Low Blood Sugar May Cause Cardiac Arrest — New Guidelines Proposed

What Was Studied and Why It Matters

When someone goes into cardiac arrest, emergency teams follow a checklist of reversible causes — things that, if caught and treated quickly, could save the person's life. For decades, this checklist has been known as the "4H 4T" framework, covering conditions like low oxygen, blood clots, and dangerous changes in potassium levels.

But researchers from a 2026 study published in Diabetes Therapy argue that this checklist has a significant gap: it leaves out low blood sugar (hypoglycaemia) and dangerous heart rhythm problems (arrhythmias). For people with diabetes, this omission could be fatal.

What the Researchers Found

The research team reviewed clinical studies, patient case reports, and experimental data to build their case. Here is what the evidence showed:

• Low blood sugar can trigger cardiac arrest. When blood glucose drops too low, it disrupts the heart's electrical system — specifically something called the QT interval. This disruption can set off a deadly chain reaction in heart rhythm known as the "R-on-T phenomenon," which can cause the heart to stop.
• People with diabetes are especially vulnerable. Those managing diabetes with insulin or certain medications are at higher risk of hypoglycaemic episodes, making this a particularly urgent concern for the diabetes community.
• Sepsis increases the risk further. Serious infections can cause blood sugar to crash, compounding the cardiovascular danger.
• Heart rhythm problems are also missing from the checklist. Both abnormally fast and abnormally slow heart rhythms frequently lead to cardiac arrest, yet neither is formally listed as a reversible cause in current guidelines.

What the Researchers Are Proposing

The authors are calling for an updated framework — the "5H 5T" model — that adds hypoglycaemia and heart rhythm disorders to the official cardiac arrest checklist. This would mean:

• Emergency responders would routinely check blood glucose during resuscitation attempts
• Healthcare providers would receive updated training to look for low blood sugar as a potential cause of cardiac arrest
• Resuscitation guidelines worldwide would be revised to reflect this evidence

What This Means for Diabetes Patients

If you or someone you care for is managing diabetes, this research is a powerful reminder of why consistent blood sugar monitoring matters — not just for day-to-day health, but in life-or-death emergencies. Keeping reliable glucose monitoring supplies on hand is essential. MDS Diabetes offers a wide range of blood glucose meters, test strips, and continuous glucose monitoring (CGM) accessories to help you stay on top of your levels every day.

It also highlights the importance of making sure your emergency contacts and healthcare team know you have diabetes, so that low blood sugar is considered quickly if you ever need emergency care.

Bottom Line

A growing body of evidence shows that low blood sugar can cause cardiac arrest — yet current emergency guidelines don't tell responders to check for it. Researchers are pushing for updated protocols that include blood glucose testing as a standard part of cardiac resuscitation. For people living with diabetes, this science reinforces just how critical tight glucose monitoring truly is.