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