Wes Todd Questions Flashcards
Define: Disinfect
Destroy most pathogens on instruments. Un-safe for living tissues
Define: Bacteriostatic
Inhibits or stops the growth of bacteria (-static = hold steady)
Define: Antiseptic
Destroy most pathogens on living tissue, safe to use on skin
Define: Sterilize
Destroys all microorganisms
Define: Aseptic
Destroys all pathogens (-sepsis = infection)
A patient with AF is scheduled for PVI; he is NPH-insulin dependent. what specific precautions should be taken?
Avoid reversing heparin with protamine
What is the normal electrolyte lab value for K?
3.5 - 5.5
What is the normal electrolyte lab value for Platelets?
> 80 000
What is the normal electrolyte lab value for INR?
< 1.5
What is the normal electrolyte lab value for WBC?
< 12 000
What is the normal electrolyte lab value for Na?
135 - 145
What is the normal electrolyte lab value for Cl?
95 - 105
What is the normal electrolyte lab value for Ca?
0.8 - 1.0
What is the normal electrolyte lab value for Mg?
1.5 -2.1
Grossman and Peterson state, what is the most important factor in reducing complication rates invasive procedures?
Meticulous attention to details of technique
What is the only absolute contraindication to a PVI ablation procedure for AF?
Atrial thrombus on TEE
A major complication of pericardial centesis is the needle puncturing the heart, and its vessels. What part of the heart is least likely and least dangerous complication due to needle puncture?
LV (due to thick cardiac muscle)
In an electrical injury, what is the pathway of current most likely to be fatal?
hand to hand
What is the term for when the heart is insensitive to stimuli and cannot be depolarized by stimulation (such as pacing)?
Refractory
The sympathetic nervous system stimulation of the heart primarily affects the heart rate by altering what phase of the SA node action potential?
Phase 4
What ion concerning the transfer across the myocardial cell membrane happens throughout systole?
potassium leaks out and calcium seeps in
What part of the ventricular action potential is the “resting” membrane potential?
phase 4
What is the trans-membrane potential when a purkinje cell is in the resting state?
Polarized and negatively charged
Compared to a myocardial cell - SA node cells are prone to a faster _________ because of their steeper phase ___________.
Automaticity, phase 4
The SA and AV node depol come through what channels?
Slow Ca ++ channel
What cardiac tissue has the fastest electrical conduction velocity?
Purkinje Fibers
Sympathetic nervous stimulation of the heart primarily affects the rate by altering what phase of the SA node action potential?
Phase 4
Concerning ion transfer, what crosses the myocardial cell membranes throughout systole?
potassium leaks out
What is the trans-membrane potential when a Purkinje cell is in the resting state?
It is Polarized and negatively charged inside
The plateau phase of the ventricular action potential occurs on the surface ECG during ________ and during mechanical ___________.
QT interval and systole
Which two cardiac tissues have a slow phase 0 action potential and thus a slow conduction velocity?
SA nose and AV node
What is the response of cardiac tissues paced during the relative refractory period?
Requires higher mA but create a weaker contraction
What causes fractionated electrograms?
Nonuniform anisotropy (zigzag conduction)
Anistropy is the property where conduction is nonuniform, as opposed to to isotropy, which is normal concentric conduction in all directions.
What is the term for the pause after rapid atrial pacing is ceased?
Over drive suppression
Most arrhythmias in the EP lab are cause by what mechanism?
Re-entry
The “triggered” mechanism may cause an arrhythmia. Triggered arrhythmias are often associated with digitalis toxicity or elevated interventricular Ca++ levels. What mechanism causes triggered arrhythmias?
after-depolarization
How is the interval for the intra-atrial conduction time measured?
“P” wave to the “A” wave
If there is a prolonged HV where would we suspect the block?
infra-hisian block
more severe than a supra-hisian block
What 3 segments make up the PR interval?
PA, AH and HV
A HIS bundle electrogram has the following measurements: AH = 160 ms, HV = 40 ms and QRS = 180 ms. What is the diagnosis?
Supra-hisian, 1st degree AVB
In measuring EGMs, the earliest recorded atrial activation is almost always taken from the ____ while the earliest recorded ventricular activation is almost always taken from the _____.
Surface P wave, surface QRS complex
What is the term for when a V wave appears on the RA electrode?
Far field sensing
What information does the “stim” channel contain?
pacing output
Define: Incremental pacing (decremental)
pacing at a constant cycle length slightly shorter than the patient’s spontaneous rhythm then decreasing the cycle length ( or increasing pacing rate) by small steps
Define: Burst pacing
pacing at a fixed cycle length
Define: Pace mapping
a mapping technique designed to help locate the tachycardia focus by paving at different endocardial sites an comparing the characteristics/morphology of the paced beat to the reference beat. The reference beat is an ECG recorded during the clinical tachycardia.
Define: Entrainment mapping
Pacing at a cycle length slightly shorter than the tachycardia. If post pacing interval is short then the catheter is in the reentry circuit.
Define: Extrastimulus Testing
Drive train of typically 8 beats followed by 1, 2 or 3 premature beats. (S1, S1, S1……. S2, S3)
Define: ATP
Anti Tachycardic Pacing - pacing the heart faster than its intrinsic heart rate. Used for VT
What is the most common type of reentrant tachycardia?
AVNRT
Define: Macro reetrant
A circuit including the atrium, AV node, His/Purkinje system, ventricle and accessory pathway
Define: Antedromic pathway
down accessory pathway (AP), up the node (AV node)
Define: Orthodromic pathway
down node (AV), up accessory pathway (AP)
What is the most common SVT?
Atrial fibrillation
What is the most common type of A. flutter?
right atrium with counterclockwise propagation
What kind of reentry tachycardia is A. Flutter?
Macro reentry
What two conditions are associated with A. Fib?
hypertension and mitral regurgitation
What are the types of A. Fib?
Spontaneous or persistent
After being used in a patient, what type of catheters are considered “single use devices” and may be re-sterilized by 3rd party reproccesor companies and then reused on other patients?
Diagnostic EP catheters
because they have no lumen
What French size is a catheter with an outer diameter of 2.66mm?
8F
When using a 5F selective catheter through a 90 cm 5F sheath in cardiovascular procedures; it will be almost impossible to ______.
Flush the sheath because it is too tight
What mapping catheter uses 64 electrodes on eight self expanding splines as shown on x-ray?
basket catheter
What are the steerable catheters with handles and large platinum tips designed for?
radiofrequency ablations
What is the Hansen Robotic system?
Remotely steers guider catheters
What does the Ensite Velocity contact mapping system utilize?
Electrical impedance mapping
What does the Ensite non-contact mapping balloon catheter do with each heart beat?
Acquires all EGMs in one heart beat
What do closely spaced bipolar cardiac electrodes record locally?
Depolarization only (phase 0)
What should the ECG be filtered at?
0.1 - 100 Hz
What is the normal EGM filter settings for bipolar EP catheters?
30 - 300 Hz
If large T waves in an electrogram interfere with A or V wave recognition, what should you do?
Raise the high-pass filter
When filtering an EGM, a low pass filter setting of 500 would mean what?
Frequencies above 500 Hz will be eliminated
When a mapping catheter is guided to the site of origin of a focal tachycardia its distal bipolar EGM records the earliest intrinsic presystolic deflection. To confirm the focus, switch your mapping catheter to ____ and look for a ____.
Unipolar (filter settings 30 - 300 Hz), positive QR of R deflection
In general what is the longest amount of time a standard diagnostic guide wire should be used in the body before it is removed and carefully wiped with a heparinized gauze?
3 min
What are the standard equipment sizes of micropuncture introducer sets?
21-gauge needle, .018 inch wire
Compared to bipolar pacemakers the unipolar electrode configuration is more prone to what?
Pectoralis muscle stimulation and oversensing of EMI and muscle artifacts
Compared to the PPM, what does a TVP have considering voltage?
constant voltage and generates up to 20 volts
When connecting a bipolar pacing lead to the PSA or pulse generator the distal electrode should be connected to the __________ terminal.
black active negative
The 1st extrastimuli after a pulse train is labeled what?
S2
What are the two types of programmable paced beats?
Extrastimuli and incremental
A pulse train of 8 paced beats with a fixed cycle length is termed as what?
incremental pacing
When using the auto-decrement feature on a stimulator, what does a pause of 2000 indicate?
2 sec delay between drivetrains
The new RF transseptal needle that may be used to puncture a fibrotic or aneurysmal atrial septum has what feature?
side holes for pressure and contrast
In cardiovascular Doppler, what is the usual target off of which the ultrasound waves are reflected back?
RBC
What type of ultrasound test is the best way to rule out atrial thrombi prior to PVI?
TEE
What is a major advantage to using intracardiac echocardiography over a TEE?
General anesthesia is not needed
What does intracardiac echocardiography use as an injectable agent to view shunts or distinguish the right heart from the left heart chambers?
agitated saline (bubble study)
What type of ablation method is best suited for AVNRT slow path ablation?
RF
What type of ablation method is best suited for PVI for AF?
Cryoballoon
What type of ablation method is best suited for AFL cavo-tricuspid isthmus ablation?
Irrigated RF
What type of ablation method is best suited for AP near the AV node or in CS?
Cryocatheter
During RF ablation, what mode of heating is responsible for increasing the temperature of the ablation electrode and the closest 1-2mm of tissue?
Resistive heating
During RF ablation, what type of heating increases the temperature of the deeper tissue 2-5 mm beneath the electrode?
conductive heating
Using irrigated RF ablation catheter, how much power will be lost to passing blood if only half of the eletcrodes is in contact with the tissue?
more than half the power will be lost
What is the main mechanism of RF ablation?
tissue heating (burning)
With standard saline closed irrigated tip ablation catheters, what should be done to avoid endocardial burning and char formation when more than 30 watts are being delivered?
increase the flow to 15 - 30 ml/min
What type of pump is usually used with cooled or open irrigated ablation catheters?
Peristaltic (roller)
What is the cryoablation balloon for PVI inflated with?
N2O (Nitrous Oxide), the same a cryoablation
The cryoballoon (artic front) has 2 balloons one inside and one out. What is the reasoning for this?
Inflated with N2O and the other is to detect any leaks in the other balloon
How should you prep the cryo balloon prior to use?
Never pull the balloon sheath off the catheter
What size sheath does the artic frost catheter require?
12F
At what temperature and for how long is cryomapping performed?
-30 C for <60 sec
In cryoablation, when is the formation of an ice ball at the catheter tip and adherence to the myocardium is indicated?
Distal electrodes show electrical noise
Which valves are open during ventricular systole?
Semilunar valves
Where is the fibrous skeleton of the heart or annuli fibrosis located?
Around the heart valves
Where is the CS os located?
Posterior to the tricuspid valve
Where is the fossa ovale located?
Superior - posterior to the CS os
Where is the crista terminalis located?
Anterior to the IVC
What is the valve over the CS ostium that may interfere with the placement of the CS catheter?
Thebesian valve
To record the earliest depolarization from the SA node, where should you position the EP electrode?
Near the RA high lateral wall near the junction of the SVC
What does Bachman’s bundle connect?
RA - LA
The SA node lies at the junction of the SVC and the _______.
Superior end of crista terminalis
The SA node is innervated with which fibers of the autonomic nervous system?
Sympathetic and parasympathetic
The sides of the triangles of Koch are formed by the tricuspid annulus, the AV node, and what other boundary?
Tendon of todaro
The superior border of the triangle of koch is the tendon of todaro and it normally contains which pathway?
AV node fast pathway
Where are the pectinate muscles in the left atrium?
LA appendage
The vena cavae have a smooth inner endothelial lining, but the RA is heavily pectinated. What RA structure separates smooth muscle from pectinated muscle?
Crista terminalis
Most high-frequency depolarizations found in AF patients originate from where?
Muscular sleeve of the PVs
What is the diaphragmatic surfrace of the LV called?
Inferior wall
