Diaphragmatic Motion During Cheyne-Stokes Respiration by Navigator Magnetic Resonance Imaging
A 66-year-old man with a history of cardiomyopathy was referred for cardiac MRI to evaluate ventricular function and coronary anatomy. Functional MRI studies demonstrated mildly depressed left ventricular systolic function and an ejection fraction of 48% (normal >59%). Coronary MRI was performed during free breathing with a diaphragmatic navigator positioned at the dome of the right hemidiaphragm. While the patient was sleeping, navigator monitoring (Figure) of diaphragmatic position demonstrated periods of apnea (A) alternating with periods of rapid breathing (RB) in a crescendo-decrescendo pattern of ventilation diagnostic of Cheyne-Stokes respiration. Cheyne-Stokes respiration, typically diagnosed by polysomnography and overnight oximety, is more commonly observed in NYHA class III-IV heart failure, results in sleep fragmentation, and is thought to be associated with an increased risk of cardiovascular morbidity and mortality.