ST elevation occurring during stress testing.

A case is presented of significant reversible ST elevation occurring during treadmill testing, and the coronary anatomy and subsequent course are described, indicating that ischemia is a potential cause of this electrocardiographic finding.

Transthyretin cardiac amyloidosis: an under-diagnosed cause of heart failure.

Introduction: Cardiac amyloidosis is the most common cause of infiltrative cardiomyopathy and is associated with a poor prognosis. Transthyretin cardiac amyloidosis, particularly the type caused by the mutation that replaces the amino acid valine with the amino acid isoleucine at position 122 (Val122Ile), is most common among African- Americans above 65 years of age. Evidence suggests that this mutation is an important, though under-diagnosed, cause of heart failure in this population.

Wenckebach responsive to cephalosporins - it must be Lyme carditis.

A 37-year-old female presented to the hospital with erythema migrans and fatigue developed hypotension and variable episodes of AV block, including both Mobitz I and complete AV block. She was treated with IV antibiotics and her arrhythmia resolved within 24 hours without any further intervention.

Congenital complete heart block in a 71-year old.

A case of a 71-year-old male with congenital complete heart block is discussed. Patient remained asymptomatic with stable electrocardiograms.

Intermittent left bundle branch block.

Presenting electrocardiograms of intermittent left bundle branch block in a 60-year-old female.

Pre-excitation syndrome: ablating the pathway.

Disappearance of a delta wave in a patient with pre-excitation is demonstrated following successful ablation.

Electrical alternans vs. pseudoelectrical alternans.

Beat-to-beat variations in QRS amplitude or axis may be caused by several conditions.

Atrial flutter with aberrant conduction in a patient taking amphetamine salts and caffeine.

A case is presented of a man with a life-threatening tachyarrhythmia precipitated by ingested substances.