Heart–lung interactions in COVID-19: prognostic impact and usefulness of bedside echocardiography for monitoring of the right ventricle involvement

Abstract

Due to the SARS-CoV-2 infection–related severe pulmonary tissue damages associated with a relative specific widespread thrombotic microangiopathy, the pathophysiologic role of heart–lung interactions becomes crucial for the development and progression of right ventricular (RV) dysfunction. The high resistance in the pulmonary circulation, as a result of small vessel thrombosis and hypoxemia, is the major cause of right heart failure associated with a particularly high mortality in severe COVID-19. Timely identification of patients at high risk for RV failure, optimization of mechanical ventilation to limit its adverse effects on RV preload and afterload, avoidance of medication-related increase in the pulmonary vascular resistance, and the use of extracorporeal membrane oxygenation in refractory respiratory failure with hemodynamic instability, before RV failure develops, can improve patient survival. Since it was confirmed that the right-sided heart is particularly involved in the clinical deterioration of patients with COVID-19 and pressure overload-induced RV dysfunction plays a key role for patient outcome, transthoracic echocardiography (TTE) received increasing attention. Limited TTE focused on the right heart appears highly useful in hospitalized COVID-19 patients and particularly beneficial for monitoring of critically ill patients. In addition to detection of right-sided heart dilation and RV dysfunction, it enables assessment of RV-pulmonary arterial coupling and evaluation of RV adaptability to pressure loading which facilitate useful prognostic statements to be made. The increased use of bedside TTE focused on the right heart could facilitate more personalized management and treatment of hospitalized patients and can contribute towards reducing the high mortality associated with SARS-CoV-2 infection.

The Right Ventricle in COVID-19

“…Technical issues may be of particular concern for strain imaging, where the quality of images is essential for accurate strain tracking [42], which underlies the need of skilled and experienced echocardiographers to properly assess RV function in these complicated patients [43]. To summarize, there is now substantial evidence that RV dysfunction is a hallmark pathophysiological alteration associated with COVID-19, as extensively reviewed by Dandel [51]. RV dilation occurs in up to 49% of patients, while RV systolic dysfunction occurs in up to 40%.…”

Long-Term Prognostic Impact of Right Ventricular Dysfunction in Patients with COVID-19

“…RV dysfunction could also affect the LV loading and LVEF by ventricular interdependence. The resulting reduction of the cardiac output, which impairs the blood supply to vital organs, can further aggravate the critical condition of the patient by exposing the overloaded RV to ischemia [29]. In COVID-19 patients, all this is amplified by the pulmonary microangiopathy with small vessel thrombosis, which explains the particularly high incidence of cardiorespiratory failure in critically ill COVID-19 patients [29].…”

“…The resulting reduction of the cardiac output, which impairs the blood supply to vital organs, can further aggravate the critical condition of the patient by exposing the overloaded RV to ischemia [29]. In COVID-19 patients, all this is amplified by the pulmonary microangiopathy with small vessel thrombosis, which explains the particularly high incidence of cardiorespiratory failure in critically ill COVID-19 patients [29]. The theoretical central role, as a long-term prognostic factor of RV dysfunction, was consistent with previous studies demonstrating the association between RV failure and in-hospital mortality [14][15][16].…”

The Clinical Role of Right Ventricle Changes in COVID-19 Respiratory Failure Depends on Disease Severity

“…Serial echocardiography and an appreciation of the characteristic features of COVID-19–induced respiratory failure may provide insights. As discussed by Dandel 2 , 6 and others, 7 , 8 RV dilatation and dysfunction reflect and follow COVID-19–induced pulmonary thrombotic microangiopathy, a feature recognized as a characteristic pattern of COVID-19. 9 , 10 Thus, RV dilatation and dysfunction may be considered a marker of COVID-19 disease severity but may not fully explain why these changes are not directly related to mortality, especially in critically ill patients.…”

“… 4 The tricuspid annular plane systolic excursion and/or sPAP recently was investigated in 92 patients with COVID-19–related acute respiratory failure (64%) requiring ventilatory support, and was shown to be an independent predictor of death, with a calculated cut-off of 0.635 mm/mmHg. 6 Because RV failure is more frequent and pronounced in more severe forms of COVID-19 respiratory failure, it can be presumed that different echocardiographic patterns may be detectable across disease severity progression, probably from isolated systolic pulmonary hypertension to overt RV dilatation and dysfunction. Accordingly, in 28 patients with COVID-19–related acute respiratory distress syndrome (ARDS) admitted to our intensive care unit (ICU) assessed by serial echocardiography, sPAP was elevated in all patients on ICU admission but subsequently declined during ICU stay.…”