vagal stimulation (valsalva, carotid pressure), inflammation of SA node (rheu fever, myocarditis), factors released after MI (glutamic acid, aspartic acid, hyperkalemia)
Name 3 causative factors of bradycardia
acute inferior wall infarct, ischemia, low pO2, high pCO2, low pH, high BP, Sick Sinus Syndrome (alternates w tachy), digitalis toxicity
What are some important medical conditions that cause bradycardia?
Sinus Bradycardia, Non Conducting Atrial Bigeminy, SA Block, AV block
What 4 heart conditions can cause bradycardia?
normal P, QRS and T. There is variance in the P to P (or R to R) cycle and a rate below 60.
What are the EKG findings for sinus bradycardia?
abnormal P wave due to ectopic atrial focus. QRS complex dropped when atrial signal hits the AV node during its refractory period. in bigeminy, this is every other beat.
What are the EKG findings for non-conducting atrial bigeminy?
pause in heart beats. escape beats seen are narrow, indicating they are junctional.
What are the EKG findings for sinoatrial node block?
sinus rhythm but with 2 atrial beats to 1 ventricular
What are the EKG findings of atrioventricular node block?
sawtooth P waves with rate of 250 to 250 beats per minute. QRS/ventricular rate is slow.
What are the EKG findings of atrial flutter with bradycardia?
even faster than atrial flutter, rapid p waves showing atrial quivering. Atrial beats up to 350 or 400. QRS/ventricular rate may be normal.
What are the EKG findings of atrial fibrillation with bradycardia?
bradycardia and tachycardia in addition to long pauses
What are the EKG findings of sick sinus syndrome?
if hemodynamically unstable, treat with atropine. can also treat w epinephrine, pacemaker.
When should bradycardia be treated? What drug is used?
valvular diseases esp mitral, coronary artery disease, elev BP
What heart conditions can cause tachycardia?
100 to 250 beats per minute, short QRS (.10 sec or less), P wave may be absent, S-ST depression
What are the EKG findings of supraventricular tachycardia?
P wave replaced by F waves which are rapid fire irregular quiverings of the atria, normal QRS complex that is irregular in time. Much more chaotic than flutter.
What are the EKG features of atrial fibrillations with tachycardia?
sawtooth P waves, normal QRS, P:QRS ratio can be 2:1 all the way up to 8:1 and typically 2:1 or 4:1. Much more regular, sharp waves than fibrillation.
What are the EKG findings of atrial flutter with tachycardia?
3 or more different P waves, PR interval varies, irregular rhythm
What are the EKG findings of Multifocal Atrial Tachycardia?