Preoperative Tricuspid Regurgitation Is Associated With Long-Term Mortality and Is Graded More Severe Than Intraoperative Tricuspid Regurgitation.

OBJECTIVES: To determine whether preoperative (preop) tricuspid regurgitation (TR) severity grade was associated with postoperative mortality, to examine the correlation between pre-op and intraoperative (intraop) TR grades, and to understand which TR grade had better prognostic predictability in cardiac surgery patients. DESIGN: Retrospective. SETTING: Single institution. PARTICIPANTS: Patients. INTERVENTIONS: Preop and intraop echocardiography TR grades of 4,232 patients who had undergone cardiac surgeries between 2004 and 2014 were examined. MEASUREMENTS AND MAIN RESULTS: Kaplan-Meier curves and Cox proportional hazard models were used to determine the association between TR grades and the primary endpoint of all-cause mortality. The Wilcoxon signed-rank test and Spearman's rank correlation were analyzed to assess the similarity and correlation between preop and intraop-grade pairs. Multivariate logistic regression models of the area under the curve characteristics were compared for prognostic implications. Kaplan-Meier curves demonstrated a strong relationship between preop grades and survival. Multivariate models showed significantly increased mortality starting at mild preop TR (mild TR: hazard ratio [HR] 1.24; 95% CI 1.05-1.46, p = 0.013; moderate TR: HR 1.60; 95% CI 1.05-1.97, p < 0.001; severe TR: HR 2.50; 95% CI 1.74-3.58, p < 0.001). Preop TR grades were mostly higher than intraop grades. Spearman's correlation was 0.55 (p < 0.001). The area under the curves of preop and intraop TR-based models were almost identical (0.704 v 0.702 1-year mortality and 0.704 v 0.700 2-year mortality). CONCLUSIONS: The authors found that echocardiographically-determined preop TR grade at the time of surgical planning was associated with long-term mortality, starting even at a mild grade. Preop grades were higher than intraop grades, with a moderate correlation. Preop and intraop grades exhibited similar prognostic implications.

A Novel 3-Dimensional Approach for the Echocardiographic Evaluation of Mitral Valve Area After Repair for Degenerative Disease.

BACKGROUND: Currently available 2-dimensional (2D) echocardiographic methods for accurately assessing the mitral valve orifice area (MVA) after mitral valve repair (MVr) are limited due to its complex 3-dimensional (3D) geometry. We compared repaired MVAs obtained with commonly used 2D and 3D echocardiographic methods to a 3D orifice area (3DOA), which is a novel echocardiographic measurement and independent of geometric assumptions. METHODS: Intraoperative 2D and 3D transesophageal echocardiography (TEE) images from 20 adult cardiac surgery patients who underwent MVr for mitral regurgitation obtained immediately after repair were retrospectively reviewed. MVAs obtained by pressure half-time (PHT), 2D planimetry (2DP), and 3D planimetry (3DP) were compared to those derived by 3DOA. RESULTS: MVAs (mean value ± standard deviation [SD]) after MVr were obtained by PHT (3 ± 0.6 cm), 2DP (3.58 ± 0.75 cm), 3D planimetry (3DP; 2.78 ± 0.74 cm), and 3DOA (2.32 ± 0.76 cm). MVAs obtained by the 3DOA method were significantly smaller compared to those obtained by PHT (mean difference, 0.68 cm; P = .0003), 2DP (mean difference, 1.26 cm; P < .0001), and 3DP (mean difference, 0.46 cm; P = .003). In addition, MVA defined as an area ≤1.5 cm was identified by 3DOA in 2 patients and by 3DP in 1 patient. CONCLUSIONS: Post-MVr MVAs obtained using the novel 3DOA method were significantly smaller than those obtained by conventional echocardiographic methods and may be consistent with a higher incidence of MVA reduction when compared to 2D techniques. Further studies are still needed to establish the clinical significance of 3D echocardiographic techniques used to measure MVA after MVr.

Echocardiographic Assessment of Mitral Stenosis Orifice Area: A Comparison of a Novel Three-Dimensional Method Versus Conventional Techniques.

BACKGROUND: A comprehensive evaluation of mitral stenosis (MS) severity commonly utilizes two-dimensional (2D) echocardiography techniques. However, the complex three-dimensional (3D) structure of the mitral valve (MV) poses challenges to accurate measurements of its orifice area by 2D imaging modalities. We aimed to assess MS severity by comparing measurements of the MV orifice area using conventional echocardiography methods to 3D orifice area (3DOA), a novel echocardiographic technique which minimizes geometric assumptions. METHODS: Routine 2D and 3D intraoperative transesophageal echocardiographic images from 26 adult cardiac surgery patients with at least moderate rheumatic MS were retrospectively reviewed. Measurements of the MV orifice area obtained by pressure half-time (PHT), proximal isovelocity surface area (PISA), continuity equation, and 3D planimetry were compared to those acquired using 3DOA. RESULTS: MV areas derived by PHT, PISA, continuity equation, 3D planimetry, and 3DOA (mean value ± standard deviation) were 1.12 ± 0.27, 1.03 ± 0.27, 1.16 ± 0.35, 0.97 ± 0.25, and 0.76 ± 0.21 cm, respectively. Areas obtained from the 3DOA method were significantly smaller than areas derived from PHT (mean difference 0.35 cm, P < .0001), PISA (mean difference: 0.28 cm, P = .0002), continuity equation (mean difference: 0.43 cm, P = .0015), and 3D planimetry (mean difference: 0.19 cm, P < .0001). MV 3DOAs also identified a significantly greater percentage of patients with severe MS (88%) compared to PHT (31%, P = .006), PISA (42%, P = .01), and continuity equation (39%, P = .017) but not in comparison to 3D planimetry (62%, P = .165). CONCLUSIONS: Novel measures of the stenotic MV 3DOA in patients with rheumatic heart disease are significantly smaller than calculated values obtained by conventional methods and may be consistent with a higher incidence of severe MS compared to 2D techniques. Further investigation is warranted to determine the clinical relevance of 3D echocardiographic techniques used to measure MV area.

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.

Providing initial transthoracic echocardiography training for anesthesiologists: simulator training is not inferior to live training.

OBJECTIVE: Transthoracic echocardiography (TTE) is finding increased use in anesthesia and critical care. Efficient options for training anesthesiologists should be explored. Simulator mannequins allow for training of manual acquisition and image recognition skills and may be suitable due to ease of scheduling. The authors tested the hypothesis that training with a simulator would not be inferior to training using a live volunteer. DESIGN: Prospective, randomized trial. SETTING: University hospital. PARTICIPANTS: Forty-six anesthesia residents, fellows, and faculty. INTERVENTIONS: After preparation with a written and video tutorial, study subjects received 80 minutes of TTE training using either a simulator or live volunteer. Practical and written tests were completed before and after training to assess improvement in manual image acquisition skills and theoretic knowledge. The written test was repeated 4 weeks later. MEASUREMENTS AND MAIN RESULTS: Performance in the practical image-acquisition test improved significantly after training using both the live volunteer and the simulator, improving by 4.0 and 4.3 points out of 15, respectively. Simulator training was found not to be inferior to live training, with a mean difference of -0.30 points and 95% confidence intervals that did not cross the predefined non-inferiority margin. Performance in the written retention test also improved significantly immediately after training for both groups but declined similarly upon repeat testing 4 weeks later. CONCLUSIONS: When providing initial TTE training to anesthesiologists, training using a simulator was not inferior to using live volunteers.

Joint preoperative transthoracic and intraoperative transoesophageal echocardiographic assessment of functional mitral regurgitation severity provides better association with long-term mortality.

OBJECTIVES: Functional mitral regurgitation (MR) is observed with ischaemic heart disease or aortic valve disease. Assessing the value of mitral valve repair or replacement (MVR/P) is complicated by frequent discordance between preoperative transthoracic echocardiographic (pTTE) and intraoperative transoesophageal echocardiographic (iTOE) assessment of MR severity. We examined the association of pTTE and iTOE with postoperative mortality in patients with or without MR, at the time of coronary artery bypass grafting (CABG) and/or aortic valve replacement without MVR/P. METHODS: Medical records of 6629 patients undergoing CABG and/or aortic valve replacement surgery with or without functional MR and who did not undergo MVR/P were reviewed. MR severity assessed by pTTE and iTOE were examined for association with postoperative mortality using proportional hazards regression while accounting for patient and operative characteristics. RESULTS: In 72% of 709 patients with clinically significant (moderate or greater) functional MR detected by pTTE, iTOE performed after induction of anaesthesia demonstrated a reduction in MR severity, while 2% of patients had increased severity of MR by iTOE. iTOE assessment of MR was better associated with long-term postoperative mortality than pTTE in patients with moderate MR [hazard ratio (HR) 1.31 (1.11-1.55) vs 1.02 (0.89-1.17), P-value for comparison of HR 0.025] but was not different for more than moderate MR [1.43 (0.96-2.14) vs 1.27 (0.80-2.02)]. CONCLUSIONS: In patients undergoing CABG and/or aortic valve replacement without MVR/P, these findings support intraoperative reassessment of MR severity by iTOE as an adjunct to pTTE in the prediction of mortality. Alone, these findings do not yet provide evidence for an operative strategy.

Literature and new innovations leading to the rise and fall of the Swan-Ganz catheter.

BACKGROUND: In 1970, Harold James Charles Swan and William Ganz published their work on the pulmonary artery catheter (PAC or Swan-Ganz catheter). They described the successful bedside use of a flow-directed catheter to continuously evaluate the heart, and it was used extensively in the years following to care for critically ill patients. In recent decades, clinicians have reevaluated the risks and benefits of the PAC. AIM: We acknowledge the contributions of Swan and Ganz and discuss literature, including randomized controlled trials, and new technology surrounding the rise and fall in use of the PAC. METHODS: We performed a literature search of retrospective and prospective studies, including randomized controlled trials, and editorials to understand the history and clinical outcomes of the PAC. RESULTS: In the 1980s, clinicians began to question the benefits of the PAC. In 1996 and 2003, a large observational study and randomized controlled trial, respectively, showed no clear benefits in outcome. Thereafter, use of PACs began to drop precipitously. New less and noninvasive technology can estimate cardiac output and blood pressure continuously. CONCLUSIONS: Swan and Ganz contributed to the bedside understanding of the pathophysiology of the heart. The history of the rise and fall in use of the PAC parallels the literature and invention of less-invasive technology. Although the PAC has not been shown to improve clinical outcomes in large randomized controlled trials, it may still be useful in select patients. New less-invasive and noninvasive technology may ultimately replace it if literature supports it.

Cardioscopic tricuspid valve repair in a beating ovine heart.

BACKGROUND: Open heart surgery is commonly associated with cardiopulmonary bypass and cardioplegic arrest. The attendant risks of cardiopulmonary bypass may be prohibitive in high-risk patients. We present a novel endoscopic technique of performing tricuspid valve repair without cardiopulmonary bypass in a beating ovine heart. METHODS: Six sheep underwent sternotomy and creation of a right heart shunt to eliminate right atrial and right ventricular blood for clear visualization. The superior vena cava, inferior vena cava, pulmonary artery, and coronary sinus were cannulated, and the blood flow from these vessels was shunted into the pulmonary artery via a roller pump. The posterior leaflet of the tricuspid valve was partially excised to create tricuspid regurgitation, which was confirmed by Doppler echocardiography. A 7.0-mm fiberoptic videoscope was inserted into the right atrium to visualize the tricuspid valve. Under cardioscopic vision, an endoscopic needle driver was inserted into the right atrium, and a concentric stitch was placed along the posterior annulus to bicuspidize the tricuspid valve. Doppler echocardiography confirmed reduction of tricuspid regurgitation. RESULTS: All animals successfully underwent and tolerated the surgical procedure. The right heart shunt generated a bloodless field, facilitating cardioscopic tricuspid valve visualization. The endoscopic stitch resulted in annular plication and functional tricuspid valve bicuspidization, significantly reducing the degree of tricuspid regurgitation. CONCLUSION: Cardioscopy enables less invasive, beating-heart tricuspid valve surgery in an ovine model. This technique may be useful in performing right heart surgery without cardiopulmonary bypass in high-risk patients.

Preoperative Cardiac Stress Tests Ordered in the Preoperative Evaluation Clinic: A Retrospective Review of Ordering Patterns.

BACKGROUND: The role of anesthesiologists has expanded from operating rooms to preoperative evaluation clinics. This role involves performing preoperative cardiovascular evaluation and optimization of patients before elective surgery, which can include ordering cardiac stress tests. We aimed to study the ordering patterns by anesthesiologists for preoperative cardiac stress tests, focusing on whether societal and institutional guidelines and recommendations were used. Choice of type of cardiac stress test was also examined. METHODS: A single center retrospective chart review from December 1, 2005 to May 31, 2015 was performed on 492 patients who had a cardiac stress test ordered by an anesthesiologist. Patients were categorized by indication for ordering the cardiac stress test based on societal practice guidelines, institutional guidelines or other relevant reasons at the time of patient encounter. Those "other" category cardiac stress tests were assessed for indication and evaluated by physician peer review to see if there was peer agreement for being appropriately ordered. Exercise electrocardiography (ECG) cardiac stress tests ordered were evaluated for appropriateness based on baseline resting ECG findings. Patients with left bundle branch block (LBBB) or right ventricular (RV) pacing were evaluated for appropriateness of proper cardiac stress test modality based on whether a pharmacological vasodilator cardiac stress test was ordered. RESULTS: Analysis of the cardiac stress tests ordered showed that 43% were ordered according to American College of Cardiology/American Heart Association guidelines, 29% were ordered according to institutional guidelines, and 28% were categorized as "other". Of the 28% "other" cardiac stress tests, 53% were in agreement for ordering by peer review. Sixty-four exercise ECG cardiac stress tests were ordered, of which 58% were appropriate based on having no baseline resting ECG abnormalities. Fifty-one patients were identified as having a resting ECG of LBBB or RV pacing of which 41% had an appropriate pharmacological vasodilator cardiac stress tests ordered. CONCLUSIONS: Anesthesiologists order most preoperative cardiac stress tests according to professional societal or institutional guidelines (72%), yet they are not always choosing the best modality of cardiac stress test. A significant portion of cardiac stress tests are ordered (28%) based on clinical judgment, likely due to the lack of guidelines and recommendations being all-encompassing on many commonly encountered preoperative patient situations.

Adjustable, physiological ventricular restraint improves left ventricular mechanics and reduces dilatation in an ovine model of chronic heart failure.

BACKGROUND: Ventricular restraint is a nontransplantation surgical treatment for heart failure. The effect of varying restraint level on left ventricular (LV) mechanics and remodeling is not known. We hypothesized that restraint level may affect therapy efficacy. METHODS AND RESULTS: We studied the immediate effect of varying restraint levels in an ovine heart failure model. We then studied the long-term effect of restraint applied over a 2-month period. Restraint level was quantified by use of fluid-filled epicardial balloons placed around the ventricles and measurement of balloon luminal pressure at end diastole. At 4 different restraint levels (0, 3, 5, and 8 mm Hg), transmural myocardial pressure (P(tm)) and indices of myocardial oxygen consumption (MVO2) were determined in control (n=5) and ovine heart failure (n=5). Ventricular restraint therapy decreased P(tm) and MVO2, and improved mechanical efficiency. An optimal physiological restraint level of 3 mm Hg was identified to maximize improvement without an adverse affect on systemic hemodynamics. At this optimal level, end-diastolic P(tm) and MVO2 indices decreased by 27% and 20%, respectively. The serial longitudinal effects of optimized ventricular restraint were then evaluated in ovine heart failure with (n=3) and without (n=3) restraint over 2 months. Optimized ventricular restraint prevented and reversed pathological LV dilatation (130+/-22 mL to 91+/-18 mL) and improved LV ejection fraction (27+/-3% to 43+/-5%). Measured restraint level decreased over time as the LV became smaller, and reverse remodeling slowed. CONCLUSIONS: Ventricular restraint level affects the degree of decrease in P(tm), the degree of decrease in MVO2, and the rate of LV reverse remodeling. Periodic physiological adjustments of restraint level may be required for optimal restraint therapy efficacy.

Severity of tricuspid regurgitation is associated with long-term mortality.

OBJECTIVES: To determine the association between intraoperative/presurgical grade of tricuspid regurgitation (TR) and mortality, and to determine whether surgical correction of TR correlated with an increased chance of survival compared with patients with uncorrected TR. METHODS: The grade of TR assessed by intraoperative transesophageal echocardiography (TEE) before surgical intervention was reviewed for 23,685 cardiac surgery patients between 1990 and 2014. Cox proportional hazard regression models were used to determine association between grade of TR and the primary endpoint of all-cause mortality. Association between tricuspid valve (TV) surgery and survival was determined with Cox proportional hazard regression models after matching for grade of TR. RESULTS: Kaplan-Meier survival curves demonstrated a relationship between all grades of TR. Multivariable analysis of the entire cohort demonstrated significantly increased mortality for moderate (hazard ratio [HR], 1.24; 95% confidence interval [CI], 1.1-1.4; P < .0001) and severe TR (HR, 2.02; 95% CI, 1.57-2.6; P < .0001). Mild TR displayed a trend for mortality (HR, 1.07; 95% CI, 0.99-1.16; P = .075). After matching for grade of TR and additional confounders, patients who underwent TV surgery had a statistically significant increased likelihood of survival (HR, 0.74; 95% CI, 0.61-0.91; P = .004). CONCLUSIONS: Our study of more than 20,000 patients demonstrates that grade of TR is associated with increased risk of mortality after cardiac surgery. In addition, all patients who underwent TV surgery had a statistically significantly increased likelihood of survival compared with those with the same degree of TR who did not undergo TV surgery.

Aortic Atheroma Increases the Risk of Long-Term Mortality in 20,000 Patients.

BACKGROUND: The association between long-term survival and aortic atheroma in cardiac surgical patients has not been comprehensively investigated. In this study we determine the relation between grade of atheroma and the risk of long-term mortality in a retrospective cohort of more than 20,000 patients undergoing cardiac operation during a 20-year period. METHODS: We included 22,304 consecutive intraoperative transesophageal and epiaortic ultrasound examinations performed at Brigham and Women's Hospital between 1995 and 2014, with long-term follow-up. The extent of atheromatous disease recorded in each examination was used for analysis. Mortality data were obtained from our institution's data registry. Mortality analyses were done using Cox proportional hazard regression models with follow-up as a time scale. We repeated the analysis in a subgroup of 14,728 patients with more detailed demographic characteristics, including postoperative stroke, queried from the institutional Society of Thoracic Surgeons database. RESULTS: A total of 7,722 mortality events and 872 stroke events occurred. Patients with atheromatous disease demonstrated a significant increase in mortality across all grades of severity, both for the ascending and descending aorta. This relation remained unchanged after adjusting for additional covariates. Adjustments for postoperative stroke resulted in only minimal attenuation in the risk of postoperative mortality related to aortic atheroma. CONCLUSIONS: Aortic atheromatous disease of any grade in the ascending and descending aorta is a significant long-term risk of long-term, all-cause mortality in cardiac operation patients. This association remains independent of other conventional risk factors and is not related to postoperative cerebrovascular accidents.

The usefulness of transesophageal echocardiography during intraoperative cardiac arrest in noncardiac surgery.

According to guidelines established by the American Society of Anesthesiologists and the Society of Cardiovascular Anesthesiologists, life-threatening hemodynamic disturbances are classified as a category I indication for the intraoperative use of transesophageal echocardiography (TEE). However, the usefulness of TEE during intraoperative cardiac arrest and its impact on patient management have not been rigorously investigated. Using our departmental TEE database, we identified a population of 22 patients who underwent noncardiac surgical procedures and experienced unexpected intraoperative hemodynamic collapse requiring the initiation of Advanced Cardiac Life Support procedures between the time of induction of general anesthesia and the termination of the surgical procedure. Results of TEE examinations, patient records, detailed operative records, and outcome of patients were reviewed for the utility of TEE to diagnose the etiology of the hemodynamic collapse. Furthermore, the impact on subsequent patient management was evaluated. A primary suspected diagnosis of the underlying pathological process was established in 19 of 22 patients with TEE, including 9 with thromboembolic events, 6 with acute myocardial ischemia, 2 with hypovolemia, and 2 patients with pericardial tamponade. A definitive diagnosis could not be made in 3 patients with TEE. In 18 patients, TEE guided specific management beyond implementation of Advanced Cardiac Life Support protocols, including the addition of surgical procedures in 12 patients. Fourteen patients survived to leave the operating room, and 7 of these patients were eventually discharged from the hospital. Thus, TEE may provide additional diagnostic information in patients with intraoperative cardiac arrest and may directly guide specific, potentially life-saving therapy.

Three Portraits, 2 Artists, and 1 Harvard Department of Anaesthesia: the Brigham Chairs and the Artists Who Rendered Them.

BACKGROUND: Many forms of art accurately depict physical attributes of their subjects. But how precisely do portraits capture personal, emotional, and behavioral aspects of individuals holding leadership positions in academic departments of anesthesiology? METHODS: We examined formal portraits of the first three academic chairmen of anesthesiology in our department - Leroy D. Vandam, Benjamin G. Covino, and Simon Gelman and obtained information about the artists (George Augusta and Marc Klionsky) regarding how they conducted research on their subjects, and the methods they used to depict significant character traits into their art. We then correlated the artistic depiction with known biographical and behavioral qualities of these leaders. RESULTS: We found that the artists were remarkably astute in their observations and that they successfully captured both physical and emotional aspects of these chairmen in their portraits. Moreover, in one instance, significant early life experiences were added to the composition with subtlety. Individuals familiar with these chairmen and aware of their management style can easily appreciate the techniques employed by the artists. SUMMARY: We conclude that art successfully depicted personal and executive attributes of these three academic anesthesia chairmen.

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.

Right heart failure: an ischemic model and restraint therapy for treatment.

BACKGROUND: Right heart failure is poorly understood and treated. In left heart failure, ventricular restraint can reverse pathologic left ventricular remodeling. The effect of restraint in right heart failure, however, is not known. We hypothesize that ventricular restraint can be applied selectively to the right ventricle (RV) to promote RV reverse remodeling. METHODS: Right heart failure was induced by right coronary artery ligation in a sheep model. Eight weeks later, a saline-filled epicardial balloon was placed around the RV surface for restraint. Restraint level was defined by measuring balloon luminal pressure at end-diastole. Maximum balloon pressure was determined by the amount of balloon pressure required to decrease systemic mean arterial pressure by 10 mm Hg. We determined end-diastolic transmural myocardial pressure, indices of myocardial oxygen consumption, and RV diastolic compliance at 4 different restraint levels. RESULTS: After coronary ligation, RV ejection fraction (EF) decreased from 0.574±0.04 to 0.362±0.03 (p<0.05). End-diastolic RV volume increased from 70.8 mL/m2±9 to 82.2 mL/m2±7 (p<0.05) by magnetic resonance imaging. After application of restraint to the RV only, RV transmural pressure decreased significantly by 27%. Greater levels of restraint also improved RV EF (0.347±0.06 to 0.473±0.05) but did not change RV end-diastolic volume. CONCLUSIONS: A model of ischemic right heart failure was successfully created. Selective RV restraint results in improved mechanical efficiency, decreased wall stress, and improved EF. The benefits of restraint in right heart failure warrant further investigation.