Author(s): Francisco Ramón Breijo- MárquezThe decrease of the cardiac electrical systole – short PR and QTc intervals in the same electrocardiogram, also known as “Electrocardiographic Breijo Pattern” - is increasingly studied by several authors. The vast majority of the time it can be overlooked in an electrocardiogram tracing. More than 127 cases have been studied and cross-checked by our research team so far. Its diagnosis is indispensable in eluding of the most heartbreaking consequence: avoidable death. Despite the fact that for many authors, the cardiac electrical systole comprises only from the beginning of the Q wave to the end of the T wave – that is, depolarization and repolarization of the ventricles -, the atria are also part of it. Consequently, the P wave, as well as the PR segment, must be a part of the electrical cardiac systole. When there is a shortening of the PR interval along with a shortening of the QT interval, we should talk about: Decrease of cardiac electrical systole.