Scientists at the University Medical Center Göttingen have upended decades of conventional wisdom about atrial fibrillation, revealing that the condition damages both chambers of the heart far more severely than previously understood. Until this discovery, researchers and cardiologists focused almost exclusively on the left atrium as the site of disease—but the new findings show that the right atrium undergoes equally profound changes, transforming how doctors may need to approach treatment.
Atrial fibrillation, the most common persistent heart rhythm disorder worldwide, affects approximately 1.8 million people in Germany alone. The condition causes chaotic electrical activity in the heart's atria, resulting in irregular and often dangerously fast heartbeats. Patients typically experience palpitations, shortness of breath, reduced physical performance, and exhaustion. While some forms of atrial fibrillation resolve on their own, the persistent variant is far more problematic—it doesn't disappear and leads to progressive structural damage that significantly increases the risk of stroke, heart failure, and premature death.
For decades, the hunt for effective treatments centered on the left atrium and the pulmonary veins that feed into it, long identified as the primary triggers of arrhythmia. But a research team led by Prof. Dr. Niels Voigt, Professor of Molecular Pharmacology at UMG, along with Dr. Christof Lenz and postdoctoral researcher Dr. Aiste Liutkute, decided to investigate whether the right atrium might also be affected. Their findings, published in the journal Cardiovascular Research, revealed something striking: the right atrium undergoes profound remodeling that increasingly mirrors the damage seen in the left.
The team analyzed tissue samples collected from both atria during heart surgery in patients with persistent atrial fibrillation, comparing them with healthy control samples from non-transplanted donor hearts. Using state-of-the-art mass spectrometry—a high-resolution analytical method that identifies and quantifies molecules with precision—the scientists examined thousands of proteins simultaneously to map disease-related changes. They created the first comprehensive reference library of the human heart proteome and supplemented their findings with microscopic examination of tissue scarring, biochemical confirmation of protein changes, and blood markers indicating cardiac stress.
The results were unambiguous. In both the right and left atria, the researchers found increased tissue scarring, a breakdown of critical heart muscle structures, and clear signs of cellular stress and remodeling. These changes fundamentally impair the normal electrical signaling required for the heart to beat in rhythm. "The results suggest that persistent atrial fibrillation must be understood as a disease of both atria," said Dr. Liutkute, the study's first author. This insight could explain why established therapies so often fail to produce lasting results in long-standing cases—current treatments have been targeting only half the problem.
The implications are significant. Dr. Lenz noted that existing therapeutic procedures focus primarily on the left atrium, but the team's data suggest that in the future, both atria may need to be taken into account to a greater extent. This reframing could reshape clinical practice, pushing cardiologists to develop more comprehensive approaches that address the disease as it actually manifests: a condition affecting the entire dual-chambered system rather than a localized dysfunction. For the millions living with atrial fibrillation, this new understanding offers hope that more effective treatments may finally be within reach.