Ventricular hypertrophy
Classification & external resources

ICD-10	I51.7
ICD-9	429.3

Although ventricular hypertrophy may occur in either the left or right or both ventricles of the heart, left ventricular hypertrophy (LVH) is more commonly encountered.

Physiology

The ventricles are the chambers in the heart responsible for pumping blood either to the lungs (right ventricle) or the rest of the body (left ventricle). Increased ventricular mass is an adaptation by the ventricle(s) of the heart to increased stress, such as chronically increased volume load (preload) or increased pressure load (afterload).

It is a physiological response that enables the heart to adapt to increased stress; however, the response can become pathological and ultimately lead to a deterioration in function. For example, hypertrophy is a normal physiological adaptation to exercise that enables the ventricle to enhance its pumping capacity. Aerobic training results in the heart being able to pump a larger volume of blood through an increase in the size of the ventricles. Anaerobic training results in the thickening of the myocardial wall to push blood through arteries compressed by muscular contraction. This type of physiologic hypertrophy is reversible and non-pathological, increasing the heart's ability to circulate blood. Chronic hypertension causes pathological ventricular hypertrophy. This response enables the heart to maintain a normal stroke volume despite the increase in afterload. However, over time, pathological changes occur in the heart that lead to a functional degradation and heart failure.

If the precipitating stress is volume overload (as through aerobic exercise, which increases blood return to the heart through the action of the skeletal-muscle pump), the ventricle responds by adding new sarcomeres in-series with existing sarcomeres (i.e. the sarcomeres lengthen rather than thicken). This results in ventricular dilation while maintaining normal sarcomere lengths - the heart can expand to receive a greater volume of blood. The wall thickness normally increases in proportion to the increase in chamber radius. This type of hypertrophy is termed eccentric hypertrophy.

In the case of chronic pressure overload (as through anaerobic exercise, which increases resistance to blood flow by compressing arteries), the chamber radius may not change; however, the wall thickness greatly increases as new sarcomeres are added in-parallel to existing sarcomeres. This is termed concentric hypertrophy. This type of ventricle is capable of generating greater forces and higher pressures, while the increased wall thickness maintains normal wall stress. This type of ventricle becomes "stiff" (i.e., compliance is reduced) which can impair filling and lead to diastolic dysfunction.

See also

• Cardiac fibrosis
• Cardiology
• Cardiomegaly
• Cardiovascular disease
• Right ventricular hypertrophy

External links

• Tutorial at University of Utah

•  • [ e] Circulatory system pathology (, )
Hypertension	Hypertensive heart disease - Hypertensive nephropathy - Secondary hypertension (Renovascular hypertension)
Ischaemic heart disease	Angina pectoris - Prinzmetal's angina - Myocardial infarction - Dressler's syndrome
Pulmonary circulation	Pulmonary embolism - Cor pulmonale
Pericardium	Pericarditis - Pericardial effusion - Cardiac tamponade
Endocardium/heart valves	Endocarditis - Mitral regurgitation - Mitral valve prolapse - Mitral stenosis - Aortic valve stenosis - Aortic insufficiency - Pulmonary valve stenosis
Myocardium	Myocarditis - Cardiomyopathy (Dilated cardiomyopathy, Hypertrophic cardiomyopathy, Loeffler endocarditis, Restrictive cardiomyopathy) - Arrhythmogenic right ventricular dysplasia
Electrical conduction system of the heart	Heart block: AV block (First degree, Second degree, Third degree) - Bundle branch block (Left, Right) - Bifascicular block - Trifascicular block Pre-excitation syndrome (Wolff-Parkinson-White, Lown-Ganong-Levine) - Long QT syndrome - Adams-Stokes syndrome - Cardiac arrest Arrhythmia: Paroxysmal tachycardia (Supraventricular, AV nodal reentrant, Ventricular) - Atrial flutter - Atrial fibrillation - Ventricular fibrillation - Premature contraction (Atrial, Ventricular) - Sick sinus syndrome
Other heart conditions	Heart failure - Cardiomegaly - Ventricular hypertrophy (Left, Right)
Cerebrovascular diseases	Intracranial hemorrhage/cerebral hemorrhage: Extra-axial hemorrhage (Epidural hemorrhage, Subdural hemorrhage, Subarachnoid hemorrhage) - Intra-axial hematoma (Intraventricular hemorrhages, Intraparenchymal hemorrhage) - Anterior spinal artery syndrome - Binswanger's disease - Moyamoya disease
Arteries, arterioles and capillaries	Atherosclerosis (Renal artery stenosis) - Aortic dissection/Aortic aneurysm (Abdominal aortic aneurysm) - Aneurysm - Raynaud's phenomenon/Raynaud's disease - Buerger's disease - Arteritis (Aortitis) - Intermittent claudication - Arteriovenous fistula - Hereditary hemorrhagic telangiectasia - Spider angioma
Veins, lymphatic vessels and lymph nodes	Thrombosis/Phlebitis/Thrombophlebitis (Deep vein thrombosis, May-Thurner syndrome, Portal vein thrombosis, Venous thrombosis, Budd-Chiari syndrome, Renal vein thrombosis, Paget-Schroetter disease) - Varicose veins (Hemorrhoid, Esophageal varices, Varicocele, Gastric varices, Caput medusae) - Superior vena cava syndrome - Lymph(Lymphadenitis, Lymphedema, Lymphangitis)
See also (, )