Cardiac involvement in patients recovered from COVID-19 identified using left ventricular longitudinal strain

Cardiovascular Complications and Imaging in the Era of the COVID-19 Pandemic 2020 to Present

The COVID-19 pandemic has impacted the world that was not previously conceivable. In early 2020, hospitals on all continents were overwhelmed with patients afflicted with this novel virus, with unanticipated mortality worldwide. The virus has had a deleterious effect, particularly the respiratory and cardiovascular systems. Cardiovascular biomarkers demonstrated an array of cardiovascular insults from hypoxia to inflammatory and perfusion abnormalities of the myocardium to life-threatening arrhythmias and heart failure. Patients were at increased risk of a pro-thrombotic state early in the course of the disease. Cardiovascular imaging became a primary tool in diagnosing, prognosing and risk-stratifying patients. Transthoracic echocardiography became the initial imaging modality in management of cardiovascular implications. In addition to cardiac function, LV longitudinal strain (LVLS) and right ventricular free wall strain (RVFWS) were indicators of increased morbidly and mortality. Cardiac MRI has become the diagnostic cardiovascular imaging for myocardial injury and tissue evaluation in the age of COVID-19.

Evaluation of cardiovascular autonomic dysfunction in symptomatic post-COVID-19 patients using the heart rate variability (HRV) and detection of subtle LV dysfunction using 2D global longitudinal strain (GLS)

AIM

The COVID-19 disease primarily affects the respiratory system; however, cardiac involvement has been documented in the acute phase. We aimed to evaluate the cardiac autonomic function and subtle left ventricular dysfunction in those subjects recovered from mild to moderate acute COVID-19 patients but still symptomatic.

METHODS AND RESULTS

The study group was composed of 50 subjects with confirmed mild to moderate COVID-19. All subjects underwent routine 2D echocardiography assessment in addition to 2D speckle tracking and 24 h Holter monitoring for HRV analysis. The mean age of the study population was 42 ± 18 years; symptoms were reported as follows 27 (54%) had dyspnoea, 17 (34%) had palpitation, and 7 (14%) had dizziness. Time domain parameters Standard Deviation of NN intervals (SDNN), Standard Deviation of the Average NN intervals for each 5 min segment of a 24 h HRV recording (SDANN), and Root Mean Square of Successive RR interval Differences (rMSSD) were diminished with mean SDNN value being markedly impaired in 12 (24%) patients, while frequency domain parameters as assessed by the ratio of the Low-Frequency band power to the High-Frequency band power (LF/HF) with the mean of 1.837 with 8% of the patients being impaired. SDNN was significantly reduced in patients with impaired global longitudinal strain (p 0.000). The global longitudinal strain was diminished in 10 patients (20%); also, 80% of the patients with impaired GLS had decreased SDNN.

CONCLUSION

Our study targeted patients experiencing prolonged symptoms after COVID-19 illness. We detected a high incidence of GLS impairment using Speckle Tracking Echocardiography (STE) and a significant prevalence of diminished HRV. HRV (especially SDNN) and GLS were found to be significantly correlated.

Can Global Longitudinal Strain Assess Asymptomatic Subtle Left Ventricular Dysfunction in Recovered COVID-19 Patients?

Background

Coronavirus disease 2019 (COVID-19) might be associated with cardiac injury as a part of multisystem affection in response to cytokine storms. However, left ventricular (LV) function appears preserved in most of the cases, whereas subtle LV dysfunction might happen in others. Hence, we tried to detect subtle LV dysfunction in patients with COVID-19 using global longitudinal strain (GLS).

Patients and Methods

We performed a single-center observational study on 90 stable patients who were recently recovered from mild to moderate COVID-19 infections. A transthoracic echocardiographic examination was done for all patients, and GLS assessment was used as an indicator of LV function.

Results

The population age ranged from 27 to 66 years, and the majority of patients were males (54, 73.3%). Besides, 46.7% of the included patients were smokers, 33.3% had hypertension, and 23.3% were diabetics. All the patients had normal LV internal dimensions and ejection fractions. However, 33.3% of them had subclinical LV dysfunction as expressed by reduced GLS. There was no statistically significant correlation between GLS and age, gender, or other risk factors, whereas troponin and C-reactive protein significantly correlated with GLS.

Conclusions

Recovered patients from recent mild to moderate COVID-19 infections might show subtle LV dysfunction as manifested by reduced GLS.

Strain Echocardiography in Acute COVID-19 and Post-COVID Syndrome: More than Just a Snapshot

Speckle-tracking echocardiography (STE) has become an established, widely available diagnostic method in the past few years, making its value clear in cases of COVID-19 and the further course of the disease, including post-COVID syndrome. Since the beginning of the pandemic, many studies have been published on the use of STE in this condition, enabling, on the one hand, a better understanding of myocardial involvement in COVID-19 and, on the other, a better identification of risk to patients, although some questions remain unanswered in regard to specific pathomechanisms, especially in post-COVID patients. This review takes a closer look at current findings and potential future developments by summarising the extant data on the use of STE, with a focus on left and right ventricular longitudinal strain.

Clinical profile and the extent of residual myocardial dysfunction among patients with previous coronavirus disease 2019

BACKGROUND

Many patients who have recovered from their coronavirus disease 2019 (COVID-19) episode continue to remain symptomatic and seek medical opinion. The clinical characteristics and echocardiography findings of such subjects have not been adequately studied.

METHODS

The study included 472 subjects (age 54.0 ± 13.4 years, 57% men) with previous COVID-19 (median duration since COVID-19 12.0 weeks, interquartile range 9.0-26.0 weeks) and 100 controls (age 53.9 ± 13.6 years, 53% men). All subjects underwent detailed clinical assessment and echocardiography, including measurement of left ventricular (LV) ejection fraction (EF) and global longitudinal strain (GLS).

RESULTS

Less than third (29.2%) of the post-COVID subjects had needed hospitalization for their initial infection. Exertional dyspnea or breathing difficulty at rest were the commonest reasons for post-COVID presentation. As compared to controls, the post-COVID subjects had impaired LV systolic (LVEF 63.2 ± 2.2 vs. 61.9 ± 4.6, P = 0.007; GLS - 19.9 ± 2.6% vs. -17.6 ± 3.4%, P < 0.001) and diastolic function. Majority of those with reduced LV GLS had preserved LVEF. The patients presenting before 12 weeks were more likely to be symptomatic, but LV GLS did not differ. The patients needing hospitalization had higher burden of co-morbidities and significantly reduced LV GLS as compared to those who had received domiciliary treatment. The patients in the lowest GLS tertile were older, had higher burden of co-morbidities, and had had more severe initial infection with greater need for hospitalization, oxygen therapy and steroids. The need for hospitalization was independently associated with lower GLS at the time of current presentation.

CONCLUSION

This study shows that impairment of LV systolic and diastolic function is common among subjects recovering from previous COVID-19 episode. The patients with more severe initial infection have more marked impairment of LV function and this impairment persists even after several months of recovery from the initial infection. Routine measurement of GLS may be helpful since LV systolic dysfunction in these patients is mostly subclinical.

Cardiopulmonary work up of patients with and without fatigue 6 months after COVID-19

The pathogenesis of long-Covid symptoms remains incompletely understood. Therefore, we aimed to determine cardiopulmonary limitations 6 months after surviving COVID-19 using pulmonary function tests, echocardiographic studies to the point of analysis of global-longitudinal-strain (GLS), which describes the cycling myocardium deformation and provides better data on left ventricular (LV) dysfunction than LV ejection fraction (LVEF), and validated questionnaires. Overall, 60 consecutive hospitalized patients were included (61 ± 2 years, 40% treated in the ICU). At follow-up (194 ± 3 days after discharge), fatigue was the most prevalent symptom (28%). Patients with fatigue were more symptomatic overall and characterized by worse quality of life (QoL) scores compared to patients without fatigue (all p < 0.05), mainly due to limited mobility and high symptom burden. While PFT variables and LVEF were normal in the vast majority of patients (LVEF = 52% (45-52%)), GLS was significantly reduced (- 15% (- 18 to - 14%)). However, GLS values were not different between patients with and without fatigue. In conclusion, fatigue was the most prevalent long-Covid symptom in our cohort, which was associated with worse QoL mainly due to limited mobility and the high burden of concomitant symptoms. Patients showed a subtle myocardial dysfunction 6 months after surviving COVID-19, but this did not relate to the presence of fatigue.

The Evolving Role of Echocardiography During the Coronavirus Disease 2019 Pandemic

Coronavirus disease 2019 (COVID-19) has been associated with a wide spectrum of cardiovascular manifestations. Since the beginning of the pandemic, echocardiography has served as a valuable tool for triaging, diagnosing and managing patients with COVID-19. More recently, speckle-tracking echocardiography has been shown to be effective in demonstrating subclinical myocardial dysfunction that is often not detected in standard echocardiography. Echocardiographic findings in COVID-19 patients include left or right ventricular dysfunction, including abnormal longitudinal strain and focal wall motion abnormalities, valvular dysfunction and pericardial effusion. Additionally, some of these echocardiographic abnormalities have been shown to correlate with biomarkers and adverse clinical outcomes, suggesting an additional prognostic value of echocardiography. With increasing evidence of cardiac sequelae of COVID-19, the use of echocardiography has expanded to patients with cardiopulmonary symptoms after recovery from initial infection. This article aims to highlight the available echocardiographic tools and to summarize the echocardiographic findings across the full spectrum of COVID-19 disease and their correlations with biomarkers and mortality.