Right ventricular echocardiographic predictors of postoperative supraventricular arrhythmias after thoracic surgery: a pilot study

Effects of lung resection on heart structure and function: A tissue Doppler ultrasound survey of 43 cases

Changes in heart structure and function after lung resection in patients with lung cancer are challenging to manage. Therefore, a non-invasive and reliable measurement tool to gauge such changes is critical. The purpose of the present study was to compare cardiological changes before and after lung resection using tissue Doppler imaging (TDI). A total of 43 patients (19 men and 24 women) with primary non-small cell lung cancer (n=37) and metastatic cancer in the lungs (n=6) were enrolled in the study.nTDI was used to determine the thickness of the ascending aorta, the open size of the ascending valve, the anterior-oposterior diameters of the left atrium and left ventricle, and the thickness of the ventricular septum and right ventricle before and after lung resection. Left ventricular (LV) ejection fraction (EF), pulmonary valve flow rate, tricuspid annular or mitral leaflet tip early (E) peak/late (A) diastolic blood flow velocities, tricuspid regurgitation flow, the lateral mitral annulus early (e') diastolic velocity and mitral E/e' ratio were used to determine LV filling pressure. Results revealed no significant differences between male and female patients in terms of the open size of the ascending valve, the anterior-posterior diameter of the left ventricle and the mitral E/e' ratio. Significant differences were found in the width of the ascending aorta, anterior-posterior diameter of the left atrium, width of the LV septum and right ventricular (RV) diameter before and after lung resection. Finally, there were significantchanges in EF and tricuspid pressure. The results indicated that TDI was useful as a non-invasive method for assessing left and right heart function following lung resection. The LV and RV dimensions were affected, but LV filling pressure was preserved after lobectomy.

Incidence and characteristics of early elevation of cardiac troponin I after intrathoracic surgery: A single-center retrospective observational study

The early elevation of cardiac troponins within 24 hours after noncardiac surgery is reportedly associated with increased postoperative morbidities. Several predisposing factors, including the frequent occurrence of hypoxia and increased pulmonary arterial pressure, may likely contribute to this elevation, especially after intrathoracic surgery. Therefore, this retrospective study aimed to elucidate the incidence and characteristics of the early elevation of cardiac troponin I after intrathoracic surgery. This study included 320 patients who underwent intrathoracic surgery between January 1, 2018, and June 30, 2021. Specific perioperative variables were retrospectively collected from their electrical clinical records. The serum concentration of high-sensitivity cardiac troponin I (hs cTnI) was measured twice immediately after the intensive care unit arrival and on the following day. We grouped these patients into two: the early elevation of hs cTnI (EECT) group (hs cTnI value > 26.2 ng/L by at least 1 measurement) and the non-early elevation (non-EECT) group. Patient characteristics were then compared between these groups. The hs cTnI level elevated within 24 hours postoperatively in 103 patients (32.2%). In univariate analysis, intraoperative variables, including the duration of unilateral ventilation (199.2 minutes, P = .0025) and surgery (210.6 minutes, P = .0012), estimated blood loss volume (406.7 mL, P = .0022), percentage of stored red blood cell (RBC) transfusion (10.7%, P = .0059), and percentage of lobectomy or combination of other lung resection types (88.3%, P = .00188), were significantly higher in the EECT group than in the non-EECT group. In the log-rank test, prolonged hospitalization was more prevalent in the EECT group (P = .0485). Furthermore, multivariate analysis revealed 3 independent risk factors for the early elevation of hs cTnI: coexisting chronic renal failure (odds ratio [OR], 3.25), lobectomy or combined resections (OR, 2.65), and stored RBC transfusion (OR, 3.41). The early elevation of hs cTnI commonly occurs after intrathoracic surgery, with an incidence of 32.2%. Its 3 independent risk factors are coexisting chronic renal failure, lung resection type, and stored RBC transfusion.

Perioperative cardiovascular pathophysiology in patients undergoing lung resection surgery: a narrative review

Although thoracic surgery is understood to confer a high risk of postoperative respiratory complications, the substantial haemodynamic challenges posed are less well appreciated. This review highlights the influence of cardiovascular comorbidity on outcome, reviews the complex pathophysiological changes inherent in one-lung ventilation and lung resection, and examines their influence on cardiovascular complications and postoperative functional limitation. There is now good evidence for the presence of right ventricular dysfunction postoperatively, a finding that persists to at least 3 months. This dysfunction results from increased right ventricular afterload occurring both intraoperatively and persisting postoperatively. Although many patients adapt well, those with reduced right ventricular contractile reserve and reduced pulmonary vascular flow reserve might struggle. Postoperative right ventricular dysfunction has been implicated in the aetiology of postoperative atrial fibrillation and perioperative myocardial injury, both common cardiovascular complications which are increasingly being appreciated to have impact long into the postoperative period. In response to the physiological demands of critical illness or exercise, contractile reserve, flow reserve, or both can be overwhelmed resulting in acute decompensation or impaired long-term functional capacity. Aiding adaptation to the unique perioperative physiology seen in patients undergoing thoracic surgery could provide a novel therapeutic avenue to prevent cardiovascular complications and improve long-term functional capacity after surgery.

Recommendations from the Italian intersociety consensus on Perioperative Anesthesia Care in Thoracic surgery (PACTS) part 1: preadmission and preoperative care

INTRODUCTION

Anesthetic care in patients undergoing thoracic surgery presents specific challenges that necessitate standardized, multidisciplionary, and continuously updated guidelines for perioperative care.

METHODS

A multidisciplinary expert group, the Perioperative Anesthesia in Thoracic Surgery (PACTS) group, comprising 24 members from 19 Italian centers, was established to develop recommendations for anesthesia practice in patients undergoing thoracic surgery (specifically lung resection for cancer). The project focused on preoperative patient assessment and preparation, intraoperative management (surgical and anesthesiologic care), and postoperative care and discharge. A series of clinical questions was developed, and PubMed and Embase literature searches were performed to inform discussions around these areas, leading to the development of 69 recommendations. The quality of evidence and strength of recommendations were graded using the United States Preventative Services Task Force criteria.

RESULTS

Recommendations for preoperative care focus on risk assessment, patient preparation (prehabilitation), and the choice of procedure (open thoracotomy vs. video-assisted thoracic surgery).

CONCLUSIONS

These recommendations should help pulmonologists to improve preoperative management in thoracic surgery patients. Further refinement of the recommendations can be anticipated as the literature continues to evolve.

Effects of Inhaled Iloprost on Lung Mechanics and Myocardial Function During One-Lung Ventilation in Chronic Obstructive Pulmonary Disease Patients Combined With Poor Lung Oxygenation

BACKGROUND

The ventilation/perfusion mismatch in chronic obstructive pulmonary disease (COPD) patients can exacerbate cardiac function as well as pulmonary oxygenation. We hypothesized that inhaled iloprost can ameliorate pulmonary oxygenation with lung mechanics and myocardial function during one-lung ventilation (OLV) in COPD patients combined with poor lung oxygenation.

METHODS

A total of 40 patients with moderate to severe COPD, who exhibited the ratio of partial pressure of arterial oxygen to the fraction of inspired oxygen (PaO2/FIO2) <150 mm Hg 30 minutes after initiating OLV, were enrolled in this study. Patients were randomly allocated into either ILO group (n = 20) or Control group (n = 20), in which iloprost (20 μg) and saline were inhaled, respectively. The PaO2/FIO2 ratio, dead space, dynamic compliance, and tissue Doppler imaging with myocardial performance index (MPI) were assessed 30 minutes after initiating OLV (pre-Tx) and 30 minutes after completion of drug inhalation (post-Tx). Repeated variables were analyzed using a linear mixed-model between the groups.

RESULTS

At pre-Tx, no differences were observed in measured parameters between the groups. At post-Tx, PaO2/FIO2 ratio (P < .001) and dynamic compliance (P = .023) were significantly higher and dead space ventilation was significantly lower (P = .001) in iloprost group (ILO group) compared to Control group. Left (P = .003) and right ventricular MPIs (P < .001) significantly decreased in ILO group compared to Control group.

CONCLUSIONS

Inhaled iloprost improved pulmonary oxygenation, lung mechanics, and cardiac function simultaneously during OLV in COPD patients with poor lung oxygenation.

Effects of Positive End-Expiratory Pressure on Pulmonary Oxygenation and Biventricular Function during One-Lung Ventilation: A Randomized Crossover Study

Although the application of positive end-expiratory pressure (PEEP) can alter cardiopulmonary physiology during one-lung ventilation (OLV), these changes have not been clearly elucidated. This study assessed the effects of different levels of PEEP on biventricular function, as well as pulmonary oxygenation during OLV. Thirty-six lung cancer patients received one PEEP combination of six sequences, consisting of 0 (PEEP_0), 5 (PEEP_5), and 10 cmH₂O (PEEP_10), using a crossover design during OLV. The ratio of arterial oxygen partial pressure to inspired oxygen fraction (P/F ratio), systolic and diastolic echocardiographic parameters were measured at 20 min after the first, second, and third PEEP. P/F ratio at PEEP_5 was significantly higher compared to PEEP_0 (p = 0.014), whereas the P/F ratio at PEEP_10 did not show significant differences compared to PEEP_0 or PEEP_5. Left ventricular ejection fraction (LV EF) and right ventricular fractional area change (RV FAC) at PEEP_10 (EF, p < 0.001; FAC, p = 0.001) were significantly lower compared to PEEP_0 or PEEP_5. RV E/E’ (p = 0.048) and RV myocardial performance index (p < 0.001) at PEEP_10 were significantly higher than those at PEEP_0 or PEEP_5. In conclusion, increasing PEEP to 10 cmH₂O decreased biventricular function, especially on RV function, with no further improvement on oxygenation compared to PEEP 5 cmH₂O during OLV.

The utility of transthoracic echocardiographic measures of right ventricular systolic function in a lung resection cohort

Right ventricular (RV) dysfunction occurs following lung resection and is associated with post-operative complications and long-term functional morbidity. Accurate peri-operative assessment of RV function would have utility in this population. The difficulties of transthoracic echocardiographic (TTE) assessment of RV function may be compounded following lung resection surgery, and no parameters have been validated in this patient group. This study compares conventional TTE methods for assessing RV systolic function to a reference method in a lung resection population. Right ventricular index of myocardial performance (RIMP), fractional area change (FAC), tricuspid annular plane systolic excursion (TAPSE) and S′ wave velocity at the tricuspid annulus (S′), along with speckle tracked global and free wall longitudinal strain (RV-GPLS and RV-FWPLS respectively) are compared with RV ejection fraction obtained by cardiovascular magnetic resonance (RVEF_CMR). Twenty-seven patients undergoing lung resection underwent contemporaneous CMR and TTE imaging; pre-operatively, on post-operative day two and at 2 months. Ability of each of the parameters to predict RV dysfunction (RVEF_CMR <45%) was assessed using the area under the receiver operating characteristic curve (AUROCC). RIMP, FAC and S′ demonstrated no predictive value for poor RV function (AUROCC <0.61, P > 0.05). TAPSE performed marginally better with an AUROCC of 0.65 (P = 0.04). RV-GPLS and RV-FWPLS demonstrated good predictive ability with AUROCC’s of 0.74 and 0.76 respectively (P < 0.01 for both). This study demonstrates that the conventional TTE parameters of RV systolic function are inadequate following lung resection. Longitudinal strain performs better and offers some ability to determine poor RV function in this challenging population.

The right ventricular response to lung resection

OBJECTIVES

Lung cancer is a leading cause of cancer death and in suitable cases the best chance of cure is offered by surgery. Lung resection is associated with significant postoperative cardiorespiratory morbidity, with dyspnea and reduced functional capacity as dominant features. These changes are poorly associated with deterioration in pulmonary function and a potential role of right ventricular (RV) dysfunction has been hypothesized. Cardiovascular magnetic resonance imaging is a reference method for noninvasive assessment of RV function and has not previously been applied to this population.

METHODS

We used cardiovascular magnetic resonance imaging to assess the RV response to lung resection. Cardiovascular magnetic resonance imaging with volume and flow analysis was performed on 27 patients preoperatively, on postoperative day 2 and at 2 months. Left ventricular ejection fraction and RV ejection fraction, the ratio of stroke volume to end systolic volume, pulmonary artery acceleration time, and distensibility of main and branch pulmonary arteries were studied.

RESULTS

Mean ± standard deviation RV ejection fraction deteriorated from 50.5% ± 6.9% preoperatively to 45.6% ± 4.5% on postoperative day 2 and remained depressed at 44.9% ± 7.7% by 2 months (P = .003). The ratio of stroke volume to end systolic volume deteriorated from median 1.0 (quartile 1, quartile 3: 0.9, 1.2) preoperatively to median 0.8 (quartile 1, quartile 3: 0.7, 1.0) on postoperative day 2 (P = .011). On postoperative day 2 there was a decrease in pulmonary artery acceleration time and operative pulmonary artery distensibility (P < .030 for both). There were no changes in left ventricular ejection fraction during the study period (P = .621).

CONCLUSIONS

These findings suggest RV dysfunction occurs following lung resection and persists 2 months after surgery. The deterioration in the ratio of stroke volume to end systolic volume suggests a mismatch between afterload and contractility. There is an increase in indices of pulsatile afterload resulting from the operative pulmonary artery.

The Utility of Eccentricity Index as a Measure of the Right Ventricular Function in a Lung Resection Cohort

Context

Right ventricular (RV) dysfunction occurs after lung resection and is associated with postoperative morbidity. Noninvasive evaluation of the RV is challenging, particularly in the postoperative period. A reliable measure of RV function would have value in this population.

Aims

This study compares eccentricity index (EI) obtained by transthoracic echocardiography (TTE) with cardiovascular magnetic resonance (CMR) determined measures of RV function in a lung resection cohort. CMR is the reference method for noninvasive assessment of RV function.

Design and Setting

Prospective observational cohort study at a single tertiary hospital.

Materials and Methods

Twenty-eight patients scheduled for elective lung resection underwent contemporaneous TTE and CMR imaging preoperatively, on postoperative day (POD) 2 and at 2-month. Systolic and diastolic EI was measured offline from anonymized and randomized TTE and CMR images.

Statistical Analysis

Bland-Altman analysis was performed to determine agreement between EI^TTE and EI^CMR. Changes over time and comparison with CMR determined RV ejection fraction (RVEF^CMR) was assessed.

Results

Bland-Altman analysis showed a negligible mean difference between EI^TTE and EI^CMR, but limits of agreement were wide (SD 0.24 and 0.28). There were no significant changes in EI^TTE and EI^CMR over time (P > 0.35). We found no association between EI^TTE with RVEF^CMR at all-time points (P > 0.22). Systolic and diastolic EI^CMR on POD 2 demonstrated moderate association with RVEF^CMR (r = -0.54 and r = -0.59, P ≤ 0.01). At 2-month, only diastolic EI^CMR correlated with RVEF^CMR (r = -0.43, P = 0.03). There were no meaningful associations between EI^TTE and EI^CMR with TTE-derived RV systolic pressure (P > 0.31).

Conclusions

TTE determined EI is not useful as a noninvasive method of assessing RV function following lung resection.

The Right Ventricle During Selective Lung Ventilation for Thoracic Surgery

The right ventricle (RV) has been an area of evolving interest after decades of being ignored and considered less important than the left ventricle. Right ventricular dysfunction/failure is an independent predictor of mortality and morbidity in cardiac surgery; however, very little is known about the incidence or impact of RV dysfunction/failure in thoracic surgery. The pathophysiology of RV dysfunction/failure has been studied in the context of acute respiratory distress syndrome (ARDS), cardiac surgery, pulmonary hypertension, and left ventricular failure, but limited data exist in literature addressing the issue of RV dysfunction/failure in the context of thoracic surgery and one-lung ventilation (OLV). Thoracic surgery and OLV present as a unique situation where the RV is faced with sudden changes in afterload, preload, and contractility throughout the perioperative period. The authors discuss the possible pathophysiologic mechanisms that can affect adversely the RV during OLV and introduce the term RV injury to the myocardium that is affected adversely by the various intraoperative factors, which then makes it predisposed to acute dysfunction. The most important of these mechanisms seems to be the role of intraoperative mechanical ventilation, which potentially could cause both ventilator-induced lung injury leading to ARDS and RV injury. Identification of at-risk patients in the perioperative period using focused imaging, particularly echocardiography, is paramount. The authors also discuss the various RV-protective strategies required to prevent RV dysfunction and management of established RV failure.

The use of echocardiographic indices in defining and assessing right ventricular systolic function in critical care research

PURPOSE

Many echocardiographic indices (or methods) for assessing right ventricular (RV) function are available, but each has its strengths and limitations. In some cases, there might be discordance between the indices. We conducted a systematic review to audit the echocardiographic RV assessments in critical care research to see if a consistent pattern existed. We specifically looked into the kind and number of RV indices used, and how RV dysfunction was defined in each study.

METHODS

Studies conducted in critical care settings and reported echocardiographic RV function indices from 1997 to 2017 were searched systematically from three databases. Non-adult studies, case reports, reviews and secondary studies were excluded. These studies' characteristics and RV indices reported were summarized.

RESULTS

Out of 495 non-duplicated publications found, 81 studies were included in our systematic review. There has been an increasing trend of studying RV function by echocardiography since 2001, and most were conducted in ICU. Thirty-one studies use a single index, mostly TAPSE, to define RV dysfunction; 33 used composite indices and the combinations varied between studies. Seventeen studies did not define RV dysfunction. For those using composite indices, many did not explain their choices.

CONCLUSIONS

TAPSE seemed to be the most popular index in the last 2-3 years. Many studies used combinations of indices but, apart from cor pulmonale, we could not find a consistent pattern of RV assessment and definition of RV dysfunction amongst these studies.

Usefulness of right ventricular dysfunction to predict new-onset atrial fibrillation following coronary artery bypass grafting

Postoperative atrial fibrillation (AF) is a serious yet common complication after coronary artery bypass grafting (CABG) surgery. Risk factors for postoperative AF have been identified, including echocardiographic parameters, and these are relied on to implement preventative strategies that reduce the incidence of AF. There has yet to be a study examining the impact of echocardiographic right-sided cardiac parameters on the prediction of postoperative AF. Thus, a panel of right-sided cardiac parameters was measured in a cohort of patients undergoing isolated CABG surgery, excluding those who did not have echocardiographic assessment within 30 days before surgery and those with any history of AF. The primary outcome was postoperative AF defined as any episode of AF requiring treatment during the index hospitalization. Postoperative AF occurred in 197 of 768 patients (25.6%); these were older and more likely to have hypertension and chronic kidney disease. After adjustment for clinical and echocardiographic variables, left atrial volume index ≥34 ml/m(2) (odds ratio [OR] 1.98, 95% confidence interval [CI] 1.36 to 2.87), abnormal right ventricular myocardial performance index (OR 1.50, 95% CI 1.01 to 2.24), and advancing age (OR 1.05, 95% CI 1.03 to 1.07) were found to be independent predictors of postoperative AF. In conclusion, right ventricular myocardial performance index is a novel predictor of postoperative AF in patients undergoing isolated CABG surgery and appears to be additive to established risk factors such as age and left atrial volume.

Progress in perioperative echocardiography: focus on safety, clinical outcomes, 3-dimensional imaging, and education

Gastric decompression with an orogastric tube after anesthetic induction does not appear to enhance image quality for routine cases. The insertion of a transesophageal echocardiographic (TEE) probe can cause significant upper-airway trauma, which can be minimized with rigid laryngoscopy. Limited TEE imaging without transgastric views appears to be safe and clinically adequate in patients with advanced liver disease and esophageal varices. Although esophagogastric perforation because of transesophageal echocardiography is rare, the risk is significantly higher with advanced age and female sex. The echocardiographic assessment of right ventricular function and left ventricular diastolic function can improve the prediction of atrial arrhythmias after elective lung resection. Furthermore, asymptomatic left ventricular systolic or diastolic dysfunction is an independent predictor of cardiovascular mortality and morbidity after open vascular surgery. Advances in 3D echocardiography have shown that hypertrophic cardiomyopathy frequently is associated with changes in the mitral valve complex that predispose to left ventricular outflow tract obstruction. Furthermore, 3D imaging of the mitral apparatus has highlighted the importance of the annular saddle shape and the anatomic variability in ischemic mitral regurgitation. Education in perioperative echocardiography is experiencing high demand that can be satisfied partially with simulators and Internet-based educational activities. These modalities will aid in the dissemination of echocardiography through perioperative practice.