Clin Med: Cardio II Flashcards
Takotsubo cardiomyopathy mimics…
MI, but w/o ischemia
Stress cardiomyopathy: Background
Temp heart condition w/ rapid heart muscle weakening following extreme stress
Stress cardiomyopathy: pathophys
Catecholamines released during stress affect the myocardium of the heart
Examples of severe emotional stress
- death of loved one
- divorce
- breakup
- losing job, home, money
Examples of severe physical stress (5)
- severe pain
- running marathon
- asthma attack
- stroke
- surgery
Stress cardiomyopathy is more prevalent in which gender?
female
Stress cardiomyopathy: S/S
- angina
- diaphoresis
- nausea
- vomiting
- dyspnea
- palpitations
- decr BP
Stress cardiomyopathy: Dx
- Hx of stressful, emotional, or physical event
- EKG (ST elevation or T wave inversion)
- Blood test (Troponin & cardiac enzymes typically normal vs MI)
- Coronary angiogram (no obstruction)
- Ventriculography (LV Gram) & Echo (ballooning of LV w/ unusual muscle wall movement)
- Cardiac MRI
Stress cardiomyopathy: Tx
- usually resolves w/ med management
- ACE inhibitors (control BP)
- Beta blockers (regulate HR)
- Diuretics (maintain fluid balance)
- Anti-anxiety meds & stress management techniques
Cardiac muscle contraction is dependent on…
- Na+
- K+
- Ca++
3 general categories of dysrhythmias
- Slow
- Fast
- Other
Sinus bradycardia: Hx
- Syncope
- Dizziness
- Lightheadedness
- Chest pain
- Shortness of breath
- Exercise intolerance
Sinus bradycardia can be normal in which people?
athletes
Rate for Sinus bradycardia
< 60bpm
What can causes Sinus bradycardia?
- hypothermia
- hypothyroidism
- drugs (beta blockers, Ca++ channel blockers)
- myocarditis,
- hypoglycemia
Sinus bradycardia: Hx
- Syncope
- Dizziness
- Lightheadedness
- Chest pain
- SOB
- Exercise intolerance
In pts w/ sinus bradycardia what should you ask about?
- Cardiac history (MI, CHF, valve dz)
- Meds, Toxic exposures
Sinus bradycardia: PE
- Will depend on underlying cause & severity
- Decr LOC
- Cyanosis
- Peripheral edema
- Dyspnea
- Syncope
- Mottled skin
Which pts do we usually see heart blocks in ?
elderly patients
Sinus bradycardia: Dx Labs/imaging
- EKG
- Electrolytes (Na+, K+, Ca++, Mg++)
- Glucose
- Thyroid Function Test
- Toxicology screens
- Troponin
- Others based on probable underlying cause
What is troponin?
cardiac enzyme that is elevated when heart muscle has died due to lack of O2 (MI)
Sinus Bradycardia: Tx
- Treat underlying cause, but do not delay care
- Atropine
- Transcutaneous pacing
- Transvenous pacing
**Expert consult
What is the main med used for Sinus bradycardia?
Atropine
How does atropine work?
binds to & inhibitors muscarinic receptors–> producing wide range of anticholinergic effects–> increases HR
Define a heart block
term for arrhythmia where there is a delay or “block” somewhere along the conduction system
Why do heart blocks occur?
Usually occur as a result of damage to the conduction system (fibrosis, ischemia), but often idiopathic
Where is the signal delayed in a 1st degree AV block?
AV node
What is the PR interval in a 1st degree AV block?
> 200ms
How does the pt usually present w/ 1st degree AV block
asymptomatic & found incidentally
Does a 1st degree AV block require tx?
not usually unless underlying cause (i.e. electrolyte imbalance or due to meds)
Other names for 2nd degree Type I heart block
- Mobitz Type I
- Wenckebach
NOTE
2nd degree: Type I has a consistent P:QRS ratio
2nd degree Type I is often transient, but may occur due to…
- myocardial ischemia
- myocarditis
- cardiac surg
Describe a 2nd degree Type I
Progressive lengthening of the PR interval until a QRS is dropped
When does 2nd degree Type I need tx?
doesn’t need treatment unless symptomatic
2nd degree Mobitz Type I: Tx
Atropine
only if symptomatic
Describe PR interval & QRS complex for 2nd degree Type II heart block.
- PR interval consistent
- Intermittent dropped QRS complexes (may be fixed)
2nd degree Type II heart block usually due to…
- ischemia–> damage to the conducting system
- Lyme Dz
3rd degree heart block aka…
complete heart block
3 degree heart block: Tx
- required transcutaneous pacing STAT
- transvenous cardiac pacing
- some will req permanent cardiac pacing
A 3rd degree heart block is…
total block b/t atria & ventricles
3rd degree heart block: S/S
- fatigue
- chest pain
- SOB
- dyspnea
- may be hemodynamically unstable
Describe sinus tachycardia.
regular narrow-complex tachycardia
Describe P wave and QRS complex for Sinus Tachycardia.
- P wave is before every QRS
may be hard to see if fast
Sinus tachycardia: HR
> 100 in adults (peds depends on age)
Sinus Tachycardia: almost always due to…
some underlying issue
Sinus Tach: other common cause (10)
- exercise
- pain
- fever
- hyperthyroidism
- HF
- anemia
- alcohol withdrawal
- drug use
- caffeine
- dehydration
Sinus Tach: Tx
treat underlying issue
AVNRT is a type of…
supraventricular tachycardia
Describe AVNRT
regular, narrow tachycardia
AVNRT Rate
170 - 180
can be as high as 300
AVNRT: S/S
- palpitations**
- lightheadedness
- dyspnea
AVNRT is most common in which gender?
females
AVNRT: Stepwise tx
vagal maneuvers–> adenosine–> BB–> cardioversion
Which “A” drug is used for AVNRT?
adenosine
Atrial flutter: Rate
300 -400
Atrial flutter pattern?
saw tooth pattern w/ narrow QRS
Atrial flutter: S/S
asymptomatic or have palpitations/lightheadedness
Atrial flutter: Tx if stable
rate control w/ diltiazem or verapamil
Atrial flutter: Tx if unstable
anticoagulation & cardioversion
What is Afib & cause?
a common supraventricular tachyarrhythmia caused by uncoordinated atrial activation & associated w/ an irregularly irregular ventricular response
Most common arrhythmia that is considered as irregularly irregular?
Afib
NOTE
Afib is a MAJOR preventable cause of stroke
Define persistent AF
AF that fails to self-terminate w/n 7 days.
- Often req pharmacologic or electrical cardioversion to restore sinus rhythm.
Categories of Afib
- Paroxysmal AF
- Persistent AF
- Long-standing persistent AF
- Permanent AF
Define paroxysmal AF
AF that terminates spontaneously or w/ intervention w/n 7 days of onset. Episodes may recur w/ variable frequency.
Define long-standing persistent AF
AF that has lasted >12mo
NOTE
While a pt who has had persistent AF can have later episodes of paroxysmal AF, AF is generally considered a progressive disease.
Define permanent AF
used to identify ppl w/ persistent Afib where a joint decision by the pt & clinician has been made to no longer pursue a rhythm control strategy.
Describe prevalence of Afib
- 1-2% of gen pop
- 9% is > 65yo
Most common 2ndary causes for AFib
- HTN
- CAD
Afib: pathophys
several reentrant circles in the atria that causes random signals to get through to the ventricles which usually have a normal rate
Afib: Hx-S/S
- usually firstly asymptomatic
S/S
- palpitations
- SOB
- lightheadedness/dizziness
- focal neurological deficit (embolic stroke)**
Afib: PE
- Irregularly irregular HR
- may have evidence of HF
- Evidence of underlying issues (hyperthyroidism, etc)
Afib: Dx labs/imaging
- EKG
- TTE or TEE
- TSH
- Check for suspected underlying conditions
What fraction of pts w/ new onset Afib will spontaneously revert to NSR w/o need for cardioversion?
2/3
New Onset Unstable Afib: Tx
- IV BB (esmolol, propranolol, metoprolol) or CCB (diltiazem or verapamil)
- Heparin
- Electrical cardioversion if severe HTN, pulmonary edema, ischemia*
- Admit