LAUSR

Refractory atrial arrhythmias often require repeat catheter ablations causing decreased atrial compliance. Overtime, dyspnea may develop from secondary elevated pulmonary pressures because of a noncompliant left atrium (LA), referred to as the stiff LA syndrome. We present a case of a patient with a complicated arrhythmia history refractory to antiarrhythmic medications necessitating multiple ablations presenting with dyspnea on exertion. Cardiopulmonary exercise testing (CPET) with invasive hemodynamic measurement supported the diagnosis of stiff LA syndrome noticeable only during exercise. The patient is a 68-year-old male with a history of atrial arrhythmias refractory to anti-arrhythmic medications and repeat left atrial ablations who presents with exercise intolerance. A transthoracic echocardiogram showed preserved ejection fraction, biatrial enlargement, grade II diastolic dysfunction, and mildly elevated right ventricular systolic pressure, while a nuclear perfusion myocardial scan, cardiac computed tomography angiography, CPET, pulmonary function test, and ventilation-perfusion scan were unremarkable. Diuretics for presumed heart failure with preserved ejection fraction subsequently caused orthostatic symptoms. As such, he was referred for a repeat CPET with the addition …