B51-13 The Hidden Threat: A Case of Missed Aortic Dissection at Presentation

Abstract Introduction Ascending aortic dissection (AD) is a life-threatening condition that can present with symptoms mimicking acute myocardial infarction (MI). Severe aortic insufficiency (AI) often complicates AD and may go unrecognized. Computed tomography angiography (CTA) is considered the imaging of choice because it has high sensitivity and specificity in diagnosing AD. We present a case of missed AD on CTA that was eventually discovered intraoperatively. Case Report A 53-year-old male patient with a medical history of hypertension presented to the emergency department with acute chest pain radiating to his left arm. Vital signs were: heart rate 117 beats per minute, blood pressure (BP) 137/69 mmHg, respiratory rate 20 breaths per minute, and oxygen saturation of 69% on room air. Electrocardiogram was concerning for acute MI. He was immediately taken to the catheterization laboratory. Coronary angiography revealed no obstructive coronary disease, but showed a dilated ascending aorta with aortic insufficiency. CTA was performed and showed mild ectasia of the ascending aorta measuring 4.4 cm, without evidence of AD. He was admitted to the critical care unit for close monitoring. Shortly after, his clinical condition deteriorated with a BP of 204/20 mmHg and hypoxia secondary to acute heart failure, requiring intubation. Despite the negative findings on CTA, a multidisciplinary team involving critical care, cardiology, and cardiothoracic surgery decided to manage the patient based on his overall clinical picture. Labetalol infusion was initiated, and he was taken to the operating room, where transesophageal echocardiography (TEE) revealed an acute ascending AD. He underwent surgical repair and made a full recovery. Discussion Ascending AD is considered a medical emergency. Patients typically present with acute chest, back, or abdominal pain. Patients may have wide pulse pressure and/or unequal pulses or BP between the arms. Magnetic resonance angiography (MRA), TEE, or CTA can be used in diagnosis. Rapid diagnosis is crucial and CTA is usually preferred because it’s faster to obtain and has a high sensitivity of 98-100%. Although extremely rare, false-negative results can occur, and can lead to delayed diagnosis and potentially fatal outcomes. This case underscores the importance of maintaining a high index of suspicion for AD, even in the absence of clear findings on CTA. In patients presenting with severe chest pain and wide pulse pressure, AD should be considered a potential diagnosis. When CTA is inconclusive, additional imaging modalities, such as MRA or TEE, are essential for accurate diagnosis and guiding timely surgical intervention. This abstract is funded by: None