Quiz 2: EKG Flashcards
What is EKG?
It measures the electrical activity of the heart
What does an EKG determine?
-Heart rate
-Rhythm
What is Phase 0 of EKG?
-Depolarization and rapid entry of Na+
-PR interval
What is Phase 1 of EKG?
-Early depolarization, K+ slowly enters
-QRS (ask Dr. Z)
What is Phase 2 of EKG?
-Plateau continues and slower entry of Ca2+
-ST segment
What is Phase 3 of EKG?
-K+ moves out of the cells
-T wave
What is Phase 4 of EKG?
-Resting phase
-Rest between T and P waves
What are the 4 main electrophysiologic principles?
-Automaticity: pacemaker ability
-Rhythmicity: systematic pattern
-Conductivity: spreads impulse
-Contractility: contraction ability
What is the function of the SA node? What is the intrinsic rate of the SA node?
-Activation of the atria
-Intrinsic rate: 60-100 bpm
What is the function of the AV node? What is the intrinsic rate of the AV node?
-Activation of the ventricles
-Intrinsic rate: 40-60 bpm
What is the intrinsic rate of the Bundle of His and Purkinje Fibers?
Intrinsic rate is 30-40 bpm
How many seconds is 1 large square on an EKG graph?
0.2 seconds
How many large boxes is 3 seconds? How many are 6 seconds?
-15 boxes= 3 seconds
-30 boxes= 6 seconds
How is heart rate calculated with an EKG graph?
-Uses a 6 second tracing
-Count # of QRS complexes in 6 second interval and multiply by 10
What is the P wave on an EKG?
Depolarization of the atria
What is the PR interval on an EKG?
-Onset of P wave to onset of R wave
-Measures the time between onset of atrial depolarization (SA node) and ventricular depolarization (AV node)
How many small squares is a normal PR interval?
3-5 small squares
What is the QRS complex?
-Onset of Q wave to end of S wave
-Measures the depolarization of the ventricles
How many small squares is a normal QRS complex?
1.5-3 small squares
What is the Q wave?
First downward deflection or negative deflection in the QRS complex
What is the R wave?
First upward or positive deflection in the QRS complex
What is the S wave?
Second downward or negative deflection in the QRS complex
What does assessment of the cardiac cycle via EKG include?
-Assessment of P wave
-Assessment of PR interval
-Assessment of QRS complex
-Assessment of QRS interval (duration)
-Assessment of T wave
-Evaluate R to R wave interval (is it regular)
-Evaluate HR
-Observation of pt and any symptoms
What is a term for a normal EKG with a normal HR?
Normal sinus rhythm
What is sinus bradycardia?
Slow HR (< 60 bpm) but normal rhythm
What is sinus tachycardia?
Fast HR (> 100 bpm) but normal rhythm
What are the different types of irregular atrial rhythms?
-Premature atrial contraction (PAC)
-Atrial tachycardia
-Atrial fibrillation
-Atrial flutter
What is a premature atrial contraction (PAC)? How would this look on an EKG?
-Atria contracts prematurely
-Shorter distance between T and P wave of next heart beat
What are causes of PACs? Are they dangerous?
-Often benign and non-lethal
-If underlying cardiac conditions: can be an early sign of CVD
-HTN, caffeine
-Pregnancy
-COPD, asthma
-Metabolic: hyperthyroid disease
-Stress or extreme fatigue
-Some medications for asthma or hayfever
What are symptoms of PACs?
-Patient may not have any symptoms
-A skipped heart beat
-Fatigue or SOB
-Exercise intolerance
-Chest pain (advanced)
What should a PT do if they notice a PAC?
-If it is new, report to nurse/doctor
-Reduce intensity and monitor vitals
-Report to team
What is atrial tachycardia? What will it look like on an EKG?
-Also known as supraventricular tachycardia
-Atrial depolarization is happening so fast you cannot see the P wave
-No P waves, it is hidden in the QRS complex
What are causes of atrial tachycardia?
-HTN and cardiomyopathy
-Previous MI
-Excessive use of alcohol, cocaine, or other stimulants
-An “irritable focus” when cells outside the SA node start generating an electrical pulse
-Sometimes idiopathic
What are symptoms of atrial tachycardia?
-Palpitations
-Fainting
-Chest pain
-SOB
-Fatigue
-Exercise intolerance
What should a PT do if they notice atrial tachycardia?
-Tell someone!!!
-Document what you were doing when this happened
-Reduce intensity and monitor vitals
-Alert team
What is atrial fibrillation? What does it look like on an EKG?
-Atria are rapidly beating
-Absence of P wave and jagged baseline
-Irregular ventricular response: irregular rhythm
What is atrial flutter? What does it look like on an EKG? What is the atria to ventricular contraction ratio?
-Atria are rapidly beating
-Normal rhythm
-Rapid ventricular response
-4:1 AV conduction (4 atrial contractions to 1 ventricular contraction)
-“Saw-toothed” flutter appearance, multiple P waves
What are causes of A-fib and A-flutter?
-Anything that interferes with electrical conductivity of SA node and associated internodal fibers/Bachman’s bundle
-Advanced age or genetic factors
-Congenital heart disease or underlying heart disease
-Increased alcohol consumption
-Endocrine disorders
-Neurological disorders
-Hemodynamic stress
-Obstructive sleep apnea
-Inflammation: myocarditis, pericarditis
-Any condition that leads to inflammation, stress, damage, or ischemia
What are symptoms of A-fib and A-flutter?
-Tachycardia
-SOB
-Dizziness
-Syncope
-Fatigue
-Exercise intolerance
-Chest pain or anxiety
-Night sweats or waking up with palpitations
What should a PT do if they notice A-fib or A-flutter?
-If new onset or worsening, stop activity, call in team, and monitor patient
-Pulse is irregular with a-fib
-If they are on beta blockers use RPE
-Deep breathing can help slow HR
What happens with the electrical activity during A-flutter?
Electrical impulses don’t travel in a straight line, they move in a circle inside the atria which results in a regular tachycardia
What happens with the electrical activity in A-fib?
Electrical signals travel through the atria fast and disorderly, which makes them quiver instead of squeezing strongly causing tachycardia and irregular rhythm and a reduced atrial kick
What are the different types of irregular ventricular rhythms?
-Ventricular arrhythmias
-Premature ventricular complex (PVC)
-Ventricular tachycardia
-Ventricular fibrillation
What is premature ventricular complex (PVC)? What does it look like on an EKG?
-Ventricles contract prematurely
-Inverted QRS complex and larger amplitude
-No P wave
When does a PT need to stop activity with PVCs?
-“PVC runs in three’s, let them be”
-If there are 3 or more PVCs in a row or if they are becoming more frequent with activity, STOP
-Report to medical team
What is a burst of ventricular tachycardia?
3 or more PVCs in a row
What are causes of PVCs?
-Excessive caffeine intake
-Electrolyte imbalances: hypokalemia, hypomagnesmia, hypercalcemia
-Hyperthyroidism
-Excessive alcohol, tobacco, or stimulant use
-Cardiac: post MI, myopathies, MV prolapse
-Anemia
-Most have no etiology
-Prevalent in 40-75% of patients that were on 24-48 hour Holtor Monitors
What are symptoms of PVCs?
-Very often asymptomatic or benign palpitation
-Lightheadedness, chest pain, chest discomfort, dyspnea, and anxiety
-Rarely syncope
-May possibly palpate or auscultate a missed beat
What are treatments for PVCs?
-Rarely need treatments
-Anti-arrhythmics
-Cardiac ablation to treat aberrant SA node cells
What should the PT do if they notice a PVC?
-If it is 1 or 2, monitor and keep going
-Increasing in frequency, reduce intensity or stop
What is burst ventricular tachycardia (V-tach)?
5-6 PVCs in a row, fast rhythm
What should the PT do if they notice a burst V-tach?
-Stop exercise
-Notify team
-Monitor patient
What is sustained V-tach?
-Bizarre widened QRS complexes, no P waves
-Rate over 100 bpm
What should someone do if they notice sustained V-tach?
-Call someone ASAP because this can quickly turn into ventricular fibrillation or death
-Stop all activity immediately
What are causes of V-tach? How dangerous is it?
-Potentially life threatening if sustained > 30 seconds
-Ischemia or MI
-Acute coronary syndrome
What are symptoms of V-tach?
-Syncope
-SOB due to pulmonary edema
-Cardiac arrest and even sudden cardiac death
-This is a RAPID RESPONSE or CODE situation
What is Torsade de Pointes?
V-tach with increasing and decreasing amplitude
What is ventricular fibrillation (V-fib)?
-Chaotic wave pattern and no pulse
-Irregularly shaped wave forms that reflect multiple ventricular foci firing randomly in v-fib
-This lack of organization prevents measurement of HR
What are the causes and symptoms of V-fib?
-MI or other damage to heart wall or conduction system
-Severe & sustained electrolyte imbalances, especially hypokalemia
-Syncope or near syncope
-Significant SOB
-Cardiac arrest
What should a PT do if they notice V-fib?
Call a code and start CPR!!!
What are the different types of atrioventricular heart blocks?
-1st degree AV heart block
-2nd degree AV heart block
-3rd degree AV heart block
What are the two types of 2nd degree AV blocks?
-2nd degree Mobitz Type I/ Wenkebach
-2nd degree Mobitz Type II
What is a 1st degree AV block? What does it look like on an EKG?
-Delay in conduction
-“If the R is far from P, then you have a 1st degree”
What is a 2nd degree AV Mobitz Type I/Wenkebach? What does it look like on an EKG?
-Partially blocked conduction
-“Longer, longer, longer, drop! Then you have a Wenkebach”
-Gradual elongation of PR interval then a QRS complex is dropped
-Regularly irregular
What is a 2nd degree AV Mobitz Type II? What does it look like on an EKG?
-Partially blocked conduction
-“If some P’s don’t get through then you have a Mobitz II”
-Intermittent dropped QRS complex that is not in a type I pattern
-P waves are consistent even if there is no QRS complex following it
What is a 3rd degree AV block? What would it look like on an EKG?
-Complete block in conduction
-“If P’s and Q’s don’t agree, then you have a 3rd degree”
-Fixed P-P interval
-No relationship between P and QRS waves
What are the causes of heart blocks?
-CAD with and without MI
-Cardiomyopathy
-Autoimmune disorders such as Lupus and Sarcoidosis
-Infections, cancers, or inflammation
-Congenital
-Hyperkalemia
What are symptoms of 1st degree heart blocks?
Will likely be asymptomatic
What are symptoms of 2nd degree heart blocks?
-Dizziness or syncope
-Palpitations or chest pain
-SOB
-Fatigue
-Exercise intolerance
What are symptoms of 3rd degree heart blocks?
-Intense tiredness
-Irregular rhythm
-Dizziness or syncope
-Cardiac arrest
What should a PT do if they notice a 1st degree heart block?
-If asymptomatic, continue to monitor
-Notify team if it is not yet known
What should a PT do if they notice a 2nd degree heart block?
-Notify team
-Reduce intensity and monitor
-May get a pacemaker
What should a PT do if they notice a 3rd degree heart block?
-Notify team!!!
-Do not treat until a pacemaker has been placed!
What is a NSTEMI? What might this look like on an EKG?
-Non-ST segment elevation myocardial infarction
-T wave inverted
What is a STEMI? What might this look like on an EKG?
-ST-segment elevation myocardial infarction
-ST segment is elevated and above the isoelectric line
Is a STEMI or NSTEMI more dangerous? Why?
-STEMI is more dangerous
-It indicates acute injury
-If ST-segment elevation is present with acute onset of chest pain (hours), this is a cardiac emergency!
