Pulmonary Hypertension – Cor Pulmonale
- Pulmonary hypertension (PH) is the presence of elevated pulmonary arterial pressures (mPAP >25mmHg) resulting most commonly from LV dysfunction, lung disease and chronic thromboembolism.
- Cor pulmonale is defined as RV dysfunction arising from all forms of PH excluding LV dysfunction.
- It can be a life-threatening condition when it presents acutely as a massive PE, ARDS, exacerbation of interstitial lung disease, or noncompliance with cardiopulmonary medications.
- Progressive RV dysfunction can lead to LV failure due to interventricular dependence.
- Maintenance of volume homeostasis often requires aggressive diuresis to avoid hypervolemia.
- Other treatment options include pulmonary vasodilators and inotropes.
- All five WHO categories of chronic PH can result in RV dysfunction.
- Group I: Pulmonary arterial hypertension (idiopathic, hereditary, toxin/drug-induced, HIV, scleroderma).
- Group II: secondary to LV dysfunction.
- Group III: secondary to chronic lung disease and/or hypoxia (COPD, interstitial lung disease, obstructive sleep apnea).
- Group IV: secondary to chronic thromboembolic pulmonary hypertension.
- Group V: Unclear or multifactorial etiology.
Clinical Presentation/Initial Investigations
- Early PH may present with non-specifically as exertional dyspnea.
- Progression to cor pulmonale is marked by worsening signs of RV dysfunction which may have a multi-system effect:
- Cardiac: elevated JVP, peripheral edema, RV heave, loud P2, right-sided regurgitant murmurs and may have chronically elevated BNP/cardiac biomarkers.
- GI: hepatosplenomegaly, ascites, markers of cholestasis and liver dysfunction.
- Renal: AKI with elevated BUN/creatinine.
- ECG may show atrial fibrillation from right atrial enlargement, right axis deviation, or signs of RV strain (ST depression/T wave inversion in inferior leads, most pronounced in lead III) although normal ECG does not exclude PH.
- CT may show enlarged main pulmonary artery >29mm, reversed flow of contrast to the hepatic vein, or RV dilatation (RV/LV diameter >1).
- Early identification of patients with hemodynamically unstable cor pulmonale is critical to providing them with RV-friendly resuscitation.
- Clinicians should maintain high index of suspicion for PH in patients with prior history of PE, COPD/interstitial lung disease, or connective tissue disease and other inflammatory states.
- Radiological investigations include:
- Informal bedside ultrasound looking for signs of RV dysfunction (tricuspid annular plane systolic excursion, D-shaped left ventricle, McConnell’s sign or RV free wall akinesis with sparing of apex).
- Formal echocardiography if available for cardiology consultation.
- Pulmonary CT chest with contrast to rule out PE and assess lung parenchyma.
- RV dysfunction exists along a spectrum ranging from systemic congestion to frank hypotension and multi-organ failure (MOF), and signs of impending RV failure should prompt urgent consult with intensivist and high-priority transport to critical care center.
- It is essential to maintain volume homeostasis and both hypovolemia/hypervolemia should be avoided.
- Volume overload is especially detrimental to RV dysfunction and should be managed aggressively with diuretics.
- Maintain MAP>65 as RV is particularly prone to ischemia due to the increased oxygen demand from RV dilatation.
- For vasopressor support, use with 1.2-2.4mcg/hr vasopressin; 0.05-0.2mcg/kg/min NEP is likely equal in efficacy.
- For inotropic support, use 2.5-7.5mcg/kg/min dobutamine; milrinone is also an option.
- Consider use of pulmonary vasodilators, such as inhaled and parenteral epoprosternol and nitric oxide.
- Persistently poor hemodynamics should prompt strong consideration for ECMO.
- Early guidance from consulting services (ICU, cardiology, IM) is recommended.
- Maintaining sinus rhythm and/or rate control is exceedingly important.
- Consider cardioversion if acute AF, otherwise rate control with amiodarone IV with judicious use of beta blockers or CCB if BP allows.
- Treat underlying lung disease (e.g., AECOPD, pleural effusion, atelectasis, pneumonia).
- Provide supplemental O2 as required.
- Attempts should be made to avoid worsening RV afterload through intubation by trialing non-invasive measures (CPAP, BiPAP).
Quality Of Evidence?
We are highly confident that the true effect lies close to that of the estimate of the effect. There is a wide range of studies included in the analyses with no major limitations, there is little variation between studies, and the summary estimate has a narrow confidence interval.
We consider that the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. There are only a few studies and some have limitations but not major flaws, there are some variations between studies, or the confidence interval of the summary estimate is wide.
When the true effect may be substantially different from the estimate of the effect. The studies have major flaws, there is important variations between studies, of the confidence interval of the summary estimate is very wide.
Use of pulmonary arterial pressures from Doppler echocardiography in risk stratifying PH: MODERATE. Strong correlation with PH severity as seen on RHC.
Use of inotropic agents in acute PH: MODERATE. Benefit in hemodynamic profile in multiple, small RCTs.
Use of inhaled NO in acute PH: MODERATE. May be benefit, especially when in combination with milrinone.
Use of diuretics in RV failure: LOW. There is no high-quality evidence in RVF as most data is derived from studies on LVF.
OTHER RELEVANT INFORMATION
- Internal Book of Critical Care (IBCC): Right ventricular failure due to pulmonary hypertension. https://emcrit.org/ibcc/rv/#relationship_between_RV_failure_&_pulmonary_hypertension
- RV enlargement on bedside ultrasound https://www.coreultrasound.com/right-heart-strain/
- McConnell’s Sign https://www.youtube.com/watch?v=lpIjAYF1V3I
- LITFL: RV strain (ECG) https://litfl.com/right-ventricular-strain-ecg-library/
Frost A, Badesch D, Gibbs JSR, et al. Diagnosis of pulmonary hypertension. Eur Respir J 2019;53.
Galie N, Humbert M, Vachiery JL, et al. 2015 ESC/ERS Guidelines for the diagnosis and treatment of pulmonary hypertension: The Joint Task Force for the Diagnosis and Treatment of Pulmonary Hypertension of the European society of Cardiology (ESC) and the European Respiratory Society (ERS) Endorsed by: Association for European Paediatric and Congenital Cardiology (AEPC), International Society for Heart and Lung Transplantation (ISHLT), Eur Heart J 2015.
Nathan SD, Barbera JA, Gaine SP, et al. Pulmonary hypertension in chronic lung disease and hypoxia. Eur Respir J 2019;53(1):180914. Review.
Konstam MA, Kiernan MS, Berstein D, et al. Evaluation and Management of Right-Sided Heart Failure: A Scientific Statement from the American Heart Association. Circulation 2018; 137:e578.
Banerjee D, Haddad F, Zamanian RT, Nagendran J, Right ventricular failure: a novel era of targeted therapy. Curr Heart Fail Rep. 2010;7:202-211.
The purpose of this document is to provide health care professionals with key facts and recommendations for the diagnosis and treatment of patients in the emergency department. This summary was produced by the BC Emergency Medicine Network and uses the best available knowledge at the time of publication. However, healthcare professionals should continue to use their own judgment and take into consideration context, resources and other relevant factors. The BC Emergency Medicine Network is not liable for any damages, claims, liabilities, costs or obligations arising from the use of this document including loss or damages arising from any claims made by a third party. The BC Emergency Medicine Network also assumes no responsibility or liability for changes made to this document without its consent.
Last Updated Feb 17, 2022
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