Table 1.

Study variables

Categories of the variables (number of the variables in the group)	Study variables
Demographic data (2)	• Sex • Age at the onset of hyperthyroidism
Characteristics of hyperthyroidism course (11)	• Thyroid function: ▪ thyroid-stimulating hormone level ▪ free triiodthyronine level ▪ free tetraiodthyronine level • Thyroid-stimulating hormone receptors antibodies level (only in subjects with Graves’ disease) • Hyperthyroidism duration (for patients with AF - before AF development), months • Subclinical hyperthyroidism duration (more/less than year) • The periods of hypothyroidism (absence/presence) • The relapses of hyperthyroidism (the number of relapses) • Weight loss at the onset of hyperthyroidism (during first 1–6 months) • Hyperthyroidism genesis (Graves’ disease, toxic adenoma, multinodular toxic goiter) • Extrathyroidal Graves’ disease manifestations (ophthalmopathy, pretibial myxedema)
Metabolic parameters, smoking status and blood tests during hyperthyroidism (11)	• Body mass index • Carbohydrate metabolism disorders (diabetes mellitus, impaired fasting glucose, impaired glucose tolerance) • Lipid panel: ▪ Total cholesterol ▪ Triglycerides ▪ High density lipoproteins ▪ Low density lipoproteins • Smoking history • Potassium serum level • Hemoglobin level • Renal function: ▪ Serum creatinine concentration ▪ Estimated glomerular filtration rate
Initial cardiovascular status (4)	• Arterial hypertension (absence/presence, target ABP/ABP above target) • Coronary heart disease (absence/presence, a prior history of myocardial infarction) • Rhythm disorders (premature atrial and ventricular contraction, supraventricular and non-sustained ventricular tachycardia, wandering of atrial pacemaker) • Congestive heart failure (absence/presence)
Cardiovascular status during hyperthyroidism (6)	• Arterial hypertension (absence/presence, target ABP/ above target ABP) • Heart rate (recorded during physical examination, conducted in the period of overt hyperthyroidism before the therapy initiation), beat per minute • Rhythm disorders: ▪ premature atrial contraction ▪ premature ventricular contraction ▪ other: supraventricular and non-sustained ventricular tachycardia, wandering of atrial pacemaker • Congestive heart failure (absence/presence)
Heart rate-reducing therapy (2)	• Heart rate-reducing therapy before hyperthyroidism • Heart rate-reducing therapy during hyperthyroidism

AF atrial fibrillation; ABP arterial blood pressure