SCST-D1 SCST DIPLOMA IN ECG
INTERPRETATION EXAM 2026 PRACTICE EXAM
◉ PSVT (Paroxysmal Supraventricular Tachycardia) AKA: AV nodal
Re-entrant Tachycardia. Answer: Rate: Tachycardia (usually 150 -
200)
P wave: Absent or Inverted (like junctional escape)
QRS: Normal (may be wide, pseudo R')
Conduction: P-R interval < 0.12 seconds (if P)
Rhythm: Regular (abrupt onset and termination)
Carotid massage: slows or terminates
◉ Atrial flutter. Answer: Rate:Atrial 250-350
Ventricular: 100 -175
P: Irregular or absent, often "saw tooth"
QRS: Normal
Conduction: AV Block (2:1 > 3:1, 4:1)
Rhythm: Regular (usually)
- Often underlying cardiac disease
Carotid massage: increases block
◉ Atrial fibrillation. Answer: Rate: Atrial 400-650;
,Ventricular usually 120 - 180
P wave: Not present; often wavy baseline
QRS: Normal
Conduction: Variable AV conduction
Rhythm: Irregularly Irregular
- chaotic, unpredictable depolarizations w/i atrium, no atrial kick
- CAD, HTN, COPD, etc.
Carotid massage: may slow ventricular rate
◉ MAT (Multifocal Atrial Tachycardia):. Answer: Rate: Atrial varies,
Ventricular 100-200
P wave: ≥ 3 different 'P' waves
QRS: Normal
Conduction: AV conduction, P-R intervals vary
Rhythm: Irregularly irregular
Carotid massage: no effect
Etiology: longstanding COPD, etc.
◉ Wandering Atrial Pacemaker. Answer: Rate: Atrial & Ventricular
45 - 100 (slow MAT)
P wave: ≥ 3 different 'P' waves
QRS: Normal
, Conduction: P-R intervals vary
Rhythm: Irregularly irregular
Carotid massage: no effect
◉ PAT
(Paroxysmal (episodic) Atrial Tachycardia). Answer: Rate: 100 -
200; Ventricular 1:1 (or 2:1, 3:1, 4:1)
P wave: Usually present, abnormal
QRS: Normal
Conduction: P-R interval varies (dt ectopic sites)
Rhythm: Regular (warm up &/or cool down)
Carotid massage: no effect, or only mild slowing
◉ bigeminy?. Answer: 1:1 ratio of normal:PVC
◉ trigeminy?. Answer: 2:1 ratio of normal:PVC
◉ PVCs (Premature Ventricular Contractions). Answer: Rate:
Regular underlying rate (usually)
P wave: Absent (or abnormal) in PVC
QRS: PVC: wide > 0.12 seconds; shape is bizarre; T wave inversion
Conduction: Normal before & after PVC
INTERPRETATION EXAM 2026 PRACTICE EXAM
◉ PSVT (Paroxysmal Supraventricular Tachycardia) AKA: AV nodal
Re-entrant Tachycardia. Answer: Rate: Tachycardia (usually 150 -
200)
P wave: Absent or Inverted (like junctional escape)
QRS: Normal (may be wide, pseudo R')
Conduction: P-R interval < 0.12 seconds (if P)
Rhythm: Regular (abrupt onset and termination)
Carotid massage: slows or terminates
◉ Atrial flutter. Answer: Rate:Atrial 250-350
Ventricular: 100 -175
P: Irregular or absent, often "saw tooth"
QRS: Normal
Conduction: AV Block (2:1 > 3:1, 4:1)
Rhythm: Regular (usually)
- Often underlying cardiac disease
Carotid massage: increases block
◉ Atrial fibrillation. Answer: Rate: Atrial 400-650;
,Ventricular usually 120 - 180
P wave: Not present; often wavy baseline
QRS: Normal
Conduction: Variable AV conduction
Rhythm: Irregularly Irregular
- chaotic, unpredictable depolarizations w/i atrium, no atrial kick
- CAD, HTN, COPD, etc.
Carotid massage: may slow ventricular rate
◉ MAT (Multifocal Atrial Tachycardia):. Answer: Rate: Atrial varies,
Ventricular 100-200
P wave: ≥ 3 different 'P' waves
QRS: Normal
Conduction: AV conduction, P-R intervals vary
Rhythm: Irregularly irregular
Carotid massage: no effect
Etiology: longstanding COPD, etc.
◉ Wandering Atrial Pacemaker. Answer: Rate: Atrial & Ventricular
45 - 100 (slow MAT)
P wave: ≥ 3 different 'P' waves
QRS: Normal
, Conduction: P-R intervals vary
Rhythm: Irregularly irregular
Carotid massage: no effect
◉ PAT
(Paroxysmal (episodic) Atrial Tachycardia). Answer: Rate: 100 -
200; Ventricular 1:1 (or 2:1, 3:1, 4:1)
P wave: Usually present, abnormal
QRS: Normal
Conduction: P-R interval varies (dt ectopic sites)
Rhythm: Regular (warm up &/or cool down)
Carotid massage: no effect, or only mild slowing
◉ bigeminy?. Answer: 1:1 ratio of normal:PVC
◉ trigeminy?. Answer: 2:1 ratio of normal:PVC
◉ PVCs (Premature Ventricular Contractions). Answer: Rate:
Regular underlying rate (usually)
P wave: Absent (or abnormal) in PVC
QRS: PVC: wide > 0.12 seconds; shape is bizarre; T wave inversion
Conduction: Normal before & after PVC
