Papillary muscles

Looks like

Cone-shaped muscles rising from the inner walls of both ventricles — three on the right, two on the left — tied to the valve leaflets by the chordae tendineae.

What it does

Tighten as the heart squeezes, holding the mitral and tricuspid leaflets so they close and do not flip back into the atria.

Keeping it well

A heart attack can rupture one (usually the back one on the left, which has a single blood supply), causing sudden severe mitral leak, breathlessness and shock; it needs emergency surgery.

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 attack
• Heart failure
• Heat exhaustion & heatstroke
• Hypertrophic cardiomyopathy
• Hypothermia & frostbite
• Infective endocarditis
• Kawasaki disease
• Long QT syndrome
• Malnutrition & refeeding syndrome
• Muscular dystrophy
• Myocarditis
• Orthostatic hypotension & POTS
• Panic disorder
• Pericardial effusion & tamponade
• Pericarditis
• Polymyalgia rheumatica
• Rhabdomyolysis
• Rheumatic fever & rheumatic heart disease
• Sarcoma
• Sarcopenia
• Shock (circulatory failure)
• Sudden cardiac arrest
• Sudden infant death syndrome
• Supraventricular tachycardia
• Takotsubo (stress) cardiomyopathy
• Tetanus
• Tuberous sclerosis complex
• Valve disease (stenosis & regurgitation)
• Wolff–Parkinson–White syndrome