Related Experiment Video
Updated: Jan 29, 2026

Acute Myocardial Infarction in Rats
Published on: February 16, 2011
17β-Estradiol Does Not Designate Non-Sex-Specific Early Ventricular Arrhythmia in Acute Myocardial Infarction, in
Niya E Semedzhieva1, Adelina Tsakova2, Vesela Lozanova3
1Clinic of Internal Medicine, University Emergency Medicine Hospital 'Pirogov', 1606 Sofia, Bulgaria.
None:
Despite the evidence from experimental studies that endogenous hormones have sex-related effects on action potential duration, the relationship between gonadal steroids and ventricular repolarization in acute myocardial infarction (AMI) is not clear. We tested the hypothesis that endogenous 17β-estradiol (E2) and 17β-estradiol-to-testosterone ratio (E2/T) are associated with inflammation, influencing the occurrence of early ventricular arrhythmia (VA) in AMI. Electrocardiographic (ECG) repolarization indices, including resting heart rate (HR), corrected QT (QTc) interval, QTc minimum (QTcmin), QTc maximum (QTcmax), and QTc dispersion (QTcd), along with E2, total T, and the ratio of E2 to T (E2/T), were measured and analyzed after percutaneous coronary intervention in 86 patients (36 women, 41.9%). In a non-specific sex analysis, the incidence of early VA in the course of AMI was determined by the ejection fraction of the left ventricle (OR 0.876, p = 0.054), and by the peak levels of plasma C-reactive protein (OR 1.026, p = 0.077). Endogenous plasma 17β-estradiol tended to be higher in cases with early ventricular arrhythmia (124.5 ± 79 vs. 181 ± 192.8, p = 0.089). 17β-estradiol levels were significantly predicted by C-reactive protein (OR 1.050, p = 0.042). This study found that reduced systolic function of the left ventricle and higher peak CRP levels are associated with endogenous plasma 17β-estradiol in the acute phase of MI, and predicted the risk of early in-hospital ventricular arrhythmia.
Related Concept Videos
ECG Interpretation of Arrhythmias II: Atrial, Junctional and Ventricular Arrhythmias
ECG Interpretation of Arrhythmias I: Sinus Arrhythmias
Types of Arrhythmias
Sinus Node Arrhythmias
Sinus Bradycardia: Originating from the sinoatrial (SA) node, sinus bradycardia involves slower impulses, resulting in a heart rate of less than 60 beats per minute (bpm). Causes include sleep, vagal stimulation, beta-blockers, hypothyroidism,...
Sex-linked Disorders
Mechanism of Cardiac Arrhythmias
Phase Contrast and Differential Interference Contrast Microscopy
In-phase-contrast microscopes, interference between light directly passing through a cell and light refracted by cellular components is used to create high-contrast, high-resolution images without staining. It is the oldest and simplest type of microscope that creates an image by altering the wavelengths of light rays passing through the specimen. Altered wavelength paths are created using an annular stop in the condenser. The annular stop produces a hollow cone of...
Group Design

