What question did this study set out to answer?

Determine the electrophysiological effects of intravenous mexiletine on cardiac impulse formation and conduction in humans with and without pre-existing conduction abnormalities.

December 1, 1976HeartOpen Access

Electrophysiological effects of mexiletine in man.

View Full Paper

Ask AI

Bookmark

Why the study?

Does intravenous mexiletine alter electrophysiological parameters in patients with normal or abnormal cardiac conduction?

Population

25 patients

Design

Case_series

Authors

JRJulius C. RoosUniversity of Amsterdam APA C Paalman ADArend J. DunningUniversity of Amsterdam

Discussion

Member takes

Implication

May warrant caution in conduction disease; leaves open mexiletine's role in reentrant tachycardias pending controlled data.

Key Points

Determine the electrophysiological effects of intravenous mexiletine on cardiac impulse formation and conduction in humans with and without pre-existing conduction abnormalities.
Assessed 25 patients (5 with normal conduction and 20 with varied disturbances of impulse formation and conduction).
Administered intravenous mexiletine at 200 to 250 mg over 5 minutes, followed by continuous infusion of 60 to 90 mg/h.
Evaluated conduction parameters via His bundle electrography, atrial pacing, and the extrastimulus method.
Mexiletine increased AV nodal conduction time at paced rates, shifted the Wenckebach point to lower atrial rates, and prolonged the AV nodal functional refractory period in 12 of 14 patients.
HV intervals prolonged by a mean of 11 ms in 8 patients (unchanged in 17), with concurrent increases in both the relative and effective refractory periods of the His-Purkinje system.
Adverse effects included non-cardiac events in 7 of 25 patients and cardiac complications in 2 patients (one serious), with sinoatrial recovery time worsening specifically in 3 patients with sinus node dysfunction.

Structured PICO

Does intravenous mexiletine alter electrophysiological parameters in patients with normal or abnormal cardiac conduction?

Population

25 patients (5 with normal conduction and 20 with a variety of disturbances of impulse formation and conduction)

Intervention

Intravenous mexiletine (200 to 250 mg given over 5 minutes, followed by continuous infusion of 60 to 90 mg per hour)

Outcome

Electrophysiological effects measured by His bundle electrography, atrial pacing, and the extrastimulus method (including sinus frequency, atrial refractoriness, sinoatrial recovery time, AV nodal conduction time, and refractory periods)surrogate

Intravenous mexiletine prolongs AV nodal conduction and His-Purkinje refractoriness, suggesting it should be avoided in patients with pre-existing conduction impairment but may be useful for AV nodal re-entrant tachycardias.

Cite This Study

Roos et al. (1976) studied this question.

synapsesocial.com/papers/6a9466bbce9e54907c6e4f6a https://doi.org/10.1136/hrt.38.12.1262

View Full Paper

Ask AI

Bookmark

Electrophysiological effects of mexiletine in man.

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Electrophysiological effects of mexiletine in man.

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Also Consider

Also Consider