Term
| What are the indications for Ablation? |
|
Definition
•Presence of life-threatening arrhythmias
•Drug-refractory tachycardias which incorporate a bypass tract
•Presence of tachyarrhythmias incorporating a bypass tract in a young person facing a lifetime of expense and morbidity of drug therapy |
|
|
Term
| What are the indications for doing a EP Study? |
|
Definition
•To assess conduction delays or blocks
•To evaluate and/or isolate the mechanism of SVT
•To evaluate and/or isolate the mechanism of VT
•Indications for patients with documented or suspected arrhythmias that require further study:
–Sinus node disease
–AV conduction delays or blocks
–Differentiate between SVT and VT |
|
|
Term
| The only definitive way to differentiate SVT with aberrancy (wide QRS complex tachycardia) from VT is what? |
|
Definition
|
|
Term
| An EP Study is mandatory if any of these are planned? |
|
Definition
–Automatic implantable cardioverter defibrillator (AICD)
–Surgical therapy ablation |
|
|
Term
| What are the contraindications to an EP Study? |
|
Definition
•When acute factors make the findings unrepresentative of the patient’s usual state.
–Electrolyte imbalance
–Acute ischemia
–Drug toxicity
•Any patient with cardiac disease makes it likely that induced arrhythmias will be extremely difficult to terminate such as:
–Acute myocardial infarction (AMI)
–Unstable angina
–Class IV heart failure
–Aortic ostium (AO) stenosis |
|
|
Term
| What are the risks and complications associated with cardiac catheterizations? |
|
Definition
–Thromboembolism
–Perforation
–Infection
–Arrhythmias |
|
|
Term
| What are the risks and complications associated with electrical stimulation performed during an EP study? |
|
Definition
•Atrial fibrillation
–Atrial stimulation may induce a-fib and with patients with WPW, a rapid ventricular response may occur causing hemodynamic compromise which requires urgent cardioversion.
–Non-symptomatic usually converts on its own after a couple of hours.
•Ventricular stimulation studies may still be performed during atrial fibrillation.
–Ventricular tachycardia/fibrillation |
|
|
Term
| What is a major risk associated with EP studies? |
|
Definition
| Induction of unstable ventricular arrhythmias is the major risk associated with EPS requiring immediate cardioversion/defibrillation. |
|
|
Term
| Surface ECG leads during EP studies are important why? |
|
Definition
–To determine morphology of induced arrhythmias
–To detect evidence of pre-excitation
–To find the earliest ventricular activity
–At least three surface ECG leads are recorded simultaneously with intracardiac ECG’s during EP studies. |
|
|
Term
| What is all of the equipment needed to perform EP studies? |
|
Definition
•Fluoroscopy unit
•Programmable stimulator
•Multichannel Physiologic Recorder
•Resuscitation equipment
•Introducer kit (Per-Q tray) / Cutdown tray
•Junction box or switch box
•Intracardiac electrode catheters
•Platinum tip unipolar electrode catheter
•NBIH bipolar temporary pacing electrode
•Tripolar catheters
•Quadripolar catheters
•Quadripolar His bundle electrode |
|
|
Term
| What are the catheter placement sites? |
|
Definition
•High right atrium (HRA)
•Coronary sinus (CS)
•His bundle (HBE)
•RV apex (RVA) |
|
|
Term
| What is the most common site for stimulation and recording in the right atrium? Why? |
|
Definition
–Most common site for stimulation and recording is the high posterolateral wall at the junction of the SVC in the region of the SA node. (HRA)
–SVC-Atrial junction site depolarizes the earliest (50% of population)
–Midlateral RA (2-3 cm inferior from the HRA site) depolarizes earlier in the other 50%. |
|
|
Term
| Catheter placement in the left atrium may be approached directly through what? |
|
Definition
–Atrial septum via atrial septal defect (ASD)
–Patent foramen ovale
–Transseptal needle puncture using the right femoral vein route |
|
|
Term
| What is the most commonly approached indirect method of recording the left atrium? |
|
Definition
| Most commonly approached indirectly by recording from the coronary sinus using the left basilic vein route (can also use IJ) |
|
|
Term
| When withdrawing de-saturated blood from the coronary through a luminal catheter what should the saturation be? |
|
Definition
| Less than 30% saturation through a luminal catheter |
|
|
Term
| Most easily identified and reproducible site for stimulation and recording |
|
Definition
|
|
Term
| When is Left Ventricle access required? |
|
Definition
| Access required for patients with pre-excitation syndrome and ventricular tachyarrhythmia's for stimulation and recording |
|
|
Term
| Catheter placement at the bundle of his is best accomplished how? |
|
Definition
| Best accomplished by the passage of tripolar or quadripolar catheter into RV using right femoral vein route and withdrawing across the tricuspid valve under fluoroscopy until a bundle potential is recorded |
|
|
Term
| What is the bundle of his? |
|
Definition
| (The bundle of His is a collection of heart muscle cells, specialized for electrical conduction, discovered by Swiss cardiologist Wilhelm His |
|
|
Term
| When reviewing the his bundle electrogram, which one should you use for your measurements? |
|
Definition
| The most proximal pair of electrodes displaying the His bundle electrogram with a large atrial electrogram should be used since the initial portion of the His bundle originates in the membranous atrial septum |
|
|
Term
| What is an Electrophysiology study? |
|
Definition
| Electrophysiology study is the technique of recording electrical potentials from conduction system within the heart. |
|
|
Term
| What are the components of the Intracardiac Conduction System that you will review in a EP Study? |
|
Definition
•SA node
•Internodal conduction pathways
•AV node
•Bundle of His
•Right and left bundle branches |
|
|
Term
| The decision for a pacemaker with most patients with sinus node disease is based on what? |
|
Definition
| History and Ambulatory monitoring |
|
|
Term
| The decision for a pacemaker in most cases for AV conduction delays or blocks is based on what? |
|
Definition
| History and surface ECG for patients with AV block |
|
|
Term
| What patients constitute a significant portion of patients with SVT requiring study? |
|
Definition
| patients with Wolff-Parkinson-White syndrome |
|
|
Term
| What are the ECG characteristics for Wolff-Parkinson-White syndrome? |
|
Definition
•QRS widened
•PR interval shortened
•Upstroke of QRS is slurred (delta wave). |
|
|
Term
| At least how many surface ECG leads are required during EP Studies? |
|
Definition
|
|
Term
| When must you use anticoagulation therapy when doing EP Studies? |
|
Definition
| When catheters are left in place for an extended period of time (45 minutes) and mandatory in left sided studies |
|
|
Term
| What is the normal value for CSNRT? |
|
Definition
|
|
Term
| What is the typical value range for SACT? |
|
Definition
|
|
Term
| What kind of data is need prior to ablation techniques being performed? |
|
Definition
| Data obtained from mapping to locate accessory pathways needed prior to ablation techniques |
|
|
Term
| What are the different types of ablation? |
|
Definition
•Cryoablation
•DC ablation
•Radiofrequency ablation (RF)
•Laser ablation |
|
|
Term
| A cryoablation catheter removes heat from the tissue to cool it to temperatures as low as what? |
|
Definition
| negative 75 degrees Celsius |
|
|
Term
| Results in electrophysiologic changes in the arrhythmogenic tissue render it nonarrhythmogenic tissue. |
|
Definition
|
|
Term
| Radiofrequency ablation (RF) is the most commonly used due to what advantages:? |
|
Definition
–Absence of barotrauma
–Absence of pain
–Lack of stimulation of muscles
–Control of focal injury
–Smaller lesions than with DC ablation |
|
|
Term
| Use of alternating current resulting in thermal injury with coagulation necrosis and desiccation |
|
Definition
| Radiofrequency ablation (RF) |
|
|
Term
| What are the "tools" of EP studies? |
|
Definition
| Incremental pacing and the introduction of programmed single or multiple extrastimuli during sinus or paced rhythms are the "tools" of EP studies |
|
|
Term
| When is the stimulation threshold determined in EP? |
|
Definition
|
|
Term
| Incremental pacing technique is used for what? |
|
Definition
–Evaluating sinus node function
–Evaluating AV node conduction
–Inducing SVT and ventricular arrhythmias
–Terminating SVT and ventricular arrhythmias |
|
|
Term
| What are the two types of incremental pacing? |
|
Definition
•Decremental pacing
•Ramp pacing |
|
|
Term
| What are the advantages of Decremental pacing? |
|
Definition
| Advantage includes time allowed for assessment after each step. |
|
|
Term
| What are the advantages of Ramp pacing? |
|
Definition
| Advantage includes shortened study if all that is needed is the A-V nodal Wenckebach |
|
|
Term
|
Definition
| Begins at a cycle length slightly below the intrinsic rate with progressive shortening of the cycle length in 10 to 50 msec decrements up to 250 msec and/or cycle length at which A-V Wenckebach occurs. |
|
|
Term
|
Definition
| Is a continuous paced drive with gradual decreases in cycle lengths after several paced complexes at same cycle length until A-V Wenckebach occurs. (Shorter technique than Decremental pacing with both being comparable.) |
|
|
Term
| When doing atrial pacing most patients develope Wenckebach type II block at what paced atrial cycle lengths? |
|
Definition
|
|
Term
| What is the normal response to atrial pacing? |
|
Definition
Normal response to atrial pacing is for the A-H interval to gradually lengthen as the cycle length is decreased until A-V nodal block.
–Wenckebach-type II appears. |
|
|
Term
| Prolongation of the H-V interval (or infra- block) produced at paced cycle lengths of 400 msec or greater are abnormal and probably signify what? |
|
Definition
| impaired infranodal conduction (BBB) |
|
|
Term
| Ventricular Pacing resulting in ventriculo-atrial (V-A) conduction occurs in what % of population? |
|
Definition
| Occurs in 40 to 90% of patients depending on population studied |
|
|
Term
| What is the fulcrum of the conduction system? |
|
Definition
|
|
Term
| Normal response to incremental ventricular pacing is what? |
|
Definition
| A gradual prolongation of V-A conduction |
|
|
Term
| Improvement of V-A conduction after giving drugs suggest that the site of block is where? Which drugs can you use? |
|
Definition
-AV node
–Atropine or isoproterenol affect only AV node conduction |
|
|
Term
| Relative Refractory Period (RRP) |
|
Definition
| Longest coupling interval of a premature impulse that results in prolonged conduction of the premature impulse relative to that of the basic drive. |
|
|
Term
| Marks the end of the full recovery period, the zone during which conduction of the premature and basic drive impulses are identical |
|
Definition
| Relative Refractory Period (RRP) |
|
|
Term
| Effective Refractory Period (ERP) |
|
Definition
| Longest coupling interval between the basic drive and the premature impulse that fails to propagate through a cardiac tissue. |
|
|
Term
| Where must the Effective Refractory Period (ERP) be measured? |
|
Definition
Must be measured proximal to the refractory tissue.
–Atrium: Longest S1 - S2 fails to depolarize the atrium.
–AV node: Longest A1 - A2 fails to propagate to His bundle. |
|
|
Term
| Functional Refractory Period (FRP) |
|
Definition
| Minimum interval between two consecutively conducted impulses through a cardiac tissue. |
|
|
Term
| The paced drive (Drive Train) should be at a fixed cycle length within the physiologic range, which is what? |
|
Definition
|
|
Term
| Stimulus strength of the drive train has been standardized as what? |
|
Definition
| Twice the diastolic threshold |
|
|
Term
| Typical normal values for ERP are what? |
|
Definition
–Atrial: 200 – 270 msec
–A-V node: 280 – 450 msec
–Ventricle: 200 – 270 msec |
|
|
Term
| What paper speed should the SA node function (SNRT, SACT) be recorded at? |
|
Definition
|
|
Term
| What paper speed should refractory period studies be recorded at? |
|
Definition
|
|
Term
| What paper speed should detailed mapping of the endocardial activation be recorded at? |
|
Definition
|
|
Term
| What is the range of paper speed? What is the accuracy at the minimum and maximum speeds? |
|
Definition
Range between 100 mm/sec to 400 mm/sec affects the accuracy of measuring an intracardiac interval:
•Accuracy at 100 mm/sec is +/- 5 msec.
•Accuracy at 400 mm/sec is +/- 1 msec. |
|
|
Term
| What is measured from onset of surface ECG (P wave) to first rapid atrial deflection of the HBE? What is the normal value? |
|
Definition
-P-A Interval
-Normal time 20 to 50 msec |
|
|
Term
| Prolongation of the P-A Interval is usually a result of what? |
|
Definition
| atrial enlargement or atrial hypertrophy |
|
|
Term
| What is measured from the onset of the atrial spike on HBE to the onset of the His bundle spike? What is the normal value? |
|
Definition
-A-H Interval
-Normal conduction time (in sinus rhythm) 45 to 140 msec |
|
|
Term
| Prolongation of the A-H Interval indicates what? |
|
Definition
|
|
Term
| The A-H Interval can vary by how much due to sympathetic/parasympathetic tone? |
|
Definition
|
|
Term
| What is measured from the earliest deflection of the His bundle potential from baseline to the earliest onset of ventricular activation recorded from multiple surface ECG leads or from the ventricular ECG in the HBE? What is the normal value? |
|
Definition
-H-V Interval
-Normal interval 35 to 55 msec |
|
|
Term
| Prolongation of the H-V Interval represents what? |
|
Definition
| Prolongation represents bundle branch block that may require permanent pacing |
|
|
Term
| In assessing the A-V conduction system, 90% of A-V conduction defects can be defined within what electrogram? |
|
Definition
|
|
Term
| What is the normal duration of the HBE? |
|
Definition
|
|
Term
| His bundle deflection should be no less than how many msec from the ventricular depolarization in adults? |
|
Definition
•35 msec
•Deflection occurring 30 msec or less before ventricular activation reflects a recording of a bundle branch potential usually the right |
|
|
Term
| Describe the Intra-atrial activation and conduction. |
|
Definition
•Normal activation can begin either in the high or midlateral RA.
•Spreads to the low atrium and A-V junction, then to the LA |
|
|
Term
| Earliest retrograde atrial depolarization is recorded where in what sequence? |
|
Definition
| Earliest retrograde atrial depolarization is recorded in the HBE, then in the adjacent RA and CS, and finally in the HRA and LA. |
|
|
Term
| What is diagnosed when a precipitous fall in blood pressure is accompanied by a reduction in heart rate (low 40s or lower). |
|
Definition
|
|
Term
| What is hypotension not associated with decreased heart rate. |
|
Definition
|
|
Term
| What is diagnosed by a gradual (not precipitous) fall in blood pressure without any significant change in heart rate. It eventually reaches levels associated with loss of consciousness (LOC). |
|
Definition
Autonomic dysfunction
(Patients with autonomic dysfunction also demonstrate an abnormal response to the Valsalva maneuver in that they do not exhibit blood pressure overshoot when the maneuver is terminated.) |
|
|
Term
| Medications that commonly contribute to syncope include what? |
|
Definition
–Antihypertensives (all of them)
–Tricyclic antidepressants
–Phenothia/ine
–Quinidine/quinine |
|
|
