‘This Is Us’ Gives Surprising New Detail About Jack’s Death In 1970-Set Flashback Scene

Spoiler alert: This article contains spoilers from the This Is Us Season 3 episode “Vietnam.”

This Is Us just went far back into Jack Pearson’s past and gave viewers new insight into his untimely death 28 years after he served in the Vietnam War. In the Season 3 episode “Vietnam,” viewers were served a huge chunk of the Pearson patriarch’s backstory as well as a major detail related to his death in the late 1990s.

While viewers joined Jack (Milo Ventimiglia) in the war-ridden jungles in 1970, further flashback scenes revealed that he had a pre-existing heart condition that initially caused him to be ineligible for the draft, according to Vanity Fair.

Last season, This Is Us fans saw Jack’s death story play out in the “Super Bowl Sunday” episode. The beloved character saved his family from a house fire but inhaled massive amounts of smoke and later suffered cardiac arrest. It was explained that the smoke inhalation caused a “widowmaker’s heart attack.” But in the “Vietnam” episode, it was revealed that Jack’s pre-existing heart condition may have contributed to his untimely death.

In a flashback scene to the 1950s, Jack’s mom (Laura Neimi ) noticed her young son’s heart was beating extremely fast. Young Jack assured her it was always like that.

Flash forward to 1970, when during a visit to his family doctor it is revealed that Jack suffered from tachycardia—an abnormally rapid heart rate—and could not pass the medical exam required to be drafted into the war. But the Pearson superhero told his doc he wanted to enlist so he could be with his brother Nicky (Michael Angarano). Reluctantly, the doctor instructed Jack to do 100 pushups and then catch his breath before his military medical exam as a way to fake his results.

Realizing that Jack has always had heart issues… WHY?! #ThisIsUs pic.twitter.com/QrD141W0Y7

— This Is Us (@NBCThisisUs) October 17, 2018

While he made his way into the war, it now seems likely that Jack’s pre-existing heart condition contributed to his death nearly 30 years after he served in Vietnam. Per the Mayo Clinic, “if left untreated, tachycardia can disrupt normal heart function and lead to serious complications” that include sudden cardiac arrest.

The new twist about Jack’s heart condition also helps to make more sense of his death. When Jack’s death played out last season in the “Super Bowl Sunday” episode, many real-life cardiologists raised eyebrows at how it was portrayed.

Neeraj Badhey, an interventional cardiologist with Texas Health Physicians Group, told Dallas News if Jack died from cardiac arrest caused by smoke inhalation, he probably would have died at the scene or on the way to the hospital, not hours later.

And James de Lemos, professor of medicine at UT Southwestern Medical Center in Dallas, said, “With smoke inhalation, it’s more likely he would have had respiratory issues, but it is still technically possible. This is TV.”

This Is Us airs Tuesdays at 9 p.m. on NBC.