Abstract Abdominal pulsations in an elderly patient often raise concern for an abdominal aortic aneurysm (AAA), a life-threatening condition. However, rare non-vascular causes can mimic this presentation. We report a unique case of a patient with a cardiac resynchronization therapy (CRT) device presenting with abdominal pulsations due to diaphragmatic stimulation from a coronary sinus lead, masquerading as AAA. Case Presentation A 60-year-old male with a history of non-ischemic cardiomyopathy (EF 30%) and CRT device placement six months prior presented with rhythmic abdominal pulsations noted over the past few weeks. He denied chest pain, dyspnea, palpitations, or syncope. He described the pulsations as “jerky movements” synchronized with his heartbeat, particularly noticeable when lying flat or after meals.Vital signs were stable. Cardiopulmonary examination was unremarkable. However, visible abdominal wall movements synchronous with the cardiac rhythm were noted. Concern was initially raised for an underlying abdominal aortic aneurysm. An urgent abdominal ultrasound and CT angiogram were performed, both of which showed no evidence of AAA or vascular pathology.Further evaluation including interrogation of his CRT device revealed that the left ventricular (LV) lead, positioned in the coronary sinus, was inadvertently stimulating the left phrenic nerve. This explained the diaphragmatic contractions manifesting as abdominal wall pulsations, simulating vascular pathology.The LV lead output was reprogrammed and subsequently turned off, with resolution of the patient’s symptoms within 24 hours. He remained asymptomatic at 3-day follow-up with no recurrence of abdominal pulsations. Discussion Phrenic nerve stimulation (PNS) is a recognized but often overlooked complication of CRT implantation, especially when LV leads are placed in the lateral or posterior branches of the coronary sinus, which lie in proximity to the phrenic nerve. PNS can present with hiccups, chest wall twitching, or abdominal wall movements, often mistaken for gastrointestinal or vascular etiologies.This case underscores the importance of considering device-related complications in patients with cardiac implants presenting with atypical symptoms. Abdominal pulsations typically prompt evaluation for AAA, yet non-vascular causes, including phrenic nerve capture, should be included in the differential, particularly when imaging is negative and a CRT device is present.Prompt recognition and device reprogramming can resolve symptoms without invasive procedures. Conclusion This case highlights a rare, benign, but alarming presentation of phrenic nerve stimulation due to LV lead placement in a CRT device, mimicking an AAA. Awareness of this potential complication can prevent unnecessary diagnostic workup and expedite symptom resolution through device reprogramming. This abstract is funded by: None
Nazeef et al. (2026) studied this question.