First-degree AV block
Fatigue and Facial Weakness After Time in the Woods
A 39-year-old man reports three weeks of fatigue and facial weakness after time in the woods.
Look for
- One conducted P wave for each QRS.
- Prolonged PR: 384 ms according to the source.
Where to look. In lead II, measure from P onset to QRS onset, then compare several cycles.
Conduction from atria to ventricles is delayed, without loss of conduction on this tracing. First-degree AV block has an adult PR interval above 200 ms.
Lyme carditis is documented during evaluation; the ECG identifies conduction delay rather than its cause.
References & provenance
The ECG Made Easy, 9e, ch. 3, PDF 71–75; Lilly, 6e, ch. 12, p. 291–292.
A Case of Lyme Carditis With Variable Heart Block Successfully Treated With Oral Doxycycline
Ian Del Valle; Victor Hoang; Stuart T Wood; Alexander Muacevic; John R Adler. A Case of Lyme Carditis With Variable Heart Block Successfully Treated With Oral Doxycycline. 2022. doi:10.7759/cureus.24729. Figure 1. CC BY 4.0. CC BY 4.0
Adaptation: cropping and removal of headers/annotations outside the tracing where applicable; metadata removed. Waveforms have not been redrawn.
Compared with the published source; no independent clinical validation is claimed.
Original annotations & limitations
BAV du premier degré
Homme de 39 ans; fatigue depuis trois semaines et faiblesse faciale; PR de 384 ms et cardite de Lyme rapportés.
Le BAV est évoqué dans une question du cahier, mais ses critères ECG ne constituent pas un objectif formel explicite identifié.