Using the LV Waveform to Troubleshoot Suction Events

The left ventricular (LV) waveforms displayed on the Automated Impella® Controller (AIC) can provide information to assist in troubleshooting suction events for patients supported with an Impella® heart pump. In this video, Jason Richard, an advanced Impella® devices trainer, discusses how to recognize and manage suction using LV waveform information.

Jason describes how to recognize and address diastolic suction and continuous suction. In both cases, the first step upon seeing a yellow suction alarm is to turn down the P-level as instructed on the console. Then, observe the placement signal waveforms.

A patient experiencing diastolic suction may have normal systolic pressure on the LV waveform and negative diastolic pressures that recover by the end of diastole. The console also displays low diastolic flows. Such a diastolic suction event can be caused by the patient’s preload. Check the patient’s volume status first, then confirm positioning.

A patient experiencing continuous suction may show systolic LV numbers, shown in white, that are uncoupled from the aortic numbers shown in red. Diastolic LV numbers are also very negative and the maximum and minimum flows displayed on the console are lower than expected. The entire LV placement signal waveform shifts downward. Such continuous suction may be related to positioning.

In both suction scenarios, be sure to consider other clinical factors when troubleshooting suction. When a suction alarm is present and the patient’s central venous pressure (CVP) is elevated, this could indicate increased volume in the right ventricle (RV), but decreased volume in the LV. It is important to check the RV function, by either calculating PAPi or using echocardiography, to determine if escalation for RV support is required. Early identification of RV failure is critical for a positive outcome.

Utilizing the LV waveforms as described in this video can reduce the average duration of suction in a case as well as the time to resolve that suction event. Addressing suction quickly is crucial for pump management as prolonged suction can lead to blood incompatibility and compromised hemodynamics.