R Wave Peak Time

AKA “Intrinsicoid deflection”

Definition

• The time from the onset of the earliest Q or R wave to the peak of the R wave in the lateral leads (aVL, V5-6).
• Represents the time taken for excitation to spread from the endocardial to the epicardial surface of the left ventricle.
• R-wave peak time is said to be prolonged if > 45ms.

Causes of Prolonged RWPT

• Left anterior fascicular block
• Left ventricular hypertrophy
• Left bundle branch block

Prolonged R-wave peak time in aVL due to left anterior fascicular block

Further Reading

• ECG BASICS — Waves, Intervals, Segments and Clinical Interpretation
• ECG CLINICAL CASES — Your favourite ECG’s placed in clinical context with a challenging Q&A approach
• ECG and Cardiology Eponymous Syndromes — Cheats guide to eponymous emancipation
• ECG Exam Template — a framework for the FACEM part 2 exam.
• ECG Reference Sites on the WEB — the best of the rest

Author Credits

References

• Surawicz B, Knilans T. Chou’s Electrocardiography in Clinical Practice (6th edition), Saunders 2008.
• Wagner, GS. Marriott’s Practical Electrocardiography (11th edition), Lippincott Williams & Wilkins 2007.