What question did this study set out to answer?

To evaluate the cardiac conduction mechanisms causing short P-R intervals and paroxysmal tachycardias using His bundle electrograms.

May 1, 1971CirculationOpen Access

His Bundle Electrograms in Patients with Short P-R Intervals, Narrow QRS Complexes, and Paroxysmal Tachycardias

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Population

3 patients with short P-R intervals, narrow QRS complexes, and a history of paroxysmal tachycardias

Design

Case_series

Authors

ACAgustín CastellanosElectrophysiology AAA S AghaUniversity of Miami MTMICHAEL P. TESSLERUniversity of Miami Hospital

Discussion

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Implication

Electrophysiological studies in patients with short P-R intervals and narrow QRS complexes suggest the presence of an A-V nodal bypass tract capable of bidirectional conduction.

Key Points

To evaluate the cardiac conduction mechanisms causing short P-R intervals and paroxysmal tachycardias using His bundle electrograms.
Recorded His bundle electrograms during sinus rhythm, atrial stimulation at varying cycle lengths, and intermittent atrial pacing in three patients (N=3).
Shortening of the P-R interval was driven by decreased low right atrium-to-His (LRA-H) interval conduction times during both antegrade and retrograde (V-A) conduction.
Intermittent atrial pacing demonstrated refractory behavior of accessory pathways in two patients, while programmed atrial stimulation successfully induced reciprocating tachycardia with prolonged triggering conduction in one patient.

Structured PICO

Population

3 patients with short P-R intervals, narrow QRS complexes, and a history of paroxysmal tachycardias

Intervention

His bundle electrogram recording and atrial stimulation

Outcome

Electrophysiological characteristics of A-V conduction (LRA-H interval)surrogate

Electrophysiological studies in patients with short P-R intervals and narrow QRS complexes suggest the presence of an A-V nodal bypass tract capable of bidirectional conduction.

Cite This Study

Castellanos et al. (1971) studied this question.

synapsesocial.com/papers/6a82a86b5bcab2ccdb8d64d0 https://doi.org/10.1161/01.cir.43.5.667

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Implication

Electrophysiological studies in patients with short P-R intervals and narrow QRS complexes suggest the presence of an A-V nodal bypass tract capable of bidirectional conduction.

His Bundle Electrograms in Patients with Short P-R Intervals, Narrow QRS Complexes, and Paroxysmal Tachycardias

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

His Bundle Electrograms in Patients with Short P-R Intervals, Narrow QRS Complexes, and Paroxysmal Tachycardias

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Also Consider

Also Consider