Left Anterior Fascicular Block[edit | edit source]

Introduction[edit | edit source]

A Left Anterior Fascicular Block (LAFB) is an electrocardiographic finding characterized by a slightly widened QRS duration.

Pathophysiology[edit | edit source]

ECG showing Left Anterior Fascicular Block.

LAFB occurs due to a conduction delay or blockage in the left anterior fascicle of the heart's ventricular conduction system, leading to altered electrical activity.

ECG Characteristics[edit | edit source]

Key ECG features of LAFB include:

Slightly widened QRS complex (typically <120 ms)
Left axis deviation
Small q waves and tall R waves in the lateral leads

Causes[edit | edit source]

LAFB can be associated with:

Hypertensive heart disease
Aortic stenosis
Cardiomyopathies
Myocardial infarction
Degenerative changes in the conduction system

Clinical Significance[edit | edit source]

While LAFB itself usually does not cause symptoms, it can be indicative of underlying heart disease and may affect the interpretation of the ECG in the context of myocardial ischemia.

Diagnosis[edit | edit source]

Diagnosis of LAFB is primarily based on ECG findings. Additional tests might include echocardiography or MRI to assess structural heart abnormalities.

Treatment[edit | edit source]

LAFB does not typically require specific treatment but managing underlying conditions is crucial. Regular cardiac evaluation is recommended.

Prognosis[edit | edit source]

The prognosis of LAFB varies depending on the associated cardiac conditions.

Epidemiology[edit | edit source]

LAFB is more commonly seen in older adults and those with hypertension or other forms of heart disease.

References[edit | edit source]

External Links[edit | edit source]

Left anterior fascicular block Resources
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