What is the most common cause of enlarged heart
Pro Research Analysisby 
Searched over 200M research papers
Most Common Cause of Enlarged Heart: Hypertension
Hypertension and Left Ventricular Hypertrophy (LVH)
Hypertension (HTN) is widely recognized as the most common cause of an enlarged heart, specifically through the development of left ventricular hypertrophy (LVH) . When the heart is subjected to high blood pressure, it must work harder to pump blood, leading to the thickening of the heart muscle, particularly the left ventricle. This condition is known as hypertensive heart disease and includes other complications such as left atrial enlargement, diastolic dysfunction, and functional mitral regurgitation.
Mechanisms of Cardiac Enlargement
The process of cardiac enlargement due to hypertension involves several mechanisms. Increased pressure load on the heart leads to hypertrophy, where the heart muscle thickens to cope with the increased workload. This hypertrophy is often accompanied by fibrosis, inflammation, and oxidative stress, which further contribute to the remodeling of the heart tissue and can lead to arrhythmias and sudden cardiac death (SCD) .
Other Contributing Factors
While hypertension is the primary cause, other factors can also lead to an enlarged heart. These include valvular defects, intracardiac shunts, and conditions that increase the volume load on the heart, such as aortic incompetence and persistent ductus arteriosus . Additionally, genetic mutations play a significant role in conditions like hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM), which can also result in an enlarged heart.
Hypertrophic Cardiomyopathy (HCM) and Athlete's Heart
Hypertrophic cardiomyopathy (HCM) is another significant cause of an enlarged heart, particularly in young individuals and athletes. HCM is characterized by the thickening of the heart muscle, which can lead to impaired filling and outflow of blood, increasing the risk of sudden cardiac death. However, it is important to differentiate HCM from "athlete's heart," a benign condition where the heart enlarges due to intense physical training without adverse effects.
Conclusion
In summary, hypertension is the most common cause of an enlarged heart, primarily through the development of left ventricular hypertrophy. This condition is exacerbated by factors such as fibrosis, inflammation, and genetic mutations. While other conditions like valvular defects and cardiomyopathies also contribute to cardiac enlargement, hypertension remains the predominant cause. Effective management of hypertension is crucial in preventing the progression of heart enlargement and associated complications.
Sources and full results
Most relevant research papers on this topic