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Echocardiographic diagnosis of pulmonary hypertension (PH) in horses is usually based on Doppler interrogation of tricuspid (TR) or pulmonic regurgitation (PR). This study aimed at investigating two-dimensional echocardiographic (2DE) variables, including pulmonary artery diameter (PAD) and pulmonary artery distensibility index (PADI), to diagnose PH. 41 healthy horses; 82 horses with TR or PR and normal intracardiac pressure gradients; and 35 horses with TR or PR velocities indicating PH. The 2DE variables were compared between groups, cut-offs for the diagnosis of PH were determined, and conditional inference trees served to identify the variable best predicting PH in the absence of TR or PR. Horses with PH had larger end-diastolic cross-sectional (short-axis) PAD (PAD ed-sx) (5.8 ± 1.0 cm; mean ± SD) and smaller PADI [/PADps] (15.4 ± 7.7%) than healthy horses (5.0 ± 0.6 cm, P<0.0001; 20.5 ± 4.4%, P<0.001) and horses with TR or PR but no PH (5.3 ± 0.6 cm, P=0.003; 18.8 ± 4.2%, P=0.005). PAD ed-sx predicted PH with sensitivity (Se) = 36% and specificity (Sp) = 94% (cut-off 6.0 cm, AUC = 0.668, P=0.002), while PADI [/PADps] predicted PH with Se = 43% and Sp = 92% (cut-off 13.7%, AUC = 0.662, P=0.004). In the absence of TR, PAD ed-sx and the end-diastolic long-axis aortic diameter-to-PAD ed-sx ratio (AoD ed-lx /PAD ed-sx) were most suitable to diagnose PH. Pulmonary artery crosssectional (short-axis) diameter at end-diastole measured in a right-parasternal long axis view of the left ventricular outflow tract and Pulmonary artery distensibility index were moderately specific but not very sensitive to diagnosing PH. Nonetheless, they may be used as complementary indices suggesting PH in the absence of TR or PR. [ABSTRACT FROM AUTHOR]

Abstract Aims The angiotensin receptor–neprilysin inhibitor (ARNI), sacubitril/valsartan, has been shown to be effective in treatment of patients with heart failure (HF), but limited data are available in patients with advanced disease. This retrospective observational study assessed the effects of ARNI treatment in patients with advanced HF. Methods and results We reviewed medical records of all advanced HF patients evaluated at our centre for unconventional therapies from September 2016 to January 2019. We studied 44 patients who started ARNI therapy and who had a haemodynamic assessment before beginning ARNI and after 6 ± 2 months. The primary endpoint was variation in pulmonary pressures and filling pressures at 6 months after starting ARNI therapy. Mean patient age was 51.6 ± 7.4 years; 84% were male. At 6 ± 2 months after starting ARNI, there was significant reduction of systolic pulmonary artery pressure [32 mmHg, interquartile range (IQR) 27–45 vs. 25 mmHg, IQR 22.3–36.5; P

Echocardiograms provide important information for the evaluation and management of patients with pulmonary hypertension. Right ventricular free wall strain measurements provide additional information about the longitudinal contractile function of the right ventricle. Clinical information, including echocardiographic measurements and right heart hemodynamic parameters, on patients undergoing right heart catheterization for evaluation of possible pulmonary hypertension was collected retrospectively. This study included 60 patients (35 women) with a mean age of 62.6 ± 14.8 years. For World Health Organization categories, 32 patients were in Group 1, 12 in Group 2, 4 in Group 3, 3 in Group 4, and 7 had mixed clinical features of both Group 2 and Group 3. The mean pulmonary artery pressure was 40.6 ± 13.2 mm Hg. The right atrial volume index had significant positive correlations with the brain natriuretic peptide level, right ventricular volume index, left atrial volume index, and right atrial pressure and negative correlations with the cardiac index and mixed venous oxygen saturation. The mean right ventricular free wall strain was −17.85 ± 5.56%; it did not have significant correlations with right heart hemodynamic parameters. Therefore, the right atrial volume index but not the right ventricular strain index provides important objective information for the evaluation of patients with possible pulmonary hypertension. [ABSTRACT FROM AUTHOR]

Aims: The angiotensin receptor–neprilysin inhibitor (ARNI), sacubitril/valsartan, has been shown to be effective in treatment of patients with heart failure (HF), but limited data are available in patients with advanced disease. This retrospective observational study assessed the effects of ARNI treatment in patients with advanced HF. Methods and results: We reviewed medical records of all advanced HF patients evaluated at our centre for unconventional therapies from September 2016 to January 2019. We studied 44 patients who started ARNI therapy and who had a haemodynamic assessment before beginning ARNI and after 6 ± 2 months. The primary endpoint was variation in pulmonary pressures and filling pressures at 6 months after starting ARNI therapy. Mean patient age was 51.6 ± 7.4 years; 84% were male. At 6 ± 2 months after starting ARNI, there was significant reduction of systolic pulmonary artery pressure [32 mmHg, interquartile range (IQR) 27–45 vs. 25 mmHg, IQR 22.3–36.5; P < 0.0001] and mean pulmonary artery pressure (20 mmHg, IQR 15.3–29.8 vs. 17 mmHg, IQR 13–24.8; P = 0.046). Five of 22 patients (23%) were deferred from the heart transplant list because of improvement, whereas four were listed de novo. After 23 ± 9 months, three patients were treated with a left ventricular assist device implantation, whereas six patients underwent heart transplantation (one in emergency conditions for refractory ventricular tachycardia). Conclusions: Sacubitril/valsartan is effective in reducing filling pressures and pulmonary pressures in patients with advanced HF. The absence of adverse events during follow‐up suggests that sacubitril/valsartan is safe and well‐tolerated in this cohort of patients. [ABSTRACT FROM AUTHOR]

Abstract Background Acute pulmonary thromboembolism is the most dangerous presentation of venous thromboembolic disease. The role of thrombolysis in massive pulmonary embolism has been studied extensively, but the same is not there for submassive pulmonary embolism. This study is aimed at evaluating the effects of thrombolysis in acute submassive pulmonary embolism. This was a prospective, case-control, observational study. Patients presenting with acute submassive pulmonary embolism were divided into thrombolysis group and control group depending on whether they received thrombolysis plus anticoagulation or anticoagulation only, respectively. Results A total of 86 patients were included in the study. Forty-two patients were in the thrombolysis group, and 44 patients were in the control group. The mean ± SD age in the control and thrombolysis groups was 63.3 ± 14.7 and 56.4 ± 13.8 years, respectively. The two groups were well matched in sex distribution and associated comorbidities like COPD, active surgery, major trauma, and immobilization. On echocardiography, dilated RA/RV in pre-treatment vs. post-treatment was seen in 20 (45.5%) vs. 20 (45.5%) in the control group and 26 (61.9%) vs. 11 (26.2%) in the thrombolysis group. Similarly, RV systolic dysfunction in pre-treatment vs. post-treatment was seen in 24 (54.5%) vs. 21 (47.7%) in the control group and 22 (52.4%) vs. 8 (19.0%) in the thrombolysis group. Pulmonary artery pressure in pre-treatment vs. post-treatment was 64.4 ± 15.0 vs. 45.9 ± 9.9 mmHg in the control group and 68.3 ± 17.4 vs. 31.4 ± 6.9 mmHg in the thrombolysis group. In control vs. thrombolysis group, there were 5 vs. 1 death, 6 vs. 1 hemodynamic decompensation, and 6 vs. 1 patient needing mechanical ventilation. Conclusion Thrombolysis in submassive pulmonary embolism is associated with better right ventricular functions, lower pulmonary artery pressures, and comparable mortality rates.

Background: Acute pulmonary thromboembolism is the most dangerous presentation of venous thromboembolic disease. The role of thrombolysis in massive pulmonary embolism has been studied extensively, but the same is not there for submassive pulmonary embolism. This study is aimed at evaluating the effects of thrombolysis in acute submassive pulmonary embolism. This was a prospective, case-control, observational study. Patients presenting with acute submassive pulmonary embolism were divided into thrombolysis group and control group depending on whether they received thrombolysis plus anticoagulation or anticoagulation only, respectively. Results: A total of 86 patients were included in the study. Forty-two patients were in the thrombolysis group, and 44 patients were in the control group. The mean ± SD age in the control and thrombolysis groups was 63.3 ± 14.7 and 56.4 ± 13.8 years, respectively. The two groups were well matched in sex distribution and associated comorbidities like COPD, active surgery, major trauma, and immobilization. On echocardiography, dilated RA/RV in pre-treatment vs. post-treatment was seen in 20 (45.5%) vs. 20 (45.5%) in the control group and 26 (61.9%) vs. 11 (26.2%) in the thrombolysis group. Similarly, RV systolic dysfunction in pre-treatment vs. post-treatment was seen in 24 (54.5%) vs. 21 (47.7%) in the control group and 22 (52.4%) vs. 8 (19.0%) in the thrombolysis group. Pulmonary artery pressure in pre-treatment vs. post-treatment was 64.4 ± 15.0 vs. 45.9 ± 9.9 mmHg in the control group and 68.3 ± 17.4 vs. 31.4 ± 6.9 mmHg in the thrombolysis group. In control vs. thrombolysis group, there were 5 vs. 1 death, 6 vs. 1 hemodynamic decompensation, and 6 vs. 1 patient needing mechanical ventilation. Conclusion: Thrombolysis in submassive pulmonary embolism is associated with better right ventricular functions, lower pulmonary artery pressures, and comparable mortality rates. [ABSTRACT FROM AUTHOR]

Pulmonary hypertension due to left heart disease (PH-LHD) frequently complicates heart failure with reduced ejection fraction (HFrEF). Specific therapies for PH have not offered an advantage in patients with PH-LHD. The combined angiotensin receptor blocker–neprilysin inhibitor (ARNI), sacubitril/valsartan, is a novel therapy that can increase levels of natriuretic peptides (NPs). The resulting action on natriuresis and vasodilation may play an important role in the reduction of pulmonary pressures. Here, we report how the use of ARNI in two patients with HFrEF has resulted in an improvement in PH and, consequently, in clinical status and prognosis. < Learning objective: Sacubitril/valsartan (ARNI) is the newest neurohormonal agent approved for therapy in heart failure with reduced ejection fraction (HFrEF). Pulmonary hypertension (PH) due to left heart disease (PH-LHD) is frequent in patients with HFrEF and is associated with a reduced functional class and poor prognosis. The use of ARNI has been associated with a relevant reduction in pulmonary pressures in two cases of PH-LHD.> [ABSTRACT FROM AUTHOR]

Objectives: Doppler echocardiography is a well-recognized technique for the noninvasive evaluation of pulmonary artery pressure; however, little information is available concerning patients receiving mechanical ventilation. Furthermore, recent studies have debatable results regarding the relevance of this technique to assess pulmonary artery pressure. The aim of our study was to reassess the accuracy of Doppler echocardiography to evaluate pulmonary artery pressure and to predict pulmonary hypertension.Design: Prospective observational study.Setting: Amiens ICU, France.Patients: ICU patients receiving mechanical ventilation.Interventions: In 40 patients, we simultaneously recorded Doppler echocardiography variables (including tricuspid regurgitation and pulmonary regurgitation) and invasive central venous pressure, systolic pulmonary artery pressure, diastolic pulmonary artery pressure, and mean pulmonary artery pressure.Measurements and Main Results: Systolic pulmonary artery pressure assessed from the tricuspid regurgitation derived maximal pressure gradient added to the central venous pressure demonstrated the best correlation with the invasive systolic pulmonary artery pressure (r = 0.87) with a small bias (-3 mm Hg) and a precision of 9 mm Hg. A Doppler echocardiography systolic pulmonary artery pressure greater than 39 mm Hg predicted pulmonary hypertension (mean pulmonary artery pressure ≥ 25 mm Hg) with 100% sensitivity and specificity. Tricuspid regurgitation maximal velocity greater than 2.82 m/s as well as tricuspid regurgitation pressure gradient greater than 32 mm Hg predicted the presence of pulmonary hypertension. Pulmonary regurgitation was recorded in 10 patients (25%). No correlation was found between pulmonary regurgitation velocities and either mean pulmonary artery pressure or diastolic pulmonary artery pressure. Pulmonary acceleration time less than 57 ms and isovolumic relaxation time less than 40 ms respectively predicted pulmonary hypertension 100% of the time and had a 100% negative predictive value.Conclusions: Tricuspid regurgitation maximal velocity pressure gradient added to invasive central venous pressure accurately estimates systolic pulmonary artery pressure and mean pulmonary artery pressure in ICU patients receiving mechanical ventilation and may predict pulmonary hypertension. [ABSTRACT FROM AUTHOR]

Pulmonary artery catheterization is a diagnostic procedure in which a catheter is inserted through a central vein and advanced toward the pulmonary artery to measure right atrial, right ventricular, and pulmonary artery pressures, estimate cardiac output, identify intracardiac shunts, and measure pulmonary vascular resistance. Hemodynamic measurements can provide a better understanding of the pathophysiology of heart failure and pulmonary hypertension, but their proper assessment and optimal use can be challenging due to differences in techniques that can lead to differences in conclusions and therapeutic management strategies. In this review, we will discuss right heart catheterization and its role in clinical practice (e.g., shunt evaluation, management of cardiogenic shock) and summarize important concerns related to measurement and interpretation., Competing Interests: None., (AJCD Copyright © 2023.)

Background: Heart Failure (HF) imposes a relevant burden and a considerable health concern, with high prevalence and mortality rates. This study was conducted to assess the cost-effectiveness of remote cardiac monitoring with the CardioMEMS Heart Failure System., Methods: In the present systematic review, several scholarly databases were searched and updated from inception up to September 20, 2022. The objective of the present review was formulated according to the patient/population, intervention, comparison and outcomes format. Mortality rate, hospitalization rate, quality-adjusted life year (QALY), total costs, and the incremental cost-effectiveness ratio regarding the use of the CardioMEMS System were the key outcomes of the present study. The quality of included studies was assessed using the Consolidated Health Economic Evaluation Reporting Standards 2022 (CHEERS) checklist., Results: Finally, 5 articles were retained and analyzed in the present systematic review. All studies employed the Markov and decision tree models. Results show that the CardioMEMS system reduced mortality and hospitalization rate and created a higher QALY. In all selected countries the CardioMEMS method is a more expensive method than the standard of care (SoC), with the highest cost in the United States (US) ($201,437) and the lowest cost in the United Kingdom ($25,963), respectively. the highest willingness to pay in the US and the lowest in Italy ($100,000 and $33,000 per QALY), respectively. Results showed that the most cost per QALY for the CardioMEMS system was in the US and the lowest was in the Netherlands ($46,622 and $26,615 per QALY), respectively., Conclusion: In all selected countries, CardioMEMS is a cost-effective method for monitoring and managing pulmonary artery pressures in HF patients. Strategies such as CardioMEMS, which decrease the rate of hospitalization, are likely to be only more cost-effective in the future., Competing Interests: The authors declare that they have no competing interests., (© 2023 Iran University of Medical Sciences.)

Introduction: As pulmonary artery catheter (PAC) use declines, search continues for reliable and readily accessible minimally invasive hemodynamic monitoring alternatives. Although the correlation between inferior vena cava collapsibility index (IVC-CI) and central venous pressures (CVP) has been described previously, little information exists regarding the relationship between IVC-CI and pulmonary artery pressures (PAPs). The goal of this study is to bridge this important knowledge gap. We hypothesized that there would be an inverse correlation between IVC-CI and PAPs. Methods: A post hoc analysis of prospectively collected hemodynamic data was performed, examining correlations between IVC-CI and PAPs in a convenience sample of adult Surgical Intensive Care Unit patients. Concurrent measurements of IVC-CI and pulmonary arterial systolic (PAS), pulmonary arterial diastolic (PAD), and pulmonary arterial mean (PAM) pressures were performed. IVC-CI was calculated as ([IVC max − IVC min]/IVC max) × 100%. Vena cava measurements were obtained by ultrasound-credentialed providers. For the purpose of correlative analysis, PAP measurements (PAS, PAD, and PAM) were grouped by terciles while the IVC-CI spectrum was divided into thirds (<33, 33-65, ≥66). Results: Data from 34 patients (12 women, 22 men, with median age of 59.5 years) were analyzed. Median Acute Physiologic Assessment and Chronic Health Evaluation II score was 9. A total of 76 measurement pairs were recorded, with 57% (43/76) obtained in mechanically ventilated patients. Correlations between IVC-CI and PAS (rs = −0.334), PAD (rs = −0.305), and PAM (rs = −0.329) were poor. Correlations were higher between CVP and PAS (R2 = 0.61), PAD (R2 = 0.68), and PAM (R2 = 0.70). High IVC-CI values (≥66%) consistently correlated with measurements in the lowest PAP ranges. Across all PAP groups (PAS, PAD, and PAM), there were no differences between the mean measurement values for the lower and middle IVC-CI ranges (0%-65%). However, all three groups had significantly lower mean measurement values for the ≥66% IVC-CI group. Conclusions: Low PAS, PAD, and PAM measurements show a reasonable correlation with high IVC-CI (≥66%). These findings are consistent with previous descriptions of the relationship between IVC-CI and CVP. Additional research in this area is warranted to better describe the hemodynamic relationship between IVC-CI and PAPs, with the goal of further reduction in the reliance on the use of PACs. [ABSTRACT FROM AUTHOR]

Aim To examine the relationship between plasma levels of N-terminal-proB type natriuretic peptide (NT-proBNP) and various echocardiographic and hemodynamic parameters in patients with mitral stenosis undergoing percutaneous transvenous mitral commissurotomy (PTMC). Materials and methods The study population consisted of 100 patients with rheumatic mitral stenosis who underwent PTMC. NT-proBNP levels in these patients were measured before PTMC and 48 hours after PTMC. These levels were then correlated with various echocardiographic and hemodynamic parameters measured before and after PTMC. Results Eighty-one percent of the study population were women, and the most common presenting symptom was dyspnea which was present in 94% of the patients. Dyspnea New York Heart Association class correlated significantly with baseline NT-proBNP levels ( r = 0.63; p < 0.01). The plasma NT-proBNP levels in these patients increased as echocardiogram signs of left atrial enlargement and right ventricular hypertrophy developed ( r = 0.59, p < 0.01). Patients in atrial fibrillation had significantly higher NT-proBNP levels than patients in sinus rhythm. Baseline NT-proBNP levels correlated significantly with left atrial volume ( r = 0.38; p < 0.01), left atrial volume index ( r = 0.45; p < 0.01), systolic pulmonary artery pressures ( r = 0.42; p < 0.01), and mean pulmonary artery pressures ( r = 0.41; p < 0.01). All patients who underwent successful PTMC showed a significant decrease in NT-proBNP (decreased from a mean 763.8 pg/mL to 348.6 pg/mL) along with a significant improvement in all echocardiographic and hemodynamic parameters ( p < 0.01). The percent change in NT-proBNP correlated significantly with the percent improvement noted with left atrial volume ( r = 0.39; p < 0.01), left atrial volume index ( r = 0.41; p < 0.01), systolic ( r = 0.32, p < 0.01), and mean pulmonary artery pressures ( r = 0.31, p < 0.01). Conclusions The decrease in NT-proBNP levels following PTMC reflects an improvement in clinical and hemodynamic status; hence, it is reasonable to suggest that NT-proBNP is helpful in evaluating the response to PTMC. [ABSTRACT FROM AUTHOR]

Background: Heart failure (HF) readmission continues to be a major health problem. Monitoring pulmonary artery pressure (PAP) and thoracic impedance (TI) are the two modalities utilized for early identification of decompensation in HF patients. We aimed to assess the correlation between these two modalities in patients who simultaneously had both the devices., Methods: Patients with history of New York Heart Association class III systolic HF with a pre-implanted intracardiac defibrillator (ICD) capable of monitoring TI and pre-implanted CardioMEMs™ remote HF monitoring device were included. Hemodynamic data including TI and PAPs were measured at baseline and then weekly. Weekly percentage change was then calculated as: Weekly percentage change = (week 2 - week1)/week 1 × 100. Variability between the methods was expressed by Bland-Altman analysis. Significance was determined as a P-value < 0.05., Results: Nine patients met the inclusion criteria. There was no significant correlation between the assessed weekly percentage changes in pulmonary artery diastolic pressure (PAdP) and TI measurements (r = -0.180, P = 0.065). Using Bland-Altman analytic methods, both methods had no significant difference in agreement (0.011±0.094%, P = 0.215). With the linear regression model applied for Bland-Altman analysis, the two methods appeared to have proportional bias without agreement (unstandardized beta-coefficient of 1.91, t 22.9, P ≤ 0.001)., Conclusion: Our study demonstrated that variations exist between measurement of PAdP and TI; however, there is no significant correlation between weekly variations between them., Competing Interests: The authors declare that they have no conflict of interest., (Copyright 2023, Aggarwal et al.)

Objective: To assess the usefulness of central venous pressure (CVP), diastolic right ventricular pressure, and pulmonary capillary wedge pressure (PCWP) waveform analysis in predicting fluid responsiveness. Design: A prospective observational study. Setting: Tertiary care university hospital. Patients: Forty-four patients undergoing coronary artery bypass grafting. Interventions: Analysis of the a/v wave ratio of the PCWP, CVP, and right ventricular dP/dt to predict an increase in stroke volume >15% after the administration of 500mL of colloid. Measurements and Main Results: Forty-four patients were enrolled in this study and 7 were excluded. There were 24 responders and 13 nonresponders. No differences in mean CVP and PCWP values between the responders and the nonresponders were found. The only parameter associated with a significant response to volume infusion was the ratio of the a/v waves of the PCWP tracing (p = 0.0001). The performance of the a/v wave ratio>1 of the PCWP tracing in predicting fluid responsiveness was evaluated by constructing a receiver operating characteristic curve. The area under the receiver operating characteristic curve was 0.89 (95% confidence interval, 0.79-0.99; p<0.05). Conclusions: The a/v ratio measured on the PCWP tracing is a predictor of fluid responsiveness in patients with preserved left ventricular function undergoing coronary artery bypass grafting. [Copyright &y& Elsevier]

High altitude acclimatization produces a suite of physiological changes that might support an improved athletic performance at low altitude and thus lead to the strategy of athletic training at high altitude. Although there is substantial literature on high altitude physiology in humans, there are few studies on horses. Our interest in the physiological responses to high altitude in equids has been driven by the concerns of how athletic performance is altered at altitude and how conditioning at altitude may improve performance subsequently at low altitude. This review serves to illustrate what is currently know about the physiological changes of horses to altitude, at rest and during exercise, and to highlight how performance is impacted both at high altitude and subsequent return to low altitude. [ABSTRACT FROM PUBLISHER]

Echocardiograms provide important information for the evaluation and management of patients with pulmonary hypertension. Right ventricular free wall strain measurements provide additional information about the longitudinal contractile function of the right ventricle. Clinical information, including echocardiographic measurements and right heart hemodynamic parameters, on patients undergoing right heart catheterization for evaluation of possible pulmonary hypertension was collected retrospectively. This study included 60 patients (35 women) with a mean age of 62.6 ± 14.8 years. For World Health Organization categories, 32 patients were in Group 1, 12 in Group 2, 4 in Group 3, 3 in Group 4, and 7 had mixed clinical features of both Group 2 and Group 3. The mean pulmonary artery pressure was 40.6 ± 13.2 mm Hg. The right atrial volume index had significant positive correlations with the brain natriuretic peptide level, right ventricular volume index, left atrial volume index, and right atrial pressure and negative correlations with the cardiac index and mixed venous oxygen saturation. The mean right ventricular free wall strain was -17.85 ± 5.56%; it did not have significant correlations with right heart hemodynamic parameters. Therefore, the right atrial volume index but not the right ventricular strain index provides important objective information for the evaluation of patients with possible pulmonary hypertension., (Copyright © 2022 Baylor University Medical Center.)

Objectives: To compare the physiology of apneic oxygenation with low-tidal-volume (VT) ventilation during harvesting of the left internal mammary artery., Design: Prospective, single-center, randomized trial., Setting: Single-center teaching hospital., Participants: The study comprised 24 patients who underwent elective coronary artery bypass grafting surgery., Interventions: Apneic oxygenation (apneic group: 12 participants) and low-VT ventilation (low-VT group: 12 participants) (2.5 mL/kg ideal body weight) for 15 minutes during harvesting of the left internal mammary artery., Measurement and Main Results: The primary endpoint was an absolute change in partial pressure of arterial carbon dioxide (PaCO 2 ). Secondary endpoints were changes in arterial pH, pulmonary artery pressures (PAP), cardiac index, and pulmonary artery acceleration time and ease of surgical access. The mean (standard deviation) absolute increase in PaCO 2 was 31.8 mmHg (7.6) in the apneic group and 17.6 mmHg (8.2) in the low-VT group (baseline-adjusted difference 14.2 mmHg [95% confidence interval 21.0-7.3], p<0.001). The mean (standard deviation) absolute decrease in pH was 0.15 (0.03) in the apneic group and 0.09 (0.03) in the low-VT group baseline-adjusted difference 0.06 [95% confidence interval 0.03-0.09], p<0.001. Differences in the rate of change over time between groups (time-by-treatment interaction) were observed for PaCO 2 (p<0.001), pH (p<0.001), systolic PAP (p = 0.002), diastolic PAP (p = 0.023), and mean PAP (p = 0.034). Both techniques provided adequate ease of surgical access; however, apneic oxygenation was preferred predominantly., Conclusions: Apneic oxygenation caused a greater degree of hypercarbia and respiratory acidemia compared with low-VT ventilation. Neither technique had deleterious effects on PAP or cardiac function. Both techniques provided adequate ease of surgical access., (Copyright © 2016 Elsevier Inc. All rights reserved.)