What can be identified as the “female ECG” is a J point lower than 0.1 mV in the precordial leads with a sudden transition from QRS complex to ST segment in precordial leads. The “male form” of ECG has a J point higher than 0.1 mV in at least one of the four leads and an ST angle of ≥20 in at least one of those leads. We often find the so-called juvenile form of ECG (negative T-wave in the V1 lead) as a normal variation of “female ECG”; consequently, T-waves have a special role in ECG analysis (6). Repolarization is under the influence of female hormones, especially the function of calcium channels, causing the QTc interval to be significantly to be significantly longer in women than in men in all age groups (studied for ages 17-75) (7). The same repolarization changes in women were also found when measuring T-wave alternans.

According to one hypothesis, the ECG difference between men and women is caused by the influence of testosterone levels, which is corroborated by ECG analysis in men who underwent orchiectomy. No significant changes in QT intervals were found in women receiving hormone supplement treatment, but QT prolongation is possible in women who are in the second phase of the menstrual cycle (6, 7). One must thus be careful in applying medication in women with prolonged QT intervals.

A meta-analysis of 74 studies which included 13,331 women and 11,511 men showed that atypical angina is 11-27% more common in women under 65 years of age than in men and women older than 75 (8). Angiographically, more than 50% of these female subjects had coronary vessel constriction that was lower than 50%, while the rest had minimal stenosis or no coronary artery disease (CAD) at all. Non-obstructive CAD is more often diagnosed in younger women who present with acute coronary syndrome (9). Women with acute myocardial infarction with ST segment elevation (STEMI) had non-obstructive CAD more frequently compared with men (10-25% vs. 6-10%, respectively). Non-obstructive CAD and atypical pain contribute to a risk of non-fatal MI that is twice as high than that of asymptomatic women (10). The failure to recognize and adequately treat women with CAD usually lies in the diagnostic procedure: the stress test is the one that is most frequently used. However, the sensitivity and specificity of this test in women is 61% and 70%, respectively. In men, the sensitivity and specificity are 72% and 77%, respectively. In addition, up to 14% of women have a false-positive result. It is thus necessary to apply different methods in the diagnostic procedure for women.

The use of stress echocardiography or one of the perfusion methods is thus recommended when suspecting CAD and in case of unclear stress test results. Positron emission tomography (SPECT) is a non-invasive method with high sensitivity (95%) and somewhat lower specificity, and the use of vasodilators (dipyridamole) during stress tests has also been shown to be effective (sensitivity 95% to 100%, specificity 89%) (11).

American studies conducted in 2017/2018 that compared the availability of the transradial approach in percutaneous coronary intervention (PCI) for the treatment of STEMI in women compared with men found that it was unsatisfactory for women. Although it is women with transradial approach who benefit most from primary PCI (reducing complications such as bleeding), it is applied far more rarely than in men (12, 13). Independent risk factors for bleeding after PCI are STEMI presentation and the female sex, which are associated with higher mortality after STEMI. The challenge in women with STEMI is to coordinate and balance medications that allow for the necessary antithrombotic/aggregation protection without increased risk of bleeding. Huded et al. in a study from 2018 on women with STEMI found a reduction in bleeding risk and the number of erythrocyte transfusions of 5.4% and 3.9%, respectively, as a result of the application of a unique diagnostic system (4-step STEMI protocol) in addition to guideline-directed medical therapy (GDMT) (13). The study compared the previous diagnostic management procedure with the newly suggested one: there was a total of 1,272 participants with STEMI (68% men, 32% women); the women where older and had more comorbid chronic diseases. The participants were divided into two groups: the group in which the new GDMT was applied regularly and the control group where the GDMT was applied less regularly before PCI. The women in the control group had a higher incidence of in-hospital stroke, vascular complications, bleeding, transfusion, and mortality. The group using the new GDMT approach achieved a reduction in 30-day mortality in women (3.2% higher in women in comparison with men, p = 0.090) in comparison with the control group (6.1% higher in women than in men, p = 0.002) (13).