Dysrhythmias: Flashcards
Also called arrhythmias
Abnormality of the cardiac rhythm of impulse generation or conduction
Cardiac Dysrhythmias
Dysrhythmias are significant for two reasons:
Indicate an underlying pathophysiologic disorder
May impair normal CO
ECG recordings allow measurement of waveform _____, _____, and ________
amplitude, duration, HR
Impulse rate between ____and ____beats/minute for normal sinus rhythm
60 and 100
Normal sinus rhythm has ______ rhythm
normal
Normal Sinus Rhythm
Starts in the ______node and follows the ____ pathway
SA; normal
P wave precedes every QRS complex
Normal Sinus Rhythm
PR, QRS, QT intervals are of normal duration
Normal Sinus Rhythm
Sinus Tachycardia manifested by abnormally fast heart rate of greater than _____beats/minute
100
Sinus Tachycardia is usually a compensatory response to increased demand for ____ or reduced _______
CO; SV
Sinus Tachycardia usually occurs from _______ activation
SNS
Treatment aimed at correcting underlying cause; sympatholytic agents or calcium-channel blocking agents may be indicated
Sinus Tachycardia
In Sinus Bradycardia, HR may be lower than _____beats/min
60
Sinus Bradycardia usually from ______ activation
parasympathetic
If slow HR precipitates low CO, treatment includes sympathomimetic or parasympatholytic drugs
Sinus Bradycardia
Associated with fluctuations in autonomic influences and respiratory dynamics
Sinus Arrhythmia
Sinus Arrhythmia may be pronounced in _____
children
Sinus Arrhythmia is _______ and needs _____ treatment
normal; no
Must be differentiated from sick sinus syndrome
May need a pacemaker
Sinus Arrhythmia
In sinus arrest, absence of impulse initiation in the heart results in electrical _______
asystole
_____ rhythm: a slower pacemaker will generally begin to fire after several seconds of sinus arrest
Pacemaker may be required in ________
Escape; Sinus Arrest
Initiation of cardiac impulse at a site other than the SA node can occur with (2)_________
SA node failure: allows a slower pacemaker to take over (escape rhythm)
Enhanced excitability, triggered activity or reentrant circuits may cause a premature depolarization and override the SA node
Escape Rhythms originate in the _____ nodal region or ventricular _____ fibers
AV; Purkinje
Junctional escape rhythm originates in the_______ (rate of ________beats/minute with normal QRS)
AV node; 40-60
Ventricular escape rhythm originates in _______(rate of _______beats/minute with abnormally wide QRS)
Purkinje fibers; 15-40
The _______ wave is abnormal/absent in escape rhythms
P
Premature atrial complexes (PACs) associated with ______
Atrial Dysrhythmias
PAC’s Originate in the _____ but not the SA node
atria
PACs occur earlier than ______, preceded by a ____ wave, and have a normal______ complex configuration
normal; P; QRS
Frequent _____ may indicate underlying pathophysiologic process and be precursors to more serious dysrhythmias
PACs
burst of atrial complexes resembling several PACs in a row
Paroxysmal focal atrial tachycardia
______ is typically manifested by a rapid atrial rate of 240-350 beats/minute with sawtooth pattern
flutter
Sawtooth pattern associated with
flutter
Type 1 flutter is ____ to ____ beats/min
240 to 350 beats/min
Type 2 flutter is over ______ beats/min
350 beats/min
_______is a completely disorganized and irregular atrial rhythm accompanied by an irregular _____ rhythm
Atrial Fibrillation; ventricular
Fibrillation can cause _____
thrombi
Ventricular Dysrhythmias result in ___________
Premature ventricular complexes (PVCs)
Premature ventricular complexes (PVCs) arise from the ventricular________
myocardium
Do not activate the atria or depolarize the sinus node
Ventricular Dysrhythmias
Premature ventricular complexes (PVCs) have a bizarre ______
QRS
A compensatory pause is normal in ______
Premature ventricular complexes (PVCs)
Bigeminy or trigeminy common in ______
Premature ventricular complexes (PVCs)
Every other beat
Bigeminy
Every third beat
Trigeminy
With high frequency, CO may be compromised in ________-
Premature ventricular complexes (PVCs)
Ventricular tachycardia is when there are 3 or more consecutive ventricular complexes at a rate greater than _____ beats/min
100
ECG depicts a series of large, wide, undulating waves
Ventricular Tachycardia
In _______ Tachycardia, P waves are not associated with the _______
Ventricular; QRS complexes
May be fatal if not rapidly managed
Ventricular Tachycardia
Antiarrhythmia drugs
CPR
Electrical cardioversion
may have to be used
Ventricular Tachycardia
Rapid, uncoordinated cardiac rhythm resulting in ventricular quivering and lack of effective contraction
Ventricular Fibrillation
ECG is rapid and erratic, with no identifiable QRS complexes
Ventricular Fibrillation
Results in death if not reversed within minutes
Ventricular Fibrillation
Defibrillation
CPR
Antiarrhythmia drugs
may be used
Ventricular Fibrillation
Include delays, blocks, and abnormal pathways
Conduction Pathway Disturbances
Conduction blocks and delays are associated with cardiac _____ and_______
ischemia and infarction
When there are conduction pathway disturbances, there are abnormal pathways that are usually ______
congenital
When there is a problem between the sinus impulse and ventricular response
Atrioventricular block
When there is an atrioventricular block, there is a defect in the _______ node, bundle of ______, or bundle _____
AV; His; branches
Is slowed or completely blocked
Atrioventricular block
Briefly explain the 3 types of atrioventricular blocks
First-degree block (usually no treatment required)
Second-degree block (types I and II)
Third-degree block (complete)
Characterized by progressive prolongation of the PR interval until one P wave is not conducted;
Type 1 (Wenckebach, Mobitz type I): Atrioventricular Second Degree Block
associated with AV nodal ischemia
Type 1 Second Degree Block
identified by a rhythm showing consistent PR interval with some nonconducted P waves
Type 2 Second Degree Block
More serious because it has a tendency to progress to complete AV (third-degree) block
Type 2 Second Degree Block
Complete heart block
Third Degree Heart Block
diagnosed when there is no apparent association between atrial and ventricular conduction; is serious, as it can lead to slow ventricular rhythm and poor CO
Third Degree Heart Block
At least 5 ways to diagnose a complete third degree block?
EKG Holter monitor Loop recorder Stress testing EPS
Treatment for __________ includes Antiarrhythmic drugs used (may be proarrhythmic), measures to improve CO (pacemakers and drugs to increase contractility)
and ablation procedures
Complete third degree block
