Case of the Month #31 Mitral stenosis and RV failure

Published 13/07/2022

What haemodynamic goals need to be achieved to further optimise her treatment and improve outcome?

  1. Control heart rate
    1. The aim is to control the ventricular rate to improve diastolic filling and reduce LA pressure. Options include correction of electrolyte levels (magnesium and potassium), medical management with Amiodarone, Digoxin and Cardioversion.

  

  1. Optimize preload
    1. Controlled diuresis using drugs or CVVHDF
    2. Maintaining a slightly higher RV transmural filling pressure of 8-12cmH2O and titrate to improvement in CO/SvO2/Echo

 

  1. Optimise Pulmonary Vascular Resistance
    1. Avoid hypoxia
    2. Avoid hypercapnia and acidosis
    3. Pulmonary Vascular Resistance is at its lowest when lung volume is at FRC; avoid lung over/under distension
    4. Pulmonary vasodilators: inhaled Nitric Oxide (improves V/Q matching and oxygenation as well), inhaled Epoprostenol

 

  1. Optimise Perfusion Pressure: noradrenaline would be the first-choice vasopressor

 

  1. Support the Right Ventricle
    1. Milrinone is an inodilator; it decreases Pulmonary Vascular Resistance and improves RV contractility; however, it causes systemic hypotension which needs to be countered with either Noradrenaline or Vasopressin
    2. Mechanical assist/VA-ECMO can off-load the ventricle and improve pulmonary dynamics

 

  1. Relieve obstruction: there have been case reports of the use of balloon mitral valvotomy to improve haemodynamics

 

Cardiac output /Cardiac index monitoring with a Pulmonary Artery catheter aids management in these complex cases. Although the Pulmonary Capillary Wedge Pressure is not a true reflection of LV End-Diastolic Pressure, it is reliable for CO and Pulmonary Arterial Pressure monitoring. Improvements in mixed venous oxygen saturation would also signal improvements in RV output and titration of vasopressors/inotropes.