Intermittent changing axis deviation with intermittent left anterior hemiblock during atrial flutter with subclinical...

Area of Science:

• Cardiology
• Endocrinology

Background:

• Subclinical hyperthyroidism (SH) is defined by suppressed thyroid-stimulating hormone (TSH) with normal free thyroxine and triiodothyronine levels.
• SH is associated with increased cardiovascular risk, including higher heart rate and supraventricular arrhythmias like atrial fibrillation and flutter.
• Intermittent changing axis deviation is a rare electrocardiographic finding, occasionally reported during atrial fibrillation.

Observation:

• This case report details a 59-year-old Italian man with atrial flutter and subclinical hyperthyroidism.
• The patient presented with intermittent changing axis deviation and intermittent left anterior hemiblock.

Findings:

• This is the first reported instance of intermittent changing axis deviation with intermittent left anterior hemiblock in a patient experiencing atrial flutter.
• The findings highlight a potential, though rare, association between subclinical hyperthyroidism, atrial flutter, and complex electrocardiographic abnormalities.

Implications:

• This case expands the understanding of potential cardiac manifestations of subclinical hyperthyroidism.
• It underscores the importance of thorough electrocardiographic evaluation in patients with subclinical hyperthyroidism and arrhythmias.
• Further research may elucidate the mechanisms linking SH, arrhythmias, and axis deviation.