Final Flashcards
(147 cards)
Dysrhythmias are caused by
Hypoxia, Ishemia, Sypathetic stimulation, drugs, Electrolyte imbalance, rate, stretch
1 reason adult cardiac arrest
underlyning heart problem. Kids- resp failure/ sepsis
Heart blood path
Superior Vena Cava, Inlet of the superior vena cava, right atrium, inlet of the inferior vena cava, Coronary sinus, Inferior vena cava, Coronary sinus, Inferior vena cava, Tricuspid valve, Right Ventricle, Interatrial septum, Interventricular Septum, Left atrium, Mitral valve, Left ventricle
Heart conduction
- SA Node
- AV node
- Bundle of His
- Bundle branches
- Purkinje fibers
AV node
- Conduction is delayed at the AV node to allow the ventricles to fill with blood
- Also limits the rate of ventricular stimulation during excessive atrial firings
Purkinje fibers
Finger like branches that penetrate the cardiac muscle
Properties of cardiac muscle
- Contractile muscle fibers
2. Auto-rhythmic cells
Contractile muscle fibers
Responsible for pumping activity of the heart, Make up bulk of musculature of myocardium
AutoRhythmic cells
Make up 1% of cardiac cells, most found in SA node, cause myocardial fibers to contract, stimulate and create action potential
Four properties of cardiac muscle
- Automaticity
- Excitability
- Conductivity
- Contractility
Excitability
Response to stimulation or irritation, Ischemia and hypoxia cause myocardial cells to become more excitable (irritated)
Conductivity
Unique ability of the heart cells to transmit electrical current from cell to cell throughout the entire conductive system
Contractility
Is the ability of cardiac muscle fibers to shorten and contract in response to an electrical stimulus
Electrolytes responsible for electricity
- Potassium (K+)
- Sodium (Na+)
- Calcium (Ca2+
Nervous system role
plays important role in the rate of impulse formation, conduction, and contraction strength
Sympathetic stimulation role
- Cause increase in HR
- Increase in AV conduction
- Increase in heart contractility
- increase in excitability
Parasympathetic stimulation role
- Decrease in HR
- Decrease in AV conduction
- Decrease in contractility
- Decrease in excitability
5 leads
White in the clouds over grass (green), with crap in the middle, then smoke (black) over fire (red)
Ectopic beat
any beat outside of SA node
foci/focus
where the ectopic beat originates
dysrhythmia
abnormal cardiac conduction, also termed arrhythmia
Escape Beat
a heart beat that originates outside the sinus node after a period of SA node inactivity
Myocardial Ischemia
partial or complete obstruction of blood flow, reducing oxygen supply to the heart
Angina
chest pain associated with reduced coronary blood flow
Stable-persistent, with excertion. Unstable-unexpected, at rest, more intense and longer