II. Causes: Mid-Systolic Murmurs
- Innocent Murmur
- Physiologic Murmur
- Pathologic
- Hypertrophic Cardiomyopathy (20 per 10,000 births)
- Murmur 2-4/6 at left lower sternal border and apex, increased with Valsalva Maneuver
- Atrial Septal Defect (5.4 per 10,000 births)
- Murmur 1-3/6 at left upper sternal border, radiating to back, with fixed split S2 Heart Sound
- Aortic Coarctation (4 per 10,000 births)
- Murmur 1-3/6 at left Scapular region
- Aortic Stenosis (3.8 per 10,000 births)
- Murmur 2-3/6 at right upper sternal border, radiating to carotid arteries
- Pulmonic Stenosis (<1 per 10,000 births)
- Murmur 1-3/6 at left upper sternal border, radiating to back and lung fields
- Hypertrophic Cardiomyopathy (20 per 10,000 births)
III. Causes: Holosystolic Murmur (Pansystolic Murmur, or early murmur)
-
Ventricular Septal Defect (30 per 10,000 births)
- Murmur 3-4/6 (less in larger VSD) harsh, at lower left sternal border, increased with hand grip
-
Mitral Regurgitation (5 per 10,000 births)
- Murmur 2-3/6 at apex radiating to axilla, with possible S3 Heart Sound (pansystolic or early blowing murmur)
-
Patent Ductus Arteriosus (newborns, 5 per 10,000 births)
- Murmur 2-4/6 at left upper sternal border, machinery sound (to and fro), also heard as Diastolic Murmur
- Tricuspid Regurgitation (<1 per 10,000 births)
- Murmur 2-3/6 at lower left sternal border
IV. Exam
- See Heart Murmur
- Dynamic Maneuvers: Affecting Left Ventricular Preload (most useful single set of dynamic tests)
- Decreased Left Ventricular Preload (e.g. Valsalva, stand from squat, forced heavy expiration)
- Increases Hypertrophic Cardiomyopathy and Mitral Valve Prolapse Systolic Murmurs
- Decreases Aortic Stenosis, Mitral Regurgitation and innocent Systolic Murmurs
- Increased left Ventricular Preload (e.g. Squat, passive leg raise)
- Increases innocent Systolic Murmurs as well as Mitral Regurgitation and Aortic Stenosis
- Decreases Hypertrophic Cardiomyopathy and Mitral Valve Prolapse Systolic Murmurs
- Decreased Left Ventricular Preload (e.g. Valsalva, stand from squat, forced heavy expiration)
- Dynamic Maneuvers: Other
- Increased Afterload (e.g. hand grip, transient arterial Occlusion with Blood Pressure cuff)
- Increases Mitral Regurgitation, pulmonic stenosis and Ventricular Septal Defect Systolic Murmurs
- Decreases Hypertrophic Cardiomyopathy, Aortic Stenosis and Mitral Valve Prolapse Systolic Murmurs
- Increased venous return and increased left Ventricular Afterload (e.g. deep or exaggerated inspiration)
- Increases tricuspid regurgitation, pulmonic stenosis Systolic Murmurs
- Decreased jugular venous return (Jugular Vein compression, or transition supine from sitting)
- Decreases Venous Hum continuous murmur
- Increased Afterload (e.g. hand grip, transient arterial Occlusion with Blood Pressure cuff)