cardiology 3: valvular heart disease and arrhythmias Flashcards
what are the 3 usual mechanisms of abnormal rhythms?
reentry, triggered activity and automaticity
what is sick sinus syndrome?
anything that causes sinoatrial syndrome
what are the 2 indications for treatment for sick sinus syndrome?
- a symptomatic patient
- tachy-brady syndrome where tx of tachyarrhythmias might precipitate or worsen bradycardia.
what is a first-degree heart block and general causes/tx?
- PR interval >200 ms
- can be caused by medications
- no tx
describe 2nd degree wenckebach?
- gradual prolongation of PR interval until QRS drops.
- Occurs during periods of high vagal tone during sleep (OSA) or in endurance athletes
what is a mobitz 2?
abrupt loss of p wave conduction to ventricle with no evidence of gradual prolongation.
what is a 3rd degree heart block?
p waves not conducted to the ventricle
how can you tell a counterclockwise rotation atrial flutter?
this is a counterclockwise rotation around the right atrium.
see negative sawtooth flutter waves in 2,3,AvF (with positive deflection in V1)
how can you tell a clockwise rotation atrial flutter?
positive flutter waves in 2,3,Avf with a negative deflection in V1
what are the types of categories of afib?
- first detected (only 1 diagnosed episode)
- paroxysmal (more than 2 episodes, self terminating <7 days, most <24 hours)
- persistent (more than 2 episodes, each last > 7 days)
- permanent (>6-12 months)
in what circumstance is immediate DC cardioversion indicated for afib?
- hemodynamic instability
- onigoing MI
- symptomatic hypotension
- angina
- heart failure
- WPW with rapid ventricular rate
in patients that you want to DC cardioversion with slow afib, considerations?
consider inserting a temporary pacemaker before DC cardioversion because the patient could have sinus nodal disease and may have asystole after cardioversion
what would you use for pharmacologic cardioversion for Afib >7 days?
- 1st line: dofetilide
- 2nd line: amiodarone or ibutilide
what would you use for pharmacologic conversion for Afib <7 days?
- 1st line: flecainide, ibutilide, dofetilide, propafenone
- 2nd line: amiodarone
- Exception: if <48 hours and poor cardiac function, amiodarone is 1st line.
in what scenarios would you not shock a hemodynamically stable patient with abnormal tachycardiac atrial rhythm?
- dig intoxication
- hypokalemia
what is a acceptible resting heart rate for Afib patients?
- <110 if LVEF>40% and no symptoms related to arrhythmias.
- The strict control of heart rate is considered 80bpm at rest or 110 bpm during a 6-minute walk.
what medications can you use for Afib rate control w/o HF?
- beta blockers (atenolol or metoprolol)
- CCB (verapamil diltiazem)
- Digoxin can be synergistic
in the acute setting, what cna you use for tx of Afib with HF and no preexcitation?
- IV beta blockers (esmolol, metoprolol, or propanolol) to slow ventricular rate
- Amniodraone to slow ventricular rate and possibly restore sinus rhythm
- CCB with caution (verapamil/diltiazem) to slow ventricular response cautiously with hypotension or heart failure because of negative inotropic effects
- Digoxin/amiodarone provided no accessory pathway
what afib rhythm control medications require hospital monitoring to initiate therapy?
dofetilide and sotalol
what do you need to keep in mind if you’re going to use a class Ic agent for Afib?
with propafeone and flecainide, unopposed use can organize Afib into Aflutter which can degenerate into VF/VT. You need to use an AV nodal blocking agent like CCB, BB, or digoxin.
what is used for medication refractory Afib?
- RF ablation of the pulmonary veins.
- provides definitive rate control but does not cure the underlying cause.
- You still need to be on anticoagulation.
when can you cardiovert a stable patient?
If<48 hours, cardiovert.
If>48 hours, anticoagulate for 3 weeks or do TEE cardioversion.
for patients undergoing cardiac surgery, what medication should be used to prevent post-operative Afib?
give oral beta blocker unless contraindicated.
which patient group does not need antithrombotic therapy for Afib?
Lone afib (age<60 w/o heart disease and w/o risk factors)
which patient group is at highest risk for thromboembolism in Afib?
rheumatic mitral stenosis and prior thromboembolism
define non-valvular afib?
not having rheumatic mitral stenosis or posthetic valves
define MAT? how do you treat it?
- atrial rate>100 beats with p waves of at least 3 distinct morphologies
- treat the underlying condition
- CCB and amiodarone might help
- Digoxin can worsen it.
what conditions do you see MAT?
- pulmonary disease
- theophylline use
- low K or low magnesium
what EKG finding suggests AVNRT?
if no p wave is seen (buried in QRS) or is seen at the end of QRS (very short R-P interval)
what EKG findings suggest AVRT?
P wave is somewhere in the ST segment (short R-P interval)
what suggests atrial tachycardia? tx?
- P wave seen after a T wave (long R-P interval)
- BB, CCB, adenosine, carotid sinus massage
basics of WPW?
- preexcitation syndrome with PR<0.12 due to delta wave and symptoms of tachycardia.
- Total QRS >0.12.
what medications can you use and not use to treat Afib with WPW?
- never use: digoxin, verapamil, or beta blockers as they can increase the refractory period in the AV node, enhancing conduction down the accessory pathway and precipitate VF.
- Use procainamide, ibutilide, or amiodarone.
when do you shock for WPW tachyarrhythmia? Preferred long term option?
- shock if any signs of hemodynamic deterioration
- watch if VR>285 BPM
- RF ablation if preferred long term option
why do PVCs have a compensatory pause?
do not reset the sinoatrial node and the time between the sinus beats that are on either side of the PCV = 2basic RR intervals
define the basics of VT?
3 or more sequential QRS complexes of ventricular origin of 100 bpm or faster.
what is the ECG criteria for VT?
- AV dissociation
- fusion and capture beats
- NW axis
- positive or negative concordance in precordial leads
- absence of rS complex in all precordial leads
- QRS width of >140 ms with a RBBB
- QRS width>160ms with a LBBB
sustained monomorphic VT treatment: stable:
amiodarone
sustained monomorphic VT treatment: unstable
shock
sustained monomorphic VT treatment: unstable and refractory to shock
amiodarone/procainamide
sustained monomorphic VT treatment: with acute mI?
amiodarone first lidocaine can be useful
what cardiac medication should you never use with any wide complex tachycardias in the emergency setting?
verapamil
which patients qualify for class I indications for ICD?
- survivors of cardiac arrest due to VF or who are unstable after VT without any reversible causes
- structural heart disease and spontaneous SVT stable or unstable
- syncope of undetermined origin with hemodynamically sustained VT/VF induced at EPS
- LVEF<35% due to prior MI 40 days out with NYHA 2/3
- LVEF<30% in NYHA Class I
- nonischemic DCM LVEF<35% and NYHA 2/3
- nonsustained VT due to prior MI with LVEF<40% and inducible VT/VF at EPS
which drugs prolong QT interval?
- Class Ia antiarrhythmic drugs (quinidine, procainamide, disopyramide)
- Class 3 antiarrhythmics (sotalol, dofetilide, and amiodarone)
- haloperidol and TCA
- antibiotics (macrolides)
- antihistamines
- Antifungal agents
how do you treat TDP?
- DC cardioversion for sustained episode
- magnesium 2-4 grams
- correction of hypokalemia
- correction of bradycardia
- never treat with class Ia or class 3 antiarrhythmics
how do you prevent recurrence of TDP?
- discontinue offending medications
- prevent bradycardia with isoproterenol or overdrive pacing
- supplement potassium and magnesium
what ekg rhtyhm do you see TDP?
polymorphic VT
define NSVT?
asymptomatic VT >3 sequential PCVs with HR>100bpm) lasting <30 seconds.
when are NSVT are at risk for sustaining VT and sudden death? tx?
ischemic cardiomyopathy (LVEF<40%) or sustained VT can be induced at EPT.
Treat with ICD implantation
under what conditions is permanent pacing recommended?
- symptomatic bradycardia
- sinus node dysfunction (sick sinus syndrome)
- AV conduction syndrome
what is the most common pacemaker and what does it stand for?
- DDD
- Dual chamber paced
- Dual chamber sensed
- dual response to sensing: triggered and inhibited
- this is the most physiologic
what is pacemaker syndrome?
- associated lightheadness/syncope
- can occur with single chamber ventricular pacing
- commonly cured by DDD which restores atrial kick
how long do you need to wait to determine if an antiarrhytmic drug is effective?
4-5 half lives
what does the 5 letters of pacers indicate?
- 1st letter - chamber paced (V/A/D (V+A)
- 2nd letter - chamber sensed (V/A/D (V+A)/O (none)
- 3rd letter - mode of response (Triggered (T), Inhibited (I), dual (T+I), None (O)
- 4th letter - programmability (P/M/C/R/O - programmable, multi programmable, communicating, rate-modulated, none)
- 5th letter - arrhythmia control - Pacing (P), shock (s), dual (P+S), none (O)
when do you avoid verapamil?
- Afib/flutter with WPW
- wide complex tachycardias
- beta blocker co-administration (both CCB and BB negative chronotropies/inotropes)
- asymptomatic HCM
- obstructive HCM with symptoms
what conditions is it okay to use verapamil?
- control ventricular response in healthy heart for Afib/flutter
- MAT
- SVT (2nd choice after adenosine)
- symptomatic treatment in HCM that is non-obstructive
- severe concentric LVH
- hypertension
major side effects of quinidine?
- prolongs QRS complex and QT interval, occasionally leading to TDP
- autoimmune Thrombocytopenia purpura
- cinchonism: hearing loss, tinnitus, and psychosis
major side effects of procainamide?
- prolongs QT and QRS
- pancytopenia
- drug induced lupus
- used in caution with HF patients due to mild myocardial depressive effect
major side effect of disopyramide?
- prolong QT, QRS and TDP
- anticholinergic so urinary retention etc
major side effect of lidocaine?
seizures
beta blockers major side effect?
- decreased libido and impotence.
- must taper slowly as beta blocker abrupt stop can precipitate angina
major side effects of amniodarone?
- corneal deposits
- pulmonary fibrosis
- hepatic toxicity
- hypo/hyperthyroidism
- grey skin
what determines a toxic level of digoxin?
- determine by ECG changes not blood levels.
- you would see bradycardia and prolonged PR interval
which patients are likely to suffer dig toxicity?
- elderly
- low potassium
- low magnesium
- low PO2
- impaired renal function
when do you use RF ablation?
- WPW
- and if not responsive to medications or preference (AVNRT, Atrial tachycardia, atrial flutter, idiopathic VT)
what is aortic stenosis generally due to? when does it present?
- age-related calcific valve degeneration
- congenital bicuspid AV - age 40 to70
- normal trileaflet AV stenotic at age>75
bedside physical exam findings for AS?
- diamond-shaped SEM at RUSBP radiating to the neck
- S4 gallop
- decreased or absent S2
- paradoxical S2 split with severe AS
Name 2 chronic conditions/mechanisms that cause CHRONIC AR?
- valve deformity (BAV, RF, endocarditis, degenerative valve disease)
- abnormal aortic root (marfan, senile aortic disease GCA, relapsing polychondirits, syphilis)
what does chronic AR cause?
LV volume overload, causing LV dilatation and drop in LV systolic function
what murmur do you see with chronic AR?
- descrendo diastolic high pitched blowing murmur.
- Loudest at LSB if due to aortic leaflet
- loudest at RSB if due to aortic root disease
what does CXR show for chronic AR?
enlarged LV which may show dilation of the ascending aorta
what is the gold standard to diagnose AR?
aortic angiography though more frequently diagnosed with echo
what is the medical treatment for chronic and severe AR?
- routine use of vasodilator therapy no longer recommended for non-severe AR
- ACE/ARBs + diuretics to treat symptoms
when is valve surgery indicated for chronic and severe AR?
- patient is symptomatic
- LVEF <55%
- LV end-systolic dimension >55mm
- LV end-diastolic dimension>75mm
what surgery is contraindicated in AR?
IABP
what is native acute AR caused by what conditions?
flail leaflet due to:
- Endocarditis
- type A aortic dissection
- trauma
what is prosthetic valve AR caused by?
- tissue valve leaflet rupture
- mechanical valve closure problems (thrombosis)
- paravalvular regurgitation due to infection
what do patients with acute AR present with?
severe pulmonary edema and low cardiac output
what is the treatment for severe AR and heart failure?
if no reversible cause, likely need immediate surgery
what are the top causes of mitral stenosis?
- rheumatic fever
- SLE
- rheumatoid arthritis
- severe valve calcification
what are typical comorbid conditions with MS?
- atrial fibrillation
- heart failure
- secondary pulmonary HTN
what murmur do you see with MS?
diastolic murmur with diastolic opening snap caused by tensing of chordae tendinae and stenotic leaflets.
S1 is accentuated and can have snapping quality.
what suggests more severe mitral stenosis?
shorter time of S2-OS interval as more severe the MS, the higher the left atrial pressure, earlier the MV is forced to open in diastole.
what is the triad seen on CXR with MS?
- prominent pulmonary artery revascularization
- enlarged left atrium
- normal sized LV
why do you see hemoptysis in MS?
due to rupture of pulmonary bronchial vessels distended by pulmonary venous hypertension
what is the initial presentation of MS in pregnancy? TX?
- new onset AF and pulmonary edema
- heart rate and volume control with BB and diuretics
- heparin instead of anticoagulation if 1st trimester
what surgical treatment do you do for MS?
percutaneous valvotomy with:
- Symptomatic MS
- asymptomatic patient with PAH >50 a rest, >60 with exercise
what conditions predispose to chronic MR?
- rheumatic heart disease
- MVP
- annulus dilation from LV dilation
- prior episode of endocarditis
- ischemic effects of the papillary muscle from CAD/MI
how does chronic MR differ from acute MR?
- heart has enlarged LA in chronic form thus less back pressure to the flow across incompetent MV resulting in a constant intensity holosystolic murmur instead of descrescendo (as in acute MR).
- Both see soft/absent S1
- wide split S2
- S3 in severe MR
what is the medical treatment for severe MR?
diuretics and afterload reducing agents (ACE/ARB).
what is the surgical treatment of chronic MR? indication?
percutaneous valve repair or valve replacement.
- if symptomatic
- asymptomatic if LVEF<65% and /or LV enlargement with LV end-systolic diatmeter>40mm
- pulmonary HTN
what is the normal variant anatomic description of MVP?
chordae tendinae are weakened causing billowing of the otherwise normal MV leaflet.
what murmur do you see with MVP?
mid systolic click followed by a mid to late systolic murmur if there is associated MR
what is the most common symptom of acute mitral regurgitation?
acute onset pulmonary edema
what are the causes of native valve AMR?
- flail leaflet (endocarditis, MVP or trauma)
- papillary muscle ischemia or fupture (MI, trauma)
- chordae tendineae rupture (endocarditis, Acute rheumatic fever, spontaneous)
what are the causes of prosthetic valve acute MR?
- tissue valve leaflet rupture
- MV closure problem (thrombosis)
- paravalvular regurgitation due to infection
what murmur do you hear with acute MR?
decrescendo systolic murmur at the apex
what is the medical and surgical treatment for acute MR?
- afterload reduction and diuresis
- IABP can help.
what are the causes of TS?
- rheumatic fever
- carcinoid
- endocarditis
carcinoid usually results in what type of murmur?
TS with TR especially if hepatic tumor.
what waveforms are seen with TS?
giant a wave caused by backflow during atrial contraction against a stenotic TV.
what do you see on EKG with TS?
- tall peaked waves in II and V1 (evidence of right atrial hypertrophy)
- no indications of RVH
what do you see on waveform of TR?
large jugular V waves representing backflow through TV during ventricular contraction
what is ebstein anomaly?
- the tricuspid septal leaflet is positioned lower in the ventricle than normal (apically displaced) so the RA appears huge and the RV is small.
- TR murmur common
- seen with ASD and with WPW.
basics of bioprosthetic valve?
- less durable but do not require anticoagulation
- indicated in patients with life expectancy <5-10 years
- women of childbearing age so no anticoagulation
balloon valvuloplasty procedure of choice for which conditions?
pulmonic valve stenosis and frequently mitral stenosis
what are the major determinants in prognosis after valve surgery?
- EF
- degree of symptoms
- type of valve surgery.
what is the INR targets for mechanical valves?
- aortic - 2-3
- mitral 2.5-3.5
Valsalva does what to murmurs?
- decrease murmur of AS
- increases HCM murmur
- increases murmur of MVP
what does a R wave in V1 tell you?
what are the two morphologies of a QRS complex?
what does poor R wave progresion indicate?
what does the following indicate?
Peaked t wave
focal flipped inverted t wave
Diffuse, flipped T waves
what is a U wave? what does a prominent vs inverted U wave show?
what is early repolarization? criteria?
what are the 3 distinct morphologies for ST-segment depression?
Define ST segment elevation/depression associated with MI?
what are the 3 main causes of ST segment elevation?
what are the causes of ST-segment depression?
describe the normal vs LVH vs RVH QRS complex?
what is the LVH ECG criteria?
ECG criteria for RVH?
describe normal, RBBB and LBB patterns?
how to diagnose LBB?
criteria for RBBB?
what causes a bifasicular block?
what are the criteria for Afib?
what are the ECG changes associated with STEMI (timing)?
Common locations of STEMI?
ECG locations on heart
what are the 3 main dx for wide QRS complex tachycardia?
