CRAT ECG Interpretation 3

Question 1

Right bundle branch block (RBBB) produces which classic ECG pattern?

Accepted Answer

RSR' (rabbit ears) pattern in V1 and wide S waves in leads I, aVL, and V6

Answer

RBBB produces the classic RSR' (M-shaped or rabbit ears) pattern in V1-V2 and wide, slurred S waves in I, aVL, V5-V6 due to delayed right ventricular activation.

Question 2

The QTc (corrected QT) is used to adjust for heart rate. Using Bazett's formula, QTc is prolonged when it exceeds which threshold in adults?

Accepted Answer

440-450 ms (with upper limits: 450 ms in men, 460 ms in women)

Answer

QTc greater than 440-450 ms in men or 460-470 ms in women is generally considered prolonged, with QTc > 500 ms carrying the highest risk for torsades de pointes.

Question 3

Wolff-Parkinson-White (WPW) syndrome produces which classic triad of ECG findings?

Accepted Answer

Short PR interval (< 120 ms), delta wave (slurred QRS upstroke), and wide QRS complex

Answer

WPW is characterized by a short PR interval (accessory pathway bypasses AV nodal delay), delta wave (early pre-excitation of the ventricle producing slurred QRS onset), and widened QRS (fusion of pre-excited and normally conducted ventricular activation).

Question 4

In a patient with suspected hyperkalemia, which ECG finding appears first as potassium rises from normal levels?

Accepted Answer

Peaked, narrow, symmetric T waves

Answer

The earliest ECG sign of hyperkalemia is peaked, narrow, symmetric (tent-shaped) T waves, appearing when serum potassium rises above approximately 5.5-6.0 mEq/L.

Question 5

Brugada syndrome is associated with which pattern on ECG?

Accepted Answer

Coved ST elevation in V1-V3 (Type 1 Brugada pattern) with right bundle branch block morphology

Answer

Brugada syndrome is diagnosed by the Type 1 pattern: coved (downsloping) ST elevation ≥ 2 mm in V1-V3 with RBBB-like morphology, associated with risk of sudden cardiac death from polymorphic VT/VF.

CRAT - Certified Rhythm Analysis Technician Practice Test

CRAT - Certified Rhythm Analysis Technician Practice Test

CRAT ECG Interpretation 3