Exercise-induced left bundle branch block during thallium 201 myocardial perfusion scintigraphy--a case report

Transient Left Bundle Branch Block in the Setting of Cardiogenic Pulmonary Edema

Cardiogenic pulmonary edema complicated by transient left bundle branch block (LBBB) is a relatively rare finding. We report a case of a 52-year-old woman with underlying heart failure but no structural heart disease who was referred for evaluation due to severe shortness of breath and documented LBBB on a 12-lead EKG. She was diagnosed with cardiogenic pulmonary edema due to medication noncompliance. With the resolution of her symptoms by treating her pulmonary edema with bisoprolol and furosemide, repeated EKG showed resolution of LBBB. A review of her medical records showed similar presentations of pulmonary edema associated with transient LBBB. In conclusion, to the best of our knowledge, transient LBBB associated with cardiogenic pulmonary edema is very uncommon. The etiology of transient LBBB remains unclear, however, the most likely theory that explains our patient's transient LBBB is a consequence of ventricular enlargement from fluid overload and cardiac muscle strain with dilatation, causing bundle conduction interruption. Our patient's cardiogenic pulmonary edema was complicated with transient LBBB in multiple previous presentations with a resolution of the LBBB after treating the underlying pulmonary edema.

Episodic Left Bundle Branch Block-A Comprehensive Review of the Literature

Episodic (transient/ intermittent) left bundle branch block (LBBB) has been associated with different conditions such as bradycardia, tachycardia, anesthesia, acute pulmonary embolism, changes in intrathoracic pressure, chest trauma, cardiac interventional procedures, mad honey poisoning, and in other clinical settings. Of note, exclusion of an acute coronary syndrome in the setting of episodic LBBB is of great importance. Moreover, episodic LBBB is sometimes symptomatic and may be associated with left ventricular systolic and/or diastolic dysfunction or conduction disturbances leading to syncope. This review article provides a comprehensive overview of the conditions associated with episodic LBBB and discusses the clinical impact of this phenomenon.