A study of ventricular contraction sequence in complete right bundle branch block by phase analysis.

Area of Science:

• Cardiology
• Nuclear Cardiology
• Electrophysiology

Background:

• Complete right bundle branch block (CRBBB) affects ventricular contraction patterns.
• Left axis deviation (LAD) can further complicate ECG findings in CRBBB.
• Detailed evaluation of right ventricular (RV) contraction sequence is crucial for understanding cardiac function.

Purpose of the Study:

• To evaluate the right ventricular contraction sequence and pattern in patients with CRBBB, with and without LAD.
• To compare these patterns with those of normal subjects using blood pool scintigraphy.
• To determine if phase analysis can quantitatively assess the degree of RBBB.

Main Methods:

• Blood pool scintigrams were acquired in the left anterior oblique projection.
• Images were analyzed using first component Fourier harmonics for phase analysis.
• Ventricular contraction patterns were compared between normal subjects and CRBBB patients (with and without LAD).

Main Results:

• Normal subjects exhibited homogeneous phase distribution in both RV and left ventricle (LV).
• CRBBB patients without LAD showed apparent RV phase delay.
• CRBBB patients with LAD displayed variable contraction patterns due to hemi-block effects.

Conclusions:

• Phase analysis of blood pool scintigrams effectively differentiates RV contraction patterns in CRBBB.
• The method allows for quantitative assessment of RBBB severity, comparable to electrical studies.
• Understanding these contraction patterns aids in diagnosing and managing CRBBB and associated conditions.