Cardiac Resynchronization Therapy Relieves Intractable Angina Due to Exercise-Induced Left Bundle Branch Block Without Left Ventricular Systolic Dysfunction: A Detailed Case Study

Angina with coronary microvascular dysfunction and its physiological assessment: a review with cases

Imagine that it is possible to know, the actual coronary blood flow. Would this not remove any doubt, if a chest pain is the heart's fault?

Persistent Exertional Chest Pain in a Marathon Runner: Exercise-induced, Painful, Left Bundle Branch Block Syndrome Treated With His-Bundle Pacing

A 49-year-old woman presented with exercise-induced chest discomfort during long-distance running that was occasionally present during rest. Significant coronary artery disease was excluded and a diagnosis of “painful left bundle branch block (LBBB) syndrome” was made after correlation of LBBB aberrancy with symptoms during Holter monitoring. The patient underwent confirmatory testing consisting of rapid atrial pacing below and above 130 beats per minute, the rate cut-off for LBBB manifestation. His bundle pacing implantation was performed resulting in both non-selective and selective morphologies depending on output, both of which manifested with a painless narrow QRS regardless of rate. She was rendered completely pain free during long-distance running and remains so 6-months later. Her pain at rest, now thought to be due to severe anxiety secondary to her painful LBBB, has also subsided. Exercise-induced, painful LBBB is a rare phenomenon that manifests as chest discomfort when LBBB is present. This disease is frequently misdiagnosed as coronary angina, has limited medical treatment options, and can be disabling. HBP is an attractive treatment for this syndrome in an effort to avoid electromechanical dyssynchrony, the presumed mechanism of discomfort. This case report adds to the growing literature of painful LBBB syndrome and its effective treatment with HBP, with the added caveat that it can present with persistent symptoms at rest, in the setting of enhanced anxiety. HBP should be considered early on in the treatment of such patients.

Dynamic left ventricular dyssynchrony and severe mitral regurgitation caused by exercise: should we go beyond the guidelines?

Guidelines for cardiac resynchronization therapy (CRT) have been established, but there may be a subgroup of patients not identified in these guidelines who may benefit from this therapy. We report a patient with a dynamic left ventricular dyssynchrony and severe mitral regurgitation caused by exercise successfully treated with CRT. Exercise testing should be considered in patients with left ventricular ejection fraction <35% and QRS <130 ms with severe heart failure symptoms that are unexplained by rest echocardiography evaluation in order to rule out ischemia and/or dynamic left ventricular dyssynchrony. In the presence of exercise-induced left ventricular bundle branch block, the implantation of CRT should be contemplated.