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Cellular and signaling mechanisms of cardiac hypertrophy
1Department of Medical-Surgical Nursing, College of Nursing, University of Illinois at Chicago.
Insights
Left ventricular hypertrophy (LVH) is a risk factor for heart problems. Over time, this condition leads to heart failure through cellular damage and reduced blood supply.
Area of Science:
- Cardiology
- Molecular Biology
- Pathophysiology
Background:
- Left ventricular hypertrophy (LVH) is a significant independent risk factor for cardiovascular morbidity and mortality.
- Initially, LVH enhances myocardial contractility and pump function.
- However, sustained LVH leads to detrimental changes including myofibril disintegration, fibrosis, and energy depletion.
Purpose of the Study:
- To summarize the pathological progression of left ventricular hypertrophy.
- To identify the key signaling pathways and molecular events involved in LVH development.
- To highlight the transition from adaptive to maladaptive cardiac remodeling.
Main Methods:
- Review of existing literature on the pathophysiology of LVH.
- Analysis of molecular and cellular mechanisms underlying cardiac hypertrophy.
- Identification of hemodynamic and nonhemodynamic stimuli triggering myocardial growth.
Main Results:
- LVH progression involves myofibril breakdown, interstitial fibrosis, and ATP depletion.
- Altered gene expression, including immediate early genes like c-fos and c-myc, plays a role.
- Myocardial ischemia occurs as the heart muscle outgrows its vascular supply, leading to heart failure.
Conclusions:
- LVH initiates as a compensatory mechanism but ultimately leads to heart failure.
- Multiple signaling pathways, including hemodynamic and hormonal factors, contribute to LVH.
- Understanding these mechanisms is crucial for developing therapeutic strategies against cardiovascular disease.
Abstract:
Left ventricular hypertrophy (LVH) is an important independent risk factor for cardiovascular morbidity and mortality. Initially LVH improves contractility and pump function; however, over time a sequence of events occurs including disintegration of myofibrils, interstitial fibrosis, adenosine triphosphate depletion, and altered gene expression. Eventually the hypertrophied myocardium outgrows its capillary bed, subendocardial ischemia develops, and the heart fails. Hemodynamic (pressure) and nonhemodynamic signals (catecholamines, angiotensin II, thyroid hormone) have been identified that stimulate hypertrophic growth of the myocardium. Evidence is also accumulating that the induction of immediate early genes such as c-fos and c-myc may participate in the development of LVH.