Approach and Dysrhythmias I - Exam 3 Flashcards
What is the tx for sinus arrhythmia?
NO treatment! It is normal for heart rate to increase with inspiration and decrease with expiration
What is sinus bradycardia defined as? What is it due to?
HR slower than 60 bpm
Due to increased vagal influence on the normal pacemaker or organic disease of the sinus node (sick sinus syndrome, etc)
What is considered severe sinus bradycardia? What does it usually indicate?
Less than 45 bpm
sinus node pathology especially in elderly patients
What are some causes of sinus bradycardia?
Drugs, increased ICP, Anterior wall MI, OSA, hypothyroidism and hypothermia
What is a presentation of sick sinus syndrome?
Commonly have recurrent supraventricular arrhythmias (such as atrial fibrillation) and bradycardia (tachy-brady syndrome) or can have sinus arrest, or persistent sinus bradycardia, chronotropic incompetence (HR will not increase with normal daily activities)
What is the tx for SSS? What do you need to check before?
If symptomatic -> Permanent pacemaker
need to make sure the SSS is NOT caused by medications. Hold meds
What is the tx for sinus bradycardia?
Without meds if the cause, rule out other possible causes, if symptomatic -> pacemaker
What is sinus tachycardia defined as? What is the MC cause?
Defined as a HR > 100bpm (adult) - (220-Age) due to impulse formation from SA node, exercise, anger/stress
Rarely, sinus tach can reach ____ and even ____ in younger pts.
Greater 160
greater 180 in younger pts
In sinus tach at rate greater than 140 bpm, _____ may be difficult to identify. What do you need to consider?
P waves
consider carotid sinus massage or vagal maneuver
______ occurs in the absence of heart disease or secondary causes with increased resting HR and/or exaggerated HR response to exercise.
Inappropriate Sinus Tachycardia
What is POTS? Who is the classic patient?
Postural orthostatic tachycardia syndrome Exaggerated sinus tachycardia elicited by upright TTT occurs in the absence of orthostatic hypotension, Young women w/o heart disease w/ normal resting HR
In symptomatic patients with inappropriate sinus tachycardia, with or without correctable cause, what is the tx?
BB are first line, consider non-DHP CCB or ivabradine
What is first degree AV block defined as?
PR interval > 0.2 second with all atrial impulses conducted
What is second degree, Mobitz type 1 AV block defined as ? What is it due to?
the AV conduction time (PR interval) progressively lengthens, with the RR interval shortening before the blocked beat
Abnormal conduction within the AV node
What is second degree, Mobitz type II AV block defined as ? What is it due to?
there are intermittently nonconducted atrial beats not preceded by lengthening AV conduction
It is usually due to block within the His bundle system.
What is third degree AV block defined as?
complete heart block; complete A-V dissociation, in which no supraventricular impulses are conducted to the ventricles
What are the causes of first degree and Mobitz type 1 block?
What are the causes of Mobitz Type II and third degree block?
What is considered a high grade AV block?
Mobitz type II and 3rd degree
What are the s/s of 1st degree AV block?
Completely asymptomatic, dx by EKG alone, no PE abnormalities
What type of block? ________Most commonly asymptomatic; however, may note palpitations, DOE, or dizziness. Will hear irregular rhythm on auscultation
Mobitz type 1 aka the patient may feel a pause
What type of block? ______ May be asymptomatic, but COMMONLY presents with palpitations, DOE, weakness, or dizziness. Will hear irregular rhythm on auscultation
Mobitz type II block aka dropping more often, the lower the HR the worse the symptoms
What kind of block? _______ Symptoms vary, and are worse with exertion; palpitations, DOE, weakness, near syncope, syncope, and/or heart failure. Symptoms vary, and are worse with exertion; palpitations, DOE, weakness, near syncope, syncope, and/or heart failure
3rd degree AV block
What diagnostic studies should you order if concerned about AV block?
EKG, telemetry monitoring, Echo, if ischemic -> cardiac cath, CBC, CMP, TSH, mag
What is the management for first degree AV block?
Nothing unless concerned for underlying heart disease but do need to avoid meds that prolong PR interval and slow AV conduction
What is the tx for Mobitz type I? What if unstable bradycardia is present?
usually stable, avoid AV node conduction slowing drugs
consider atropine, transcutaneous or transvenous pacing
What is the tx for high grade heart block?______ is typically avoided
Permanent pacemaker implantation, could also consider IV dopamine or dobutamine infusions, atropine is avoided
What is the tx for transient high grade heart block due to ACUTE organic process?
Temporary pacing
______ is a common cause of paroxysmal tachycardia. What type of patient is most common?
Paroxysmal Supraventricular tachycardia, patients with normally structured hearts
The most common mechanism for paroxysmal supraventricular tachycardia is _____. Typically initiated by a ____ or ____
reentry
PAC or PVC
What are two common types of reentry? Give a brief summary of each. Which one is MC?
AVNRT (AV nodal reentrant tachycardia) – most common form and found WITHIN the AV node
AVRT (AV reciprocating tachycardia) think OUTSIDE of itself: think WPW or LGL
- WOLFF-PARKINSON-WHITE SYNDROME is an accessory pathway that exists by __________.
Bypassing the AV node
What is the WPW pattern on EKG?
Delta wave, wide QRS and short PR
What is WPW syndrome?
WPW pattern and coexistence of a tachyarrhythmia and clinical symptoms of tachycardia such as palpitations, episodic lightheadedness, presyncope, syncope, or even cardiac arrest
What can the WPW pattern pathway lead to?
The pathway can either initiate and maintain an arrhythmia (AVRT) or allow conduction of an arrhythmia generated elsewhere (the latter can lead to significantly tachycardic rhythms predisposing patients with WPW to sudden cardiac death)
What is the tx in a PCP setting for WPW pattern present on EKG?
Refer to cardio/EP because they have high risk features that need further testing
What are the s/s of WPW? What is the timing?
Rapid heart beat, chest pain, SOB, dizzy, syncope, abrupt onset and termination, can least seconds to several hours or longer
What will the rhythm be in WPW? QRS complex? P wave?
Regular rhythm, QRS is commonly narrow but can be wide, P wave is often buried in the QRS complex
What are the mechanical tx options for WPW in an acute setting?
Valsalva, Stretching the arms and body, lowering the head between the knees, coughing and holding their breath, Splashing cold water on the face, placing ice or frozen peas on the face, carotid sinus massage (but this one should only be done by a trained provider in a healthcare setting!)
What is the initial pharm management for WPW in an acute setting?
1st: adenosine
2nd line: diltiazem or verapamil
3rd line: esmolol or Lopressor. All meds given IV. Meds do not work or CI then electric cardioversion
What is the refractory SVT drug therapy?
Amiodarone or procainamide for wide complex SVT
What is the first line tx for WPW if the pt is hemodynamically unstable?
Cardioversion (electrical)
What is the prevention/ long term management for WPW?
Catheter ablation
What is the pharm management for WPW in the long term?
BB and CCBs and may need to add on (flecainide or propafenone) or (amiodarone or sotalol)
Patients with AVRT (WPW) are also prone to ____ and _____
afib and aflutter
Most arrhythmias can be classified as one of 4 things, what are they?
Disorders of impulse formation or automaticity, abnormalities of impulse conduction, reentry, triggered activity
Define palpitations.
defined as an unpleasant awareness of the beating of the heart
When assessing a patient with palpitations, the goal is to determine whether the symptoms represent: what 4 things?
an arrhythmia that is minor and transient, significant cardiovascular disease, a cardiac manifestation of a systemic disease: such as thyrotoxicosis,. a benign somatic symptom that is amplified by underlying psychosocial characteristics of the patient
What are the historical risk factors that increase the risk of serious cardiovascular cause of palpitations?
Family hx of significant arrhythmias, personal/family hx of syncope or resuscitated sudden death, hx of MI
What are some PE findings that increase the risk of serious CV cause of palpitations?
Structural heart disease such as dilated or hypertrophic cardiomyopathies, valvular dz, laterally displaced PMI, murmurs, gallops
What are some EKG findings that increase the risk of serious CV cause of palpitations?
Prolonged QTC, bradycardia, 2nd or 3rd degree heart block, sustained ventricular arrhythmias
“Flip-flopping” (or “stop and start” or “skipped beats”) is often a result of _______
premature contractions
Rapid “fluttering in the chest” is regular think ______. If irregular think ______
regular fluttering: SVT, sinus tach, VT
Irregular flutter: afib
“Pounding in the neck” want to think ______
afib or aflutter or PAC
When working a pt up for palpitations, ALL pts need ______.
EKG
What ambulatory monitoring device? ______ 24-72 hours only and monitors every heart beat
holter monitor
What ambulatory monitoring device? ______ only records events and can be worn for 7 days up to 30 days
event monitor
What ambulatory monitoring device? ______ can be worn for 7-30 days, monitors every beat and can send information in real time
real-time monitors/patch recorders
What ambulatory monitoring device? ______ good for infrequent event and sends monthly transmission or when the pt requests the information to be transmitted
implantable loop recorders
When are invasive electrophysiology testing used?
Useful if the ambulatory monitor records a worrisome arrhythmia or if serious arrhythmias are strongly suspected despite normal findings on the appropriate ambulatory monitor
How does electrical cardioversion work? How many joules of energy? What does it cause?
Uses the application of a selected amount of energy, which is generally between 50-360 J, via two electrodes (paddles), Causes a mass depolarization of tissue and leads to prolonged refractoriness, “resetting” the action potential / impulse propagation source
________ is a chemical cardioversion therapy and is rarely used do the high amounts of monitoring, can only be used in the ICU
Ibutilide (Corvert)
Does electrical cardioversion require informed consent? Sedation?
YES to both except in the case of an unstable emergency situation
What are some risks/ complications of electrical cardioversion?
VT/VF due to general anesthesia or lack of synchronization between the DC shock and the QRS complex, Thromboembolus due to insufficient anticoagulant therap, Arrhythmias, myocardial necrosis, transient hypotension, pulmonary edema, skin burn
In a catheter ablation, circuit disruption is caused by _____ or _______.
radiofrequency or cryotherapy. Reentrant pathways are mapped and then ablated
Catheter ablation has become the primary modality of therapy for many supraventricular arrhythmias including what 3?
AV nodal reentrant tachy, paroxysmal atrial tachy, atrial flutter
What does afib ablation involve?
Is very complex and involves complete electrical isolation of the pulmonary veins (which are often the sites of initiation of atrial fibrillation) or placing linear lesions within the atria to prevent propagation throughout the atrial chamber. These are typically LESS successful
______ are also commonly performed. _____ are difficult and typically only performed in experienced centers
PVC ablations
VT ablations
______ happens in low incidences with catheter ablation. What does it result in?
perforation of the myocardial wall, results in pericardial tamponade
A rare but potentially fatal complication after catheter ablation of _____ is the development of an _______ resulting from ablation on the posterior wall of the LA just overlying the esophagus.
atrial fibrillation
atrio-esophageal fistula
Pacemakers are indicated only for ______, and do not shock (cardiovert/defibrillate) ______.
Bradyarrhythmias
tachyarrhythmias
_____ are indicated to prevent SCD, and ALL include pacemakers
ICDs (Implantable cardioverter-defibrillators
**What are the 3 pacemaker indications? What is important to note?
SYMPOTMATIC bradycardia, high- grade AV block, Sinus pauses or afib pauses with symptoms
NO REVERSIBLE CAUSES ARE IDENTIFIED
** What are the ICD indications?
Primary prevention of Sudden Cardiac Arrest (VT/VF), EF < 35% or other at-risk population (Long QT, Brugada, Hypertrophic Cardiomyopathy), Secondary prevention of Sudden Cardiac Arrest (VT/VF
How can you tell a defib wire from pacemaker wire on CXR?
Defib wires are thicker and have a shock-coil on the end
**What is the patient education regarding pacemakers and ICDs?
What is this?
Pacemake spike
What is this?
Inappropriate pacemaker spikes, needs to call cardio!
