Sharp EKG Exam 2026 | Comprehensive
Questions & Verified Detailed Solutions |
Latest ECG Study Guide
SHARP EKG EXAM 2026
Comprehensive Questions & Verified Detailed Solutions | Latest ECG Study Guide
Question 1: A 58-year-old male presents with palpitations and near-syncope. His ECG
shows a wide complex tachycardia at 180 bpm with AV dissociation, fusion beats, and
capture beats. What is the MOST likely diagnosis?
A. Supraventricular tachycardia with aberrant conduction
B. Atrial flutter with 2:1 block and bundle branch block
C. Antidromic AVRT
D. Ventricular tachycardia
E. Accelerated idioventricular rhythm
CORRECT ANSWER: D. Ventricular tachycardia
RATIONALE: The triad of AV dissociation, fusion beats (partial capture of ventricle
by both sinus and ectopic impulse), and capture beats (full sinus capture of ventricle)
are pathognomonic for ventricular tachycardia. These findings confirm independent
atrial and ventricular activity, definitively ruling out SVT with aberrancy.
Question 2: An ECG shows a regular wide complex tachycardia. The RS complex in
precordial leads has an RS interval >100ms. According to the Brugada criteria, what
does this finding indicate?
A. SVT with right bundle branch block
B. Antidromic AVRT via a left-sided accessory pathway
C. Ventricular tachycardia
D. Accelerated junctional rhythm
E. Torsades de pointes
CORRECT ANSWER: C. Ventricular tachycardia
, RATIONALE: The Brugada algorithm step 2 checks for RS interval >100ms in any
precordial lead. A prolonged RS interval suggests slow conduction through abnormal
ventricular tissue, characteristic of VT. If present, VT is diagnosed without proceeding
further in the algorithm.
Question 3: A patient's ECG demonstrates retrograde P waves following each QRS
complex with an RP interval of 90ms. The QRS is narrow. Which arrhythmia BEST fits
this description?
A. AVNRT (typical slow-fast)
B. Orthodromic AVRT
C. Atrial tachycardia
D. Junctional tachycardia
E. AVNRT (atypical fast-slow)
CORRECT ANSWER: A. AVNRT (typical slow-fast)
RATIONALE: In typical AVNRT (slow-fast), antegrade conduction occurs via the
slow pathway and retrograde via the fast pathway. This produces a very short RP
interval (<70–90ms), often causing the P wave to be buried in or just after the QRS
complex. The narrow QRS confirms supraventricular origin.
Question 4: A 45-year-old woman has an ECG with a delta wave, short PR interval
(<120ms), and wide QRS. She develops atrial fibrillation. The ventricular rate is 280
bpm with irregular, bizarrely wide QRS complexes of varying morphology. What is the
MOST dangerous concern?
A. Degeneration into complete heart block
B. Degeneration into ventricular fibrillation
C. Development of cardiac tamponade
D. Degeneration into typical AVNRT
E. Progression to third degree AV block
CORRECT ANSWER: B. Degeneration into ventricular fibrillation
, RATIONALE: In WPW syndrome with pre-excited AF, rapid antegrade conduction
through the accessory pathway bypasses the AV node (which normally limits rate).
Extremely rapid ventricular rates (>250 bpm) can degenerate into ventricular fibrillation.
AV nodal blocking agents (adenosine, beta-blockers, calcium channel blockers, digoxin)
are contraindicated as they may enhance conduction via the accessory pathway.
Question 5: An ECG shows alternating LBBB and RBBB morphology in a patient with
syncope. What does this finding most strongly suggest?
A. Myocardial infarction
B. Bifascicular block
C. Alternating bundle branch block indicating infra-Hisian disease
D. Wolff-Parkinson-White syndrome
E. Hyperkalemia
CORRECT ANSWER: C. Alternating bundle branch block indicating infra-
Hisian disease
RATIONALE: Alternating BBB (switching between LBBB and RBBB) implies
disease in all three fascicles (right bundle, left anterior, and left posterior fascicles). This
is a marker of severe infra-Hisian conduction disease with high risk of progression to
complete AV block and sudden death. Urgent pacemaker implantation is indicated.
Question 6: On a 12-lead ECG, a patient exhibits P waves that change morphology in
a single lead, with at least 3 different P wave shapes and an irregular rate of 110 bpm.
What is the diagnosis?
A. Atrial flutter with variable block
B. Sinus arrhythmia
C. Multifocal atrial tachycardia
D. Atrial fibrillation
E. Wandering atrial pacemaker
CORRECT ANSWER: C. Multifocal atrial tachycardia
, RATIONALE: MAT is defined by ≥3 distinct P wave morphologies in a single lead,
irregular P-P intervals, and a rate >100 bpm. It is most commonly associated with
severe COPD and pulmonary hypertension. Unlike AF, discrete P waves are present.
Rate <100 bpm with same features = wandering atrial pacemaker.
Question 7: A patient with a history of myocardial infarction presents with an ECG
showing a regular wide complex tachycardia at 160 bpm. The QRS axis is between -90°
and ±180° (extreme right axis deviation). What does this suggest?
A. SVT with LBBB aberrancy
B. Antidromic AVRT
C. Ventricular tachycardia
D. Hyperkalemia-induced tachycardia
E. Accelerated idioventricular rhythm
CORRECT ANSWER: C. Ventricular tachycardia
RATIONALE: Extreme right axis deviation (northwest axis, -90° to ±180°) during a
wide complex tachycardia is a Brugada criterion for VT. SVT with aberrancy rarely
produces northwest axis. This axis occurs when ventricular activation is entirely
retrograde (bottom-up), as in VT arising from the cardiac apex.
Question 8: An ECG shows a tachycardia where P waves are not visible. Suddenly,
vagal maneuver terminates it immediately. What does this MOST suggest?
A. Atrial flutter
B. Ventricular tachycardia
C. Atrial fibrillation
D. Re-entrant SVT (AVNRT or AVRT)
E. Multifocal atrial tachycardia
CORRECT ANSWER: D. Re-entrant SVT (AVNRT or AVRT)
RATIONALE: Vagal maneuvers (carotid sinus massage, Valsalva) increase
parasympathetic tone and slow AV nodal conduction. Re-entrant tachycardias that
involve the AV node as part of their circuit (AVNRT and orthodromic AVRT) depend on
Questions & Verified Detailed Solutions |
Latest ECG Study Guide
SHARP EKG EXAM 2026
Comprehensive Questions & Verified Detailed Solutions | Latest ECG Study Guide
Question 1: A 58-year-old male presents with palpitations and near-syncope. His ECG
shows a wide complex tachycardia at 180 bpm with AV dissociation, fusion beats, and
capture beats. What is the MOST likely diagnosis?
A. Supraventricular tachycardia with aberrant conduction
B. Atrial flutter with 2:1 block and bundle branch block
C. Antidromic AVRT
D. Ventricular tachycardia
E. Accelerated idioventricular rhythm
CORRECT ANSWER: D. Ventricular tachycardia
RATIONALE: The triad of AV dissociation, fusion beats (partial capture of ventricle
by both sinus and ectopic impulse), and capture beats (full sinus capture of ventricle)
are pathognomonic for ventricular tachycardia. These findings confirm independent
atrial and ventricular activity, definitively ruling out SVT with aberrancy.
Question 2: An ECG shows a regular wide complex tachycardia. The RS complex in
precordial leads has an RS interval >100ms. According to the Brugada criteria, what
does this finding indicate?
A. SVT with right bundle branch block
B. Antidromic AVRT via a left-sided accessory pathway
C. Ventricular tachycardia
D. Accelerated junctional rhythm
E. Torsades de pointes
CORRECT ANSWER: C. Ventricular tachycardia
, RATIONALE: The Brugada algorithm step 2 checks for RS interval >100ms in any
precordial lead. A prolonged RS interval suggests slow conduction through abnormal
ventricular tissue, characteristic of VT. If present, VT is diagnosed without proceeding
further in the algorithm.
Question 3: A patient's ECG demonstrates retrograde P waves following each QRS
complex with an RP interval of 90ms. The QRS is narrow. Which arrhythmia BEST fits
this description?
A. AVNRT (typical slow-fast)
B. Orthodromic AVRT
C. Atrial tachycardia
D. Junctional tachycardia
E. AVNRT (atypical fast-slow)
CORRECT ANSWER: A. AVNRT (typical slow-fast)
RATIONALE: In typical AVNRT (slow-fast), antegrade conduction occurs via the
slow pathway and retrograde via the fast pathway. This produces a very short RP
interval (<70–90ms), often causing the P wave to be buried in or just after the QRS
complex. The narrow QRS confirms supraventricular origin.
Question 4: A 45-year-old woman has an ECG with a delta wave, short PR interval
(<120ms), and wide QRS. She develops atrial fibrillation. The ventricular rate is 280
bpm with irregular, bizarrely wide QRS complexes of varying morphology. What is the
MOST dangerous concern?
A. Degeneration into complete heart block
B. Degeneration into ventricular fibrillation
C. Development of cardiac tamponade
D. Degeneration into typical AVNRT
E. Progression to third degree AV block
CORRECT ANSWER: B. Degeneration into ventricular fibrillation
, RATIONALE: In WPW syndrome with pre-excited AF, rapid antegrade conduction
through the accessory pathway bypasses the AV node (which normally limits rate).
Extremely rapid ventricular rates (>250 bpm) can degenerate into ventricular fibrillation.
AV nodal blocking agents (adenosine, beta-blockers, calcium channel blockers, digoxin)
are contraindicated as they may enhance conduction via the accessory pathway.
Question 5: An ECG shows alternating LBBB and RBBB morphology in a patient with
syncope. What does this finding most strongly suggest?
A. Myocardial infarction
B. Bifascicular block
C. Alternating bundle branch block indicating infra-Hisian disease
D. Wolff-Parkinson-White syndrome
E. Hyperkalemia
CORRECT ANSWER: C. Alternating bundle branch block indicating infra-
Hisian disease
RATIONALE: Alternating BBB (switching between LBBB and RBBB) implies
disease in all three fascicles (right bundle, left anterior, and left posterior fascicles). This
is a marker of severe infra-Hisian conduction disease with high risk of progression to
complete AV block and sudden death. Urgent pacemaker implantation is indicated.
Question 6: On a 12-lead ECG, a patient exhibits P waves that change morphology in
a single lead, with at least 3 different P wave shapes and an irregular rate of 110 bpm.
What is the diagnosis?
A. Atrial flutter with variable block
B. Sinus arrhythmia
C. Multifocal atrial tachycardia
D. Atrial fibrillation
E. Wandering atrial pacemaker
CORRECT ANSWER: C. Multifocal atrial tachycardia
, RATIONALE: MAT is defined by ≥3 distinct P wave morphologies in a single lead,
irregular P-P intervals, and a rate >100 bpm. It is most commonly associated with
severe COPD and pulmonary hypertension. Unlike AF, discrete P waves are present.
Rate <100 bpm with same features = wandering atrial pacemaker.
Question 7: A patient with a history of myocardial infarction presents with an ECG
showing a regular wide complex tachycardia at 160 bpm. The QRS axis is between -90°
and ±180° (extreme right axis deviation). What does this suggest?
A. SVT with LBBB aberrancy
B. Antidromic AVRT
C. Ventricular tachycardia
D. Hyperkalemia-induced tachycardia
E. Accelerated idioventricular rhythm
CORRECT ANSWER: C. Ventricular tachycardia
RATIONALE: Extreme right axis deviation (northwest axis, -90° to ±180°) during a
wide complex tachycardia is a Brugada criterion for VT. SVT with aberrancy rarely
produces northwest axis. This axis occurs when ventricular activation is entirely
retrograde (bottom-up), as in VT arising from the cardiac apex.
Question 8: An ECG shows a tachycardia where P waves are not visible. Suddenly,
vagal maneuver terminates it immediately. What does this MOST suggest?
A. Atrial flutter
B. Ventricular tachycardia
C. Atrial fibrillation
D. Re-entrant SVT (AVNRT or AVRT)
E. Multifocal atrial tachycardia
CORRECT ANSWER: D. Re-entrant SVT (AVNRT or AVRT)
RATIONALE: Vagal maneuvers (carotid sinus massage, Valsalva) increase
parasympathetic tone and slow AV nodal conduction. Re-entrant tachycardias that
involve the AV node as part of their circuit (AVNRT and orthodromic AVRT) depend on
