Epidemiology of perioperative RV dysfunction: risk factors, incidence, and clinical implications

In this edition of the journal, the Perioperative Quality Initiative (POQI) present three manuscripts describing the physiology, assessment, and management of right ventricular dysfunction (RVD) as pertains to the perioperative setting. This narrative review seeks to provide context for these manuscripts, discussing the epidemiology of perioperative RVD focussing on definition, risk factors, and clinical implications. Throughout the perioperative period, there are many potential risk factors/insults predisposing to perioperative RVD including pre-existing RVD, fluid overload, myocardial ischaemia, pulmonary embolism, lung injury, mechanical ventilation, hypoxia and hypercarbia, lung resection, medullary reaming and cement implantation, cardiac surgery, cardiopulmonary bypass, heart and lung transplantation, and left ventricular assist device implantation. There has however been little systematic attempt to quantify the incidence of perioperative RVD. What limited data exists has assessed perioperative RVD using echocardiography, cardiovascular magnetic resonance, and pulmonary artery catheterisation but is beset by challenges resulting from the inconsistencies in RVD definitions. Alongside differences in patient and surgical risk profile, this leads to wide variation in the incidence estimate. Data concerning the clinical implications of perioperative RVD is even more scarce, though there is evidence to suggest RVD is associated with atrial arrhythmias and prolonged length of critical care stay following thoracic surgery, increased need for inotropic support in revision orthopaedic surgery, and increased critical care requirement and mortality following cardiac surgery. Acute manifestations of RVD result from low cardiac output or systemic venous congestion, which are non-specific to the diagnosis of RVD. As such, RVD is easily overlooked, and the relative contribution of RV dysfunction to postoperative morbidity is likely to be underestimated.We applaud the POQI group for highlighting this important condition. There is undoubtedly a need for further study of the RV in the perioperative period in addition to solutions for perioperative risk prediction and management strategies. There is much to understand, study, and trial in this area, but importantly for our patients, we are increasingly recognising the importance of these uncertainties.

Impact of right ventricular systolic function after heart transplantation on exercise capacity

BACKGROUND

Right ventricular (RV) systolic parameters are difficult to assess in heart transplant recipients (HTRs) compared to healthy people because of discordant data, and their impact on exercise capacity remains undefined. We sought to retrospectively assess the impact of RV systolic function on exercise capacity after heart transplantation.

METHODS

We analyzed data from 61 HTRs who underwent transthoracic echocardiography (TTE), cardiac magnetic resonance imaging (CMR), and exercise capacity assessment by 6-minute walking test (6MWT) and cardiopulmonary exercise testing (CPET) at 1- and 2-year follow-ups.

RESULTS

Transthoracic echocardiography RV longitudinal systolic function including tricuspid annular plan systolic excursion (TAPSE), peak systolic S' wave tricuspid annular velocity (PSVtdi) and RV free wall longitudinal strain was decreased at 1 year (respectively, 15 ± 3 mm, 10 ± 3 cm/s, and -19 ± 5%) and at 2 years (respectively, 15 ± 3 mm, 10 ± 2 cm/s, and -20 ± 5%) with no significant difference between both evaluations; meanwhile, RV ejection fraction (RVEF) measured by CMR was preserved. Mean percentage of predicted peak oxygen consumption was altered, but improved between the first and second year (55 ± 18 vs 60 ± 18%, P = .038). PSVtdi was weakly correlated with 6MWT distance (r = .426, P = .017) and RVEF with the predicted distance at 6MWT (r = .410, P = .027) at the 1-year follow-up.

CONCLUSIONS

Despite decreasing values, RV longitudinal systolic function has a weak impact on exercise capacity of HTRs. PSVtdi and RVEF are the most pertinent parameters to assess the impact of RV systolic function on exercise capacity after heart transplantation. These results should lead to redefine normal RV systolic function thresholds for HTRs.

Acute right ventricular dysfunction: real-time management with echocardiography

In critically ill patients, the right ventricle is susceptible to dysfunction due to increased afterload, decreased contractility, or alterations in preload. With the increased use of point-of-care ultrasonography and a decline in the use of pulmonary artery catheters, echocardiography can be the ideal tool for evaluation and to guide hemodynamic and respiratory therapy. We review the epidemiology of right ventricular failure in critically ill patients; echocardiographic parameters for evaluating the right ventricle; and the impact of mechanical ventilation, fluid therapy, and vasoactive infusions on the right ventricle. Finally, we summarize the principles of management in the context of right ventricular dysfunction and provide recommendations for echocardiography-guided management.