[Cineangiographic and hemodynamic evaluation of left bundle branch block]
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Insights
Left bundle-branch block is associated with various heart conditions, including valve defects, ischemic heart disease, and cardiomyopathy. The study suggests underlying heart disease, not the block itself, primarily affects left ventricle function.
Area of Science:
- Cardiology
- Electrophysiology
- Cardiac Imaging
Context:
- Left bundle-branch block (LBBB) is a common cardiac conduction abnormality.
- Understanding the underlying causes and consequences of LBBB is crucial for patient management.
- Cardiac catheterization, coronarography, and ventriculography are key diagnostic tools.
Purpose:
- To investigate the etiological spectrum and hemodynamic implications of left bundle-branch block.
- To correlate electrocardiographic findings (axis deviation, QRS duration) with cardiac pathology.
- To compare coronary artery disease patterns in patients with and without LBBB.
Summary:
- Eighty-nine patients with LBBB underwent cardiac catheterization.
- Findings included valve defects (aorta), ischemic heart disease, and cardiomyopathy (congestive).
- Ischemic heart disease patients with LBBB showed more extensive coronary artery disease, particularly affecting the left anterior descending artery.
Impact:
- Left bundle-branch block is frequently associated with significant underlying heart disease.
- Prolonged QRS duration in LBBB correlates with left valve dysfunction.
- The study indicates that underlying cardiac pathology, rather than LBBB itself, is primarily responsible for left ventricular dysfunction.
Abstract:
Left cardiac catheterisation, selective coronarography and ventriculography were employed in a study of 89 patients with left bundle-branch block. Three subjects presented normal haemodynamic and cineangiographic data, 16 displayed valve defects, usually of the aorta, 34 had ischaemic heart disease, and 36 cardiomyopathy mostly of a congestive type. Deviation of the axis in excess of--30 degrees on the frontal plane appeared to be more frequently accompanied by ischaemia, though this finding was not prognostic from the haemodynamic standpoint. A prolonged QRS (over 0.15") was more frequent in valvular heart disease and accompanied by more evident left valve dysfunction. Comparison between the 34 ischaemic patients and 317 coronary patients without left bundle-branch block showed that the former has a higher frequency of leftness in the distribution of their coronary circulation, and more extensive impairment of the coronary arteries, especially the ramus interventricularis anterior. Changes in left ventricle kinetics and serious hypokinesia and/or akinesia appear to be due to the heart disease responsible of the block. The series examined did not make it clear whether this intraventricular conduction defect can cause albeit slight alterations in left ventricle wall motility.