14. HCM Flashcards Preview

EXB 112 FINAL > 14. HCM > Flashcards

Flashcards in 14. HCM Deck (17):
1

List the common and training-related abnormalities of an athlete's ECG.

  • Sinus bradycardia
  • 1° AV block
  • Incomplete RBBB
  • Early repolarization
  • Isolated QRS voltage criteria for LV hypertrophy

2

List the uncommon and training-unrelated abnormalities of an athlete's ECG.

  • T wave inversion
  • ST segment depression
  • Pathological Q waves
  • LA enlargement
  • L or R axis deviation
  • RV hypertrophy
  • Ventricular pre-excitation
  • Complete LBBB or RBBB
  • Long or short QT interval

3

What is a genetic CV disease? Characteristics?

Diseases in which one's inherited genome is the prime determinant of the presence of serious CV disease

  • Often fatal at an early age
  • Majority are asymptomatic as they develop

4

What is homocysteinuria? How does it develop?

  • Inherited metabolic disorder w/ SNPs disabling enzymes involved in interconversion/breakdown of sulphur-AAs, methione and cysteine
  • Homocysteine builds up in the bloodstream, damaging the arterial endothelial lining --> accelerated atherosclerosis and clotting events

5

Risks for individuals homozygous for homocysteinuria? Heterozygotes?

  • Homo = begin having heart attacks and strokes in their teens and twenties
  • Hetero = at increased risk for MI in mid-life (40-60 years old)

6

What % of sudden cardiac deaths in young athletes does genetic CV disease account for?

40%

7

What is the most common cause of sudden cardiac death in young athletes during exercise?

Hypertrophic cardiomyopathy

8

What is hypertrophic cardiomyopathy?

Hypertrophy that occurs in the absence of other obvious circulatory or valvular deficiencies such as hypertension and aortic stenosis

9

In what pattern is hypertrophic cardiomyopathy inherited?

Inherited in an autosomal dominant pattern

10

What fraction of the US population has hypertrophic cardiomyopathy?

1/500 peeps

11

What happens to the integrity of cardiac tissue as a consequence of HCM? Significance?

  • Increased fibrosis (interweaving of muscle and connective tissue)
  • Make cardiac muscle stiff, low compliance, low stretch --> impairs diastolic filling

12

How does hypertrophy cause an energy imbalance? What can this ultimately lead to?

  • Relative decrease in number of capillaries and increase in distance b/t capillaries
  • Increased ratio of myofibrils to mitochondria
  • Leads to ischemia b/c energy cost goes up, but O2 not increasing proportionally

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13

What characterizes diastolic dysfunction? Symptoms?

  • Impaired filling due to abnormal relaxation and increased chamber stiffness
  • Increased LA and LV end diastolic pressure
  • Sx: pulmonary congestion, exertional dyspnea, syncope

14

What is asymmetric septal hypertrophy?

Septum is growing into groove that should be LV outflow into aorta --> blood gets backed up 

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15

What is the pathology of hypertropic cardiomyopathy?

  • Cardiac myocytes are outgrowing blood supply
  • Energy cost is sky-rocketing due to both muscle mass & outflow obstruction
  • Stiff, fibrotic muscle impairs cardiac filling

16

What is the most common first symptom of hypertrophic cardiomyopathy?

Sudden death

17

Describe the cycle of pathologic hypertrophy of HCM.

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