1.06 Systolic Heart Murmurs

Cardiovascular system review for the USMLE STEP 1 Exam

• Heart murmurs are caused by turbulent blood flow in the heart

• There are 4 different types of systolic murmurs: ventricular septal defect (VSD), patent ductus arteriosus (PDA), aortic stenosis, and mitral or tricuspid regurgitation

• PDA produces a constant, machine-like murmur

• VSD produces a harsh holosystolic murmur

• Aortic stenosis produces a crescendo-decrescendo systolic ejection murmur

• Mitral and tricuspid regurgitation produce a holosystolic high pitched "blowing" murmur

• Mitral valve prolapse produces a mid-systolic click followed by a late systolic murmur

• Aortic regurgitation produces a decrescendo diastolic murmur

• Mitral stenosis produces a rumbling diastolic murmur