Abstract
<jats:p>The monograph presents the clinical course of a female patient with an exceptionally complex form of cardiomyopathy—hypertrophic cardiomyopathy (HCM) accompanied by a subaortic muscular membrane and a mixed (fixed and dynamic) obstruction of the left ventricular outflow tract (LVOT). Her medical history includes multiple intricate interventions for atrial fibrillation and flutter, which ultimately resulted in the development of stiff left atrial (Stiff LA) syndrome, characterized by irreversible calcification of the left atrial wall. The clinical condition is further complicated by severe, likely mixed-type pulmonary hypertension, associated with aneurysmal dilatation of the pulmonary artery. Despite a preserved left ventricular ejection fraction and maintained sinus rhythm, subtotal calcification of the left atrium with morphologically driven restriction of venous outflow excludes the option of isolated lung transplantation. The extent of structural damage involving both the heart and pulmonary vasculature supports combined heart–lung transplantation as the only viable therapeutic approach, in accordance with current international guidelines (ISHLT, ESC/ERS, WSPH). However, such procedures currently exceed the available expertise and capacity within the Ukrainian healthcare system. This monograph is multidisciplinary in scope and offers practical value for cardiologists, cardiac surgeons, pulmonologists, and transplant specialists</jats:p>