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Effects of intermittent left bundle branch block on left ventricular diastolic function: a case report
1Cardiac Department, Royal Brompton Hospital, London, UK.
Insights
Rate-dependent left bundle branch block can impair systolic and diastolic function, causing abnormal heart wall motion and filling patterns. These effects fully reversed when the heart
Area of Science:
- Cardiology
- Cardiac Electrophysiology
- Cardiovascular Physiology
Background:
- Assessing left ventricular (LV) function is crucial in diagnosing cardiac conditions.
- Left bundle branch block (LBBB) can affect cardiac mechanics, but its isolated impact on LV function requires further elucidation.
- Echocardiography is a primary tool for evaluating LV structure and function.
Observation:
- A case study of a patient with an echocardiographically normal left ventricle but rate-dependent left bundle branch block was examined.
- Abnormal cardiac electrical activation due to LBBB was linked to asynchronous LV wall motion.
- The patient exhibited altered LV filling patterns, mimicking those seen in severe LV disease.
Findings:
- The study found that rate-dependent LBBB caused both systolic and diastolic dysfunction.
- Asynchronous LV wall motion and abnormal filling patterns were directly associated with the LBBB.
- All observed functional abnormalities resolved when the LBBB pattern normalized.
Implications:
- This case highlights that abnormal cardiac activation, independent of structural heart disease, can induce significant LV dysfunction.
- Understanding the impact of LBBB on cardiac mechanics is vital for accurate diagnosis and management.
- Further research into the electro-mechanical coupling in LBBB is warranted to refine treatment strategies.
Abstract:
We investigated systolic and diastolic left ventricular function in a patient with an echocardiographically normal left ventricle and rate dependent left bundle branch block. Abnormal activation was associated with asynchronous left ventricular wall motion and secondary changes in filling pattern. The latter were similar to those seen in severe left ventricular disease. When the activation pattern reverted to normal, all of these abnormalities regressed. This case provides further evidence that abnormal activation can, on its own, cause left ventricular diastolic as well as systolic dysfunction.