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Left-sided intraventricular conduction delay concealed by right bundle branch block.

Agustin Castellanos¹, Freddy del Carpio Munoz, Jose A Martel

¹Division of Cardiology, Department of Medicine of the University of Miami Miller School of Medicine, Miami, FL, USA. acastell@med.miami.edu

Journal of Electrocardiology

|March 18, 2008

Summary

This summary is machine-generated.

A patient with heart failure initially showed a nonspecific intraventricular conduction delay on electrocardiogram. This was later masked by a complete right bundle branch block, suggesting concealed conduction delay.

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Area of Science:

Cardiology
Electrophysiology

Background:

Intraventricular conduction delays can complicate the interpretation of electrocardiograms (ECGs) in patients with heart failure.
Nonspecific conduction abnormalities may precede more severe conduction disturbances.

Observation:

A 69-year-old woman with severe heart failure presented with a left-sided nonspecific intraventricular conduction delay (QRS duration 0.13s) on ECG.
Specific ECG findings included notches/slurrings in left precordial R waves and right precordial S waves.

Findings:

Subsequently, the patient developed a complete right bundle branch block (CRBBB) with a prolonged QRS duration (0.17s).
The initial nonspecific delay appeared to be concealed by the more significant conduction delay of the CRBBB.

Implications:

This case supports the hypothesis that nonspecific intraventricular conduction delays can be masked by subsequent, more severe conduction blocks.
Understanding concealed conduction delays is crucial for accurate ECG interpretation in cardiac patients.
Correlates with prior Doppler tissue imaging studies postulating similar phenomena.