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[Pathologic movements of the ventricular septum in complete block of the left branch of the bundle of His and their
Insights
Echocardiography identified six abnormal ventricular septal motion types in patients with bundle-branch block. These patterns correlate with reduced left ventricular function and diminished myocardial contractility, impacting cardiac dynamics.
Area of Science:
- Cardiology
- Cardiac Electrophysiology
- Echocardiography
Context:
- Intraventricular asynchronism is characteristic of complete bundle-branch block (BBB).
- Understanding the relationship between BBB, His-Purkinje system activation, and ventricular mechanics is crucial for assessing cardiac function.
- Echocardiography offers a non-invasive method to evaluate these complex interactions.
Purpose:
- To identify and characterize abnormal ventricular septal motions in patients with complete bundle-branch block (BBB) and/or anteroapical bifurcation block.
- To correlate specific patterns of septal motion with left ventricular ejection fraction (LVEF) and overall cardiac function.
- To investigate the impact of BBB severity on cardiodynamics.
Summary:
- Echocardiographic M-mode and 2D-scanning were used to analyze 83 patients with complete BBB and/or anteroapical bifurcation block.
- Six distinct types of abnormal ventricular septal motion were identified, linked to intraventricular asynchronism and His-Purkinje system electrical propagation.
- Types I and VI abnormal septal motions were associated with reduced LVEF, particularly when BBB co-occurred with anteroapical bifurcation block. Types III and IV showed a moderate decrease in ejection fraction.
- Complete BBB, alone or with anteroapical bifurcation block, was found to decrease left ventricular function and myocardial contractility.
Impact:
- This study elucidates specific echocardiographic signatures of ventricular dysfunction in BBB.
- Findings provide insights into how electrical conduction abnormalities affect mechanical performance and ejection fraction.
- The research contributes to a better understanding of cardiodynamics in patients with conduction system disease, potentially guiding clinical assessment and management.
Abstract:
Echocardiographic tools (M-mode and 2D-scanning) were applied to examine 83 patients with complete bundle-branch block and/or its anteroapical bifurcation block. Six types of abnormal ventricular septal motions associated with the intraventricular asynchronism typical of complete bundle-branch block and with the specific features of electric pulse propagation in the His-Purkinje system were identified. There was a reduction in left ventricular ejection fraction that is peculiar to Types I and VI abnormal ventricular septal motions, whereas in patients with complete bundle-branch block, it is associated with anteroapical bifurcation block. A moderate decrease in ejection fraction is more common for Types III and IV abnormal ventricular septal motions (despite the severity of cardiac disease). Complete bundle-branch block alone and in combination with anteroapical bifurcation block contributes to a decrease in left ventricular function and diminished myocardial contractility. Whether the severity of complete bundle-branch block affects cardiodynamics is discussed in the present paper.