(Notes from Wednesday Lectures, 8/13/2014)
10a Syncope (GJ)
- “people who wake up & now feel normal”
- HOCM, longQTc, Brugada, WPW(preexcitation), AVnRT/SVT
- Life threats in stable asymptomatic pt c transient LoC…
- QTC >500 concerning: Hypomagnesemia, Hypocalcemia, Hypokalemia, Hypothermia, Congenital, Drugs…
- Brugada Syndrome is Na Channel Abnormality… unmasked by CCB or NaChBlk…
- (ST elevation c T wave inversion, nonspecific otherwise?)
- “S in V1 plus R in V5” total >35? HOCM also may have septal Q waves & nonspecific Twave changes…
1030a Electrolytes (Prasad) Hyper/HypoKalemia
- Case 1: Dialysis Dependent pt… weak, nausea, malaise, mild BPelevation… crackles on exam… anticipate hyperkalemia! EKG progression from Twave peaking to QRS widening to sine wave/VTach… odd variants include “dumping” & “z wave” patterns.
Treat c: Calcium gluconate (except c Digoxin tox!), insulin & glucose (K down 0.4 to 0.6), careful c IVF load in dialysis pts!, consider bibcarb & albuterol… lasix or dialysis to remove K.
Bicarb is still class 1A in hyperkalemic cardiac arrest.
- Case 2: 20yo college student syncope, hx bulemia… HypoK (<3), flattened Twave & Uwave present, sinus bradycardia (also found in hypoCalcemia)
- Case 3: ST depression & Twave inversion mimicking ischemia in 30F with negative troponin.
11a Small Groups (Lavoie, Prasad)
- hyperkalemia (dialysis pts c peaked T…)
- hypokalemia (bradycardic, longQTc, Uwave, flattened overall)
- hypercalcemia (short QTc, also found in digoxin toxicity)
- LVH (axis change & 35mm sV1 plus rV5) plus Twave peaking & nonspecific ST changes common in dialysis dependence.
- torsades de pointes requires Magnesium (>2g) plus ACLS (prn)… Prasad says usually takes ~6g before conversion.
- STEMI v nonspecific ST changes: distribution & shape of ST segments (III > II STE or convex up/horizontal shape is MI until proven otherwise!)
- Pericarditis: diffuse changes, concave up ST (no reciprocal change/ST depression), PR depression common c reciprocal PR elevation, downsloping of the TP segment & PR segment (Spodick sign), can be associated c myocarditis (beware resting teachycardia after treatment, IVF, etc.) & troponin elevation, most often viral illness.
12p Holy Cow Cases (Joslin)
- (Maley) SCIWORA EtOH pt… beware for revised radiology read!
- (Ku) RPA with Leukemia! (Eikanella, Strep)
1230p JrSr Sessions (Paolo, Lavoie)
- EKG Lab!
- PAILS (Posterior > Anterior > Inferior > Lateral > Septal)
- Idioventricular Rhythm (reperfusion) is good after thrombolytics
- RBBB look at slurred Swave in I & V6
- PE S1 Q3 T3 (also could be L posterior fascicle block)
- VTach~ish… go to ACLS pathway!
- PseudoRBBB with downsloping STE! ~ Brugada Syndrome (rare but happens…)
- Careful c Calcium in dialysis pts? CaCl faster but sclerosing.
- MAT v PAT (different pwave morphologies)
- Osborne Waves in hypothermia
- Sooo many QTc prolonging drugs! Torsades get Magnesium.
(fluoroquinolones, azith, zofran, reglan, TCAs, antipsychotics, methadone…)
- LGL short PR preexcitation syndrome
- Wellan’s Sign associated c ischemia! c CP, goes to cath lab… (biphasic Twave, commonly V2, V3 in multiple vessel disease.)
- Posterior MI! Tall R wave in V1 with ST depressions in V1, V2… (most common miss!)
- aVR STEMI!
- Sgarbossa Criteria for LBBB
- Spodick sign in Pericarditis c PR depression (aVR PR elevation) & diffuse ST elevations s reciprocal changes.
- Takotsubo “Octopus Pot” stress induced cardiomyopathy
- Symmetric Twave inversions can be caused by SAH! (but call ischemia until shown otherwise)
130p STEMI (Joslin)
- full thickness, sudden occlusion, troponin positive, needs cath, bad hemodynamics…
- ST elevations, Qwaves…
- PAILS mnemonic to look for reciprocal changes
- Progression: hyperactute T (asymmetric), ST elevation, Qwave, ST elevation c Twave inversion…
- Posterior STEMI needs only 0.5mm depression?!
- check aVL for Lateral STEMI
- Know R sided v Posterior EKG…
- “Old MI”? “Age Indeterminate”? Read it yourself.
- Acute LAD occlusion ~deWinter morphology, v. Chronic LAD occlusion ~Wellens morphology
- Pt c shocked resuscitation should go to cath lab.
- Paced EKG should be compared to prior, & ?consider Sgarbossa criteria.
2p NSTEMI & Ischemia (ERod)
- Ischemia is dt interruption of optimal blood flow.
- STEMI has EKG evidence of infarction & biomarker elevation.
- NSTEMI missing EKG evidence but may have biomarker elevation or Echo evidence.
- Unstable Angina is without biomarker elevation.
- Treat ACS c ASA, O2, NTG(prn)
- NSTEMI can become STEMI!… recheck for progression! ACS is dynamic process.
- Compare against old EKGs.
- EKG 1small box amplitude is 0.1mV; 1 small box across is 0.04s (large box is 0.2s)
- New ST depression threshold is >0.05mV!!! V2,V3 can be slightly >0.1mV (0.15, 0.2, 0.25 depending on age & gender by 2012 AHA guidelines) & potentially wnl!
- Most STE cutoffs are 0.1mV though.
- Twave inversions not always ischemia… can happen in LVH or SAH.
- Hyperactute Twaves in ischemia have slightly different morphology than hyperkalemia (less symmetric).
- Be careful c aVL elevations because low amplitude dt isoelectric vector may hide changes.
- Deep symmetric Twave inversions in anterior leads ~ Wellens, indicates chronic multivessel CAD… Cath only if active Sx.
- aVR should always be checked, may have apparently isolated mild elevations…
- New Tall Twave in V1 is marker of ischemia! (“NTTV1” ~Mattu)
- Inverted Uwaves predictive of L occlusion(s)? (>75%?)
- Remember ACS is dynamic continuum. Know Wellens. Careful c aVR &aVL
230p EKG Review (Deepali)
- HyperK, HypoK…
- Hypercalcemia potentially short QT (& can also cause Osborn wave, like hypothermia)
- PE has anterior lead Twave inversion in 85%! (rare pathognomonic S1Q3T3)
- Consider Thyroid causes of arrhythmia
- Myxedema Triad ~ Bradycardia, low QRS voltage, Twave flattening & inversion
3p Pediatric Syncope (Thabet)
- Syncope is loss of consciousness & postural tone with rapid return to baseline.
- Very common in kids. Always get EKG, though most is noncardiac.
- QTc, WPW, Brugada, HOCM…
- Most common cause of syncope vasovagal or idiopathic.
- Primary differential vs Seizures! (tongue biting, postictal period, headache, incontinence?)
- FamHx heart Dsx? Murmur? Orthostatics? (change >20 in HR or SBP?) Drugs/Meds?
- Consider Tox!
- Case 1: QTc prolongation & syncope dt Zofran, Risperdal, Azith… orthostatic? vasovagal? HCG? GLUCOSE? Check for hypertrophic murmur (louder when standing, lower c valsalva).
- Case 2: Actual longQTc case… check Ca, Mg, TSH… other Tox screen? give Mag…
- Plus WPW?! ~ given Digoxin dt relative contraindication for Adenosine (in Asthmatic) c syncope & SVT episode during transfer for Appendicitis?!