Electric Countershock

This was a cross-sectional study as well as a part of the Baduanjin-Eight-Silken-Movement with Self-efficacy Building for Patients with Chronic Heart Failure (BESMILE-HF) trial (NCT03180320, ClinicalTrials.gov, registration date: 08/06/2017) [6 (link)]. Patients with CHF were prospectively recruited between February 2019 and July 2022 if they fulfilled the following inclusion criteria: (1) ≥ 18 years of age; (2) met the diagnostic criteria for CHF [7 (link)]; (3) clinically stable, defined as symptoms/signs that remained generally unchanged for ≥ 1 month; (4) New York Heart Association class II or III; (5) used beta-blockers; and (6) provided informed consent [8 (link)].
The exclusion criteria were as follows: (1) patients with contraindications for exercise testing, namely, early phase after acute coronary syndrome (up to 6 weeks), life-threatening cardiac arrhythmias, acute heart failure (during the initial period of hemodynamic instability), uncontrolled hypertension (systolic blood pressure > 200 mmHg and/or diastolic blood pressure > 110 mmHg), advanced atrioventricular block, acute myocarditis and pericarditis, moderate to severe aortic valve/mitral stenosis, severe aortic valve/mitral regurgitation, severe hypertrophic obstructive cardiomyopathy, acute systemic illness, or intracardiac thrombus; (2) patients with serious acute or chronic diseases affecting major organs or with mental disorders; (3) patients with a history of cardiac surgery, cardiac resynchronization therapy, intracardiac defibrillation, or implantation of a combined device within the previous 3 months; (4) patients with a history of cardiac arrest within 1 year; (5) patients with a history of peripartum cardiomyopathy, hyperthyroid heart disease, or primary pulmonary hypertension; and (6) patients unable to perform a recumbent bicycle stress test (Fig. 1) [6 (link)].Fig. 1

Flow chart of this study

Eligible participants underwent clinical evaluation (including history of cardiac risk factors and medications), height and weight measurements, blood testing, and electrocardiography. They then underwent a cardiopulmonary exercise test (CPET) and transthoracic echocardiography assessment at rest on the same day (Fig. 2A, B). The BESMILE-HF study[6 (link)] was approved by the Ethics Committee of the Guangdong Provincial Hospital of Chinese Medicine (Approval No. B2016-202-01). All of the participants provided written informed consent.Fig. 2

Illustration of speckle-tracking echocardiography examination (A) and cardiopulmonary exercise testing (B). Strain analysis of the left atrium in the locally enlarged apical four-chamber view and the LA strain curve throughout the cardiac cycle (C). The curves of VO₂ and VCO₂ with time and work rate, respectively (D). LA, left atrial; VO₂, oxygen uptake; VCO₂, carbon dioxide uptake; VO_2max/pre, ratio of maximum to predicted oxygen uptake, WR, work rate

Thyroid parameters (PTFQI, TSH, and fT4) of a sample of patients with atrial fibrillation were compared to a reference sample of healthcare patients (case-control study). Patients with atrial fibrillation (paroxistic or persistent) who required, at least, one hospital admission were included as cases. The control sample PTFQI distribution tertiles were used as cut-offs for dividing cases and controls. We compared atrial fibrillation odds across the tertiles.
Within the cases sample, additionally, a cross-sectional study of association of the thyroid parameters with clinical characteristics was conducted (cross-sectional study).
We reviewed the 165 clinical records of the patients with atrial fibrillation who were admitted to the Miguel Servet University Hospital in Zaragoza (Spain) from July 2017 to June 2019. Exclusion criteria included previous thyroid disease or abnormal TSH and fT4 (which was the main cause of exclusion, 72%) and diseases or pharmacological treatments that interfere with the thyroid axis, among which amiodarone use accounted for the 35% of excluded pacients (Supplementary Material Table 1). Only patients who had TSH and fT4 values available before medical intervention (electrical cardioversion, catheter ablation, or treatment with amiodarone) were included. The number of patients identified for the analysis was 84 (Supplementary Material Figure 1).
Thyroid parameters of healthcare patients older than 18 years who underwent a thyroid hormone measurement across three months of 2018, in the central laboratory of the Miguel Servet University Hospital (6051 patients) were used to calculate the reference parameters for the PTFQI formula (14 (link)). Euthyroid participants of this sample constituted the control group (n=5256).
This study protocol was approved by the Ethical Committee of Clinical Research of Aragón (CEICA) (expedient numbers 19-041 and 19-519) who authorized review of clinical records.