Is there a prognostic relevance of electrophysiological studies in bundle branch block patients?
Harilaos Bogossian1,2, Gerrit Frommeyer3, Kornelius Göbbert1
1Department of Cardiology and Angiology, Lüdenscheid Clinic, Märkische Clinics GmbH, Lüdenscheid, Germany.
Insights
Electrophysiology (EP) studies with prolonged HV intervals do not reliably predict permanent atrioventricular block or mortality in patients with bifascicular block. Pacemaker implantation solely based on these EP findings is not recommended.
Area of Science:
- Cardiology
- Electrophysiology
- Clinical Medicine
Background:
- European guidelines recommend diagnostic electrophysiological (EP) studies for cardiac pacing indications in bundle branch block patients with syncope.
- This study investigates the prognostic value of EP studies for mortality and complete atrioventricular (AV) block development.
Purpose of the Study:
- To evaluate the prognostic relevance of the HV interval from EP studies in patients with symptomatic bifascicular block and first-degree AV block.
- To determine if prolonged HV intervals predict permanent AV block or increased mortality.
Main Methods:
- Thirty patients with symptomatic bifascicular block and AV block I° underwent EP studies.
- Patients were followed for a mean of 53 months for syncope or higher-degree AV block.
- HV intervals were measured and patients were grouped based on prolongation.
Main Results:
- Prolonged HV intervals (≥70 ms) were observed in 23 out of 30 patients.
- Patients in groups with HV intervals >70 ms received pacemakers per guidelines.
- The HV interval length did not correlate with the development of third-degree AV block or mortality.
Conclusions:
- Diagnostic EP studies with prolonged HV intervals are not sufficient to justify pacemaker implantation.
- Current guidelines may need re-evaluation regarding the use of HV intervals for pacing decisions in this patient group.
Background:
The present European guidelines suggest a diagnostic electrophysiological (EP) study to determine indication for cardiac pacing in patients with bundle branch block and unexplained syncope. We evaluated the prognostic relevance of an EP study for mortality and the development of permanent complete atrioventricular (AV) block in patients with symptomatic bifascicular block and first-degree AV block.
Hypothesis:
The HV interval is a poor prognostic marker to predict the development of permanent AV block in patients with symptomatic bifascicular block (BFB) and AV block I°.
Methods:
Thirty consecutive patients (mean age, 74.8 ± 8.6 years; 25 males) with symptomatic BFB and first-degree AV block underwent an EP study before device implantation, according to current guidelines. For 53 ± 31 months, patients underwent yearly follow-up screening for syncope or higher-degree AV block.
Results:
Thirty patients presented with prolonged HV interval during the EP study (mean, 82.2 ± 20.1 ms; range, 57-142 ms), classified into 3 groups: group 1, <70 ms (mean, 62 ± 4 ms; range, 57-67 ms; n = 7), group 2, >70 to ≤100 ms (mean, 80 ± 8 ms; range, 70-97 ms; n = 18), and group 3, >100 ms (mean, 119 ± 14 ms; range, 107-142 ms; n = 5). According to the guidelines, patients in groups 2 and 3 received a pacemaker. The length of the HV interval was not associated with the later development of third-degree AV block or with increased mortality.
Conclusions:
Our present study suggests that an indication for pacemaker implantation based solely on a diagnostic EP study with prolongation of the HV interval is not justified.
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