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Updated: Aug 5, 2026

Benefits of Cardiac Resynchronization Therapy in an Asynchronous Heart Failure Model Induced by Left Bundle Branch Ablation and Rapid Pacing
Published on: December 11, 2017
Alternating bundle branch block: What is the mechanism?
Pulakesh Sinha1, Suvradip Dutta1, Subhrasekhar Chakraborty1
1Department of Cardiology Manipal Hospitals, EM Bypass, Kolkata, India.
Abstract:
A 60-year-old gentleman with severe left ventricular systolic dysfunction, multivessel coronary artery disease, and chronic kidney disease presented with New York Heart Association (NYHA) class III breathlessness without any history of syncope or presyncope. The electrocardiogram (ECG) showed sinus rhythm with alternating bundle branch block and a variable PR interval. This was most likely due to consistent conduction delay through the left anterior and posterior fascicles, with intermittent conduction delay or block in the right bundle branch. The patient subsequently underwent dual chamber permanent pacemaker implantation, with the ventricular lead placed at left bundle branch area.
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