MORE DETAILED ARRYHTHMIAS Flashcards
What are the different causes of Arrhythmias?
1) Abnormal rhythmicity of the pacemaker2) Shift of pacemaker activity3) Conduction Blocks4) Abnormal pathways of impulse transmission5) Spontaneous generation of abnormal impulses
7 Questions that must be asked to determine whether or not arrythmias are present
1) What is the heart rate?2) What is the rhythm?3) Are P waves present?4) Is there a P wave for every QRS complex?5) Is there a QRS for every P?6) Are the P’s and QRS’s consistantly related?7) Do all the P’s and QRS’s look alike?
3 Different Types of Normal Cardiac Rhythms
1) Normal Sinus Rhythm2) Sinus Arrhythmia3) Wandering Atrial PacemakerLook at Lead 2 (60 Degrees)
What Arrhythmias produce different speeds of heart rate?
Sinus BrachycardiaSinus Tachycardia
Sinus arrhythmia
Impulses originate at the SA node at a varying rate = fires FASTER and then SLOWERAll complexes are normal butRHYTHMICALLY IRREGULARLongest PP or RR interval exceeds shortest by 0.16 sec or moreCAUSED BY HEAVY RESPIRATION
Wandering atrial pacemaker
Impulses originate from varying points in atria between SA and AV nodesP Wave changes configuration as signal begins at different areasQRS is NORMAL
Sinus Brachycardia
Impulses originate at SA Node at a SLOW rateNormal sinus rhythm w/ HR Parasympathetic Causes - increased vagal tone, beta-blockers, propanolol, digitalis
Sinus Tachycardia
Impulses originate at the SA Node at a RAPID rateNormal sinus rhythm w/ HR > 160 bpmSympathetic Causes = exercise, fever, hyperthyroidism, shock, etc.
Sinus arrest
Abnormal ArrhythmiaSA node stops firing (beats with a pause = NORMAL PACING WITH A BASELINE PAUSEEscape Beat = first large upward deflection after pause
A dog faints due to loss of blood to the brain. What would be the compensatory effect to help blood get to brain since blood is not fighting gravity?
Sinus Arrest
Abnormal Rythms that result from Impulse Conduction Blocks
1) 1st Degree Atrioventricular Block2) 2nd Degree AV Block3) 3rd Degree AV BlockCauses of AV Blocks include: ischemia of AV node, compression or inflammation of AV node/Bundle, and increased stimulation of heart by vagus nerve
First degree AV block
Abnormal rhythm that results from Impulse Conduction Blocks (potential wide P Wave)Fixed but PROLONGED PR INTERVALPartial block above OR below AV NodePotential Causes = Mitral insufficiency, Digoxin toxicityNot dangerous but will progress
Second degree AV block
Abnormal rhythm that results from Impulse Conduction Blocks2 Different Types:1) Mobitz Type I - PROGRESSIVE LENGTHENINGof PR interval before dropped beatCoduction starts off normal but gets progressively work with accompanied lengthening B4 dropped QRS= AV node recovers and PR Interval is normal againWenckbach PhenomenomPotential Causes = Digoxin Toxicity2) Mobitz Type II - SUDDENQRS dropped W/OUT prior PR IntervallengtheningAV Block at level of Bundle of His ORat bilateral bundle branches OR at trifascicularAtrial rate is greater than the ventricular rate (MOREP waves due to QRS drop)Non-WenkebachCan have MULTIPLEP waves without a QRS Complex
Third degree AV block
Abnormal rhythm that results from Impulse Conduction BlocksCOMPLETE AV BLOCKNO RELATIONSHIP BETWEEN P WAVES AND QRS COMPLEXES2 different scenarios - SA Node conducts impulse in atria (P waves)BUT:1) Block ABOVE AV Node= AV Node conducts impulses to ventricles2) Block BELOW AV Node = Purkinje Fibers conduct impulse to ventriclesAtria and Ventricles fire a DFFERENT ratesQRS rate is SLOWERthan the P rate bc AV node and Purkinje fibers fire at slower rates than the SA NodePacemake placed in ventricles to allow P waveand QRS complexe rates to match up
Supraventricular (ABOVE) and Ventricular Abnormalities
Different Types:1) Premature Contraction:2) Tachycardia3) Fibrillations
