Gender-related aspects in cardiac arrhythmias have gained increasing attention, still the understanding of peripartum electrical disorders remains vague. A 28-year-old woman developed palpitations and presyncopes during the post-partum period after her second pregnancy. Palpitations remained unclear until a self-recorded single-lead smartwatch ECG revealed a complete episode of a fast broad complex tachycardia (260 b.p.m.) that led to hospital admission. Echocardiography, cardiac magnetic resonance imaging, and exercise testing, showed no relevant abnormalities. Recording the tachycardia in a 12-lead-ECG could eventually be achieved revealing an inferior axis and positive concordance in the precordial leads. Episodes of ventricular tachycardia (VT) could be provoked by breast feeding and mental stress, but not induced in two electrophysiological studies. Genetic testing was normal. The patient continued to experience repeated, self-terminating VT episodes, lasting between 10 and 40 s, leading to presyncopes and a syncope with a fall. The beginning of symptoms subsequent to child birth and frequent premature ventricular contractions in her first pregnancy made hormone-induced arrhythmia a tentative diagnosis. Heart rate-corrected QT (QTc) intervals showed significant variability corresponding to the frequency of episodes in a retrospective evaluation. The cessation of breastfeeding led to a termination of arrhythmias. The patient was temporarily equipped with a wearable cardioverter defibrillator vest, an implantable cardioverter defibrillator (ICD) was not implanted. The case report highlights the potential of self-recorded, patient-activated ECG monitoring in diagnosing recurrent palpitations, and the dilemma of timing for implanting ICDs in young patients with ventricular arrythmias (VTs). Additionally, it underlines the role of post-partum hormones in the susceptibility to ventricular arrhythmias, calling for further research of gender-specific, and pregnancy-associated arrhythmias.