Through studying cardiac electrical abnormalities, Samuel Hahn ’05 analyzed the data that could improve the prognosis for patients with heart failure.
Samuel Hahn ’05 is both philosopher and scientist when describing his role in a ground-breaking research study identifying the electrical changes that lead to heart failure. As an undergraduate in the Whiting School of Engineering, the Biomedical Engineering major contributed to research that for the first time described the time-course and nature of the electrical abnormalities that are present long before a patient has any clinical signs of heart failure.
Some 5 million Americans suffer from heart failure, and more than 250,000 a year die. “Of the deaths in patients with heart failure, up to 50 percent are sudden and unexpected, and the result of lethal arrhythmias,” Hahn notes. “By defining the early electrical changes,” he observes, “we hope to identify new targets for therapy that can either reverse, or at the very least, hinder the progression of the vicious cycle of events that ultimately leads to death.” Hahn conducted his research under the guidance of Fadi G. Akar, a research assistant professor at the Johns Hopkins School of Medicine, Division of Cardiology. Hahn and Akar, who have submitted their research to a peer-reviewed journal, worked in the laboratory of Gordon F. Tomaselli, professor of Medicine and a cardiologist at Johns Hopkins Hospital.
“In the lab, we’re dealing with the big picture,” says Hahn, who is 21. Their goal is to understand the exact mechanisms underlying heart disease. “Our work with optical mapping doesn’t deal with the minute genes, but how they work together and what changes they produce,” Hahn explains. The technique of optical mapping involves staining heart tissue samples with voltage-sensitive dyes, shining light on the samples, collecting the emitted light in an optical detection system, and then converting it to current for computer analysis. Hahn’s role came in analyzing the data and helping to perform the experiments on the two phases of electrical disturbances that lead to lethal arrhythmia.
“I love designing things and getting them to work, Being an engineer teaches you to think analytically.” Samual Hahn ’05
This fall, Hahn has taken his big-picture research experience to the University of Pennsylvania School of Medicine, where he is pursuing an MD. Though he’s always wanted to be a physician, Hahn chose majoring in Biomedical Engineering over pre-med, and hopes to do further research. “I love designing things and getting them to work,” he explains. “Being an engineer teaches you to think analytically.”
Hahn’s father, Suk-kyun Hahn, MD, is an internist in private practice. His sister Sarah, a Hopkins sophomore, also has her sights set on medical school. It was their brother, David who, perhaps, has had the biggest influence on Hahn’s approach to his chosen career. In 2002, David, 15, who has Down syndrome, wanted to take part in Special Olympics. Hahn, who played intramural basketball at Hopkins, jumped at the chance to coach his brother in basketball, track, and soccer. He spent most weekends with David at the family’s home in Lutherville, Maryland. “By being with him and getting to know others in Special Olympics, I really developed a desire to help people,” Hahn says. “It’s rewarding to help him achieve his goals, however simple those goals are. I hope that I will have the same compassion and empathy when I practice medicine.”
When Hahn entered Hopkins in fall 2001, he was very interested in genetics because of David and because it was “a field just waiting to be explored,” he says. A few months prior, he had worked as a paid technician in the genetics lab of Andrew P. Feinberg, professor of Medical Genetics at Hopkins and Hahn’s next-door neighbor. Recalling his cardiology study in the Physiological Foundations course, a core Biomedical Engineering class, Hahn says, “I had seen EKGs before, but had never seen action potentials, which are electrical signals of how the ion channels in your heart work and produce contractions.” Feinberg mentioned to Hahn that Tomaselli was researching cardiac rhythms, and that led to Tomaselli’s offering the junior a for-credit position in his lab.
Akar also spotted Hahn’s talent right from the start. He recalls how Hahn “distinguished himself early on as a gifted, forwardthinking, and meticulous scientist. He learned how to approach scientific questions, identify gaps in knowledge, and design experimental procedures that would specifically answer those questions in the most effective manner.” Hahn politely deflects such compliments. Akar “gives me a lot more credit than I think I deserve. He put a lot of trust in me and trusted my work,” Hahn says. “The great thing about Hopkins is that you get to see the research aspect of medicine. I can say I was part of something bigger.”
Special thanks to Karen Blum for her contributions to this article. To learn more about the Department of Biomedical Engineering in the Whitaker Institute at Johns Hopkins, visit www.bme.jhu.edu.