Why is high systemic arterial pressure important in right ventricular (RV) failure?

From the Guidelines

Maintaining high arterial pressure in right ventricular (RV) failure is crucial to prevent right ventricular ischemia and preserve coronary perfusion to the struggling right ventricle. When the RV fails, it cannot effectively pump blood into the pulmonary circulation, leading to decreased cardiac output and potentially systemic hypotension. This hypotension reduces coronary perfusion pressure to the right ventricle itself, creating a dangerous cycle where poor perfusion further weakens RV function. According to 1, the selection of inotropes and vasopressors is challenging in PAH patients, and a major guideline is to maintain systemic vascular resistance (SVR) greater than pulmonary vascular resistance (PVR) to prevent right ventricular ischemia.

To achieve this, the following strategies can be employed:

• Use of inotropes that have neutral or beneficial effects on PVR, such as dobutamine, milrinone, and epinephrine, as mentioned in 1
• Administration of vasopressors to increase systemic vascular resistance and arterial pressure, with the goal of maintaining SVR greater than PVR
• Judicious use of fluid administration to maintain adequate preload, while avoiding excessive fluid that can overdistend the failing RV
• Consideration of inhaled nitric oxide (iNO) to acutely decrease PVR and improve cardiac output, as discussed in 1

It is essential to carefully monitor the patient's hemodynamic response to these interventions and adjust the treatment strategy accordingly. The goal is to improve coronary perfusion to the RV myocardium, enhance contractility, and support RV function, ultimately reducing morbidity, mortality, and improving quality of life.

From the Research

Importance of High Arterial Pressure in RV Failure

• High arterial pressure is crucial in right ventricular (RV) failure as it helps to maintain adequate perfusion of the right ventricle and other vital organs 2.
• In RV failure, the right ventricle is sensitive to changes in loading conditions and intrinsic contractility, and high arterial pressure can help to improve cardiac output and reduce organ congestion 2.
• The use of vasopressors such as norepinephrine can increase arterial blood pressure, which improves cardiac perfusion but also increases afterload 2.
• However, it is essential to balance the increase in arterial pressure with the potential increase in afterload to avoid worsening RV function 3.

Pathophysiology of RV Failure

• RV failure can occur due to various factors, including pulmonary hypertension, which affects not only the pulmonary vasculature but also the right ventricle 4.
• The survival of patients with pulmonary hypertension is closely related to the right ventricular function, highlighting the importance of managing RV failure effectively 4.
• The pathophysiology of RV failure involves changes in right ventricular preload, afterload, and left ventricular function, which can lead to ischemia and RV failure 2.

Treatment of RV Failure

• Treatment of RV failure focuses on alleviating congestion, improving right ventricular contractility, and reducing right ventricular afterload 2.
• Inhaled nitric oxide or prostacyclin can effectively reduce afterload by vasodilating the pulmonary vasculature 5, 2.
• Traditional positive inotropic drugs and vasopressors can also be used to enhance contractility and increase arterial blood pressure, but their use must be carefully balanced to avoid worsening RV function 2, 3.