From Science magazine:
On rounds in a 20-bed intensive care unit (ICU) one recent day, physician Joshua Denson assessed two patients with seizures, many with respiratory failure and others whose kidneys were on a dangerous downhill slide. Days earlier, his rounds had been interrupted as his team tried, and failed, to resuscitate a young woman whose heart had stopped. All shared one thing, says Denson, a pulmonary and critical care physician at the Tulane University School of Medicine. “They are all COVID positive.”
As the number of confirmed cases of COVID-19 surges past 2.2 million globally and deaths surpass 150,000, clinicians and pathologists are struggling to understand the damage wrought by the coronavirus as it tears through the body. They are realizing that although the lungs are ground zero, its reach can extend to many organs including the heart and blood vessels, kidneys, gut, and brain.
“[The disease] can attack almost anything in the body with devastating consequences,” says cardiologist Harlan Krumholz of Yale University and Yale-New Haven Hospital, who is leading multiple efforts to gather clinical data on COVID-19. “Its ferocity is breathtaking and humbling.”
More bad news:
In Brescia, Italy, a 53-year-old woman walked into the emergency room of her local hospital with all the classic symptoms of a heart attack, including telltale signs in her electrocardiogram and high levels of a blood marker suggesting damaged cardiac muscles. Further tests showed cardiac swelling and scarring, and a left ventricle—normally the powerhouse chamber of the heart—so weak that it could only pump one-third its normal amount of blood. But when doctors injected dye in the coronary arteries, looking for the blockage that signifies a heart attack, they found none. Another test revealed why: The woman had COVID-19.
How the virus attacks the heart and blood vessels is a mystery, but dozens of preprints and papers attest that such damage is common. A 25 March paper in JAMA Cardiology documented heart damage in nearly 20% of patients out of 416 hospitalized for COVID-19 in Wuhan, China. In another Wuhan study, 44% of 138 hospitalized patients had arrhythmias.
The disruption seems to extend to the blood itself. Among 184 COVID-19 patients in a Dutch ICU, 38% had blood that clotted abnormally, and almost one-third already had clots, according to a 10 April paper in Thrombosis Research. Blood clots can break apart and land in the lungs, blocking vital arteries—a condition known as pulmonary embolism, which has reportedly killed COVID-19 patients. Clots from arteries can also lodge in the brain, causing stroke. Many patients have “dramatically” high levels of D-dimer, a byproduct of blood clots, says Behnood Bikdeli, a cardiovascular medicine fellow at Columbia University Medical Center.
And yet more:
Frontera has seen patients with the brain inflammation encephalitis, with seizures, and with a “sympathetic storm,” an immune response that’s the brain’s version of a cytokine storm. Some people with COVID-19 briefly lose consciousness. Others have strokes. Many report losing their sense of smell. And Frontera and others wonder whether in some cases, infection depresses the brain stem reflex that senses oxygen starvation. This is another explanation for anecdotal observations that some patients aren’t gasping for air, despite dangerously low blood oxygen levels.
ACE2 receptors are present in the neural cortex and brain stem, says Robert Stevens, an intensive care physician at Johns Hopkins Medicine. But it’s not known under what circumstances the virus penetrates the brain and interacts with these receptors. That said, the coronavirus behind the 2003 severe acute respiratory syndrome (SARS) epidemic—a close cousin of today’s culprit—could infiltrate neurons and sometimes caused encephalitis. On 3 April, a case study in the International Journal of Infectious Diseases, from a team in Japan, reported traces of new coronavirus in the cerebrospinal fluid of a COVID-19 patient who developed meningitis and encephalitis, suggesting it, too, can penetrate the central nervous system.
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