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19 Cards in this Set
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- Back
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Sinus bradycardia
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Rate: <60 bpm
Rhythm: Regular Pacemaker site: SA node P wave: Normal morphology PR interval: Normal (0.12-0.20 sec) QRS complex: Normal (0.04-0.12 sec) |
Slowing of the SA node resultant of
Increased parasympathetic NS Intrinsic disease Drugs Digitalis Propranolol Quinidine |
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Sinus tachycardia
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Rate: >100 bpm
Rhythm: Regular Pacemaker site: SA node P wave: Normal morphology PR interval: Normal (0.12-0.20 sec) QRS complex: Normal (0.04-0.12 sec) |
At greater than 140 bpm decreases the effectiveness of stroke volume and can contribute to ischemia or infarction
Prolonged sinus tachycardia can be a sign of infarction Treat the cause |
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Sinus dysrhythmia
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Rate: 60-100 bpm
Rhythm: Irregular Pacemaker site: SA node P wave: Normal morphology PR interval : Normal (0.12-0.20 sec) QRS complex: Normal (0.04-0.12 sec) |
Often resultant of a variation of the RR interval pathologically resultant of the following:
Respiration Changes in intrathoratic pressure Enhanced vagal tone |
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Sinus Arrest
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Rate: Normal or slow
Rhythm: Irregular Pacemaker site: SA node P wave: Normal morphology PR interval: Normal (0.12-0.20 sec) QRS complex: Normal (0.04-0.12 sec) |
Occurs when the SA node fails to discharge causing a short period of cardiac standstill and is resultant of the following:
Ischemia of the SA node Digitalis toxicity Excessive vagal tone Degenerative fibrotic disease |
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Wandering Atrial Pacemaker
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Rate: Normal
Rhythm: Slightly Irregular Pacemaker site: Variable by definition P wave: Varied morphology and presence PR interval : <0.12 or >0.20 sec QRS complex: Normal (0.04-0.12 sec) |
Passive transfer of pacing from the SA node to a different location resultant of
Sinus dysrhythmias Ischemia Atrial dilation |
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Multifocal Atrial Tachycardia (MAT)
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Rate: >100
Rhythm: Irregular Pacemaker site: Atrial ectopic sites P wave: Organized, discrete, nonsinus, exhibiting at least 3 distinct forms PR interval: Variable QRS complex: <0.12 or >0.20 seconds |
Patients exhibit about 60% pulmonary disease and medications which treat these conditions can worsen MAT
Three distinct P waves which indicates ectopic foci Pulmonary disease Metabolic disorders specifically hypokalemia Cardiac ischemia Recent surgery |
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Premature Atrial Contraction (PAC)
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Rate: Dependant upon underlying rhythm
Rhythm: Dependant upon underlying rhythm, regular excluding PVCs Pacemaker site: Ectopic focus in the atrium P wave: Occurs early often hidden in the T wave PR interval: Often normal Ectopic foci near the SA node ≥0.12 seconds Ectopic foci near the AV node ≤0.12 seconds QRS complex: Normal possibly < 0.12 seconds |
Resultant of a single impulse exterior to the SA node interior to the atria causing a premature depolarization which interrupts the normal cardiac resultant of:
Caffeine, Tobacco, ETOH Ischemia heart disease Hypoxia Digitalis toxicity Idiopathic |
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Paroxysmal Supraventricular Tachycardia (PSVT)
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Rate: 150-250 bpm
Rhythm: Characteristically regular Pacemaker site: Inner atrial exterior to the AV node P wave: Often buried in the T wave PR interval: Often normal Ectopic foci near the SA node 0.12 seconds ish Ectopic foci near the AV node ≤0.12 seconds QRS complex: Normal |
Rapid atrial depolarization overrides the SA node onsets suddenly and can last seconds-hours
Usually caused by automaticity in a single atrial foci or reentry phenomenon in the AV node Precipitated by environmental factors Frequently associated by underlying atherosclerosis CVD and rumatic heart disease |
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Atrial Flutter
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Rate: 250-350 bpm Ventricular rate varies
Rhythm: Usually regular ventricular rate is dependant upon conduction Pacemaker site: Inner atrial exterior to the AV node P wave: Flutter wave present, usually regular, irregular in a variable block PR interval: Often normal but variable QRS complex: Normal |
Results from a rapid atrial reentry circuit in a SA node that is nonconductive
AV junction allows conduction ratios of 1:1 rarely, 2:1, 3:1, or 4:1 or greater depending on the electric discrepancy present |
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Atrial Fibrillation
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Rate
Atrial rate 350-750 bpm Ventricular rate is dependant upon conduction Rhythm Irregularly irregular Pacemaker site Ectopic foci in the atria P wave Usually not discernable PR interval none QRS complex Normal |
Multiple reentry sites or multiple foci within the Atrium
Frequently associated by underlying atherosclerosis CVD and rumatic heart disease |
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First degree AV block
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Rate: Dependant upon underlying rhythm
Rhythm: Usually regular; sometimes slightly irregular Pacemaker site: SA node or atria P wave: Normal PR interval: >0.20 seconds (diagnostic) QRS complex: <0.12 seconds; morphology can be odd depending on conductive disease status |
Not an intrinsically dangerous rhythm often proceeds a more advanced block
Baring significant bradycardia no treatment required Contraindicated lidocane procanimide Described by the P-QRS complex interval 5:4, 4:3, 3:2, or 2:1 pattern can be consistent or variable Can occur in healthy heart but most commonly occurs as a result of ischemia at the AV node |
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Type I second-degree AV block (Morbitz I, or Wenckebach)
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Rate: Atrial rate is unaffected the ventricular rate is ≤ normal
Rhythm: Atrial rhythm is regular, ventricular rhythm is irregular Pacemaker site: SA node or atria P wave: Not followed by QRS complexes PR interval: Becomes progressively longer QRS is dropped QRS complex: <0.12 seconds; morphology can be odd depending on conductive disease status |
An intermediate block characteristically cyclic patter with progressively longer PR intervals eventually becoming a block with a constant PP interval
Described by the P-QRS complex interval 5:4, 4:3, 3:2, or 2:1 pattern can be consistent or variable Can occur in healthy heart but most commonly occurs as a result of ischemia at the AV node |
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Type I second degree AV block
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Rate: Atrial rate is unaffected the ventricular rate is ≤ normal
Rhythm: Atrial rhythm is regular, ventricular rhythm is irregular Pacemaker site: SA node or atria P wave: Not followed by QRS complexes PR interval: Normal of conducted beats often >0.21 QRS complex: Normal or >0.12 |
An intermediate block characteristically cyclic patter with progressively longer PR intervals eventually becoming a block with a constant PP interval
Described by the P-QRS complex interval 5:4, 4:3, 3:2, or 2:1 pattern can be consistent or variable Can occur in healthy heart but most commonly occurs as a result of ischemia at the AV node |
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Type II Second-Degree AV block
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Rate: Atrial rate is unaffected the ventricular rate is bradycardic
Rhythm: Atrial rhythm is regular, ventricular rhythm is irregular Pacemaker site: SA node or atria P wave: Not followed by QRS complexes PR interval: Normal of conducted beats often >0.21 QRS complex: Normal or >0.12 |
P waves which are not conducted to the ventricles the PR interval does no lengthen
Ratios are consistent or variable 4:1, 3:1, or 2:1 Usually caused by acute MI and septal necrosis |
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Third-Degree AV block
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Rate: Atrial rate unaffected, ventricular rate 40-60
Rhythm: Rhythms are usually regular Pacemaker site: SA node or atria P wave: No relations to QRS within the T wave PR interval: No relation between the waves QRS complex: Dependant upon pacing location |
A complete block of electrical conductivity between the atria and the ventricles
The two sections of the heart conduct entirely independently of one another Resultant of acute MI digitalis poisoning or electrical deconditioning |
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Premature Junctional Contraction
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Rate: Dependant upon underlying rhythm
Rhythm: Dependant upon underlying rhythm Pacemaker site: Ectopic focus in AV junction P wave: Inverted PR interval: <0.12 greater if PJC is conducted QRS complex: >0.12 seconds if PJC is abnormally conducted |
A signal from the AV node that occurs before the next sinus beat
Can result in either a compensatory or noncompensatory pause Caffeine tobacco alcohol Sympathomimetic drugs Ischemia Hypoxia Digitalis toxicity Idiopathic |
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Junctional Escape Complexes and Rhythms
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Rate: 40-60
Rhythm: Regular in rhythm Pacemaker site: AV junction P wave: Inverted PR interval: <0.12 greater if PJC is conducted QRS complex: >0.12 seconds if PJC is abnormally conducted |
The SA node rate is slower than the AV node so the AV node overdrives the SA node (40-60) This is resultant of increased vagal tone |
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Accelerated Junctional Rhythm
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Rhythm: regular
Pacemaker site: AV junction P wave: Inverted PR interval: <0.12 greater if PJC is conducted QRS complex: Normal |
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Paroxysmal Junctional Tachycardia
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Rate: 100-180
Rhythm: regular Pacemaker site: AV junction P wave: Inverted PR interval: <0.12 greater if PJC is conducted QRS complex: Normal |
Rapid AV Junctional rhythm overriding the SA node
Also known as paroxysmal supraventricular tachycardia Frequently associated with ASHD and rheumatic heart disease |
