S4

Medical abbreviation · Cardiology

S4
Stands forFourth heart sound
CategoriesMedical

S4 stands for Fourth heart sound, a cardiology abbreviation.

Low-pitched sound in late diastole, just before S1, created when the atrium contracts against a stiff ventricle; the cadence sounds like "TEN-nes-see." It suggests left ventricular hypertrophy, hypertension, aortic stenosis or acute ischemia.

Example: S4 gallop at the apex in a patient with long-standing HTN and LVH on echo.

Usage notes

An S4 cannot occur in atrial fibrillation because there is no effective atrial contraction. It is usually abnormal in adults, although some older people without disease have one. Also called an atrial or presystolic gallop. A "summation gallop" occurs when S3 and S4 merge at fast heart rates.

More cardiology abbreviations

  • RVSP – Right ventricular systolic pressure
  • RWMA – Regional wall motion abnormality
  • S-ICD – Subcutaneous implantable cardioverter-defibrillator
  • S1 – First heart sound
  • S2 – Second heart sound
  • S3 – Third heart sound
  • SA – Sinoatrial
  • SAVR – Surgical aortic valve replacement
  • SBE – Subacute bacterial endocarditis
  • SBP – Systolic blood pressure
  • SCA – Sudden cardiac arrest
  • SCAD – Spontaneous coronary artery dissection

See all 229 cardiology abbreviations →

Edited by the AbbreviationList.com team. Spotted an error or a missing meaning? Contact us.

This entry is for general education and is not medical advice. Abbreviation use varies between institutions; always confirm in context.