Cardiac cycle timing intervals in acute COVID-19 and recovered COVID-19 with sustained symptoms

Abstract

Research is available to show that COVID-19 can result in both acute and sustained cardiac damage. Acute cardiac damage may be due to elevated inflammatory responses and can result in ischemia, which can lead to impairments in the cardiac cycle timing events. The purpose of this project was threefold: 1) to characterise cardiac cycle timing intervals in patients with COVID-19, 2) to understand the mechanisms that compromise cardiac function in post-acute COVID-19 syndrome (PACS)/long COVID, and 3) to identify unique cardiac dysfunction which can occur due to COVID-19 as compared to cardiac and respiratory disease. First, case studies showed that daily observation of cardiac function provided detailed information about the overall dynamic changes by which cardiac dysfunction occurs, and thus can be beneficial study on a case by-case basis, day-to-day during acute infection. The literature review supports the findings of altered cardiac mechanics and suggests that right ventricular dysfunction, along with global longitudinal strain and diastolic dysfunction are common findings in patients with PACS/long COVID, and a more severe acute myocardial injury during the index hospitalization appears to exacerbate cardiac function on follow-up. Finally, a Kruskal-Wallis ANOVA showed that participants with COVID-19 and sustained symptoms present with elevated systolic time and decreased IVCT in comparison to acute COVID-19, and those with respiratory and cardiac disease. These are reflected by decreases in heart, diastolic, and systolic performance indices (HPI, DPI and SPI, respectively), thereby showcasing a unique cardiac dysfunction in patients with sustained symptoms from COVID-19. Future research must consider the details of cardiac complications during the acute infection period and relate this to the cardiac function in patients with long COVID during a mid- and long-term follow-up.