CV 8 Flashcards
T/F: many normal individuals have a sinus rhythm < 60 beats/min
true
Who has faster heartbeats, children or adults?
children
classify sinus tachycardia
impulse formation
classify sinus bradycardia
impulse formation
classify sick sinus syndrome
abnormal automaticity (bradyarrhythmias)
classify bradyarrhythmias
abnormal automacity
classify tachyarrhythmias
abnormal automaticity
ectopic pacemaker foci: an ectopic focus depolarizes – and captures the ventricles producing a premature contraction
much earlier than SA node
ectopic pacemaker foci can be –
atrial or junctional
reentry: after a normal cardiac cycle, during the – a group of fibers discharge and re-excite areas that had just depolarized
refractory period
reentry can be –
PSVT (paroxysmal supravenricular tachycardia), atrial flutter, atrial fibrillation
PVC, ventricular tachycardia, Torsade de Pointe, ventricular fibrillation
ventricular complexes
< 60 beats/min
sinus bradycardia
when is sinus bradycardia normal?
physically active adults and during sleep
if sinus bradycardia is associated with CHF or low CO, it requires –
temporary or permanent electrical pacing
> 100 beats/min
sinus tachycardia
when is sinus tachycardia normal?
children, physiological stress, pain, anxiety
two types of sick sinus syndrome
persistent spontaneous bradycardia or bradycardia-tachycardia syndrome
sick sinus syndrome: bradycardia-tachycardia syndrome usually indicates heart disease in the elderly and requires –
pacemaker insertion to prevent bradycardia and drugs to control tachycardia
medical treatment of abnormal impulse formation
Ca2+ channel blockers and beta blockers
premature complexes (abnormal automaticity) are usually –
benign
narrow QRS with no apparent P
PSVT
rate for PSVT
130-220 beats/min (regular)
PSVT onset is sudden and stops abruptly hence paroxysmal and they can occur –
without heart disease
