What a Heart Attack Really Is—And How to Know If You’re at Risk

By Dr. Kevin Passero, ND

Every 40 seconds, someone in the United States has a heart attack. It’s a staggering statistic—and yet, for something so common, few people actually understand what’s happening inside the body during a heart attack.

In fact, most of us have a mental image shaped by dramatic movie scenes: someone clutching their chest, collapsing to the floor, and being rushed away by paramedics. While that scenario can be real, it doesn’t explain what’s actually going on inside the arteries—and more importantly, it doesn’t help us prevent it.

As a functional medicine doctor, I want to break this down for you in a way that’s clear, empowering, and—most of all—actionable. Because heart disease is not only the number one killer of Americans, it’s also largely preventable when we understand the why behind the problem.

Think of Your Arteries Like Plumbing Pipes

Let’s start with a simple analogy: imagine your arteries are like the pipes under your kitchen sink. They’re designed to carry a steady flow of water—in this case, oxygen-rich blood—to where it’s needed.

Over time, just like your plumbing, these pipes can get clogged. But in your body, it’s not soap scum or food particles—it’s plaque. This plaque is a mix of cholesterol, scar tissue, and immune cells that builds up quietly over years on the inside of your artery walls.

Now here’s the critical part: most heart attacks don’t happen just because the pipe slowly narrows. They happen when that built-up plaque suddenly cracks—kind of like a blister bursting—and your body tries to “patch” it by forming a clot.

That clot, intended to help, actually chokes off blood flow beyond the blockage. And just like water can’t get to your sink when the pipe is clogged, oxygen can’t get to your heart muscle. Without oxygen, heart tissue begins to die—within minutes.

That, in essence, is a heart attack.

Why Some Heart Attacks Are More Deadly Than Others

You might be wondering: why are some heart attacks minor and others fatal?

There are two main reasons:

• How much of the artery gets blocked
• Where in the heart the blockage occurs

Let’s go back to our plumbing analogy. Some blockages happen in small pipes that only feed one faucet. Others happen in the main line—and when that one clogs, the whole house loses water.

Your heart has several major arteries:

• The right coronary artery feeds the right side of your heart
• The left main coronary artery branches into two critical vessels:
  • The left anterior descending artery (LAD)
  • The left circumflex artery (LCX)

The LAD feeds the left lower chamber of the heart, which is the powerhouse responsible for pumping blood to your entire body. If that artery gets blocked at the top—a scenario known as a “widowmaker” heart attack—blood flow to the entire body, including the brain and vital organs is instantly compromised.

Why is this artery more likely to clog? Because it carries the most blood, it’s under the most pressure. And where there’s more pressure, there’s more internal wear-and-tear—something we call hemodynamic stress. That’s what triggers plaque buildup in the first place.

Not All Heart Attacks Come With Chest Pain

Most people think of a heart attack as sudden chest pain that radiates down the arm. While that’s common, it’s not the only presentation.

Some people—especially women, diabetics, and older adults—experience what’s called a “silent heart attack.”

Instead of sharp pain, they might feel:

• Fatigue
• Mild nausea
• Lightheadedness
• General discomfort

That’s why it’s dangerous to rely on symptoms alone. In many cases, the only way to know your risk is to run the right tests before danger happens.

How to Know Your Risk Before Symptoms Appear

Here’s where the good news comes in: we now have powerful, affordable, and often insurance-covered tools to predict heart attack risk years in advance.

Advanced Blood Tests

Most people are only tested for total cholesterol and LDL. But those numbers don’t tell the whole story. We now have tests that look deeper, including:

• Lipoprotein(a) – a genetic risk factor for aggressive plaque
• hs-CRP – a marker of systemic inflammation
• MPO and LP-PLA2 – indicators of vulnerable plaque that’s likely to rupture

These are just few examples of labs that give us a much clearer picture of your real cardiovascular risk.

Imaging Tools

Tests like the Coronary Artery Calcium Score and CT Coronary Angiogram can actually see if plaque is present in your arteries—even long before symptoms begin.

It’s like taking your car in for a scan before it breaks down on the highway.

Knowledge is the Key to Prevention.

If you’re in your 40s, 50s, or beyond—and especially if you have a family history of heart disease—now is the time to get curious about your own heart health.

That’s why I created a comprehensive Heart Health Blood Test Guide that walks you through every lab test I use with my patients, what they mean, and what optimal—not just “normal”—looks like.

📥 Download it here:
👉 Heart Health Blood Test Guide

And if you haven’t yet, watch my latest video where I break this all down with simple visuals:
Watch the video

Heart disease is the leading cause of death in the U.S., but it’s also one of the most preventable and treatable chronic conditions.

With the right information, early testing, and lifestyle support, you can protect your heart.

Take the time to know your risk. Your heart—and your future—depend on it.

To your health,
Dr. Kevin Passero, ND