 0.0001. CONCLUSIONS: The echocardiographic assessment of MV dysfunction after an Alfieri repair is important. Although the differences that we demonstrated between orifice areas and maximum velocities across the asymmetric orifices after a double-orifice MV repair are statistically significant, the corresponding difference in mean transorifice pressure gradient is not clinically relevant. Thus, either orifice can be interrogated with Doppler echocardiography for the determination of pressure gradients after double-orifice MV repair.

Rescue transoesophageal echocardiography for refractory haemodynamic instability during transvenous lead extraction.

AIMS: The rising number of cardiovascular implantable electronic devices has led to a steep increase in transvenous lead extractions (TLEs). Procedure-related, haemodynamically significant adverse events are uncommon during TLE yet remain an inevitable risk. While the use of transoesophageal echocardiography (TEE) as a guide to clinical decision-making during refractory circulatory instability has been well established, the specific utility of rescue TEE during TLE has not been comprehensively studied. METHODS AND RESULTS: Twenty-six patients who required emergent TEE to determine the aetiology of intractable haemodynamic instability during TLE were evaluated. Pericardial effusion requiring urgent pericardiocentesis and/or cardiac surgical intervention was diagnosed by TEE in 10 patients, and progressed to cardiac arrest in 4 patients. Haemorrhagic shock developed in two patients suffering from femoral vein laceration and right haemothorax, respectively. One additional patient developed acute respiratory compromise and right ventricular dysfunction diagnosed by TEE, which necessitated prolonged post-operative intubation and inotropic therapy. In 14 patients, TEE excluded life-threatening cardiovascular injuries and enabled the pursuit of continued medical management. Two patients with reassuring TEE findings underwent intra-operative placement of chest tubes for pneumothorax. All the 26 patients were discharged from the hospital. CONCLUSION: While TLE is a relatively safe procedure, life-threatening cardiovascular injuries remain a rare risk. In this study, the use of rescue TEE ruled out significant cardiovascular injuries in the majority of patients. Furthermore, rescue TEE had a substantial impact on the efficiency of determining the aetiology of refractory haemodynamic instability during TLE and thereby facilitated the timely initiation of definitive intervention.

Misplacement of a pulmonary artery catheter.

Placing a flow-directed pulmonary artery catheter (PAC) can be difficult and lead to serious complications. We present the case of an attempted PAC insertion in a patient undergoing implantation of a left ventricular assist device. Although physiologic pressure waveforms were established, plausible measurements of cardiac output and pulmonary capillary wedge pressure were not initially obtainable. Chest radiography showed that the catheter was looped in the pulmonary artery. This malposition could not be visualized intraoperatively by transesophageal echocardiography. The PAC was replaced in the operating room after the left ventricular assist device was implanted.

Noteworthy articles in 2013 for cardiothoracic anesthesiologists.

In 2013, the field of cardiothoracic anesthesiology has continued to grow at the same astounding rate as in previous years. It has become increasingly difficult for practicing anesthesiologists to stay current on impactful publications related to our exciting subspecialty. The scientific output has expanded to such a great extent that following the literature in specialty journals barely scrapes the surface of available knowledge. With the recent emphasis on teamwork spanning multiple medical specialties in the care for complex patients, the door has opened for our research to be presented in nontraditional, nonanesthesiology venues. In this review, we have selected a small sample of noteworthy contributions to the field of cardiothoracic and vascular anesthesiology published in 2013 with potential impact on our clinical practice.

Intraoperative evaluation of transmitral pressure gradients after edge-to-edge mitral valve repair.

OBJECTIVE: Edge-to-edge repair of the mitral valve (MV) has been described as a viable option used for the surgical management of mitral regurgitation (MR). Based on the significant changes in MV geometry associated with this technique, we hypothesized that edge-to-edge MV repairs are associated with higher intraoperative transmitral pressure gradients (TMPG) compared to conventional methods. METHODS: Patient records and intraoperative transesophageal echocardiography (TEE) examinations of 552 consecutive patients undergoing MV repair at a single institution over a three year period were assessed. After separation from cardiopulmonary bypass (CPB), peak and mean TMPG were recorded for each patient and subsequently analyzed. RESULTS: 84 patients (15%) underwent edge-to-edge MV repair. Peak and mean TMPG were significantly higher compared to gradients in patients undergoing conventional repairs: 10.7 ± 0.5 mmHg vs 7.1 ± 0.2 mmHg; P<0.0001 and 4.3 ± 0.2 mmHg vs 2.8 ± 0.1 mmHg; P<0.0001. Only patients with mean TMPG ≥ 7 mmHg (n = 9) required prompt reoperation for iatrogenic mitral stenosis (MS). No differences in peak and mean TMPG were observed among edge-to-edge repairs performed in isolation, compared to those performed in combination with annuloplasty: 11.0 ± 0.7 mmHg vs 10.3 ± 0.6 mmHg and 4.4 ± 0.3 mmHg vs 4.3 ± 0.3 mmHg. There were no differences in TMPG between various types of annuloplasty techniques used in combination with the edge-to-edge repairs. CONCLUSIONS: Edge-to-edge MV repairs are associated with higher intraoperative peak and mean TMPG after separation from CPB compared to conventional repair techniques. Unless gradients are severely elevated, these findings are not necessarily suggestive of iatrogenic MS. Thus, in the immediate postoperative period mildly elevated TMPG can be expected and tolerated after edge-to-edge mitral repairs.

Resolution of Toll-like receptor 4-mediated acute lung injury is linked to eicosanoids and suppressor of cytokine signaling 3.

The purpose of this study was to investigate roles for Toll-like receptor 4 (TLR4) in host responses to sterile tissue injury. Hydrochloric acid was instilled into the left mainstem bronchus of TLR4-defective (both C3H/HeJ and congenic C.C3-Tlr4(Lps-d)/J) and control mice to initiate mild, self-limited acute lung injury (ALI). Outcome measures included respiratory mechanics, barrier integrity, leukocyte accumulation, and levels of select soluble mediators. TLR4-defective mice were more resistant to ALI, with significantly decreased perturbations in lung elastance and resistance, resulting in faster resolution of these parameters [resolution interval (R(i)); ∼6 vs. 12 h]. Vascular permeability changes and oxidative stress were also decreased in injured HeJ mice. These TLR4-defective mice paradoxically displayed increased lung neutrophils [(HeJ) 24×10(3) vs. (control) 13×10(3) cells/bronchoalveolar lavage]. Proresolving mechanisms for TLR4-defective animals included decreased eicosanoid biosynthesis, including cysteinyl leukotrienes (80% mean decrease) that mediated CysLT1 receptor-dependent vascular permeability changes; and induction of lung suppressor of cytokine signaling 3 (SOCS3) expression that decreased TLR4-driven oxidative stress. Together, these findings indicate pivotal roles for TLR4 in promoting sterile ALI and suggest downstream provocative roles for cysteinyl leukotrienes and protective roles for SOCS3 in the intensity and duration of host responses to ALI.

Safety of transesophageal echocardiography.

Since its introduction into the operating room in the early 1980s, transesophageal echocardiography (TEE) has gained widespread use during cardiac, major vascular, and transplantation surgery, as well as in emergency and intensive care medicine. Moreover, TEE has become an invaluable diagnostic tool for the management of patients with cardiovascular disease in a nonoperative setting. In comparison with other diagnostic modalities, TEE is relatively safe and noninvasive. However, the insertion and manipulation of the ultrasound probe can cause oropharyngeal, esophageal, or gastric trauma. Here, the authors review the safety profile of TEE by identifying complications and propose a set of relative and absolute contraindications to probe placement. In addition, alternative echocardiographic modalities (e.g., epicardial echocardiography) that may be considered when TEE probe placement is contraindicated or not feasible are discussed.

The feasibility of epicardial echocardiography for measuring aortic valve area by the continuity equation.

BACKGROUND: Measuring the aortic valve area (AVA) remains an important component of a comprehensive intraoperative echocardiographic examination in patients undergoing aortic valve surgery. Epicardial echocardiography (EE) represents an accessible alternative to transesophageal echocardiography (TEE), however, its agreement and correlation with other imaging modalities for measuring AVA has not been systematically validated. METHODS: EE was used in 85 patients undergoing cardiac surgery to measure AVA (AVA-EE) using the continuity equation. AVA-EE was compared to measurements obtained by intraoperative transesophageal echocardiography (AVA-TEE) in the same population. In a subset of patients, AVA-EE was also compared to AVA measurements from either preoperative transthoracic echocardiography (AVA-TTE) (n = 65) or cardiac catheterization (AVA-Cath) (n = 35) that were acquired within 4 wk before the date of surgery. RESULTS: Adequate trans-AV Doppler recordings were obtained in 94% of patients for AVA-TEE and 100% of patients for AVA-EE. EE measurements of AVA showed close agreement with TEE measurements (mean difference [bias] +/- 95% CI = -0.09 cm(2) +/- 0.18 cm(2), r(2) = 0.83, P < 0.0001). AVA-EE also agreed well with AVA-Cath (mean difference +/- 95% CI = -0.03 cm(2) +/- 0.12 cm(2), r(2) = 0.87, P < 0.0001) and AVA-TTE (mean difference +/- 95% CI = -0.06 cm(2) +/- 0.22 cm(2), r(2) = 0.81, P < 0.0001). CONCLUSIONS: EE measurements of AVA by the continuity equation show high agreement and closely correlate with established techniques of AVA assessment.