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Why can hypertension cause the heart to enlarge and eventually weaken?

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The role of coronary artery disease in heart attack — cardiovascular disease This micrograph shows a cross section of a coronary artery narrowed by an atherosclerotic plaque (purplish matter inside the artery). Most heart attacks are caused by the rupture of an atherosclerotic plaque, which triggers the formation of a clot that abruptly blocks blood flow to part of the heart muscle.

Hypertension occurs when the body’s smaller blood vessels, known as arterioles, narrow, causing blood to exert excessive pressure against vessel walls. This increased resistance forces the heart to work harder to maintain blood flow throughout the body.12

In response to this chronic pressure overload, the heart undergoes a compensatory process called hypertrophy, where the heart muscle increases in mass to provide more power for pumping against the elevated pressure. While this adjustment initially helps the heart meet the increased demand, it is not sustainable. Over time, the heart may become weakened to the point of failure.31

The structural and functional changes associated with this type of hypertrophy include:
* Intracellular changes: The pumping system of the sarcoplasmic reticulum responsible for calcium removal slows down, and the contractile protein myosin shifts toward slower cross-bridge cycling.3
* Increased workload: The heart must continuously overcome higher peripheral resistance, which eventually leads to complications such as congestive heart failure.41

Ultimately, the persistent strain of pumping against high pressure leads to a decline in cardiac function, significantly increasing the risk of heart attack and other cardiovascular events.42