Case Review, Hemodynamics, Patient Management, Right Heart Failure
Right Heart Hemodynamics: Key to Recognizing Need for Biventricular Support
Daniel Burkhoff, MD, PhD, walks through a HARVI simulation case illustrating the use of the Impella RP® and Impella CP® heart pumps for biventricular failure. Dr. Burkhoff is, in the words of interviewer Dr. Cathy Jeon, “a true hemodynamicist.” He is director of the Cardiovascular Research Foundation also the developer of the HARVI hemodynamics app, which helps clinicians better understand what’s going on in a patient’s heart and vasculature as well as what happens from a hemodynamic and physiologic standpoint with different therapies and interventions.
The case Dr. Burkhoff presents is a patient with low aortic pressure (AoP), low left ventricular pressure (LVP), low pulmonary artery pressure (PAP), and elevated central venous pressure (CVP). Baseline values: MAP 50 mmHg, CO 1.8 L/min, CVP 22 mmHg, PCWP 17 mmHg, and PAPi 0.4. “So, we've got multiple clues here that this patient has right heart involvement,” Dr. Burkhoff explains, “mainly the elevated CVP and a low PAPi.”
Dr. Burkhoff walks through simulated treatment of this patient beginning with initiating left-sided support with Impella CP. He describes what he sees hemodynamically and concludes that isolated left-side support may not be solving the problem. “So, if you have a central line, especially if you have a right heart cath, you’ll notice, let’s say, a lower than expected wedge and a persistently elevated CVP.”
He then shows what would happen if an Impella RP was inserted and run at full speed in this patient. The flow from the RP overwhelms the CP and wedge pressure rises above desired levels. He reduces the rpms on the Impella RP and PA pressure, wedge pressure, and end diastolic pressure come down, but CVP begins to rise again. “So, this is a balance,” he tells Dr. Jeon. “The CVP and the wedge.” He explains that in some situations you cannot achieve the hemodynamic profile you are trying to target just by manipulating the speeds of left- and right-sided support.
Reminding us of the need to also medically manage these patients, Dr. Burkhoff simulates diuresis on top of biventricular support. “With this you can see that both the wedge and the CVP are going to come down into our target ranges.” He summarizes the simulation with a diagram that tracks CVP and wedge pressure over time.
“We want to recognize, as soon as possible, if biventricular support is needed because we know that persistently elevated CVP is associated with end-organ dysfunction and worse outcomes,” he tells Dr. Jeon. He also emphasizes the importance of having a central line and pulmonary artery catheter for timely assessment of hemodynamic parameters useful for identifying the need for RV support. “If you can treat early, you have probably a better chance of having full recovery. If your treatment is delayed, you are facing a markedly increased risk of mortality.”