ECG Basics Flashcards
Name 4 common cardiac presentations, for which ECGs are useful
Chest Pain (Acute Coronary Syndrome)Dyspnea / Heart FailurePalpitationsSyncope
Name 4 systemic pathologies, for which ECGs may be abnormal
SepsisPEIntracranial PathologyElectrolyte Disturbance
The 12 lead ECG consists of [two groups of leads]. [How many] leads are in each group? On which plane are they?
Praecordial/Chest leads x 6 - Horizontal (V1-6)Limb Leads x 6 - vertical (I, II, III, aVR, aVL, aVF)
Additional Lead Placements[2; think about for what]
Right Ventricular Leads: V4R-V6R (RV Infarct)Posterior Leads: V7-9 (Posterior Ischemia)
Location of SA Node
RA, near SVC entrance
Location of AV Node
RA, near Atrial Septum (and septal cusp of Tricuspid Valve)
Where do you find a U wave?
After the T wave
How to calculate rate[2 methods]
A) # QRS Complexes on 10sec Strip, multiply by 6B) 300/(#Large squares between QRS complexes)
Define quickly:Sinus TachycardiaSinus Arrhythmia
S.Tachy: p waves 1:1 with QRS, but high rateS. Arrhyth: p waves 1:1 with QRS, but irregular rate
Atrial EctopicsDefine [one liner]ECG [3 features]
Premature Atrial ComplexEarly + narrow + followed by compensatory pause(Note: followed by flat line / no QRS; then another p wave comes along causing QRS)
Ventricular EctopicsDefine [one liner]ECG [2 features]
Premature Ventricular ComplexEarly + Broad QRS
AFDefining feature [1]RhythmNeed to… [in terms of reporting, 2 subpoints]
Absence of P wavesRhythm: irregularly irregularComment on Ventricular Response Rate:>100 = Rapid Vent Response RateK 100 = Normal Vent Response Rate
Atrial FlutterDefining Feature [1]Underlying cause [simple explanation]Rhythm
“Saw Tooth” AppearanceDue to large re-entrant pathway in atriumregular 300bpm (note: atrial beats / p waves - unlike AF, p waves exist and hence their rhythm matters; p waves are the saw tooths; QRS could be normal?)
2 Types of Tachycardias
Narrow Complex Tachy (QRS K120ms / 3 small squares)Broad Complex Tachy (QRS >120ms / 3 small squares)
Paced Rhythm ECG[2 ECG Signs]
Atrial Pacing SpikeVentricular Pacing Spike
AxisTell apart via ECGA) Normal AxisB) Left Axis DeviationC) Right Axis Deviation[Leads and pattern]
A)^ Lead 1^ Lead 2 /aVFB) “Ladies Adore Diamonds”^ Lead 1v Lead 2/aVFC) “Rovers Adore Digging”v Lead 1^ Lead 2/aVF
Left Axis Deviation - Causes[5; plus one NOT]
Left Anterior HemiblockIHDCardiomyopathyHypertensionWPW - R) sided accessory pathway(Note: LV Hypertrophy is NOT a cause)
Right Axis Deviation - Causes[4]
Normal: Child or Tall-ThinRV P/V Overload (PE, RV Hypertrophy, Lung Pathology)DextrocardiaWPW - L) sided accessory pathway
Extreme Right Axis Deviation - Causes[5]
Lead TranspositionVTEmphysemaHyperkalemiaPaced Rhythm
P Wave Abnormalities [2 types; name, abnormality this is due, and explain ECG pattern]
A) P Pulmonale: RA Dilation - increased/higher P waveB) P Mitrale: LA Dilation - late LA depolarization, causing 2 peaks in p wave (“bifid p wave”)
Left Ventricular Hypertrophy- Voltage Criteria[Complicated way of detecting it on ECG]
Sum of S in V1 or V2ANDR in V5 or V6should be bigger than 7 Large Squares (35mm)(*whichever one is larger)
Q Waves[Normal1; Pathological 3 defining/identifying features]
Normal: Q Wave in Lead III (note other?)Pathological- marker of electrical silence which implies: established full thickness death of myocardium i.e. scar- >25% height of the corresponding R wave (or >40msec width, >2mm in depth)- present in MORE than 1 contiguous/adjacent lead
Bundle Branch Block- Defining Feature- Mnemonic distinguishing Left vs. Right
QRS Complex Duration >120ms (3 small sqaures)WiLLiaM MaRRoW(note: from Q to S!; plus zacken on top do help)
LBBB[2 from mnemonic; 2 other features]
V1: W (often not obvious)V6: MV5-6, I, aVL: Inverted T wavesNo septal Q waves(Note: if fat + negative in V1 = LBBB)
