Turbulent left-to-right shunt flow through the interatrial septum suggesting high left atrial pressure in patients with heart failure with preserved ejection fraction.

Lutembacher's syndrome is a combination of interatrial septal (IAS) defect or patent foramen ovale (PFO), associated with mitral stenosis. High left atrial (LA) pressure in mitral stenosis exaggerates left-to-right shunt in patients with interatrial communication. We present a case of heart failure with preserved ejection fraction. Echocardiography revealed normal left ventricular systolic function without mitral stenosis and turbulent left-to-right shunt through the IAS. The peak velocity of the shunt flow was 2.3 m/s and the estimated pressure gradient was 22 mmHg, indicating high LA pressure. The presence of turbulent left-to-right shunt through the IAS is helpful for detecting high LA pressure.