MTB and important from FA Flashcards
Left circumflex coronary artery (LCX) supplies
Lateral and posterior walls of left ventricle
Anterolateral papillary muscle
Left anterior descending artery (LAD) supplies
Anterior 2/3 of interventricular septum
Anterolateral papillary muscle
Anterior surface of left ventricle
Posterior descending/interventricular artery (PDA) supplies
Posterior 1/3 of interventricular septum
Posterior walls of ventricles
Posteromedial papillary muscle
Increased pulse pressure in
- Hyperthyroidism
- Aortic regurgitation
- Aortic stiffening (isolated systolic hypertension in elderly)
- Obstructive sleep apnea (sympathetic tone)
- Exercise (transient)
- aortic arch receptors transmit via…to…
2. carotid receptors transmit via
- VAGUS 2. GLOSSOPHARYNGEAL
both to SOLITARY nucleus of medulla
Cushing reaction triad
- hypetension
- bradycardia
- respiratory depresion
Electrolyte disturbances - ECG?
- U waves and flattened T waves in low K+
- wide QRS and peaked T waves in high K+
- torsades de pointes in low Mg2+
- QT prolongation in low Ca2+
- Bradycardia/cardiac arrest in high Mg2+
JVP - phases
a wave - c wave - x descent - v wave - y descent
JVP - a wave
atrial contraction
JVP - c wave
RV contraction (closed tricuspid valve bulging atrium)
JVP - x descent
atrial relaxation and downward displacement of closed tricuspid valve during ventricular contraction
JVP - v wave
increased right pressure due to filling against closed tricuspid valve
JVP - y descent
RA emptying into RV
AV block 1st degree - ECG / treatment
The PR interval is prolonged (>200msec)
- asymptomatic: no treatment (no matter how low HR)
- symptomatic: atropine as initial, pacemaker as most effective
AV block 2nd degree - types
Mobitz type I (Wenckebach)
Mobitz type II
Mobitz 1 - ECG, treatment, causes
progressively lengthening PR interval that results in a dropped beat
sign of normal aging of the conduction system
treat like sinus bradycardia
Mobitz 2 - ECG, mechanism, treatment
Mobitz 2 is a far more pathologic than Mobitz 1. It just drops a brat without the progressive legthening of the PR interval. It progress or deteriorates into 3rd degree AV block. Treat like 3rd degree AV block. Everyone with Mobitz II block gets a pacemaker even if they are asymptomatic
3rd degree AV block
the atria and ventricles beat intependently of each other
Sinus bradycardia - treatment
- no treatment if asymptomatic (no matter how low the heart is
- if symptomatic: use atropine as the best initial therapy, and pacemaker as the most effective therapy
58 woman 2 days after MI has VT even under aspirin, heparin, lisinopril nad metoprol. next step in
angiography for angioplasty or bypass
manage arrhythmias from ischemia by correcting ischemia
when to do precordial thump?
very recent of onset of arrest (less than 10 minutes) with no defibrillator available (you know it is recent because you saw it hapen)
VT manegment
based on the hemodynamic status
- pulselss: like VF
- hemodynamically stable: medications (amiodarone then lidocaine then procainamide), if fail, cardiovert the patient
- hemodynamicallyun stable: electrical cardioversion several times, followed by medications (such as amiodarone, lidocaine or procainamide)
VT with hemodynamic instability is defined as
- chest pain
- dyspnea/CHF
- hypotension
- confusion
Pulseless electrical activity - treatment
correct the underlying cause:
acute AF - treatment
- hemodynamically unstable: synchronized cardioversion.
- hemodynamically stable: rate control (target 60-100) with b-blockers or CA2+ blokcers. After rate control is achieved, cardiovestion. Electrical cardiovesion is preferred over pharmacological (if fails or not feasible: amiodarone etc)
chronic atrial fibrillation - routine cardioversion
not indicated because the majority of these who are converted into sinus rhythm will not stay in sinus. atrial fibrillation and flutter are caused by anatomic abnormalities of the atria due to hypertension or valvural disease. Shocking into sinus rhythm does not correct a dilated LA. over 90% will revert fibrillation even with the use of of antiarrhythmic medication
chronic atrial fibrillation - treatment
the best initial therapy for fibrillation and flutter is to control the rate with beta blockers calcium channel blockers or digoxin. Once the rate is 60-100, the most appropriate next step is to give warfarin (or dabigatran, or rivaroxaban or apixaban, OR ASPIRIN IN LOW RISK).
cardioversion after 3 weeks, and then 4 weeks anticoagulation.
chronic atrial fibrillation - anticoagulation?
without: 6 embolic strokes per year for 100 patients (6%).
with: INR 2-3, the rate is 2-3%.
you need to use heparin only if there is a current clot in the atrium