Feline pulmonary hypertension: are we overlooking an important comorbidity?

Abstract

Pulmonary hypertension (PH) is a potential complication in many disease states, yet it has been largely overlooked in feline medicine. Recently, increased awareness of potential underlying causes has led to a wider understanding of the disease process in humans, with a focus on tailoring therapy to include specific treatment of the underlying etiology. Most of these treatments are not yet available in veterinary medicine, but as they move from the human to the veterinary field, it would be beneficial to better understand the forms of PH encountered in different species. Recently, diagnosis and classification of PH in dogs has been the focus of an American College of Veterinary Internal Medicine consensus statement, yet this condition has received little attention in cats. It is therefore our intention to raise awareness of this condition in cats and to propose a classification system for the types of PH seen in feline patients. As new medications are developed for the treatment of PH, it is important to recognize which forms of PH are seen in feline patients and understand the etiology of the disease. There are many reports of PH (or suspected PH based on echocardiographic assessment) in cats. In this review, we highlight the large number of conditions, and different etiologies, that are associated with PH. Improving understanding of this condition will bring us closer to being able to investigate the benefits of potential new diagnostics and therapies as they become available.

A Case of Congenital Pulmonary Vein Stenosis with Secondary Post-Capillary Pulmonary Hypertension and Left Sided Congestive Heart Failure in a Cat

“…Pulmonary hypertension (PH) is defined as excessively high pressure in the pulmonary vasculature and is caused by increased pulmonary vasculature resistance, increased pulmonary blood flow, increased pulmonary venous pressure, or a combination thereof [ 21 , 22 , 23 ]. The condition is rarely reported in cats, and while most underlying mechanisms appear similar to those reported in humans and dogs, others may differ [ 23 ].…”

“…Pulmonary hypertension (PH) is defined as excessively high pressure in the pulmonary vasculature and is caused by increased pulmonary vasculature resistance, increased pulmonary blood flow, increased pulmonary venous pressure, or a combination thereof [ 21 , 22 , 23 ]. The condition is rarely reported in cats, and while most underlying mechanisms appear similar to those reported in humans and dogs, others may differ [ 23 ]. The most reported conditions associated with PH in cats are congenital heart disease with a left to right shunting of blood, pulmonary thromboembolism, pulmonary fibrosis, chronic upper airway obstruction, and infections with lung- and heartworms [ 23 , 24 , 25 , 26 , 27 ].…”

“…The condition is rarely reported in cats, and while most underlying mechanisms appear similar to those reported in humans and dogs, others may differ [ 23 ]. The most reported conditions associated with PH in cats are congenital heart disease with a left to right shunting of blood, pulmonary thromboembolism, pulmonary fibrosis, chronic upper airway obstruction, and infections with lung- and heartworms [ 23 , 24 , 25 , 26 , 27 ]. The cat in the present case did not have any signs of other congenital heart disease than PVS to explain PH on echocardiography.…”

Partial Pulmonary Vein Stenosis in a Cat Treated with Sildenafil: A Case Report

“…Transthoracic echocardiography was performed using an ultrasound unit (Vivid E9; GE Healthcare Co., Ltd., Tokyo, Japan) with 6-to 12-MHz phased-array transducers. Transthoracic echocardiography revealed right cardiac enlargement, pulmonary artery dilatation, ventricular septum systolic flattening, and an increased pulmonary artery to aortic ratio (MPA/Ao: 1.36; normal range: < 1.0) [1,2], indicating moderate PH (Figure 2). No abnormal septum was observed in the left atrium, and two pulmonary veins had stenosis at their inflow with increased blood flow velocities (2.42 m/s and 3.14 m/s, respectively).…”

“…Pulmonary hypertension (PH) in cats is relatively challenging to detect [1,2]. Pulmonary venous stenosis (PVS) is rare in cats and can lead to PH.…”