Asymmetric Lower Extremity Blood Pressure in Type B Aortic Dissection

Mechanism of Asymmetric Blood Pressures

• Asymmetric lower extremity blood pressures in type B aortic dissection occur due to dissection-related occlusion of aortic branch arteries, resulting in erroneously low blood pressure readings in the affected limb, according to the American Heart Association 1, 2, 3
• Branch vessel occlusion can directly obstruct iliac or femoral arterial flow, creating differential perfusion pressures between limbs, as reported by the American College of Cardiology 1, 2, 3

Clinical Implications and Assessment

• Blood pressures must be measured in both arms and both legs to determine the highest central blood pressure, as relying on a single measurement site can lead to dangerous underestimation of true systemic pressure, as recommended by the American Heart Association 1, 2, 3
• In type B dissections, 71% of patients have systolic blood pressure greater than 150 mmHg at presentation, highlighting the importance of accurate blood pressure measurement, according to the American College of Cardiology 1, 2, 3