EKG - Textbook Flashcards
what may cause sinus bradycardia
beta blockers
decreased automaticity of SA node
increased vagal stimulation
what is the most common form of sinus arrhythmia? if not this, what can cause the other form?
related to normal respiratory cycle
- rate increasing with inspiration/decreasing with expiration
infection, medication administration, and fever
explain what a sinus block is
SA node fails to initiate an impulse - typically only for one cycle
sinus pause includes
PR interval is 0.12-0.20
QRS complexes are identical and last 0.06-0.10 seconds
RR interval is regular with occasional pauses
HR between 60-100
what can cause sinus pause
sudden increase in PSNS activity
sick sinus syndrome
infection
rheumatic disease
severe ischemia or infarction of SA node
if a sinus pause is prolonged or occurs frequently what happens to CO
compromised - pt may complain of dizziness / syncope episodes
what are the characteristics of wandering atrial pacemakers
P waves present, but may look different
- P before QRS
PR intervals vary, but normal width
RR intervals vary
– <100 bpm
what populations are wandering atrial pacemaker arrhythmias often seen in
young/elderly
– ischemia or injury to SA node
– CHF
– increased vagal firing
what is a premature atrial complex defined as
ectopic focus in either atrium that initiates an impulse before the next impulse is initiated by the SA Node
defining feature of atrial tachycardia
three or more premature atrial complexes in a row
explain EKG findings of premature atrial complexes
the normal complexes look normal, but P wave of the early beats is noticeably different
P wave of the early beat may be buried within the T wave
what EKG findings are associated with atrial tachycardia
P waves may not be present before every QRS
QRS complexes are normal
RR intervals vary
HR is rapid, beating greater than 100 (maybe up to 200)
what may cause an atrial tachycardia
pulmonary disease with hypoxemia
pulmonary HTN
altered pH
– often found in those with COPD
define paroxysmal atrial tachycardia
atrial tachycardia or repetitive firing from an atrial focus
– normal sinus rhythm followed by an episodic burst of atrial tachycardia that then returns to normal
EKG finding associated with paroxysmal atrial tachycardia
rapid HR, often >160 bpm
P waves may be present or merged with T
if paryoxysmal atrial tachycardia remains for >24 hrs, what is it considered?
sustained atrial tachycardia
what can atrial flutter be caused by
rheumatic heart disease
mitral valve disease
coronary artery disease or infarction
renal failure
hypoxemia
pericarditis
what can cause atrial fibrillation
advanced age
CHF
ischemia/infarction
cardiomyopathy
rheumatic heart disease
renal failure
what is lost during atrial fibrillation
atrial kick
- up to 30% of CO is lost
explain the severity of A-Fib in patients with ventricular response greater/less than 100 bpm at rest
if less than, atrial fib is relatively benign
if more than, can begin to show signs of decomposition and need constant monitoring
explain the commonality of A-Fib
very common in older population
- will take anticoagulants
explain secondary issues related to a-fib and what can be done to prevent these issues
potential for developing mural thrombi
– due to coagulation of blood in fibrillating atria
what is a classic sign of a-fib that can be seen during intervention
very irregularly irregular pulse
define premature junctional/nodal complexes
premature impulses that arise from AV node or junctional tissues
EKG findings associated with premature junctional/nodal complexes
inverted, absent, retrograde P waves
what pathological conditions can cause premature junctional/nodal complexes
cardiac / mitral valve disease
what is junctional rhythm
when the AV junction takes over as pacemaker of the heart
EKG findings associated with junctional rhythm
absence of P waves before QRS
- may be retrograde
ventricular rate between 40-60 bpm
what can cause junctional rhythm
failure of SA Node
– sinus node disease, increased vagal tone, infarction or severe ischemia to conduction system
nodal / junctional tachycardia definition
AV junctional tissue acting as pacemaker but the rate of discharge becomes acccelerated
characteristics of nodal tachycardia in EKG
P waves absent, but retrograde P wave may be present
HR typically < 100 bpm
common causes of junctional tachycardia include
coronary artery disease
infarction
postcardiac surgery
digoxin toxicity
myocarditis
what is the sequence of events that leads to a first degree AV block
impulses initiated at SA node is delayed
- can be initiated in the AV node itself
causes AV conduction time to be prolonged
lengthening of PR interval only
what causes first degree AV blocks
coronary artery disease
rheumatic heart disease
infraction
reactions to medications
what are the names of type one, 2nd degree AV block
Wenckebach or Mobitz 1
define a second degree AV block, type 1
transient disturbance that occurs high in the AV junction
disrupts conduction of some of the impulses through the AV node
EKG characteristics of weckenbach / mobitz 1 AV block
P waves precede QRS
– progressive lengthening of PR interval until one P wave stands alone without QRS
RR interval is irregular (regularly irregular)
causes of weckenbach AV block
right CAD / infarction
digoxin toxicity
excessive beta adrenergic blockade
define 2nd degree AV block, type 2
nonconduction of an impulse to the ventricles without a change in PR interval
- site of blockage is typically below bundle of His and can be bilateral
EKG findings of mobitz 2 AV block
P wave to QRS complex ratio of 2-4:1
RR interval variance
HR is typically below 100 and can be below 60
causes of second degree, type 2 AV block
myocardial infarction - especially if LAD is involved
ischemia/infarction of AV node
digoxin toxicity
define third degree AV block
impulses conducted above the ventricle are not conducted to the ventricle
characteristics of complete heart block (3rd degree AV block) on EKG
P wave present
— no relation to QRS complex
QRS complexes and RR intervals are regular
HR may range from 30-50 bpm
causes of 3rd degree AV block
myocardial infarction
digoxin toxicity
degeneration of conduction system
how do PVCs look on an EKG
- yes the term, but describe it
wide and bizarre
- without a P wave
- followed by complete compensatory pause
define bigeminy PVCs
every other beat is a PVC
define trigeminy PVCs
every 3rd beat is a PVC
define multifocal PVCs
if more than one PVC is present and no two appear similar in configuration
define unifocal PVCs
PVC appear identical in configuration
explain paired / triplet PVCs
– any indication?
paired = two in a row together
triplet = three in a row together, VTACH
– call code bro
what is an interpolated PVC
one that falls between two normal sinus beats that are separated by a normal RR interval
PVCs are often common in the presence of
ischemia
cardiac disease
overdistension of ventricle - CHF / cardiomyopathy
acute infarction
irritation of myocardium or its vessels
chronic lung disease
what does a PVC feel like
pause or skip in regular rhythm that usually is followed by a stronger beat
why may PVCs be felt
decreased preload with PVC beat
followed by long compensatory pause
allow for increased filling time of ventricle
an increased preload for the beat following the PVC and increased SV
PVCs are considered to be life threatening if
paired together
multifocal
>6 a min
land directly on T wave
triplets or more
what is the HR associated with V-Tach
100-250
causes of V-tach
ischemia
acute infarction
coronary artery disease
HTN heart disease
reaction to medication
what is the EKG reading that looks like a sound wave / sound cloud logo
tosade de pointes
HR = 240-250
what is ventricular fibrillation
erratic quivering of ventricular muscle
- no cardiac output will occur
