deck 7 Flashcards
Name 6 EKG findings associated with acute CNS disorder.
the mnemonic is PIPPI Long-stocking:
- Precordial “cerebral T waves”
- Ischemic ST changes (ischemia vs. injury)
- Prominent U waves
- Prolonged QTc
- Infarct (Q waves, usually transient)
- LA arrhythmia (Afib)
Criteria for prolonged QTc in females and males?
prolonged QT interval definition:
- for males: QTc > 450 ms
- for females: QTc > 460 ms
What percentage of acute CVAs are complicated by acute MI?
~5-10%
Irregularly-irregular narrow-complex rhythm w/ rate 210 bpm
think of Afib w/ bypass tract
Differential diagnosis of short PR interval? (2)
- short PR, (+) delta wave: WPW pattern
- short PR, (-) delta wave: junctional rhythm
Usual EKG pattern for pt who is post-pericardiotomy?
focal epicardial injury pattern
(regional concave-up ST elevations)
Describe the 5 EKG phases of QWMI and discuss their time-of-onset relative to coronary occlusion.
- hyperacute phase: hyperacute TWs* (0-15 mins)
- injury phase: STIP WITHOUT Q waves (seconds to minutes)
- acute MI: STIP + Q waves +/- TIRP (as early as 2 hours)
- recent MI: isoelectric ST + Q waves + TIRP (days)
- old MI: Q waves only [no TIRP, no STIP] (days)
key:
- STIP = ST injury pattern
- TIRP =T wave Ischemic Repol Pattern (biphasic TWs vs. TWIs)
sinus bradycardia with ventricular rate of 35
think of sinoatrial exit block
- sinus bradycardia with rate < 40 → think of 2:1 sinoatrial exit block
Name 3 causes of a superiorally-directed P wave axis (negative p wave inferiorally).
- ectopic atrial rhythm (low atrial) → will have PR > 120 ms
- junctional rhythm w/ retrograde P wave activation → has PR < 120 ms
- lead displacement
Common cause of RAD in pt with potassium of 8.2?
LPFB
- Hyperkalemia can cause transient LAFB or LPFB
Typical EKG changes for mild hyperkalemia (K+ = 5.5-6.5)? (3)
- sinoatrial: none
- AVN: none
- HPS: reversible hemiblock
- Ventricular: T wave peaking, QT shortening
Typical EKG changes seen in moderate-range hyperkalemia (K = 6.5-7.5)? (4)
- sinoatrial: slowed atrial conduction (P wave flattening)
- AVN: 1st deg AVB
- HPS: non-specific IVCD
- Ventricular: ST depressions
Progression of EKG changes that are found with profound hyperkalemia (K > 7.5)? (5)
- atrial: sinus arrest* (manifested as complete P wave loss)
- AVN: none
- HPS: sine-wave IVCD -> AIVR vs. VT vs. VF (complete conducting system failure)
- ventricular: ST elevations
*P wave loss may also be explained by complete failure of SA conduction
Arrhythmias that can arise in setting of hypokalemia? (5)
- sinoatrial: PAT w/ exit block
- AVN/HPS: 1st deg AVB, wenchebach
- Ventricular arrhythmias: PVCs, VT/VF
Name 5 typical ASD secundum EKG findings.
The 5 Rs:
- RV volume overload (incomplete RBBB)
- RAD
- RAE [1/3 of cases]
- Really long PR (1st deg AVB) [20% of cases]
- +/- RVH
Which part of the QRS should be used to analyze the axis?
the first 60-80 milliseconds
LAFB can masque which type of acute MI?
acute inferior wall MI
LPFB can masque the presence of which syndrome?
Lateral wall STEMI
Which type of rate-dependent bundle branch block is more common and why?
Rate-dependent RBBB
The right bundle takes longer to repolarize
Most common cause of sinus pause?
blocked APC
EKG criteria for sinus arrhythmia (SArr)? (2)
both of the following must be present to code SArr:
- “accordion effect”: phasic change in PP interval related to respiratory cycle
- “minimum PP differential” criterion: longest and shortest PP intervals should vary by AT LEAST 160 ms OR 10%
Demand PM doesn’t fire during a 2-second pause on a rhythm strip, followed by resumption of normal V-pacing. Diagnosis and potential causes (3)?
dx = OVERSENSING
may be caused by:
- myopotential inhibition
- programming error (oversensing of the T-wave)
- lead fx
EKG presentation of hypercalcemia? (3)
- h/o lung CA or multiple myeloma
- QTc shortening (due to ST segment truncation)
- PR prolongation
