Heart Rhythm Flashcards
Normal cardiac cycle (NSR):
What happens at P wave?
Atrial depolarization
Normal cardiac cycle (NSR):
What happens at P-R interval?
Time required for impulse to travel from atria through conduction system to purkinje fibers
Normal cardiac cycle (NSR):
What happens at QRS wave?
Ventricular DEpolarization
Normal cardiac cycle (NSR):
What happens at ST segment?
Beginning of ventricular REpolarization
Normal cardiac cycle (NSR):
What happens at T wave?
Ventricular repolarization
Normal cardiac cycle (NSR):
What happens at QT interval?
Time for electrical systole
How would you calculate HR on the ECG?
Number of intervals between QRS complex’s in a 6 second strop and multiply by 10
What are some etiologic factors of arrythmias? (8)
Ischemic conditions of the myocardium Electrolyte imbalance Acidosis or alkalosis Hypoxemia HyPOtension Emotional stress Drugs Alcohol Caffeine
Ventricular arrhythmias: originate from _____ _____ in the ventricles (outside of normal condition system)
Ectopic focus
Ventricular arrhythmias: significant in adversely affecting ____ ____
Cardiac output
Ventricular arrhythmias: include ____ _____ _____: which are a premature beat arising from the ventricles
Premature ventricle contraction (PVCs)
PVCs on ECG look like what?
NO P WAVE
Bizarre and wide QRS that is premature
Followed by long compensatory pause
Serious PVCs are defined as > ___ per minute
6
Ventricular tachycadia (VT): a run of ____ or more PVC occurring sequentially; with a very paid rate ____-_____ bpm
3
150-200
V Tach: usually the result of an ______ ventricle
Ischemic
On ECG, V tach looks like what?
Wide bizarre QRS waves, no P waves
Seriously compromised cardiac output
What is non sustained v tach? (NSVT)?
3 or more consecutive beats in duration
Terminating spontaneously in less than 30 seconds
What is VT (sustained v tach)?
VT > 30 seconds in duration and/or requiring termination due to hemodynamic compromise in less than 30 seconds
Ventricular fibrillation (VF): a \_\_\_\_\_\_, emergency situation requiring EMS CPR needed, defibrillation, medications
PULSELESS
Vfib is characterized by chaotic activity of ventricle originating from _____ ______
Unable to determine _____
Multiple foci
Rate
On ECG, V fib looks like
Bizarre, erratic activity WITHOUT QRS complex
Vfib has no effective _____ _____. Clinical death within _____ minutes
Cardiac output
4-6 minutes
Atrial arrhythmias (supraventricular): _____ and ______ firing of one or more ectopic focus in the _____ (outside the sinus node)
Rapid and repetitive
Atria
Atrial arrhythmias: on ECG, ______ are abnormal or not identifiable (Afib)
P waves
Atrial arrhythmias: rhythm may be irregular, chronic or occurring ________
Paxosymally
Atrial tachycardia ______ bpm
Atrial flutter _____ bpm
Atrial fibrillation _____ bpm
140-250
250-350
>300
In Atrial arrhythmias, cardiac output is usually maintained if ____ is controlled
Rate
AV blocks: abnormal delays or failure to conduct through normal conducting system: how many types?
4:
First, second, third (complete), bundle branch blocks
If ventricular rate is slowed, what is decreased?
CO
Which heart block is life threatening?
Third degree
3rd deg/complete heart block requires what medication? And what kind of surgery?
Atropine
Pacemaker implantation
With impaired coronary perfusion (ischemia or injury), the __________ becomes depressed
ST segment
ST segment depression can be ______, _______, or ______
Upsloping
Horizontal
Downsloping
St segment depression or elevation greater than __ mm measured at the __ point in __ consecutive leads is considered abnormal, except in leads _________
1 mm
J point
2
V2-V3
ST elevation of
> or = ___mm in men > or = 40
> or = ___mm in men < 40
> or = ___mm in women
Is abnormal?? Doesn’t say in book
2
- 5
- 5
ECG changes with an acute MI: acute ST elevations present in leads over the infarcted area:
Anterior wall: changes in ______
V1-V6
ECG changes with an acute MI: acute ST elevations present in leads over the infarcted area:
Anteroseptal wall: changes in __________
V1-V2
ECG changes with an acute MI: acute ST elevations present in leads over the infarcted area:
Anteroapical wall: Changes in _______
V3-V4
ECG changes with an acute MI: acute ST elevations present in leads over the infarcted area:
Anterolateral wall: changes in _______, __, ____
V5-V6, I, aVL
ECG changes with an acute MI: acute ST elevations present in leads over the infarcted area:
Lateral wall: changes in ________
Leads I and aVL
ECG changes with an acute MI: acute ST elevations present in leads over the infarcted area:
Inferior wall:
II, III, aVF
ECG changes with an acute MI: acute ST elevations present in leads over the infarcted area:
Posterior wall:
Not seen on typical ECG, changes in V7-9
Hyperkalemia: does what to ECG?
Wide QRS
Flattens P wave
T wave becomes peaked
Hypokalemia: does what to ECG?
Flattens T waves (or inverts)
Produces a U wave
Hypercalcemia: does what to ECG?
Widens QRS
Shortens QT interval
Hypocalcemia: does what to ECG?
Prolongs QT interval
Hypothermia: does what to ECG?
Elevates ST segment
Slows rhythm
Digitalis: does what to ECG?
Depresses ST segment
Flattens T wave or inverts
QT shortens
Quinidine: does what to ECG?
QT lengthens
T wave flattens (or inverts)
QRS lengthens
Beta blockers (propranolol (inderal): does what to ECG?
Decrease HR
Blunts HR response to exercise
Nitrates (nitroglycerin): does what to ECG?
Increases HR
Antiarrhythmic agents: does what to ECG?
May prolong QRS and QT intervals
Holter monitoring: continuous ambulatory ECG monitoring via tape for up to ___ hours
Used to evaluate cardiac rhythm, transient symptoms, pacemaker function, effect of meds
Allows correlation of symptoms with ______
24
Activities
