Right Ventricle in Acute and Chronic Pulmonary Embolism (2013 Grover Conference Series)

Abstract

Venous thromboembolism (VTE) encompasses deep-vein thrombosis and pulmonary embolism (PE). It is the third-most-frequent cardiovascular disease, with an overall annual incidence of 1-2 per 1,000 population. Chronic thromboembolic pulmonary hypertension (CTEPH) is regarded as a late sequela of PE, with a reported incidence varying between 0.1% and 9.1% of those surviving acute VTE. Right ventricular (RV) function is dependent on afterload. The most precise technique to describe RV function is invasive assessment of the RV-to-pulmonary vascular coupling. However, assessments of RV afterload (i.e., steady and pulsatile flow components and their product, the RC-time) may be useful hemodynamic surrogates of coupling. RV load is different in acute and chronic PE. In acute PE, more than 60% occlusion of the crosssectional area of the pulmonary artery within a short period of time leads to abrupt hemodynamic collapse. If the time of occlusion is limited to ∼15 seconds, significant decreases in fractional area change, tricuspid annulus systolic excursion, and RV free-wall deformation (strain) occur, with the latter showing significant postsystolic shortening. These changes have similarities to ischemic stunning, and they recover within minutes. In CTEPH, studies of pulmonary vascular resistance (PVR) and pulmonary arterial compliance demonstrated low RC-times that were further lowered after pulmonary endarterectomy (PEA). Immediate postoperative PVR was the only predictor of long-term survival/freedom from lung transplantation, suggesting that the effect of PEA on opening vascular territories to flow outweighs its effect on proximal stiffness. This review summarizes the current knowledge on vascular and intrinsic RV adaptation to VTE, including CTEPH, and the role of imaging.Keywords: right ventricle, hemodynamics, pulmonary heart disease, pulmonary embolism. Venous thromboembolism (VTE) encompasses deep-vein thrombosis (DVT) and pulmonary embolism (PE).It is the third-most-frequent cardiovascular disease, with an overall annual incidence of 1-2 per 1,000 population. Chronic thromboembolic pulmonary hypertension (CTEPH) is regarded as a late sequela of PE. Right ventricular (RV) function is an important determinant of long-term outcome in patients with acute PE and CTEPH. In these conditions, the right ventricle (RV) is subjected to abnormal and increased loading that varies in timing, magnitude, and duration. Consequently, RV dysfunction and pulmonary hypertension (PH) are variably present at initial presentation of acute PE. After an episode of PE, pulmonary hemodynamics and RV function normalize within a few weeks in the majority of patients. CTEPH results from persistence of thrombotic obstructions in the pulmonary vasculature in the presence of significant positive and obliterative vascular remodeling and chronic elevation in pulmonary pressures. CTEPH leads to a progressive increase in RV afterload, causing RV dysfunction and eventually RV failure and death. The condition is underdiagnosed, and the true ...

Interobserver agreement between non‐cardiologist veterinarians and a cardiologist after a 6‐hour training course for echographic evaluation of basic echocardiographic parameters and caudal vena cava diameter in 15 healthy Beagles

“…Moreover, focused cardiac ultrasound helps direct therapeutic interventions, including the need for volume resuscitation, vasopressors, and inotropes, as well as diuretics and vasodilators . Focused cardiac ultrasound can also be used to identify findings suggestive of pulmonary embolism (right ventricular enlargement), or more commonly in veterinary medicine to identify pericardial effusion and caudal vena cava (CVC) distension …”

Effect of Percutaneous Suction Thromboembolectomy on Improved Right Ventricular Function

“…An important consequence of PE is elevated RV afterload and increased wall tension, which can lead to dysfunction. 13 In turn, RV dysfunction is associated with increased short-term mortality rates in patients with PE. 14 Therefore, the improved RV function in this series, wherein most patients (62%) had thrombi in the pulmonary system, signifies an important outcome.…”

Interventional Therapy for Pulmonary Embolism

“…However, the emphasis is on effective hemodynamic unload- ing of the right ventricle. 23 To this end, we employ escalating levels of intervention depending on the case, starting with ultrasound-assisted catheter-directed thrombolysis escalating to AngioVac, delivered via a subxiphoid or direct RV access approach, followed by open surgical thrombectomy.…”