Cardiac Monitoring - ECGs Flashcards
What is the definition of Aberrant?
Abnormal
Aberrant refers to any deviation from the normal cardiac conduction patterns.
What does Arrhythmia mean?
Irregularity or absence of a heartbeat.
Arrhythmia is also known as dysrhythmia.
What is Asystole?
(Cardiac Arrest, Ventricular Standstill): The absence of a heartbeat.
Asystole indicates a critical state requiring immediate medical intervention.
Define Atrioventricular Block.
A cardiac impulse conduction disturbance in the atrioventricular (AV) node, bundle of His, or its branches.
What is an Automatic Beat?
An impulse arising in an automatic focus, independent of the dominant rhythm.
What does AV Dissociation refer to?
The independent beating of the atria and ventricles.
What is Bigeminy?
A normal beat alternating with a premature beat.
Define Block in the context of cardiac conduction.
A pathologic delay or interruption in impulse conduction.
What is Bradycardia?
A heart rate slower than the normal for that pacemaker site; e.g., less than 60 beats/minute for the sinoatrial (SA) node.
What is Bradydysrhythmia?
Any rhythm disturbance causing a slow heart rate (less than 60 beats/minute).
What does Bundle Branch Block indicate?
An abnormality in cardiac impulse conduction through the fibers of the bundle of His.
What is a Compensatory Pause?
The period following a premature contraction during which the heart regulates itself, allowing the SA node to resume normal conduction.
Define Ectopic Beat.
A beat originating from a source of cardiac stimulus other than the SA node, usually caused by some irritation of the myocardium.
What is an EKG (or ECG)?
Electrocardiogram; a graphic tracing of the electrical activity of the heart.
What does Electromechanical Dissociation mean?
Electrical activity without evidence of myocardial contraction.
What is an Escape Beat?
An automatic beat that occurs after an interval longer than the dominant cycle.
What is Conduction Time?
The interval between the origination of an impulse at the SA node and the stimulation of ventricular contraction.
Fill in the blank: Dysrhythmia is any disturbance in the _______.
normal rhythm of the heartbeat.
What is Extrasystole?
An ectopic beat, occurring before the next dominant beat, that depends on and couples with the preceding beat.
Define Fibrillation.
Quivering or uncoordinated muscular contraction.
What is a Fusion Beat?
Simultaneous activation of one chamber of the heart by two foci.
What does Group Beating mean?
A pattern of repetitive QRS complexes.
What is Heart Block?
Impairment of cardiac conduction so that electrical impulses from the atria fail to pass through the AV node to the ventricles.
What characterizes Idiojunctional Rhythm?
A relatively slow, independent rhythm that arises in the AV junction and controls the ventricles.
What is Mobitz Type I (Wenckebach) Block?
A second-degree or partial AV block in which the P-R interval increases progressively until the atrial impulse arrives during the absolute refractory period.
What is Mobitz Type II Block?
A second-degree or partial AV block characterized by the sudden nonconduction of an atrial impulse.
What is the function of a Pacemaker?
The SA node initiates the electrical impulse that sets the rhythm of cardiac contractions.
Define Parasystole.
An ectopic, independent rhythm that operates concurrently with the dominant rhythm.
What does Paroxysmal mean?
Recurring suddenly and abruptly.
What is Sinus Arrhythmia?
A slight variation or irregularity in sinus rhythm or normal heartbeats.
Define Systole.
Contraction of the heart, which causes ejection of blood from the heart chambers.
What is Tachycardia?
A heart rate faster than the normal for that pacemaker site; e.g., greater than 100 beats/minute for the SA node.
What does Tachydysrhythmia indicate?
Any rhythm disturbance causing a fast heart rate (over 100 beats/minute).
Describe the blood flow through the heart.
Superior and Inferior Vena Cava -> Right Atrium -> Tricuspid Valve -> Right Ventricle -> Pulmonic Semilunar Valve -> Pulmonary Arteries -> Lungs -> Pulmonary Veins -> Left Atrium -> Bicuspid (mitral) Valve -> Left Ventricle -> Aortic Semilunar Valve -> Body.
What is Frank Starling’s Law?
The more the ventricle is filled with blood during diastole, the greater the volume of ejected blood will be during the resulting systolic contraction.
How do cardiac muscle cells differ from skeletal muscle cells?
Cardiac muscle cells have a much longer refractory period.
List the four characteristics inherent to cardiac cells.
- Automaticity
- Excitability
- Conductivity
- Contractility
What is the role of the conduction system in the heart?
It generates an action potential without outside stimulation by the CNS or PNS.
What triggers tachycardia in relation to the SA node?
Calcium channels become more permeable when stimulated by the SNS or Epi.
What is the heart rate controlled by under normal conditions?
The SA node.
What is indicated by the ECG waveform?
A recording of electrical impulses produced by the heart.
What does the ‘P’ wave represent?
Contraction of the atria.
What is the PR Interval?
Measured from the beginning of the ‘P’ wave to the beginning of the ‘QRS’ complex.
What does the QRS complex represent?
Depolarization of the ventricles.
What is the maximum duration of the QRS complex?
Should not exceed 0.12 secs.
What is ventricular REPOLARIZATION?
The process beginning normally flat in appearance, measured from the end of the QRS complex to the beginning of the T wave.
What does the ST Segment represent?
Ventricular REPOLARIZATION, normally upright, asymmetric, and curved.
What is the T Segment in an ECG?
Not visible in all ECGs; may be due to repolarization of the Purkinje Fibers, not significant in ECG interpretation.
What is the U Wave?
A wave that can be present in an ECG; its significance varies.
What is the normal duration of a P Wave?
< 0.08 sec or 2 boxes.
What is the normal range for the P-R Interval?
0.12-0.20 sec or 3-5 small boxes.
What is the normal duration for the QRS complex?
< 0.12 sec or 3 small boxes.
What are the two main characteristics to assess in an ECG?
Rate (Fast/Slow) and Rhythm (Regular/Irregular).
What does a P Wave to QRS ratio indicate?
Presence and uprightness of the P Wave.
What does a short P-R Interval indicate?
A direct reflection of the AV node pause.
What defines a Normal Sinus Rhythm?
Rate of 60-100 bpm, regular rhythm, upright P wave preceding each QRS, P-R Interval of 0.12-0.20 secs, and QRS of 0.12 secs or less.
What is Sinus Bradycardia?
Rate < 60 bpm, regular rhythm, upright P wave preceding each QRS, and P-R Interval of 0.12-0.20 secs.
What are common causes of Sinus Bradycardia?
- Fitness level * Myocardial Infarction (MI) * Vagal Stimulation * Hypothermia * Medications.
What defines Sinus Tachycardia?
Rate of 100-150 bpm, regular rhythm, upright P wave preceding each QRS, and P-R Interval of 0.12-0.20 secs.
What is Atrial Fibrillation?
A chaotic depolarization of the atria resulting in an irregular rhythm.
What are the characteristics of Atrial Flutter?
Rate depends on AV pause, rhythm can be regular/irregular, flutter waves present, and QRS of 0.12 secs or less.
What is a Premature Atrial Complex (PAC)?
An early heartbeat originating in the atria, with a different P wave morphology.
What defines Supraventricular Tachycardia (SVT)?
Rate > 150 bpm, regular rhythm, often buried P wave, and QRS of 0.12 secs or less.
What is Junctional Escape Rhythm?
Rate of 40-60 bpm, regular rhythm, P wave may be hidden or inverted, and QRS of 0.12 secs or less.
What are the characteristics of Idioventricular Rhythm?
Rate of 20-40 bpm, regular rhythm, no P wave, and QRS > 0.12 secs.
What causes Ventricular Arrhythmias?
QRS complexes originate from below the AV node and are wide due to slow conduction through intercalated disks.
What is the significance of the T wave morphology in Idioventricular Rhythm?
Opposite deflection on the T wave.
What is the typical rate for Accelerated Idioventricular Rhythm?
Rate of 40-100 bpm, regular rhythm, no P wave, and QRS > 0.12 secs.
What is Ventricular Tachycardia?
A condition caused by an irritable foci creating a loop of depolarization in the ventricles.
Contractions may be weak enough to cause pulseless V-Tach.
What is the rate range for Ventricular Tachycardia?
100-260 bpm (with or without a pulse)
Describe the rhythm of Ventricular Tachycardia.
Regular (unifocal) or irregular (multifocal)
What is the QRS duration in Ventricular Tachycardia?
> 0.12 secs, opposite deflection on ‘T’ wave
List the common causes of Ventricular Tachycardia.
- MI
- Meds
- CHF
What is a Premature Ventricular Complex (PVC)?
An early contraction originating in the ventricles, which may or may not cause a contraction.
What is the rhythm of a Premature Ventricular Complex (PVC)?
Underlying rhythm can be regular or irregular
What is the QRS duration in a Premature Ventricular Complex (PVC)?
> 0.12 secs
List the causes of Premature Ventricular Complex (PVC).
- MI
- Meds
- CHF
- Hypoxia
- Exercise
What are the patterns of Premature Ventricular Complex (PVC)?
- Couplets
- Salvo
- Bigeminy
- Trigeminy
- Quadrigeminy
- Unifocal
- Multifocal
What is Ventricular Fibrillation?
A chaotic electrical activity in the ventricles, leading to ineffective contractions.
What are the causes of Ventricular Fibrillation?
- MI
- Ventricular Tachycardia
- Any cause of cardiac arrest
What is Asystole/Ventricular Standstill?
The absence of any electrical activity in the heart.
List the causes of Asystole/Ventricular Standstill.
- MI
- End stage cardiac arrest
- Ventricular Tachycardia
- Ventricular Fibrillation
What is Pulseless Electrical Activity (PEA)?
Any electrical activity observed on ECG without a palpable pulse.
What are the causes of Pulseless Electrical Activity (PEA)?
- MI
- Meds
- PE
- Acidosis
- Tension pneumothorax
- Pericardial tamponade
- Hypoxia
- Hypovolemia
- Electrolyte imbalance
Can a PCP treat based on rhythm interpretation?
No, treatment based on rhythm interpretation is outside the scope of practice for PCPs.
What is required to defibrillate V-Fib or PV-Tach?
Use the AED’s analyze feature.
What is the significance of stopping the ambulance during AED analysis?
To prevent artifact from being interpreted as V-Fib.
What is First Degree AV Block?
A delay in conduction through the bundle of His, where each vehicle takes longer than expected but all get through.
What is the PRI duration in First Degree AV Block?
> 0.2 secs
What is the QRS duration in First Degree AV Block?
0.12 secs or less
What is the characteristic of Second Degree Type I (Mobitz I) AV Block?
Gradually lengthening PRI until a QRS complex is dropped.
What is the rhythm pattern in Second Degree Type I AV Block?
Atrial rate is regular, ventricular rate is irregular.
Describe Second Degree Type II (Mobitz II) AV Block.
Structural damage to one part of the AV node, where some QRS complexes are dropped without a gradual lengthening of PRI.
What is the rhythm pattern in Second Degree Type II AV Block?
Atrial rate is regular, ventricular rate is irregular.
What defines Third Degree AV Block?
Complete failure of the AV node to conduct atrial impulses, leading to AV dissociation.
What is the ventricular rate in Third Degree AV Block?
20-40 bpm, may be faster if distal parts of the AV node are spared.
How are P waves and QRS complexes related in Third Degree AV Block?
P waves occur regularly and do not relate to QRS complexes.
What is Defibrillation?
The act of arresting fibrillation by applying electric shock across the chest.
What are the indications for Defibrillation?
- Ventricular Fibrillation
- Pulseless Ventricular Tachycardia
What is Cardioversion?
The conversion of one cardiac rhythm to another, usually from abnormal to normal.
What are the indications for Cardioversion?
- Unstable Ventricular Tachycardia with a pulse
- Unstable SVT/PSVT
- Unstable rapid Atrial Fibrillation
- Unstable rapid Atrial Flutter
What is External Transcutaneous Pacing?
A temporary method for cardiac pacing using large surface electrodes.
What are the indications for External Transcutaneous Pacing?
- Hemodynamically significant bradydysrhythmias unresponsive to atropine
- Asystolic cardiac arrest
What is required for Lifepak Safety during use?
Direct supervision by ESA faculty.
What should documentation include after a procedure/treatment?
- Interpretation
- Pertinent positives
- Pertinent negatives
- Copy of rhythm strip
What is a prominent feature of organized atrial activity on an ECG?
A prominent P wave should be displayed.
What is important to note regarding ECG findings?
They should be correlated with clinical observations of the patient.
