Infra-His Block in a Normal Heart

Mohammad Alasti, MD, Abolfath Alizadeh, MD, Amirfarjam Fazelifar, MD, Mohammad Ali
Sadr-Ameli, MD

Department of Pacemaker and Electrophysiology, Rajaie Cardiovascular Medical Center, Vali-
asr Avenue, Tehran, IRAN.

Address for correspondence: Mohammad Alasti, M.D., Department of Pacemaker and
Electrophysiology, Rajaie Cardiovascular Medial Center, Vali-asr Avenue, Tehran, IRAN.
E Mail: [email protected]

Key Words: His-purkinje system; infra-his block

A 55 year old man with history of palpitation was referred for electrophysiologic study.
Baseline ECG, physical examination and transthoracic echocardiographic study were normal.
Electrophysiologic study revealed normal AH and HV intervals. Pacing of right atrium with a
cycle length of 300 msec showed 2:1 AV block. AH interval was 252 msec and the block was
infra-his (Figure 1). With continual of right atrial pacing, one to one AV conduction with
increasing AH interval to 282 msec and QRS widening (LBBB pattern) were being observed.
HV intervals during 2:1 block and during 1:1 AV conduction were normal. What is the
mechanism? Is it an abnormal finding in this patient?

Figure 1

Indian Pacing and Electrophysiology Journal (ISSN 0972-6292), 6(3): 184-185 (2006)

More intriguing information

1. The name is absent
2. DISCRIMINATORY APPROACH TO AUDITORY STIMULI IN GUINEA FOWL (NUMIDA MELEAGRIS) AFTER HYPERSTRIATAL∕HIPPOCAMP- AL BRAIN DAMAGE
3. The name is absent
4. Auctions in an outcome-based payment scheme to reward ecological services in agriculture – Conception, implementation and results
5. Keynesian Dynamics and the Wage-Price Spiral:Estimating a Baseline Disequilibrium Approach
6. Disentangling the Sources of Pro-social Behavior in the Workplace: A Field Experiment
7. MULTIPLE COMPARISONS WITH THE BEST: BAYESIAN PRECISION MEASURES OF EFFICIENCY RANKINGS
8. How does an infant acquire the ability of joint attention?: A Constructive Approach
9. The name is absent
10. The Challenge of Urban Regeneration in Deprived European Neighbourhoods - a Partnership Approach