Interventricular septum

Looks like

The thick muscular wall down the middle of the heart, separating the left and right pumping chambers.

What it does

Keeps high-pressure red blood apart from low-pressure blue blood and helps squeeze both ventricles.

Keeping it well

A hole in it is one of the commonest heart defects at birth; many small ones close by themselves. It can thicken abnormally in hypertrophic cardiomyopathy, which runs in families — fainting during exercise or a relative's sudden death young warrants a heart scan.

Related conditions

• 22q11.2 deletion syndrome (DiGeorge)
• Aortic stenosis
• Atrial flutter
• Botulism
• 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)
• Fibromyalgia
• Frailty & falls in older age
• Friedreich's ataxia
• Heart failure
• Heat exhaustion & heatstroke
• Hypertrophic cardiomyopathy
• Hypothermia & frostbite
• Kawasaki disease
• Long QT syndrome
• Malnutrition & refeeding syndrome
• Muscular dystrophy
• Myocarditis
• Orthostatic hypotension & POTS
• Panic disorder
• Pericardial effusion & tamponade
• Pericarditis
• Polymyalgia rheumatica
• Rhabdomyolysis
• Sarcoma
• Sarcopenia
• Shock (circulatory failure)
• Sudden cardiac arrest
• Sudden infant death syndrome
• Supraventricular tachycardia
• Takotsubo (stress) cardiomyopathy
• Tetanus
• Tuberous sclerosis complex
• Wolff–Parkinson–White syndrome