Transplanting Cells Instead of Whole Hearts: A Conversation with Jeffrey Olgin
I’m grateful that I’ve got rhythm – or at least good heart rhythm. Millions of Americans don’t. The incidence of hearts that sometimes quiver ineffectually is on the rise. Mainly it’s because people are living longer, often with conditions that can threaten the heart’s ability to transmit electrical signals in an orderly way.
Jeffrey Olgin
These electrical signals move in waves – like falling dominoes – from muscle cell to muscle cell within the heart. Different parts of the heart muscle contract in turn, causing the heart’s four chambers to pump lifeblood throughout our bodies.
Cardiovascular disease and high blood pressure frequently contribute to the development of abnormal heart rhythms, or arrhythmias. Among the most common arrhythmias are atrial fibrillation and ventricular fibrillation.
Atrial fibrillation refers to the irregular beating of the heart’s smaller, upper chambers. It is not usually a death sentence, but it typically causes fatigue and greatly increases the risk for stroke.
Ventricular fibrillation refers to the quivering of the heart’s big lower chambers, which propel oxygenated blood into the major arteries. Ventricular fibrillation is rapidly fatal if normal rhythm cannot be restored within a matter of seconds. Unfortunately, the first sign of heart disease in many people is sudden cardiac arrest – a heart attack that disrupts the effective pumping rhythm of the ventricles.
Many people survive heart attacks. However, the heart does not regrow muscle cells – called myocytes – that may have died during a heart attack. With a loss of conducting cells, the waves of electricity that once flowed through the heart in perfect order may become permanently prone to disruption, causing arrhythmia.
There are treatments for arrhythmias – drugs, implantable devices, even the destruction of small bits of heart muscle that transmit wayward signals, a technique pioneered at UCSF. But these treatments do not always work.
Jeffrey Olgin, MD, chief cardiologist of electrophysiology at UCSF, is collaborating with Israeli stem cell researcher Lior Gepstein, MD, PhD, to grow and transplant cells with tailor-made electrical properties into rodents, with the aim of developing a new treatment to correct some of the toughest cases of arrhythmias in humans. In each case, the treatment would be developed from cells taken from the patient’s own skin, which should eliminate the risk of tissue rejection. We speak with Jeff Olgin today on the UCSF Science Café.
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