Pulmonary hypertension? Flashcards
What is pulmonary hypertension?
increased pressure within the pulmonary vasculature
What three mechanisms can cause pulmonary hypertension?
increased pulmonary blood flow, increased pulmonary vascular resistance, increased pulmonary venous pressure, or a combination
What are the echocardiographic signs of PH in dogs?
remember, no definitive
Assessment of tricuspid velocity RV systolic dysfunction/ thickening Poor filling of LV Flattening of septum Pulmonary artery enlargement RA enlargement Enlargement of the caudal vena cava
What are the clinical signs of PH?
Strongly suggestive: Syncope Cardiogenic ascites Respiratory distress at rest Activity or exercise terminating in respiratory distress
Possibly suggestive Tachypnoea at rest Increased resp effort at rest Prolonged postexercise or post‐activity tachypnea Cyanotic or pale MM
What are the six categories of PH?
Pulmonary arterial hypertension
Pulmonary hypertension due to left heart disease
Pulmonary hypertension secondary to respiratory disease, hypoxia or both
Pulmonary emboli/thrombi/thromboemboli
Parasitic disease (Dirofilaria or Angiostrongylus infection)
PH with multifactorial or unclear mechanisms
What are some general methods of limiting disease for PH patients?
Exercise restriction
Prevention of contagious respiratory pathogens using vaccination and parasitic disease (eg, Dirofilaria and Angiostrongylus) control using chemoprophylaxis in endemic areas
Avoidance of pregnancy (because of potential to exacerbate PH and because of the possibility of transmission of genetic contributors)
Avoidance of high altitude and air travel
Avoidance of nonessential wellness procedures (eg, dental cleanings) and elective surgery requiring general anaesthesia
How would you treat dogs with right to left shunting, erythrocytosis, and clinical signs?
periodic phlebotomy, typically with fluid replacement. Hydroxyurea can be considered as an alternative to decrease red cell volume
How do you treat PH?
Mostly resolves around treating the cause of it
Specifically can use a PDE5i - mostly sildenafil - this can lead to acute pulmonary oedema and should not be first line in those with heart disease.
When is sildenafil likely to be useful?
bidirectional or right‐to‐left shunting in an attempt to improve clinical signs and help manage erythrocytosis. In this scenario, hematocrit might serve as an objective variable to monitor response to the PDE 5i. In‐hospital monitoring when PDE 5i treatment is initiated is advisable
Can give to those with left heart disease but not those with CHF
Outline the use of sildenafil in heart patients
recommended for dogs with clinical (eg, jugular venous distension, fluid wave on abdominal palpation, or auscultable pleural fluid line) and ultrasonographic (abdominal or pleural effusion without another cause along with RA enlargement, caudal vena caval distension, hepatic venous distension or hepatomegaly) evidence of right‐sided heart failure.
considered in dogs with exertional syncope without another identifiable cause that have failed to respond to other treatments for preclinical LHD (eg, pimobendan).
considered for dogs with a high probability of PH with compensated LHF (ie, dogs previously diagnosed with LHF and on HFM but that do not currently have pulmonary edema) that develop cardiogenic ascites. Treatment should be carried out by up‐titration of HFM to offset the potential risk of inducing pulmonary edema.
considered for dogs with compensated LHF and a high probability of PH (ie, dogs previously diagnosed with LHF and on HFM but that do not currently have pulmonary edema) that develop exertional syncope without another identifiable cause
Do give to respiratory disease
Do give to pulmonary embolism dogs
Consider in heart/lung worm cases with PH
How can you monitor PH?
Clinical improvement, thoracic radiography, pulse oximetry, and arterial blood gases represent the most useful serial diagnostic tests. Other means of monitoring include echocardiography, N terminal pro‐B‐type natriuretic peptide, 6‐minute walk test (6MWT), and voluntary activity monitors.
What respitatory diseases can cause PH?
3a. Chronic obstructive airway disorders
3a1. Tracheal or mainstem bronchial collapse
3a2. Bronchomalacia
3b1. Interstitial lung disease
3b1a. Fibrotic lung disease
3b1b. Cryptogenic organizing pneumonia/secondary organizing pneumonia
3b1c. Pulmonary alveolar proteinosis
3b1d. Unclassified interstitial lung disease
3b1e. Eosinophilic pneumonia/eosinophilic bronchopneumopathy
3b2. Infectious pneumonia
3b3. Diffuse pulmonary neoplasia
3c. Obstructive sleep apnea/sleep disordered breathing
3d. Chronic exposure to high altitudes
3e. Developmental lung disease
3f. Miscellaneous: bronchiolar disorders
