Left ventricular hypertrophy

As left ventricular hypertrophy (LVH ), also called left ventricular hypertrophy, refers to the tissue enlargement (hypertrophy ), the heart muscle (myocardium ) of the left heart chamber ( ventricle) concerns. The LVH is a special form of cardiomegaly ( abnormal enlargement of the heart ).

Epidemiology

About 20 to 60% of patients with chronic hypertension have left ventricular hypertrophy.

Pathology

When left ventricular hypertrophy is an adaptation mechanism ( adaptation ) of the heart to increased chronic stress on the heart muscle of the left ventricle. The trigger for this increased stress can be both hemodynamic, and non- hemodynamic processes. For example, hypertension (high blood pressure), cause valvular heart disease or hypertrophic cardiomyopathy, a left ventricular hypertrophy. The heart muscle mass increases as a result of increased stress. The main difference to a sport heart, a non-pathological cardiomegaly is that while the diastolic and systolic functions are altered by hypertrophy of muscle tissue located between the connective and adipose tissue. In addition, the macro-and microvascular blood flow is disturbed.

The mass of the heart also increases a healthy person in proportion to his age. This increase in mass is caused by the increase in the wall thickness of the left ventricle substantially. The cause of this is a concomitant loss of elasticity with age of the heart muscle and arterial blood vessels that lead to high blood pressure at rest and especially during exercise.

In the pathogenesis, other factors such as age, gender, ethnicity, body mass index, the stimulation of the renin -angiotensin -aldosterone system and the sympathetic nervous system plays an important role in addition to the direct correlation to systolic blood pressure.

The increased pressure load on the heart initially leads to an increase in muscle fiber size. The muscle fiber length and the chamber volume will not change it. Hypertrophy of the heart muscle is concentric. Is the pressure load is so high that the force of contraction of the muscle is no longer sufficient, as remains after the systole ( the ejection phase of the heart in which the heart contracts ) increased blood in the chamber, the end-diastolic volume increases and a Gefügedilatation ( rearrangement in structure of the heart muscle) develops.

Clinical Relevance

In addition to age, left ventricular hypertrophy is the most important predictor of cardiovascular disease hypertensive patients. She is an independent risk factor for coronary heart disease, sudden cardiac death, heart failure and stroke, and thus for cardiovascular morbidity and mortality in their entirety.

Diagnosis

The electrocardiogram shows left ventricular hypertrophy increased Sokolow -Lyon index and an index of over Lewis 1.7 mV. Through imaging techniques such as echocardiography ( ultrasound of the heart ), or cardiac magnetic resonance imaging ( MRI ), the left ventricular hypertrophy be made visible.

Treatment

Depending on the cause of LVH may be temporary, this form of cardiomegaly. A reduction in blood pressure may cause a regression of the tissue augmentation. The ideal treatment of left ventricular hypertrophy are not yet available. Usually, beta-blockers and calcium antagonists, such as verapamil prescribed. They improve diastolic filling and coronary perfusion without hypertrophy stimulate further. ACE inhibitors reduce blood pressure and increase cardiac output.

History of Medicine

The British physician and "Father of Nephrology " Richard Bright (1789-1858) recognized in 1827 as first the relationship between left ventricular hypertrophy and dilatation of the aorta in patients with end-stage renal failure. 1933 could determine experimentally Alfred Chanutin and Edwin E. Barksdale from the University of Virginia, that increases with increasing arterial blood pressure, the diameter of the left ventricular muscle fibers.