Lecture 3 (Conduction Disorder)-Exam 2 Flashcards
Sick Sinus Syndrome:
* What is it?
* What does not meet the physiologic needs of body?
- Dysfunction of SA automaticity and impulse generation
- Atrial rate does not meet physiologic needs of body
Sick Sinus Syndrome
* What is the MCC?
* What can be apart of sick sinus syndrome?
MCC – idiopathic SA node fibrosis
* Sinus bradycardia
* Sinus pause < 3 seconds
* Sinus arrest > 3 seconds
* Bradycardia-tachycardia syndrome
What are some pharm causes of SSS?
What do you need to diagnosis SSS?
Bradycardia ± tachycardia plus
Symptoms of end organ hypoperfusion
* Presyncope/syncope (CNS)-MC
* Lightheadedness
* Confusion
* Fatigue
* Palpitations
Who is hemodynamically unstable with SSS?(5)
What is the first line treatment of SSS?
atropine
SSS treatment algorithm:
* What dx tests and placements should you do?
* What is the first dose?
* What can be successful at first? BUT what should you be prepared for?
- ECG: electrocardiogram; BP: blood pressure; IV: intravenous; PPM: permanent pacemaker; SSS: sick sinus syndrome.
- The initial dose of atropine is 0.5 mg IV push. This dose may be repeated every three to five minutes to a total dose of 3 mg
- While transcutaneous pacing may be initially successful in stabilizing the patient, it may not be consistently reliable and is frequently uncomfortable for the patient. Prepare for urgent transvenous pacing (if required) and obtain central venous access (preferably right internal jugular vein access).
SSS treatment algorithm:
* What should you look for once they are stable?
Reversible causes:
* Medications
* Electrolyte abnormalities
* Ischemia
* Automic dysfunction
When is a permanent pacemaker recommended?
* What are the pros (2) and one con?
PPM placement recommended for symptomatic patients with SSS and documented bradycardia
* Relieves symptoms
* Improves QOL
* Does not impact survival
LAST LINE
Bradycardia treatment algoritum
* What do you do first?
* How do you identify and treat underlying causes?
* What happens if there is persistent bradyarrhtythmia?
* What do you give?
What is the dosing of atropine, dopamine and epinephrine?
What is the MOA of atropine?
Blocks acetylcholine from binding to muscarinic receptors
Blocks the rest and digest effects of the parasympathetic nervous system on the heart
* Rapid firing of nodes
* Decrease conduction time of AV node
* Increases HR
Atropine:
* What are the cardiac indications? (2)
- First-line therapy for symptomatic bradycardia
- Structural disease of infra-nodal system of the heart or heart rate < 50 bpm
What are the SE of Atropine?(6)
- Xerostomia
- Blurred vision
- Tachycardia
- Flushing
- Constipation
- Urinary retention
What is the dose of atropine?
0.5 to 1mg IV push q3 to 5min; max 3mg
What are the causes and clinical signifiance of all 4 types of AV blocks?
Heart Block Causes:
* What is key?
* What can be some causes?
Heart block causes:
* What do you give for overdoses on CCB, BB, digoxin?
- CCB - calcium
- Beta blockers - glucagon / insulin
- Digoxin - digibind
Heart Block causes:
* What do you do/give for hypothermia, hypothyroidsm and lyme’s disease?
- Hypothermia - re-warm
- Hypothyroidism - levothyroxine
- Lyme’s Disease - ceftriaxone
- past lecture: Ceftriaxone for advance, doxy for not advance and amox for preg
First degree Mobitz I treatment
* What is it?
* What is the txt for table, aymptomatic patients?
* What is the txt for unstable patients?
Prolonged conduction through AV node
Stable, asymptomatic patients (MC)
* Watch and wait
* Look for underlying cause
Unstable patients – drug therapy
* Atropine
First degree /Mobitz I treatment
* What is rarely indicated?
* What may patients with low BP or HF require?
- Pacing is rarely indicated
- Patients with low BP or HF may required pressors / transvenous pacing
Second degree Mobitz II treatment
* What is it?
* What do you do for stable patients?
- Conduction disease below AV node (Bundle of His)
- Stable patients: Transcutaneous pacer pads in place
Second degree Mobitz II treatment
* What is the treatment for unstable (4)
* What should you do once stabilized?
* What if nothing is found?
Unstable
1. Atropine
2. Transcutaneous pacing
3. Dopamine (low BP) or dobutamine (HF)
4. Transvenous pacing
Once stabilized evaluate for reversible causes
Permanent pacemaker if no underlying cause found / does not respond to treatment