Anterior leaflet of mitral valve

Looks like

The larger, curtain-like flap of the valve between the left atrium and left ventricle, continuous with the aortic valve base.

What it does

Closes with the posterior leaflet when the ventricle squeezes, so blood goes out to the body, not back to the lungs.

Keeping it well

Can bulge back (prolapse) or be damaged by rheumatic fever. Breathlessness or a new murmur needs a heart ultrasound.

Related conditions

• 22q11.2 deletion syndrome (DiGeorge)
• Aortic stenosis
• Atrial flutter
• Cardiomyopathy (dilated, restrictive, arrhythmogenic)
• Chagas disease
• Congenital heart defects
• Coronary artery disease
• Diphtheria
• Down syndrome (trisomy 21)
• Eating disorders
• Extra heartbeats (ectopics and palpitations)
• Fainting (syncope)
• Friedreich's ataxia
• Heart failure
• High blood pressure
• High cholesterol
• Hypertrophic cardiomyopathy
• Hypothermia & frostbite
• Infective endocarditis
• Kawasaki disease
• Long QT syndrome
• Metabolic syndrome
• Myocarditis
• Orthostatic hypotension & POTS
• Panic disorder
• Pericardial effusion & tamponade
• Pericarditis
• Peripheral artery disease
• Phaeochromocytoma & hyperaldosteronism
• Pre-eclampsia
• Raynaud's phenomenon
• Rheumatic fever & rheumatic heart disease
• Sepsis
• Shock (circulatory failure)
• Sudden cardiac arrest
• Sudden infant death syndrome
• Supraventricular tachycardia
• Takotsubo (stress) cardiomyopathy
• Tuberous sclerosis complex
• Valve disease (stenosis & regurgitation)
• Vasculitis (GCA & others)
• Wolff–Parkinson–White syndrome