Respiration Flashcards
What is the definition of Pulmonary Hypertension (PH)?
Abnormally increased pressure within the pulmonary vasculature
Causes can involve increased pulmonary blood flow, pulmonary vascular resistance, or pulmonary venous pressure.
What is the normal pulmonary arterial pressure (PAP) at rest in humans?
> 25 mmHg
This indicates the threshold for diagnosing pulmonary hypertension.
What are the primary pathophysiologic effects of pulmonary hypertension?
- Right ventricular (RV) hypertrophy due to increased workload
- Potential progression to RV dysfunction and failure
- Excessive pulmonary arterial vasoconstriction
Develops via nitric oxide, endothelin, and prostacyclin pathways.
What is postcapillary PH characterized by?
Increased pulmonary arterial pressure (PAP) due to increased pulmonary arterial wedge pressure (PAWP)
Increased PAWP > 15 mmHg and due to left heart disease.
What are the classifications of Pulmonary Hypertension in dogs?
- Group 1: Pulmonary Arterial Hypertension (PAH)
- Group 1’: Pulmonary veno-occlusive disease or pulmonary capillary hemangiomatosis
- Group 2: PH due to Left Heart Disease (LHD)
- Group 3: PH due to Respiratory Disease/Hypoxia
- Group 4: PH due to Pulmonary Emboli/Thrombi
- Group 5: PH due to Parasitic Disease
- Group 6: Multifactorial/Unclear Mechanisms
Each group has specific causes and characteristics.
What are strong clinical symptoms of pulmonary hypertension?
- Syncope
- Exercise intolerance
- Respiratory distress
- Right-sided heart failure
Possible indicators include tachypnea and cyanotic mucous membranes.
What is the gold standard for diagnosing PH?
Right Heart Catheterization (RHC)
It is rarely performed in dogs and is the only definitive diagnosis.
What is the primary non-invasive method to estimate pulmonary arterial pressure?
Echocardiography with Doppler: estimation of PAP and structural changes
It relies on Doppler-derived tricuspid regurgitation velocity (TRV) and cardiac structural changes.
Fill in the blank: The presence of pulmonary arterial filling defects may indicate _______.
pulmonary hypertension
What are some treatment strategies for pulmonary hypertension?
- Exercise restriction
- Preventive measures for parasitic diseases
- Avoidance of high-altitude environments
- Group-specific management
Treatment also includes addressing comorbidities and PH-specific therapies.
What medications are used for pre-capillary PH?
- Phosphodiesterase-5 Inhibitors (e.g., sildenafil, tadalafil)
- Antithrombotic Therapy for Group 4
These medications augment the vascular nitric oxide pathway.
How should PH-specific drugs be handled in post-capillary PH?
Avoid PH-specific drugs unless significant pre-capillary PH is also present
This avoids complications in treatment.
What are the goals for monitoring pulmonary hypertension?
- Track progression via echocardiography
- Monitor for clinical improvement or stability
- Reassess underlying disease management
Monitoring NT pro-BNP and 6-minute walk test can also be helpful.
True or False: Prognosis for dogs with mild PH and well-managed primary diseases is often unfavorable.
False
They may have a favorable outlook.
What are the limitations of current diagnostic tools for pulmonary hypertension?
- Rely on estimates and subject to variability
- Lack extensive prospective studies in veterinary medicine
This complicates evidence-based decision-making.
