Applied anatomy of the heart Flashcards
Where is referred cardiac pain usually felt?
T1-4 medial arm
Neck
Jaw
Also to epigastrium T5-T9
Why might somatic pain and visceral (heart) pain get confused?
Visceral afferents travel in the same pathway as sensory nerve fibres in the skin
Brain cannot differentiate and therefore somatic and visceral pain are confused
What % of the septum do the left and right coronary arteries supply?
Left = anterior ⅔ of coronary septum Right = posterior ⅓
Which leads give a view of the septum of the heart (LAD)?
V1
V2
Which leads give an anterior view of the heart (LAD)?
V3
V4
Which leads give a lateral view of the heart (Left circumflex or diagonal branch of LAD)?
V5
V6
aVL
I
Which leads give an inferior view of the heart (RCA or left circumflex)?
aVF
II
III
What type of cardiac hypertrophy is caused by pressure overload? What can cause pressure overload?
Concentric hypertrophy
Caused by hypertension and aortic stenosis, strength training
What type of cardiac hypertrophy is caused by volume overload? What can cause volume overload?
Eccentric hypertrophy
Caused by athletes, pregnancy + valve disease
Can lead to aortic or mitral regurgitation
Describe the effects of concentric hypertrophy on the structure and function of the heart.
Increase in myocyte cell width
Thick walls and small lumens
Compliance is reduced –> Can lead to eccentric as reduced compliance can cause volume overload
Ventricular filling is compromised
Describe the effects of eccentric hypertrophy on the structure and function of the heart.
Increase in myocyte cell length
Chamber dilatation
Elevated oxygen demand and lower mechanical efficacy
Describe how the heart remodels after injury and how this can lead to systolic and diastolic dysfunction.
- New sarcomeres
- Reduced capillary:myocyte ratio (dye to insufficient apoptosis)
Result = - Increased fibrous tissue ‘stiffen’
- Myocytes undergo apoptosis
Systolic = reduced ejection fraction Diastolic = increased resistance
What are the states of the AV and semilunar valves during S1 (systole) and S2 (diastole)?
S1 = AV valves close; semilunar valves open S2 = AV valves open; semilunar valves close
Mitral regurgitation:
- In what situations does it occur?
- What are the structural changes to the heart?
- What is heard on auscultation?
- Valve prolapse or rheumatic heart disease
- Left atrial enlargement and left ventricular eccentric hypertrophy
- Auscultation = Systolic murmur; between S1 and S2 –> heard at the apex
Aortic stenosis:
- What are the structural changes to the heart?
- What is heard on auscultation?
- LV concentric hypertrophy –> less compliance and reduced coronary blood flow
- Systolic murmur (during mid-systole) –> heard at right second intercostal space
