Intraoperative diaphragmatic stimulation by a cardiac resynchronization therapy defibrillator presenting as hiccups

Pacemaker-related diaphragmatic contractions are a phenomenon encountered in cardiology practice. With informed consent from the patient, this letter reports a case of this condition under general anesthesia, presenting as hiccups. A 44-yr-old female patient with a history of back pain was diagnosed with lumbar stenosis and presented for posterior instrumentation surgery. She had a height of 163 cm and weight of 104 kg; her known comorbidities included obesity (body mass index [BMI], 39.1 kg m-2), type 2 diabetes, and nonischemic dilated cardiomyopathy with a left bundle branch block and an implanted cardiac resynchronization therapy–defibrillator (CRT-D) device (INOGENTM X4 CRT-D model G148, Boston Scientific Corporation, Marlborough, MA, USA). General anesthesia (GA) was induced, the patient wa positioned prone, and neuromonitoring was initiated.Intravenous infusions of propofol and remifentanil were initiated for maintenance of GA. Preoperatively, a cardiologist reprogrammed the CRT-D device; the pacing mode was kept the same to ensure left ventricle (LV) functionality and tachycardia therapy was deactivated (even though magnet application effects on the device are the same as those of the abovementioned configuration, the prone position would have hindered the ability to maintain the position of the magnet).