New Echocardiography Research Suggests Emerging Marker for Cardiomyopathy Detection in Patients with Duchenne Muscular Dystrophy

Could an emerging echocardiographic marker lead to earlier detection of cardiomyopathy in patients with Duchenne muscular dystrophy (DMD)? In a new study, recently published in the Journal of Cardiovascular Development and Disease, researchers assessed whether increased integrated wall stress (IWS), as a marker of total left ventricular workload, could indicate pre-clinical cardiomyopathy in patients with DMD. The study authors determined that IWS — a product of peak systolic wall stress (PS-WS) calculated with M-mode echocardiography as well as heart rate — was significantly elevated in a DMD-A cohort (DMD patients with left ventricular shortening fraction (LVSF) > 30 percent) in comparison to a control cohort and even higher in patients with DMD-B (those with DMD and LVSF < 30 percent). While cardiomyopathy is a common dilemma, lead study author Takeshi Tsuda, M.D., maintained in a recent interview with Diagnostic Imaging that there is a distinct difference with DMD cardiomyopathy and the IWS marker facilitates earlier detection in this patient population. “(The IWS assessment) is a very measurable but simple technology, (which) tells us something is occurring before we see visible systolic function changes,” noted Dr. Tsuda, a pediatric cardiologist at Nemours Children’s Health in Wilmington, Del. Dr. Tsuda emphasized that the study findings with the IWS assessment show that the heart muscle is not the only factor to consider in the development of DMD cardiomyopathy. “(The IWS method) lets you see that it’s not just the heart muscle that is causing trouble. Both the heart muscle problem and sinus tachycardia are both giving rise to the pathological process. Now there is very little we can do with the muscle cells, but we can control the heart rate to reduce the interior wall stress. As a result, we can retard or attenuate the progression of disease. That's a major reason to introduce this (IWS assessment) method,” emphasized Dr. Tsuda. (Editor’s note: For related content, see “Study: Photon-Counting CT Reduces Radiation Dosing by More than 40 Percent in Kids with Congenital Heart Disease,” “FDA Expands Approval of Cardiac Ultrasound Imaging Agent for Pediatric Patients” and “FDA Approves Pediatric Use of Ultrasound-Enhancing Agent in Suboptimal Echocardiogram Cases.”) For more insights from Dr. Tsuda, watch the video below.