THE RHYTHM OF THE HEART Flashcards
what does the PR interval represent?
slow conduction through the AV node
what does the QRS interval represent?
slow conduction through the ventricular myocardium
what does the QT interval represent?
repolaristion of the ventricular myocardium
what is the normal PR interval?
<200ms
what is the normal QRS interval?
<110ms
whats a normal QT interval?
<460ms
what is normal sinus rhythm?
regular with a rate of 60-100
what is sinus bradycardia?
a sinus rhythm with a resting heart rate of 60 beats per minute or less
what is asystole?
when the heart ceases to beat
what do you see on an ECG of first degree heart block?
regular QRS complexes but the PR interval is prolonged
what do you see on an ECG of second degree heart block type 1?
QRS complexes are not regular
P waves get further away from QRS complex as ventricular rate is slower than atrial rate
what do you see on an ECG of second degree heart block type 2?
regular QRS complexes
2 P waves for every QRS
what do you see on an ECG of third degree heart block?
regular QRS complexes but these are wide
p waves are totally unrelated to QRS compelxes
what is sinus arrest?
cessation of sinus node activity for a short period.
what would you see on an ECG in left bundle branch block?
WiLLiaM
Big V in V1 and M in V6
what would you see on an ECG in right bundle branch block?
MaRRoW
M in V1 and W in V6
what is the treatment for supraventricular tachycardia?
adenosine
what does atrial flutter look like on an ECG?
multiple p waves for every QRS
narrow complex tachycardia
what does atrial fibrillation look like on an ECG?
chaotic aortic electrical activity
irregularly irregular QRS complexes
what would you see on an ECG of Torsades de Pointes?
ventricular tachycardia that looks like twisting points or peaks
how do we treat atrial fibrillation?
rhythm control
ventricular rate control
anti-thrombotics
what does the CHADS2VASC score tell us?
who would benefit the most from anticoagulation - estimates risk of stroke
what are electrical shocks synced to?
QRS complexes
how do you treat sinus tachycardia?
Investigate and remove cause. Think about hyperthyroidism, anxiety, heart failure, hypovolemia, septicemia, haemorrhaging etc