How Can You Mend a Broken Heart? Flow Dynamics in Arrhythmias

Dr. Hatoum and PhD student Brennan Vogl test heart valves for overall performance and energetics, turbulence generated, sinus hemodynamics (aortic and pulmonic), as well as ventricular, atrial, pulmonic, and aortic flows.

Biomedical Engineering Assistant Professor Hoda Hatoum talks about her cardiovascular research along with PhD student Brennan Vogl, one of the first students to join her Biofluids Lab in the fall of 2020.

Dr. Hoda Hatoum

“One thing we can do in the lab is to study just how AFib ablation impacts the heart’s left atrial flow, says Hatoum.

Atrial fibrillation, when the heart beats in an irregular way, affects up to 6 million individuals in the US, a number expected to double by 2030. More than 454,000 hospitalizations with AFib as the primary diagnosis happen each year. Current treatment guidelines recommend antiarrhythmic drugs as initial therapy, but their efficacy is limited and comes with the risk of serious adverse effects. Another option, catheter ablation, electrically isolates the pulmonary veins—the most frequent site of AFib triggers—with more success and an excellent safety profile.

Brennan Vogl
An actual human heart is about the size of your fist, shaped like an upside down pear. Every cell in your body gets blood from your heart (except for your corneas).

“Our research seeks to better understand flow dynamics of the heart during arrhythmia, complex structural heart biomechanics, prosthetic heart valve engineering, and the structure-function relationships of the heart in both health and disease,” Hatoum says.

Why hearts? “It all started with my doctoral program,” Hatoum recalls. “I had the opportunity to work closely with clinicians, to attend their structural heart meetings, and to plan with them the appropriate therapy to be administered for patients. Every patient is very different, which makes the problem exciting and challenging at the same time.”

Hatoum earned her BS in Mechanical Engineering from the American University of Beirut and her PhD in Mechanical Engineering from the Ohio State University (OSU). She was awarded an American Heart Association postdoctoral fellowship, and completed her postdoctoral training at the Ohio State University and at Georgia Institute of Technology before joining the faculty at Michigan Tech.

“One of my goals is to evaluate and provide answers to clinicians so they know what therapy suits their patients best.”

Hoda Hatoum

Now, working in her own Biofluids Lab at Michigan Tech, Hatoum integrates principles of fluid mechanics, design and manufacturing, and clinical expertise with collaborators nationwide (including Mayo Clinic, Ohio State, Vanderbilt, Piedmont Hospital and St. Paul’s Hospital Vancouver)–all to find solutions for cardiovascular flow problems. 

Play Biomedical Engineering Biofluids Lab Aortic Valve Models video
Preview image for Biomedical Engineering Biofluids Lab Aortic Valve Models video

Biomedical Engineering Biofluids Lab Aortic Valve Models

These aortic valves open and close based via the contraction of a pump, controlled by a LabView program. See more during Husky Bites!

In her lab, Hatoum designed and built a pulse duplicator system—a heart simulator—that emulates the left heart side of a cardiovascular system. She also uses a particle image velocimetry system that allows her to characterize the flow field in vessels and organs.

Hatoum and her team of students use these devices to develop patient-specific cardiovascular models, conducting in vitro tests to assess the performance and flow characteristics of different heart valves. “We use idealized heart chambers or patient-specific ones. We test multiple commercially available prosthetic heart valves—and our in-house made valves, too.”

From the Biofluids Lab website: a wide array of current commercial bioprosthetic transcatheter mitral valves.

Hatoum’s team also designs their own heart valve devices.

“Currently, transcatheter heart valves are made of biological materials, including pig or cow valves, that are prone to degeneration. This can lead to compromised valve performance, and ultimately necessitate another valve replacement.”

To solve this problem, Hatoum collaborates with material science experts from different universities in the US and around the world to utilize novel biomaterials that are biocompatible, durable and suitable for cardiovascular applications. 

Which area of research pulls Dr. Hatoum’s heartstrings the most? “Transcatheter aortic heart valves,” she says. (Look closely at this photo to see the closed leaflets of an aortic valve.)

“With the rise of minimally-invasive surgeries, the clinical field is moving towards transcatheter approaches to replace heart valves, rather than open heart surgery,” she explains. “With the challenges that come with TAVs, and with the low-risk population targeted, I believe this is an urgent field to look into, so we can minimize as much as possible any adverse outcomes, improve valve designs and promote longevity of the device.”

The treatment of congenital heart defects in children is another strong focus for Hatoum, who devises alternatives for highly-invasive surgeries for pulmonary atresia and Kawasaki disease. She collaborates with multiple institutions to acquire patient data, then, using experimental and computational fluid dynamics, she examines the different scenarios of various surgical design approaches.

“One very important goal is to develop predictive models that will help clinicians anticipate adverse outcomes,” she says.

“In some centers in the US and the world, the heart team won’t operate without engineers modeling for them—to visualize the problem, design a solution better, improve therapeutic outcomes, and avoid as much as possible any adverse outcomes.”

Hoda Hatoum
Dr. Hoda Hatoum grew up in Lebanon. She’s a big fan of road trips.

Brennan Vogl was the first student to begin working with Hatoum in the lab when she arrived at Michigan Tech in 2020. “It is a great pleasure to work with Brennan,” says Hatoum. “He is very responsible and focused. He handles multiple projects, both experimental and computational, and excels in all aspects of them. I am proud of the tremendous improvement he keeps showing, and his constant motivation to do even better.”

Dr. Hatoum, how did you first get into engineering? What sparked your interest?

As a high-school student, I got the chance to go on a school trip to several universities and I was fascinated by the projects that mechanical engineering students did. That was what determined my major and what sparked my interest.

Hometown, family?

I was raised in Kab Elias, Bekaa, Lebanon. It’s about 45 kilometers (28 miles) from the Lebanese capital, Beirut. The majority of my family still lives there.

‘My niece took this image from the balcony of our house in Lebanon, located in Kab Elias. It shows the broad landscape and the mountains, and the Lebanese coffee cup that’s basically iconic.”

What do you like to do in your spare time?

I like to watch TV, read stories (thrillers) and go on road trips.

The sun temple in the Haidara ruins near Dr. Hatoum’s hometown of Kab Elias in Lebanon are believed to date back to the Roman era.
Snow on the ground in Kab Elias.

How can a student request to join your Biofluids lab?

I currently work with two PhD students and two undergraduates. Usually, an email with interest in the research that I do is sufficient. Our lab employs both mechanical engineering students and biomedical engineering students because of our focus on mechanics. When a student first joins our lab, they do not have any idea about any of the problems we are working on. As they get exposed to to them, they add their own valuable perspective.

The student experience is an amazing one, and one that is rewarding.

Brennan, how did you first get into engineering? What sparked your interest?

I first got into engineering when I participated in Michigan Tech’s Summer Youth Program (SYP). At SYP I got to explore all of the different engineering fields and participate in various projects for each field. Having this hands-on experience really sparked my interest in engineering.

Hometown, family?

I grew up in Saginaw, Michigan. My family now lives in Florida, so I get to escape the Upper Peninsula cold and visit them in the warm Florida weather.

Brennan loves to ski in Houghton’s plentiful powder, but he’s an even bigger fan of warm, sunny weather.
Poppy is on the left and Milo is on the right.

Pets? Hobbies?

I enjoy skiing, and I have two Boston Terriers—Milo and Poppy. They live with my parents in Florida. I don’t think they would be able to handle the cold here in Houghton, as much as I would enjoy them living with me.