MedicalResearch.com Interview with:
Sakthivel Sadayappan, PhD, MBA
Associate Professor Department of Cell and Molecular Physiology
Loyola University Chicago Health Sciences Division
Maywood, IL 60153-5500, USA.
MedicalResearch: What is the background for this study? What are the main findings?
Dr. Sadayappan: Hypertrophic cardiomyopathy (HCM) is the most common form of genetic heart defect, affecting 1 in 500 people in the general population. HCM results in excessive thickening of heart muscle without an obvious cause, such as hypertension or exercise stress. Often, HCM results in sudden cardiac arrest as a result of cardiac arrhythmia. Electrocardiogram, echocardiogram and cardiac magnetic resonance imaging are commonly used to diagnose HCM. However, genetic defects in more than 10 genes could also cause HCM, and standard screening for these genes is readily available. Notwithstanding our ability to diagnose the disease, a major challenge arises from its heterogeneity. That is, individuals with the same genetic defect often present with different symptoms, ranging from no symptoms at all to severe heart enlargement. Therefore, treatment options vary from person to person, and, at present, no permanent cure is available for HCM. Beta-blockers, calcium antagonists and anti-arrhythmic drugs are currently being used to manage the disease. However, scientists must discover the reasons that explain why some people experience more severe symptoms than others.
In today’s modern world, people are afflicted with stresses including, for example, diabetes, hypertension, hyperlipidemia (high cholesterol), and alcoholism. Therefore, we have hypothesized that additional cardiac stresses can aggravate the onset of Hypertrophic cardiomyopathy. To prove our hypothesis, we used a mouse model having a genetic defect known to affect cardiac muscle contractility. We subjected these mice to severe cardiac stress over a period of 12 weeks. Compared with normal mice, we found that the mutant mice showed significant cardiac abnormalities, including those associated with HCM. Thus, this demonstrated, for the first time, that additional cardiac stress applied in the presence of known genetic defects exacerbates the onset of HCM. Continue reading