Cardio day 2 Flashcards
What is a Normal Resting CO
5-6L/min
What is a Normal Resting Rate of the SA node
60-100bpm
What is the pacemaker of the heart
Sinoatrial Node (SA Node)
What is a Normal Resting Rate of the Atrioventricular Node (AV Node)
(40-60 bpm)
What is a Normal Resting Rate of the Purkinje Fibers
(20-40 bpm)
depolarization means
an electrical impulse that causes contraction of an area.
A refractory period is when
the heart cant pulse because it needs to repoloarize
What is (systole)
a sequence of atrial/ventricular CONTRACTION caused by cell DEPOLARIZATION
What is(diastole)
relaxation caused by repolarization (Return of the heart to its previous resting state, the relaxation of the myocardial muscle.)
How narrow should a QRS complex be
less than 100ms wide
What does the p wave show
contraction of the atria (don’t need much power to contract so hill is smaller) refilling of atria happen during QRS
What does the t wave show
repolarization (refilling) of the VENTRICLES
Each small square measured horizontally on an ECG represents_____ seconds in time.
0.04
Each small square measured vertically on an ECG represents the voltage, or amplitude, as __ mm of height.
1
To accurately review a rhythm strip you need a___second strip (measured by notches as top or bottom of strip)
six
IS PT IS HAVING A PROCEDURE ON A STEP DOWN UNIT, YOU SHOULD USE TELEMETRY OR A HARDWIRE MONITOR
USE HARDWIRE NOT TELEMETRY SINCE HARD WIRE IS USED DURING PROCEDURES
Difference Between Cardiac Monitoring and 12-Lead EKG
12 LEAD LOOKS AT ALL ASPECTS OF THE ELECTRICITY OF THE HEART, MORE LEADS THAN
Cardiac monitoring is continuous monitoring used for individuals who are in critical care, does not look at multiple aspects of the heart. If wonky might order an EKG
T/F: LEAD 2 SHOULD ALWAYS BE UPRIGHT AND POSITIVE
True
What are the 5 steps to Analyzing Cardiac Rhythms
Determine regularity (top of QRS to top of QRS). if they vary more than 0.12 seconds the rhythm is considered irregular
Calc HR: Multiply number of QRS complex by 10
Identify a P wave (size, shape, and position)
Measure P-R interval (must 5 or less boxes or Count the number of small squares and multiply by .04 seconds (normal .12-.20 sec))
Measure QRS complex
If the length between R’s in QRS complexes vary more than 0.12 seconds the rhythm is considered _________.
irregular
How do you calculate HR on a 6 second ECG strip
MULTIPLY NUMBER OF QRS COMPLEXES BY 10
IF A PR INTERVAL IS ABNORMALLY LONG IT COULD MEAN
THERE’S AN ISSUE WITH THE SA NODE (HEART BLOCKS)
How do you determine the PR interval is normal/abnormal
Count the number of small squares and multiply by .04 seconds (normal .12-.20 sec)
Narrow QRS complexes (less than 0.12 seconds) mean that the beat comes from the ___
atria
Wide QRS complexes (greater than 0.12 seconds) indicate _____ beats
ventricular
What are the timings for a normal PR interval and QRS complex
PR Interval: .12-.20 sec
QRS duration: .12 or less, *unless conduction block exists
DYSRHYTHIMAS are MOSTLY CAUSED BY __________
HYPOPERFUSION
What electrolyte imbalances can cause Dysrhythmias
Potassium (K):
Hyper: increased cardiac excitability and a higher risk of arrhythmias such as premature ventricular contractions (PVCs) or even more serious conditions like ventricular tachycardia or fibrillation.
Hypo: reduced resting membrane potential, leading to decreased excitability and potentially causing slow heart rates (bradycardia), heart block, or even cardiac arrest.
Magnesium (Mg):
Hyper: contribute to arrhythmias by prolonging the QT interval, which increases the risk of torsades de pointes, a type of polymorphic ventricular tachycardia.
Hypo: can lead to bradycardia, heart block, or even cardiac arrest due to its depressant effects on the cardiac conduction system.
Calcium (Ca):
Hyper: increased myocardial excitability and a prolonged QT interval, which can cause various types of arrhythmias, including ventricular tachycardia or fibrillation.
Hypo: decrease myocardial excitability and conduction velocity, potentially causing bradycardia, heart block, or other arrhythmia
What electrolyte does acidosis influence, and how is that related to Dysrhythmias
potassium
In acidosis, there is an increased concentration of hydrogen ions in the blood. To maintain electrical neutrality, hydrogen ions move into cells, and potassium ions (K⁺) move out of cells into the extracellular fluid. This process is known as potassium shift. Elevated potassium levels due to acidosis can lead to disturbances in cardiac conduction and increase the risk of arrhythmias.
T/F: Dysrhythmias tend to occur acutely and you won’t see sx like edema until the heart develops chronic issues.
True
What are Positive chronotropes used for and which is the most commonly administered med
(for when heart is beating too slow, speeds up HR)
Atropine
Describe Atropine
Positive chronotrope used for when heart is beating too slow, speeds up HR
Reduces salivation
Describe Diltiazem
Lowers BP and HR
Find the cause of tachy before admin because you don’t want them to return to baseline while med takes effect
For SVT, Afib, Aflutter
(give bolus then drip to slow hr down to help sa node capture and go into norm rhythm.)
Amiodarone
Amiodarone is used to treat and prevent life-threatening ventricular arrhythmias
For atrial fibrillation, atrial flutter, and ventricular tachycardia
When would you use Transcutaneous pacing
Used to temporarily stimulate the heart when there is a slow or ineffective heart rhythm, often due to BRADYCARDIA or HEART BLOCK.
a temporary measure while awaiting a permanent pacemaker insertion
Synchronized cardioversion is…
used to correct abnormal heart rhythms WITH a pulse
Typically ATRIAL fibrillation or ATRIAL flutter, or to terminate other types of TACHYCARDIAS
The shock is timed (synchronized) with the R wave of the ECG to avoid causing ventricular fibrillation.
The patient is usually sedated or anesthetized for comfort.
What is the R on T Phenomenon
when there is an impulse that is given when the t wave (when the ventricles are relaxing causes heart to Vfib)
What ECG do you defibrillate
Vtach w/out a pulse or Vfib
What is the difference between monophasic and biphasic defibrillation
Biphasic is better because the current is delivered in two directions
The PR interval typically ranges from…
0.12 to 0.20 seconds (5 small boxes/1 big box)
What do negative chronotropic medications do
Lower HR (beta blockers, digitalis, calcium channel blockers)
Nifedipine can slow down HR.
Digoxin can _____ HR, but _________ contractility.
slow
improves
How does Hypo/hyperkalemia affect the heart
alters contractility
Sinus Bradycardia Treatment
GIve atropine to increase the HR. Bit by bit and watch LOC, BP, HR come up until normal. If they are unresponsive b/c of an acute issue, relieve issue. If it won’t go away, then you need to consider pacemaker. Transcutaneous pacing does not do one time shock, it connects to the sa node and provides supportive electricity.
Why should Beta blockers or calcium channel blockers be used cautiously
(can cause vasculature to flatten)
FIRST FIGURE OUT WHY ITS HIGH, THEN TX THAT B4 USING CHRONOTROPIC MEDS
What is a noninvasive Sinus Tachycardia Treatment
Vagal maneuvers (last thing to try if fixing fever, pain doesn’t work before meds. have them bear down/cough)
What is a PAC and why should you worry about it
Premature Atrial Contraction (PAC)
Frequent PAC’s may warn of or initiate a more serious atrial rhythm such as tachycardia and atrial fibrillation (can cause SVT)
What new manifestation should you look out for as a precursor to a worse cardiac event in a pt with asymptomatic a fib
hypotension
What is a Watchman device
(mesh umbrella that goes into atria to catch clots)
A-Fib Treatment
What does a PVC look like
The ECG shows a broad and atypical QRS complex without a preceding P wave.
What is the difference between Stable vs unstable
Vtach
unstable (no pulse)
What kind of arrhythmia is caused by Digoxin toxicity
Heart blocks
T/F: 2nd DEGREE HB T1 IS WARNING FOR T2.
TRUE
T/F: 2nd DEGREE T2 IS CHARACTERIZED BY SYNCOPE
TRUE
TX for 2nd DEGREE T1 vs T2
2nd degree type I:
Atropine (MIGHT GO AWAY)
Temporary pacemaker
2nd degree type II:
pacemaker
What is the only 3rd Degree Block Treatment
Permanent pacemaker
