EKG Interpretation (2026) Actual Questions
and Answers 100% Correct (verified)
• Atrial Fibrilation -✓✓Irregularly irregular with no discernible p wave
Rhythm: Irregular
Rate: Very fast (> 350 bpm) for Atrial, but ventricular rate may be slow, normal or
fast
P Wave: Absent - erratic waves are present
PR Interval: Absent
QRS: Normal but may be widened if there are conduction delays
Cause: continuous rapid-firing of multiple atrial automaticity foci. No complete
depolarization of atria.
• Atrial Flutter -✓✓Rhythm: Regular or irregular
Rate: Fast (250-350 bpm) for Atrial, but ventricular rate is often slower
P Wave: Not observable, but saw-toothed flutter waves are present
PR Interval: Not measureable
QRS: Normal (0.06-0.10 sec)
• Ventricular Flutter -✓✓Rate: 250-350bpm
Smooth sine waves of similar amplitude.
So rapid that ventricles hardly have time to fill.
• Bundle Branch Block -✓✓Rhythm: Regular
Rate: The underlying rate
P Wave: Normal
PR Interval: Normal (0.12-0.20 sec)
QRS: Wide (>0.12 sec)
• First Degree Heart Block -✓✓Rhythm: Regular
Rate: The underlying rate
P Wave: Normal
PR Interval: Prolonged (>0.20 sec)
QRS: Normal (0.06-0.10 sec)
Notes A first degree AV block occurs when electrical impulses moving through the
Atrioventricular (AV) node are delayed (but not blocked). First degree indicates
slowed conduction without missed beats.
, • Idioventricular Rhythm -✓✓Rhythm: Regular
Rate: Slow (20-40 bpm)
P Wave: Absent
PR Interval: Not measurable
QRS: Wide (>0.10 sec), bizarre appearance
• Atrial Escape Rhythm -✓✓When atrial focus assumes pacing responsibility in
absence of Sinus Rhythm.
• Junctional Escape Rhythm -✓✓Rhythm: Regular
Rate: Slow (40-60 bpm)
P Wave: Present before, during (hidden) or after QRS, if visible it is inverted
(retrograde atrial depolarization)
PR Interval: Not measurable
QRS: Normal (0.06-0.10 sec)
Cause: Junctional focus escapes influence of overdrive suppression if there is Sinus
Arrest, and atrial foci fail to function properly OR complete conduction block in
proximal end of AV node.
• Ventricular Escape Rhythm -✓✓Ventricular automaticity focus is not regularly
stimulated by paced depolarizations from above, so it escapes overdrive
suppression to emerge as the ventricular pacemaker with rate of 20-4obpm.
Cause: Complete conduction block of ventricular conduction system (below AV
node), Ventricular foci aren't stimulated by atrial depolarization OR total failure of
SA Node and all automaticity foci above ventricles (final futile attempt to sustain
life)
Stokes-Adams Syndrome = Pacing so slow that blood flow to brain causes
syncope.
• Junctional Tachycardia -✓✓Rhythm: Regular
Rate: Fast (100-180 bpm)
P Wave: Present before, during (hidden) or after QRS, if visible it is inverted
PR Interval: Absent or short
QRS: Normal (0.06-0.10 sec)
• Multifocal Atrial Tachycardia -✓✓Rhythm: Irregular
Rate: Fast (> 100 bpm)
P Wave: Often changing shape and size from beat to beat (at least three differing
forms)
and Answers 100% Correct (verified)
• Atrial Fibrilation -✓✓Irregularly irregular with no discernible p wave
Rhythm: Irregular
Rate: Very fast (> 350 bpm) for Atrial, but ventricular rate may be slow, normal or
fast
P Wave: Absent - erratic waves are present
PR Interval: Absent
QRS: Normal but may be widened if there are conduction delays
Cause: continuous rapid-firing of multiple atrial automaticity foci. No complete
depolarization of atria.
• Atrial Flutter -✓✓Rhythm: Regular or irregular
Rate: Fast (250-350 bpm) for Atrial, but ventricular rate is often slower
P Wave: Not observable, but saw-toothed flutter waves are present
PR Interval: Not measureable
QRS: Normal (0.06-0.10 sec)
• Ventricular Flutter -✓✓Rate: 250-350bpm
Smooth sine waves of similar amplitude.
So rapid that ventricles hardly have time to fill.
• Bundle Branch Block -✓✓Rhythm: Regular
Rate: The underlying rate
P Wave: Normal
PR Interval: Normal (0.12-0.20 sec)
QRS: Wide (>0.12 sec)
• First Degree Heart Block -✓✓Rhythm: Regular
Rate: The underlying rate
P Wave: Normal
PR Interval: Prolonged (>0.20 sec)
QRS: Normal (0.06-0.10 sec)
Notes A first degree AV block occurs when electrical impulses moving through the
Atrioventricular (AV) node are delayed (but not blocked). First degree indicates
slowed conduction without missed beats.
, • Idioventricular Rhythm -✓✓Rhythm: Regular
Rate: Slow (20-40 bpm)
P Wave: Absent
PR Interval: Not measurable
QRS: Wide (>0.10 sec), bizarre appearance
• Atrial Escape Rhythm -✓✓When atrial focus assumes pacing responsibility in
absence of Sinus Rhythm.
• Junctional Escape Rhythm -✓✓Rhythm: Regular
Rate: Slow (40-60 bpm)
P Wave: Present before, during (hidden) or after QRS, if visible it is inverted
(retrograde atrial depolarization)
PR Interval: Not measurable
QRS: Normal (0.06-0.10 sec)
Cause: Junctional focus escapes influence of overdrive suppression if there is Sinus
Arrest, and atrial foci fail to function properly OR complete conduction block in
proximal end of AV node.
• Ventricular Escape Rhythm -✓✓Ventricular automaticity focus is not regularly
stimulated by paced depolarizations from above, so it escapes overdrive
suppression to emerge as the ventricular pacemaker with rate of 20-4obpm.
Cause: Complete conduction block of ventricular conduction system (below AV
node), Ventricular foci aren't stimulated by atrial depolarization OR total failure of
SA Node and all automaticity foci above ventricles (final futile attempt to sustain
life)
Stokes-Adams Syndrome = Pacing so slow that blood flow to brain causes
syncope.
• Junctional Tachycardia -✓✓Rhythm: Regular
Rate: Fast (100-180 bpm)
P Wave: Present before, during (hidden) or after QRS, if visible it is inverted
PR Interval: Absent or short
QRS: Normal (0.06-0.10 sec)
• Multifocal Atrial Tachycardia -✓✓Rhythm: Irregular
Rate: Fast (> 100 bpm)
P Wave: Often changing shape and size from beat to beat (at least three differing
forms)
