COVID-19 and Pulmonary Hypertension in Children: What Do We Know So Far?

The interplay between coronavirus disease 2019 (COVID-19) and pulmonary hypertension (PH) in children is unknown. Adults with PH are at potential risk for severe complications and high mortality due to associated comorbidities. It is difficult to extrapolate the outcomes of COVID-19 in adults to pediatric PH patients. Overall, a small number of COVID-19 cases is reported in patients with preexisting PH. Several factors may be responsible for the low incidence of COVID-19 in children with PH. Pulmonary hypertension is a rare disease, testing is not universal, and patients may have followed more rigorously the Center for Disease Control's guidelines recommended for personal protection with mask-wearing, social distancing, and hand sanitization through ongoing health education. The small number of COVID-19 cases in patients with preexisting PH does not support that PH is protective for COVID-19. However, medications used to treat PH may have some protection against COVID-19. This review discusses the pathophysiology of PH occurring with COVID-19, differences between children and adults with COVID-19, strategies for management of preexisting PH in children during the ongoing pandemic, and its impact within the field of PH.

Rare case of right ventricular dilatation associated with anomalous pulmonary venous drainage, sinus venosus atrial septal defect and persistent left superior vena cava.

A 34-year-old woman was seen in the emergency department for shortness of breath and chest pain. During a pandemic, it is easy to 'think horses and not zebras', and with a patient presenting with the classic coronavirus symptoms it would have been easy to jump to that as her diagnosis. After a careful history and examination, it became clear that there was another underlying diagnosis. Chest X-ray, echocardiogram and CT scan revealed marked right ventricular dilatation and pulmonary hypertension, alongside a persistent left superior vena cava (PLSVC). Further investigation with cardiac MRI and coronary angiography at a tertiary centre demonstrated that she not only have a PLSVC but also a partial anomalous pulmonary venous drainage and sinus venosus atrial septal defect. This case highlights the importance of considering all differentials and approaching investigations in a logical manner.

Haemodynamic characteristics of COVID-19 patients with acute respiratory distress syndrome requiring mechanical ventilation. An invasive assessment using right heart catheterization.

AIMS: Interstitial pneumonia due to coronavirus disease 2019 (COVID-19) is often complicated by severe respiratory failure. In addition to reduced lung compliance and ventilation/perfusion mismatch, a blunted hypoxic pulmonary vasoconstriction has been hypothesized, that could explain part of the peculiar pathophysiology of the COVID-19 cardiorespiratory syndrome. However, no invasive haemodynamic characterization of COVID-19 patients has been reported so far. METHODS AND RESULTS: Twenty-one mechanically-ventilated COVID-19 patients underwent right heart catheterization. Their data were compared both with those obtained from non-mechanically ventilated paired control subjects matched for age, sex and body mass index, and with pooled data of 1937 patients with 'typical' acute respiratory distress syndrome (ARDS) from a systematic literature review. Cardiac index was higher in COVID-19 patients than in controls [3.8 (2.7-4.5) vs. 2.4 (2.1-2.8) L/min/m2 , P < 0.001], but slightly lower than in ARDS patients (P = 0.024). Intrapulmonary shunt and lung compliance were inversely related in COVID-19 patients (r = -0.57, P = 0.011) and did not differ from ARDS patients. Despite this, pulmonary vascular resistance of COVID-19 patients was normal, similar to that of control subjects [1.6 (1.1-2.5) vs. 1.6 (0.9-2.0) WU, P = 0.343], and lower than reported in ARDS patients (P < 0.01). Pulmonary hypertension was present in 76% of COVID-19 patients and in 19% of control subjects (P < 0.001), and it was always post-capillary. Pulmonary artery wedge pressure was higher in COVID-19 than in ARDS patients, and inversely related to lung compliance (r = -0.46, P = 0.038). CONCLUSIONS: The haemodynamic profile of COVID-19 patients needing mechanical ventilation is characterized by combined cardiopulmonary alterations. Low pulmonary vascular resistance, coherent with a blunted hypoxic vasoconstriction, is associated with high cardiac output and post-capillary pulmonary hypertension, that could eventually contribute to lung stiffness and promote a vicious circle between the lung and the heart.

Beyond the clot: perfusion imaging of the pulmonary vasculature after COVID-19.

A compelling body of evidence points to pulmonary thrombosis and thromboembolism as a key feature of COVID-19. As the pandemic spread across the globe over the past few months, a timely call to arms was issued by a team of clinicians to consider the prospect of long-lasting pulmonary fibrotic damage and plan for structured follow-up. However, the component of post-thrombotic sequelae has been less widely considered. Although the long-term outcomes of COVID-19 are not known, should pulmonary vascular sequelae prove to be clinically significant, these have the potential to become a public health problem. In this Personal View, we propose a proactive follow-up strategy to evaluate residual clot burden, small vessel injury, and potential haemodynamic sequelae. A nuanced and physiological approach to follow-up imaging that looks beyond the clot, at the state of perfusion of lung tissue, is proposed as a key triage tool, with the potential to inform therapeutic strategies.

COVID-19 Lung Injury and High-Altitude Pulmonary Edema. A False Equation with Dangerous Implications.

Amid efforts to care for the large number of patients with coronavirus disease (COVID-19), there has been considerable speculation about whether the lung injury seen in these patients is different than acute respiratory distress syndrome from other causes. One idea that has garnered considerable attention, particularly on social media and in free open-access medicine, is the notion that lung injury due to COVID-19 is more similar to high-altitude pulmonary edema (HAPE). Drawing on this concept, it has also been proposed that treatments typically employed in the management of HAPE and other forms of acute altitude illness-pulmonary vasodilators and acetazolamide-should be considered for COVID-19. Despite some similarities in clinical features between the two entities, such as hypoxemia, radiographic opacities, and altered lung compliance, the pathophysiological mechanisms of HAPE and lung injury due to COVID-19 are fundamentally different, and the entities cannot be viewed as equivalent. Although of high utility in the management of HAPE and acute mountain sickness, systemically delivered pulmonary vasodilators and acetazolamide should not be used in the treatment of COVID-19, as they carry the risk of multiple adverse consequences, including worsened ventilation-perfusion matching, impaired carbon dioxide transport, systemic hypotension, and increased work of breathing.

A teenager with CHD and coronavirus disease 2019.

A 16-year-old girl with history of treated congenital mitral valve disease and signs of respiratory infection was admitted to our paediatric cardiology department. She was tested positive for severe acute respiratory syndrome coronavirus 2. Despite her severe pre-existing cardiac conditions with pulmonary hypertension, atrial arrhythmias and mitral valve stenosis, the infection did not lead to any cardiac or pulmonary deterioration. In adults, cardiac co-morbidities are known risk factors for a severe course of coronavirus disease 2019 infections. This case illustrates that in children even severe cardiac disease is not necessarily associated with a severe course of coronavirus disease 2019.

COVID-19 and Pneumolysis Simulating Extreme High-altitude Exposure with Altered Oxygen Transport Physiology; Multiple Diseases, and Scarce Need of Ventilators: Andean Condor's-eye-view.

BACKGROUND: Critical hypoxia in this COVID-19 pandemic results in high mortality and economic loss worldwide. Initially, this disease' pathophysiology was poorly understood and interpreted as a SARS (Severe Acute Respiratory Syndrome) pneumonia. The severe atypical lung CAT scan images alerted all countries, including the poorest, to purchase lacking sophisticated ventilators. However, up to 88% of the patients on ventilators lost their lives. It was suggested that COVID-19 could be similar to a High-Altitude Pulmonary Edema (HAPE). New observations and pathological findings are gradually clarifying the disease. METHODS: As high-altitude medicine and hypoxia physiology specialists working and living in the highlands for over 50 years, we perform a perspective analysis of hypoxic diseases treated at high altitudes and compare them to Covid-19. Oxygen transport physiology, SARS-Cov-2 characteristics, and its transmission, lung imaging in COVID-19, and HAPE, as well as the causes of clinical signs and symptoms, are discussed. RESULTS: High-altitude oxygen transport physiology has been systematically ignored. COVID-19 signs and symptoms indicate a progressive and irreversible failure in the oxygen transport system, secondary to pneumolysis produced by SARS-Cov-2's alveolar-capillary membrane "attack". HAPE's pulmonary compromise is treatable and reversible. COVID-19 is associated with several diseases, with different individual outcomes, in different countries, and at different altitudes. CONCLUSIONS: The pathophysiology of High-altitude illnesses can help explain COVID-19 pathophysiology, severity, and management. Early diagnosis and use of EPO, acetylsalicylic-acid, and other anti-inflammatories, oxygen therapy, antitussives, antibiotics, and the use of Earth open-circuit- astronaut-resembling suits to return to daily activities, should all be considered. Ventilator use can be counterproductive. Immunity development is the only feasible long-term survival tool.