Exam 1: Cardiac Electrophysiology Paper Questions Flashcards
what is a cardiac pacemaker
generates an action potential to initiate a heart beat
hypoxia
lack of oxygen in the tissue
ischemia
lack of blood supply
how could ischemia effect functioning of the heart
if there is an insufficient blood supply, there will not be enough blood for the heart to pump and it will over work to pump blood
risk for a heat attack
arrhythmia
irregular heart rate
2 predominant pacemakers
SA
AV
where is the SA node located
in the groove between the RA and the superior vena cava
what is the difference between pacemaker cells and force-producing myocytes
pacemaker cells: produce action potential to generate a heart beat
force: regulate the force that is needed to pump the blood to the body
what is a resting membrane potential
static membrane potential ratio of ions inside and outside the cell when nothing is moving
what is the cardiac pacemaker potential
depolarization
bradycardia
decreased heart rate, lower than normal
tachycardia
increased heart rate, higher than normal
what is a muscarinic receptor
acetylcholine receptors (GPCR)
what might an inward K+ current alone do to a cell’s membrane potential?
dec in cAMP , dec in Ca channels opening, dec slope of prepotential
hyperpolarize
adrenoreceptor
receptive to epinephrine and norepinephrine
systolic
top number, force your heart exerts each time it beats
diastolic
bottom number
pressure in arteries when heart rests between beats
pericardium
membrane surrounding heart
protects heart, holds it in place
first degree heart block
what does it look like on ECG
electrical impulse still reaches ventricles, but slower than normal through AV node
may look like longer period f time between the P wave and QRS wave
second degree heart block
what does it look like on ECG
signals between atria and ventricles delay or fail to conduct
PR interval longer or normal but stays constant whichever it is
ventricular septal defect
how does it effect cardiac output
hole in heart abnormal connection between ventricles
blood gets pumped to the lungs - fluid in lungs heart working harder to pump
cardiogenic shock
heart suddenly cannot pump enough blood to meet body/s needs
