The Other Ventricle With Left Ventricular Assist Devices

Lynne Warner Stevenson, MD; Jordan R.H. Hoffman, MD; Jonathan N. Menachem, MD

Disclosures

J Am Coll Cardiol. 2022;78(23) 

In This Article

Prevention of RHF After LVAD

Refining Patient Selection for LVAD

Multiple risk scores have been developed to identify patients at the highest risk for RHF after LVAD.[9,10] One of the most widely used is the Kormos Heartmate II risk score, including a higher ratio of central venous to pulmonary wedge pressure, prior ventilator support, and high blood urea nitrogen.[10] Common calculations for risk include lower RV stroke-work index and pulmonary artery pulsatility index. RHF after LVAD is consistently higher with INTERMACS profiles I-II (crash and burn shock or progressive decline despite multiple inotropic therapies).[11]

Reducing Perioperative RHF

Although preoperative RV dysfunction is a major risk factor for post-operative RHF, Table 2 in the current study[6] shows that neither did all RHF post-LVAD occur with pre-existing RHF nor did all RHF before LVAD lead to clinical RHF after LVAD. The surgery brings dramatic fluid shifts, violation of the pericardium, and changes in regional coronary blood flow. Changes in septal geometry are pronounced in the perioperative period and can be exacerbated by other problems.[12] Increasing vigilance during perioperative management may diminish insult to the RV.

Chronic Optimization of RV Shape and Work

The RV is very sensitive to afterload presented by pulmonary pressures, whose elevation most commonly reflects elevated LV filling pressures. Although resting cardiac outputs are generally close to normal, left atrial and pulmonary artery pressures are often elevated.[13] RV afterload can be reduced by increasing LVAD flow rate to decrease left atrial pressures, but interactions between the device-supported LV and the RV are complex. Increasing LVAD speed contracts the already small LV, with potential septal shift into the LV, distorting RV shape and impairing contractility, which may be further compromised by loss of pericardial constraint, leaving the infundibulum as the major unaffected segment. LV and RV filling are also influenced by mitral and tricuspid regurgitation, for which surgical intervention is controversial. Interactions between the ventricles and LVAD settings are routinely assessed by echocardiography during the ramp study,[13] which should be performed frequently to maintain optimal RV function after LVAD.

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