Arrythmia Flashcards
blood flow
atria–> ventricles–>body
cardiac conduction system
A system that coordinates electrical impulses driving blood flow through the heart.
Sinoatrial node (SA node)
dominant pacemaker for the heart
SA node function
initiates an electrical impulse and causes contraction of the atrial myocardium.
Atrioventricular node (AV node)
gatekeeper to the ventricles
AV node function
- The impulse reaches the AV node, and the AV node generates a slow action potential.
- sends an electrical impulse, activating the Bundle of His.
Bundle of His
Impulse is conducted from the Bundle of His to the Right & Left Bundle Branch.
post bundle branch (right/left) goes to
Impulse travels through the Purkinje Fibers.
from purkinje fibers
Impulse travels through the fiber network, resulting in ventricular contraction, and ejection of blood to the body.
arrythmia
Problems with the cardiac conduction system cause the heart to have an abnormal rhythm
Location
Ventricular: ventricular rhythm
Supraventricular (above ventricles): atrial rhythm
Rhythm
Fibrillation: irregular heartbeat
Bradycardia: slow heartbeat
Tachycardia: fast heartbeat
atrial fibrilation
Random impulses cause the atria to fibrillate (twitch) rapidly and randomly.
*increased risk of stroke
most common type of arrythmia
atrial fibrilation
cardiac causes
high left atrial pressures
cardiac ischemia and fibrosis
high left atrial pressures caused by
Mitral stenosis
Congestive heart failure
Cardiac ischemia and fibrosis caused by
coronary artery disease
heart attack
Three non-cardiac causes
Hypoxia
Catecholamines
Electrolyte imbalance
hypoxia caused by
pneumonia
copd
pulmonary embolism
catecholamines cause increase in SNS caused by
infection
post-surgery
electrolyte imbalance
low Mg+ and K+
pulmonary veins
carry oxygenated blood from lungs to the atria
Atrial cells
around pulmonary veins are sensitive to hypoxia
ectopy
electrical impulse coming from somewhere else other than SA node
*from atrial cells
pulmonary embolism
Blood clot gets stuck in an artery in the lung
catecholamines
a group of hormones and neurotransmitters that are released by the body in response to stress
EP and NE to beta-1 receptors
most deadly arrythmia
ventricular fibrillation
ventricular fibrillation
Ventricles quiver or twitch instead of expanding and squeezing
result of vf
No effective ventricular contraction -> no cardiac output –> no oxygen to the body –> death
causes of ventricular fibrillation
medicinal toxicity
electrical shock
medicinal toxicity
Toxic levels interfere with electrical activity of the heart
long term therapy or overdose
ex: digoxin
