Is Long COVID Syndrome a Transient Mitochondriopathy Newly Discovered: Implications of CPET

The new outbreak of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has an impact worldwide, primarily as a medical emergency. Even that the total constellation is considered as a pandemic of acute respiratory disease, coronavirus disease 2019 (COVID-19) gives rise to dysfunction in multiple organs (e.g., brain, lungs, heart, muscles) that impairs cardiopulmonary (CP) function. Parallel to the CP consequences of COVID-19 is a significant reduction in physical activity. Cardiopulmonary exercise testing (CPET) is daily used in clinical practice to define prognosis, provide risk stratification and treatment strategy. As such, the significance of CPET is crucial concerning clinical assessments of COVID-19 patients. Furthermore, new studies aim at understanding the effects of SARS-CoV-2 infection in long term. Multiple studies have investigated the cardiopulmonary function and impairment of exercise endurance in such patients, as well as a possible prolonged physical impairment. With this review, we summarize the COVID-19-associated pathophysiology for the Long COVID (LC) syndrome as well as the importance of performing CPET.

Cardiopulmonary Exercise Test-The Revolving Door of Left Ventricular Assist Devices in Heart Failure

The prevalence of heart failure has an increasing tendency in the last years. Either heart failure with reduced ejection fraction (HFrEF) or with preserved ejection fraction, the treatment depends on the severity, cause, and symptoms. In case of HFrEF, careful evaluation of patient is essential for proper diagnosis, risk stratification and treatment, which should always be individualistic. Except from daily measurements, medical treatment and eventually implantation of implantable cardioverter defibrillator or cardiac resynchronization therapy, implantation of left ventricular assist device (LVAD) belongs also to therapeutic armamentarium. Other than invasive procedures, which are required for the evaluation of every patient with HFrEF, Cardiopulmonary exercise test emerges as one of the most effective noninvasive method for diagnosis, risk stratification, and treatment strategy for these patients. Cardiopulmonary exercise test can provide means for a critical evaluation of cardiovascular system. One of the most important variables is the maximal oxygen consumption (peak VO2). Its high predictive and prognostic power makes peak VO2 essential for the evaluation of patients as candidates, not only for LVAD-implantation, but also for explantation. Furthermore, regarding cardiac rehabilitation and exercise protocols, robust literature supports a follow-up of LVAD-patients by means of cardiopulmonary exercise testing.