Cardiology

ANATOMY

BLOOD FLOW THROUGH HEART

Superior and inferior vena cava
Right atrium
Tricuspid valve
Right ventricle
Pulmonic valve
Pulmonary artery
Lungs
Pulmonary veins
Left atrium
Mitral valve (bicuspid valve)
Left ventricle
Aortic valve
Aorta
Systemic circulation

HEART SOUNDS

Due to closure of the atrioventricular valves (tricuspid and mitral)
Heard loudest at mitral and tricuspid areas
Use diaphragm of stethoscope

Due to closure of the semilunar valves (aortic and pulmonic)
Heard loudest at aortic and pulmonic areas
Use diaphragm of stethoscope

Caused by rapid ventricular filling
Heard loudest at mitral area
May be normal in young people or due to CHF or mitral regurgitation
Use bell of stethoscope

Caused by forceful atrial ejection into a distended ventricle
Heard loudest at mitral area
May be normal (children, well-trained athletes) or due to HTN or aortic stenosis
Use bell of stethoscope

MURMURS

Use the diaphragm for high-pitched murmurs.
Use the bell for low-pitched murmurs.
Loudness of murmur is not proportional to severity of disease.
The terms regurgitation, incompetence, and insufficiency are used interchangeably.

Innocent vs. Pathologic Murmur

	Innocent	Pathologic
Timing	Systolic	Diastolic
Location	Not maximally at aortic area	Originates in heart itself
Intensity	Grade 3 or less	Can be any grade
Variation with respiration	Can vary greatly (louder on inspiration)	Usually constant
Evidence of cardiac disease	No	Yes
Age	More common in children/young adults	All ages

Murmur Loudness Scale

I—barely audible

II—faint, clearly audible

III—moderately loud with no palpable thrills

IV—loud with palpable thrill likely

V—very loud, may be audible with stethoscope partly off chest. Palpable thrill likely.

VI—very loud, may be audible with stethoscope off chest. Associated with palpable thrills.

NOTE: Thrills—low-frequency cutaneous vibrations associated with loud heart murmurs. The vibration can often be felt with the hand placed on the chest.

Murmur Types

Aortic Stenosis