Wall of left atrium

Looks like

The thin muscular wall of an upper heart chamber, only a few millimetres thick.

What it does

Contracts to top up the ventricle and carries the heart's pacemaker signal from the sinus node.

Keeping it well

Stretched walls favour atrial fibrillation. A fast irregular heartbeat needs a doctor because of stroke risk.

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
• 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
• Sepsis
• Shock (circulatory failure)
• Sudden cardiac arrest
• Sudden infant death syndrome
• Supraventricular tachycardia
• Takotsubo (stress) cardiomyopathy
• Tuberous sclerosis complex
• Vasculitis (GCA & others)
• Wolff–Parkinson–White syndrome