Editor’s Note: This is the first in a series of stories explaining the scientific research underway in the Cardiovascular Genome-Phenome Study.

Anyone taking a common blood pressure drug should be interested in Christy Avery’s scientific research. She’s studying how these and other common prescription medications interact with genes.

Avery, an assistant professor of epidemiology in the Gillings School of Global Public Health at the University of North Carolina, is specifically studying why some medications increase the risk for cardiac arrhythmias in some people. Arrhythmias include rapid or slowed heart rate, irregular rhythms or skipped heartbeats that you might not even notice. But if they’re severe enough, the heart can’t pump enough blood to the body. They can lead to a heart attack, stroke or death.

Avery’s work is part of the American Heart Association’s Cardiovascular Genome-Phenome Study. CVGPS researchers use massive volumes of data from major studies, with the goal of speeding discovery of more personalized treatments and prevention for heart disease and stroke, the leading causes of death worldwide.

To study arrhythmias, Avery will plumb data from many studies including the Framingham Heart Study, the nation’s largest and longest-running heart study, and the Jackson Heart Study, the largest study ever focused on risk factors among African-Americans. African-Americans face disproportionately higher risks for high blood pressure than many other populations.

Here’s more about the project, according to Avery:

Why it matters: “Almost every American has taken at least one over-the-counter or prescription drug over the past year. With this mass exposure, it’s important that we better understand unintended adverse drug reactions so we can prevent them.

Many common drugs can interfere with the heart’s conduction, and those adverse effects are the No. 1 reason drugs are removed from the market or have restricted marketing. But sometimes it takes years — and many people exposed — to identify who will have heart problems from these prescription drugs.

Genetics are one way we can identify people who may have a problem taking a specific drug and switch them to a different drug.”

What’s going under the microscope: “We’re looking at five drugs, starting with thiazide diuretics. They’re often the first line of treatment for high blood pressure. One-third of the population that’s hypertensive takes a thiazide.

We’re also looking at beta blockers (which also treat high blood pressure, as well as heart failure), calcium channel beta blockers (for high blood pressure and other heart conditions), tricyclic antidepressants (depression) and a catch-all or potpourri group with drugs from different classes with known effects on the heart’s electrical activity.”

How this study works: “We’re collecting information on about 90,000 patients by collaborating with people around the world, so there are studies of people in many different countries. We’ve measured the heart’s electrical activity, the drugs they take and genetic variants.

That information lets us see if there are groups of people that are vulnerable, whose hearts’ electrical activity is affected by these drugs. By looking at their genetics, we can see who might have an adverse effect after taking a common drug.”

Hope for the future: “This is cool because it’s an example of using people’s genetics to immediately influence public health. We can then use this information to modify drug regimens or develop new drugs. We cannot change people’s genes, but we can change the medications they’re on.

Previously a lot of this kind of research was only done on white people. It’s important to look at other populations, so we’re also including a large number of African-Americans and Hispanic-Latinos. We want to make sure no population is left behind in precision medication initiatives.”

Read about the other studies in this series