Angioplasty guidewire-assisted transseptal puncture in a patient with a hypertrophic atrial septum. (A) Transthoracic echocardiographic image of a hypertrophic atrial septum in a patient with atrial fibrillation before the LAAO procedure. (B1–B9) Angioplasty guidewire-assisted transseptal puncture in the setting of an abnormal hypertrophic atrial septum during the LAAO procedure. BRK, Brockenbrough; GW, guidewire; IVC, inferior vena cava; LA, left atrium; LAAO, left atrial appendage occlusion; RA, right atrium; SVC, superior vena cava.