Any change of medications can affect the patient's condition, especially if they are used to control heart rhythm or other hemodynamic parameters. Changing the doses and types of drugs may affect the patient's well-being, but it is difficult to estimate, because it depends on many factors, m.in individual health, the body's reaction to drugs and other factors. It is difficult for me to give an unequivocal answer on the basis of such a short description. As a pharmacist, I can only give general information about the following drugs: Ivabradine is a medicine that reduces the heart rate by selective and specific action on the If current of the pacemaker. It is used in the symptomatic treatment of chronic stable angina in people with coronary heart disease, normal sinus rhythm and heart rate ≥70 beats / min. Ivabradine Accord: https://www.gdziepolek.pl/produkty/96575/ivabradine-accord-tabletki-powlekane/apteki Dilzem is a calcium channel inhibitor used m.in in hypertension, arrhythmias and other conditions where control of heart rate and blood vessel tone is important. The most important side effects of Dilzem include dizziness and malaise. In about 7% of patients, the drug may experience worsening of the arrhythmia or the appearance of a new one. Dilzem 90 Retard: https://www.gdziepolek.pl/produkty/23739/dilzem-retard-tabletki-o-przedluzonym-uwalnianiu/apteki The action and composition of individual drugs can be checked by clicking on the attached links on the gdziepolek.pl website, which also allows you to book them at the nearest pharmacy. If you feel worse after changing your medication, I encourage you to consult your doctor. Your well-being after changing medications is important and may require dose adjustments or therapy changes based on your doctor's assessment. If it is not possible to visit a stationary one, I encourage you to use teleadvice via, for example, the portal Gdziepolek.pl: https://www.gdziepolek.pl/telekonsultacja