BRADYCARDIA-TACHYCARDIA SYNDROME IN A POST-OPERATIVE CARDIAC SURGERY PATIENT

Abstract

The bradycardia-tachycardia syndrome is a condition characterized by episodes of supraventricular tachycardia followed by sinus bradycardia, resulting in significant heart rate variability. This syndrome can be associated with various cardiac abnormalities, including valve abnormalities and atrial dysfunction. The presented case is of a patient who sought emergency medical attention due to episodes of dyspnea with minimal exertion, orthopnea, and paroxysmal nocturnal dyspnea, associated with lower limb edema. The patient had a mechanical mitral prosthesis due to decompensated heart failure and prosthetic leaflet fracture, with three reoperations. During the physical examination, irregularities in the heart rhythm were observed, and a transthoracic echocardiogram (TTE) revealed moderate tricuspid regurgitation, moderate biatrial enlargement, and estimated pulmonary arterial hypertension of 80 mmHg. Continuous cardiac monitoring recorded prolonged pauses in the context of episodes of supraventricular tachycardia followed by sinus bradycardia, characteristic of bradycardia-tachycardia syndrome. Additionally, a normal ventricular ejection fraction, moderate biatrial enlargement, and pulmonary arterial hypertension were observed. Bradycardia-tachycardia syndrome can lead to hemodynamic changes and is associated with adverse cardiovascular risks. Treatment includes pharmacological control and, in some cases, lung transplantation. In this case, the patient received outpatient pharmacological treatment and underwent pacemaker implantation.