Cardiovascular system/ECG Flashcards
where are the ECG leads placed on the patient?
white: right forelimb
black: left forelimb
red: left hindlimb
green: right hindlimb
what does the P wave represent?
depolarization of the atria
what does an enlarged P wave mean?
atrial enlargement
what does the P-R interval represent?
atrial depolarization and conduction through the AV node
what does P-R interval prolongation mean?
1st degree AV block
what does the QRS complex represent?
depolarization of ventricles
what does a wider QRS complex mean?
abnormality
could be caused by hyperkalemia or ventricular hypertrophy
what does the T wave represent?
ventricular repolarization
what is the Q-T interval?
begins at the start of the QRS complex and finishes at the end of the T-wave
what does the Q-T interval represent?
time for ventricles to depolarize and then repolarize
sinus arrhythmia
normal HR with an increase on inspiration and a decrease on expiration
atrial fibrillation
lack of P waves, can have rates up to 600 bpm
represents severe heart disease with atrial enlargment
ventricular tachycardia
life-threatening, wide/bizarre QRS complexes without P waves and with tachycardia (HR > 180bpm)
shockable rhythm
ventricular premature contractions (VPCs)
premature P waves, many possible causes (electrolyte abnormalities, systemic disease, cardiac disease)
what do atria contain?
auricles
blind pouches (“ear flaps”)
which side is the tricuspid valve on?
right side
which side is the mitral valve on?
left side