Heart Murmurs

Heart Murmurs
By: David Leder

Outline

I. Basic Pathophysiology
II. Describing murmurs
III. Systolic murmurs
IV. Diastolic murmurs
V. Continuous murmurs
VI. Summary

Basic Pathophysiology
Murmurs = Math
Describing a heart murmur

1. Timing
o murmurs are longer than heart sounds
o HS can distinguished by simultaneous palpation of the carotid arterial pulse
o systolic, diastolic, continuous
2. Shape
o crescendo (grows louder), decrescendo, crescendo-decrescendo, plateau

3. Location of maximum intensity
o is determined by the site where the murmur originates
o e.g. A, P, T, M listening areas
4. Radiation
o reflects the intensity of the murmur and the direction of blood flow

5. Intensity
o graded on a 6 point scale
+ Grade 1 = very faint
+ Grade 2 = quiet but heard immediately
+ Grade 3 = moderately loud
+ Grade 4 = loud
+ Grade 5 = heard with stethoscope partly off the chest
+ Grade 6 = no stethoscope needed

*Note: Thrills are assoc. with murmurs of grades 4 - 6

6. Pitch
o high, medium, low
7. Quality
o blowing, harsh, rumbling, and musical
8. Others:
i. Variation with respiration

+ Right sided murmurs change more than left sided

ii. Variation with position of the patient

iii. Variation with special maneuvers

+ Valsalva/Standing => Murmurs decrease in length and intensity

EXCEPT: Hypertrophic cardiomyopathy and Mitral valve prolapse

Systolic Murmurs
* Derived from increased turbulence associated with:

1. Increased flow across normal SL valve or into a dilated great vessel
2. Flow across an abnormal SL valve or narrowed ventricular outflow tract - e.g. aortic stenosis
3. Flow across an incompetent AV valve - e.g. mitral regurg.
4. Flow across the interventricular septum

Early Systolic murmurs
1. Acute severe mitral regurgitation
2. Congenital, small muscular septal defect
3. Tricuspid regurg. with normal PA pressures

Midsystolic (ejection) murmurs
* Are the most common kind of heart murmur
* Are usually crescendo-decrescendo
* They may be:
1. Innocent
2. Physiologic
3. Pathologic

Aortic stenosis
* Loudest in aortic area; radiates along the carotid arteries
* Intensity varies directly with CO
* A2 decreases as the stenosis worsens
* Other conditions which may mimic the murmur of aortic stenosis w/o obstructing flow:

1. Aortic sclerosis
2. Bicuspid aortic valve
3. Dilated aorta
4. Increased flow across the valve during systole

Hypertrophic cardiomyopathy
Pansystolic (Holosystolic) Murmurs
1. Mitral valve regurgitation
2. Tricuspid valve regurgitation
3. Ventricular septal defect
Diastolic Murmurs
* Almost always indicate heart disease
* Two basic types:

1. Early decrescendo diastolic murmurs
2. Rumbling diastolic murmurs in mid- or late diastole

Aortic Regurgitation
* Best heard in the 2nd ICS at the left sternal edge
* High pitched, decrescendo
* Blowing quality => may be mistaken for breath sounds
* Radiation:

Mitral Stenosis
* Two components:
1. Middiastolic - during rapid ventricular filling
2. Presystolic - during atrial contraction; therefore, it disappears if atrial fibrillation develops
Continuous Murmurs

1. Cervical venous hum
2. Mammary souffle
3. Patent Ductus Arteriosus
4. Pericardial friction rub
Back to the Basics
1. When does it occur - systole or diastole
2. Where is it loudest - A, P, T, M
I. Systolic Murmurs:
1. Aortic stenosis - ejection type
2. Mitral regurgitation - holosystolic
3. Mitral valve prolapse - late systole

II. Diastolic Murmurs:
1. Aortic regurgitation - early diastole
2. Mitral stenosis - mid to late diastole

Summary
A. Presystolic murmur
o Mitral/Tricuspid stenosis
B. Mitral/Tricuspid regurg.
C. Aortic ejection murmur
D. Pulmonic stenosis (spilling through S20
E. Aortic/Pulm. diastolic murmur
F. Mitral stenosis w/ Opening snap
G. Mid-diastolic inflow murmur
H. Continuous murmur of PDA

Heart Murmurs.ppt