Title : Pericardial Constraint and Pulmonary Hypertension: A Case Series
Abstract:
Invasive hemodynamic assessment with right heart catheterization is currently indicated when the clinical assessment of volume status does not match the physiologic response to treatment, cardiogenic shock, and for the evaluation of advanced therapies such as heart transplant and left ventricular assist device implantation. Right heart catheterization should always be performed at euvolemia. Isolated pre-capillary pulmonary hypertension that results from pericardial constraint may mask itself as a combined pre- and post-capillary pulmonary hypertension. If a patient is found to be hypervolemic at the time of hemodynamic assessment, the procedure should then be repeated once the patient has received adequate diuresis. We present a series of cases that emphasize the importance of accurate diagnosis to allow for effective treatment of these patients. Pericardial compliance is directly affected by the volume status, and hypervolemic conditions may overestimate the pulmonary pressures, whereas a hypovolemic state may underestimate the pulmonary pressures. Late in disease, pericardial constraint may develop which would result in elevated left atrial pressures and an inability to accommodate a hypervolemic state. This is problematic, because if a right heart catheterization is performed for the evaluation of isolated pre-capillary pulmonary hypertension and the patient is hypervolemic, a false negative result may be present. In these cases, the hemodynamics may indicate that the underlying diagnosis is a combined pre- and post-capillary pulmonary hypertension. In each of the four cases presented, repeating the right heart catheterization once euvolemic allowed for correct re-classification as isolated pre-capillary pulmonary hypertension. This study emphasizes the importance of understanding how loading conditions affect the pericardial compliance and its impact on intracardiac pressures at the time of invasive hemodynamic assessment. Adequate diuresis is imperative prior to performing right heart catheterization in order to correctly classify the pulmonary hypertension. Patients who have true isolated pre-capillary pulmonary hypertension benefit from vasodilator therapies and other pulmonary hypertension specific medical management as per the pulmonary hypertension guidelines. Contrary to this, patients with mixed pre- and post-capillary pulmonary hypertension do not benefit from these medications, and it may cause harm. There are a large portion of patients with isolated pre-capillary pulmonary hypertension who may still benefit from pHTN specific medical management, and our objective is to help identify this patient population
