Overview
Accelerated atrioventricular (AV) conduction refers to conditions where electrical impulses travel more rapidly than normal from the atria to the ventricles, potentially leading to altered ventricular activation patterns and conduction disturbances such as bundle branch blocks.Diagnosis
Key Diagnostic Criteria:
- Abnormal QRS duration and morphology on ECG indicative of intraventricular conduction delays (e.g., left bundle branch block, right bundle branch block) 13.
- Use of R-wave offset in left chest leads (I-aVL, V5-V6) to estimate left ventricular activation delay, correlating with coronary sinus electrograms 1.
Recommended Tests:
- 12-lead ECG for assessing QRS duration and morphology 1.
- Radionuclide angiocardiography to visualize patterns of ventricular contraction 3.Management
First-Line Treatments:
- No specific pharmacological treatments mentioned for accelerated AV conduction itself; focus on managing underlying causes 13.
Adjunctive Treatments:
- Monitoring and management of arrhythmias or conduction abnormalities as indicated 2.Special Populations
Epidural Anaesthesia:
- Lumbar epidural anaesthesia with bupivacaine appears safe in patients with asymptomatic AV conduction abnormalities, with continuous ECG monitoring recommended 2.Key Recommendations
Utilize R-wave offset measurements in left chest leads (I-aVL, V5-V6) to estimate left ventricular activation delay, correlating with coronary sinus electrograms for diagnostic purposes (Evidence: Moderate) 1.
Continuous ECG monitoring is advised during procedures involving local anaesthetic administration, such as epidural anaesthesia, in patients with AV conduction defects (Evidence: Moderate) 2.
Radionuclide angiocardiography can provide non-invasive insights into ventricular contraction patterns in patients with conduction abnormalities, aiding in diagnosis (Evidence: Moderate) 3.References
1 Hara H, Niwano S, Ito H, Karakawa M, Ako J. Evaluation of R-wave offset in the left chest leads for estimating the left ventricular activation delay: An evaluation based on coronary sinus electrograms and the 12-lead electrocardiogram. Journal of electrocardiology 2016. link
2 Eledjam JJ, de la Coussaye JE, Colson P, Viel E, Bassoul B, Bertinchant JP et al.. Is epidural anaesthesia using bupivacaine safe in patients with atrio-ventricular conduction defects?. Acta anaesthesiologica Scandinavica 1989. link
3 Underwood SR, Walton S, Laming PJ, Ell PJ, Emanuel RW, Swanton RH. Patterns of ventricular contraction in patients with conduction abnormality studied by radionuclide angiocardiography. British heart journal 1984. link