Predictors of Atrial Fibrillation Recurrence in Hyperthyroid and Euthyroid Patients

The Outcome of Electrical Cardioversion in Hyperthyroid Induced Atrial Fibrillation

Hyperthyroidism is a prevalent cause of atrial fibrillation (AF). High cardiac output with low systemic vascular resistance, driven by hyperthyroidism, is associated with a rapid heartbeat, enhanced left ventricular systolic and diastolic function, and a higher incidence of supraventricular tachyarrhythmias. After returning to euthyroid status, hyperthyroidism-induced AF generally spontaneously reverts to sinus rhythm (SR), and a significant number of patients remain in chronic AF and require electrical cardioversion (ECV). After effective cardioversion, the long-term outcome of hyperthyroidism-induced persistent AF is unknown. Early ECV before the antithyroid medication should be explored for hyperthyroidism-induced AF to reduce the risk of thromboembolic consequences. The recurrence rate of AF between Hyperthyroid and Euthyroid Patients after ECV did not significantly differ. This review article compares the recurrence rate of AF as an outcome of ECV in Hyperthyroid induced atrial fibrillation.

The Real Role of β-Blockers in Daily Cardiovascular Therapy

The role of β-adrenoceptor antagonists (β-blockers) in cardiovascular therapy has been subject to diverse trends and changes over the decades. With the advent of a wide variety of excellent drugs for the treatment of antihypertension, β-blockers have been relegated from the first-line treatment of essential hypertension. However, they remain the drugs of first choice in recommendations from the respective medical societies for heart failure, coronary artery disease, and atrial fibrillation as well as in hypertension complicated with heart failure, angina pectoris, or prior myocardial infarction. When indicated, cardioselective β-blockers should be prescribed in patients with diabetes mellitus or chronic obstructive pulmonary disease. We review the available evidence for the use of β-blockers in clinical conditions in which recommendations can be made for everyday practice.

Atrial fibrillation and hyperthyroidism: A literature review

Atrial fibrillation is the most common arrhythmia worldwide with increasing frequency noted with age. Hyperthyroidism is a well-known cause of atrial fibrillation with a 16%–60% prevalence of atrial fibrillation in patients with known hyperthyroidism Ross et al. (2016). While hyperthyroidism as a causative factor of atrial fibrillation is well established, this literature review aims to answer several questions on this topic including:

1. The relationship of atrial fibrillation to hyperthyroidism

2. Atrial fibrillation as a predictor of hyperthyroidism

3. The pathophysiology of thyrotoxic atrial fibrillation

4. Subclinical hyperthyroidism and the relationship with atrial fibrillation

5. Cardioversion and Catheter ablation of hyperthyroid patients with atrial fibrillation

6. Thrombotic risk of hyperthyroid patients with atrial fibrillation

7. Management of Thyrotoxic Atrial fibrillation

8. Pharmacological rhythm control in patients with hyperthyroidism and atrial fibrillation

9. Treatment of Hyperthyroidism to prevent atrial fibrillation

10. Clinical Implications of Hyperthyroidism and Atrial Fibrillation

Auscultatory versus oscillometric blood pressure measurement in patients with atrial fibrillation and arterial hypertension

BACKGROUND

The aim of our study was to investigate the reliability of automated oscillometric blood pressure (BP) monitoring in the presence and absence of atrial fibrillation (AF) in hypertensive patients.

METHODS

BP was measured and compared in 71 randomly selected patients with AF and arterial hypertension diagnosis, 4 times each by auscultatory and oscillometric (Microlife BP A6 PC with AF detection system) methods.

RESULTS

Study included 71 patients: 36 males (mean age 67.4 years) and 35 females (70.2 years). At the time of BP measuring procedure, 36 patients were in sinus rhythm (SR) and 35 in AF. In SR patients mean systolic blood pressure (SBP) was 132 ± 17.9 mmHg with auscultatory method (AM), 137.4 ± 19.4 mmHg with oscillometric method (OM); mean diastolic BP was 77.1 ± 10.9 mmHg (AM), 78.5 ± 12.2 mmHg (OM), in AF patients mean SBP was 127.5 ± 15.1 mmHg (AM), 133.6 ± 17.4 mmHg (OM); mean diastolic BP was 81.4 ± 9.9 mmHg (AM), 83.5 ± 11.8 mmHg (OM), p = 0.037. The averages of differences for SBP and DBP in sinus rhythm group were (-5.3 mmHg (95% limits of agreement -27.2 - 16.6)) and (-1.4 mmHg (95% limits of agreement -12.8 - 10.0)), respectively. In patients with AF the averages of differences for SBP and DBP were (-6.1 mmHg (95% limits of agreement -23.9 - 11.7)) and (-2.1 mmHg (95% limits of agreement -12.9 - 8.7)), respectively.

CONCLUSIONS

The oscillometric device validated for patients with AF on average gives 5.3 mmHg higher systolic BP values for patients with SR and 6.3 mmHg higher BP values for patients with AF. However, the limits of agreement between two methods reveal wide range of random error rates which is a questionable topic in clinical practice, as it could possibly affect the treatment of arterial hypertension in patients with AF.