20) **** Sudden Cardiac Death **** Flashcards
What are possible deleterious effects of exercise on the heart?
Prolonged endurance exercise:
* Cardiac fatigue characterized by decreased ? and ?
* Typically recover within ?
High levels of exercise (e.g. CrossFit, ultramarathon) can transiently increase the risk of acute cardiovascular events.
Prolonged endurance exercise:
* Cardiac fatigue characterized by decreased CO and EF
* Typically recover within 2 days
FYI: “Acute CV events:
* Sudden cardiac death
* Diminish cardiac function
* Atrial fibrillation
* Arrhythmias
* Pathological remodeling of the heart and vasculature
Sudden Cardiac Death: define and describe
Sudden Cardiac Death
- rare but severe event in young athletes
- Caused by undiagnosed CV disease in high school athletes
Swift and unexpected cessation of all heart activity; breathing and BF stop
- Unconsciousness and death w/in seconds
Documented in most sports
* Most common during physically intense sports (e.g. basketball, soccer, football)
Sex and ethnicity contribute to sudden death risk
* Male, Black greater risk
FYI: 2% of male Italian (ewhite) athletes > = to 13 mm; 18% male Black athletes > = 13 mm; elite athletes have wall thickness consistent with HCM (lower limit cut off is 13 mm)
Most cases of sudden cardiac death in young athletes can be attributed to:
Most cases of sudden cardiac death in young athletes can be attributed to:
- Underlying identifiable CV conditions
* congenital abnormalities of heart or blood vessels
* Hypertrophic cardiomyopathy (HCM)
HCM: (mutation in sarcomeres)
* Most common underlying cause
* Increase susceptibility to SCD (avoid comptetive/high-intensity exercise)
Hypertrophic Cardiomyopathy
HCM: characterized by ?
Absence of ?
Irregular ?
HCM is characterized by:
- gross thickening of the LV walls (maximal wall thickness 13 mm, typically 15 - 52 mm) in the
- absence of LV dilatation
* Irregular heart rhythm (ventricular fibrillation) results in impaired blood being pumped (Myocytes not correlating contraction)
Sarcomere mutation
How might disorders of electrical activity/conduction lead to Sudden Cardiac Death?
Disorders of the electrical activity and conduction
* Abnormal coronary arteries
* Coronary arteries originate from an abnormal location or have an acute twisting angle that slows the blood flow
-
Commotio cordis
- Cardiac arrest → a malfunction of the heart’s electrical system causes
the heart to stop beating properly
↳ Blunt impact over heart at particular time in ECG cycle causing Cardiac arrest
- Cardiac arrest → a malfunction of the heart’s electrical system causes
Commotio Cordis:
What is it? How is it related to SCD?
Commotio cordis: Lethal disruption of heart rhythm that occurs as a result of a blow to the area directly over the heart
* If impact occurs during vulnerable pt in ECG cycle can cause ventricular fibrillation
↳VF: lethal abnormal heart rhythm
* Most common in young men playing sports with hard balls
- Cardiac arrest → a malfunction of the heart’s electrical system causes the heart to stop beating properly
- halts BF to brain/vital organs
Abnormal Coronary arteries:
How does this relate to sudden cardiac death?
-
Abnormal coronary arteries
* Coronary arteries originate from an abnormal location or have an acute twisting angle that slows the blood flow
* disrupts bf to heart (less oxygen available)
Cardiac Arrest
Define, relate to Commotio cordis and Sudden Cardiac death
Heart conditions linked to cardiac arrest?
Cardiac arrest → a malfunction of the heart’s electrical system causes the heart to stop beating properly
* halts BF to brain/vital organs
Heart issues linked:
- Ventricular tachycardia
- Ventricular fibrillation (lethal abnormal rhythm)
- Bradycardia
Commotio Cordis:
- If blunt impact occurs during sensitive time in ECG cycle may cause ventricular Fibrillation
Commotio cordis: Lethal disruption of heart rhythm that occurs as a result of a blow to the area directly over the heart
* If impact occurs during vulnerable pt in ECG cycle can cause ventricular fibrillation
↳VF: lethal abnormal heart rhythm
Sudden Cardiac Death in athletes over 30 is most-likely caused by:
Heart attack (blockage of coronary arteries) caused by plaque formation
- arteries occluded with lipid plaque (atherosclerotic coronary heart disease)
Factors increasing risk for heart attack:
- Smoking
- Hypertension
- Diabetes
- Elevated/abnormal lipids
- Family hx of heart disease
Heart attack = Blockage
Cardiac Arrest= malfunction in electrical system
