Q11 / 110
Optimal Impella positioning places the inflow approximately where?
Correct answer: C — 4–5 cm below the aortic valve within the LV
Optimal Impella positioning is best described as a range rather than a single fixed number, measured from the inflow cage (not the pigtail) to the aortic valve. Published data support approximately 3.5 cm for the Impella CP and roughly 5 cm for the Impella 5.0/5.5; the ISHLT/HFSA guideline states 3.5–4.0 cm for standard Impella devices, and the ASE guideline suggests 4–4.5 cm below the aortic valve for the inlet area. These ranges overlap but are not identical, and the common error to avoid is measuring from the pigtail rather than the inflow cage, which can lead to malposition. The ideal orientation is through the aortic valve directed toward the LV apex. Given the device's hockey-stick structure, if rotated, the orientation could point directly beneath the mitral valve, risking damage to the mitral valve, papillary muscles, and chordal structures. With any manipulation of positioning, pump speed should be reduced to P2 to prevent unintentional snaring of cardiac anatomy — P1 can result in retrograde flow through the Impella, so P2 is the lowest speed used during repositioning.
Board pearl: Impella positioning is a range, not one number — roughly 3.5–4.0 cm from the aortic valve for the CP and ~5 cm for the 5.0/5.5 — measured from the inflow cage, not the pigtail. Repositioning is done at P2, since P1 can allow retrograde flow.
Optimal Impella positioning is best described as a range rather than a single fixed number, measured from the inflow cage (not the pigtail) to the aortic valve. Published data support approximately 3.5 cm for the Impella CP and roughly 5 cm for the Impella 5.0/5.5; the ISHLT/HFSA guideline states 3.5–4.0 cm for standard Impella devices, and the ASE guideline suggests 4–4.5 cm below the aortic valve for the inlet area. These ranges overlap but are not identical, and the common error to avoid is measuring from the pigtail rather than the inflow cage, which can lead to malposition. The ideal orientation is through the aortic valve directed toward the LV apex. Given the device's hockey-stick structure, if rotated, the orientation could point directly beneath the mitral valve, risking damage to the mitral valve, papillary muscles, and chordal structures. With any manipulation of positioning, pump speed should be reduced to P2 to prevent unintentional snaring of cardiac anatomy — P1 can result in retrograde flow through the Impella, so P2 is the lowest speed used during repositioning.
Board pearl: Impella positioning is a range, not one number — roughly 3.5–4.0 cm from the aortic valve for the CP and ~5 cm for the 5.0/5.5 — measured from the inflow cage, not the pigtail. Repositioning is done at P2, since P1 can allow retrograde flow.
Source(s): Van Edom CJ, Gramegna M, Baldetti L, et al. Management of Bleeding and Hemolysis During Percutaneous Microaxial Flow Pump Support: A Practical Approach. JACC Cardiovasc Interv. 2023;16(14):1707-1720. doi:10.1016/j.jcin.2023.05.043. | Bernhardt AM, Copeland H, Deswal A, Gluck J, Givertz MM. The ISHLT/HFSA Guideline on Acute Mechanical Circulatory Support. J Card Fail. 2023;29(3):304-374. doi:10.1016/j.cardfail.2022.11.003.
Q12 / 110
Which complication is most consistent with an Impella positioned too close to the mitral valve?
Correct answer: B — Mitral valve dysfunction
Deep positioning can interfere with the mitral apparatus and cause dysfunction. A and C involve unrelated vascular territories. D is not the expected consequence of proximity to the mitral valve.
Board pearl: Check position before attributing deterioration to worsening ventricular function.
Deep positioning can interfere with the mitral apparatus and cause dysfunction. A and C involve unrelated vascular territories. D is not the expected consequence of proximity to the mitral valve.
Board pearl: Check position before attributing deterioration to worsening ventricular function.
Q13 / 110
Which is NOT a common indication for temporary RVAD support?
Correct answer: D — Severe isolated mitral stenosis
Severe isolated mitral stenosis is not a common indication for temporary RVAD support. Utilization for massive pulmonary embolism deserves a double-click: there have been case reports of its utility in these cases. ESC guidelines suggest utilization of tRVAD for acute RHF as a grade IIb recommendation. AHA guidelines still suggest VA-ECMO as a primary approach for these patients due to complete support during complex embolectomy strategies for clot retrieval. VA-ECMO is associated with greater amounts of bleeding and vascular complications; however, when direct embolectomy and surgical approaches are not planned, Impella RP may be a viable tMCS device.
Board pearl: Massive pulmonary embolism deserves a double-click: VA-ECMO remains primary in many cases, but Impella RP may be a viable tMCS device when direct embolectomy and surgical approaches are not planned.
Severe isolated mitral stenosis is not a common indication for temporary RVAD support. Utilization for massive pulmonary embolism deserves a double-click: there have been case reports of its utility in these cases. ESC guidelines suggest utilization of tRVAD for acute RHF as a grade IIb recommendation. AHA guidelines still suggest VA-ECMO as a primary approach for these patients due to complete support during complex embolectomy strategies for clot retrieval. VA-ECMO is associated with greater amounts of bleeding and vascular complications; however, when direct embolectomy and surgical approaches are not planned, Impella RP may be a viable tMCS device.
Board pearl: Massive pulmonary embolism deserves a double-click: VA-ECMO remains primary in many cases, but Impella RP may be a viable tMCS device when direct embolectomy and surgical approaches are not planned.
Source(s): Pandey et al. Hemodynamic improvement with Impella RP in acute massive pulmonary embolism: a narrative review of cardiovascular outcomes and pulmonary catheter pressure assessment. Annals of Medicine and Surgery. 2025 May 26;87(7):4303-4309.
Q14 / 110
Which temporary RV support configuration most closely reproduces native RV physiology?
Correct answer: B — Right atrium to pulmonary artery
An RVAD drains the right atrium and returns blood to the pulmonary artery, bypassing the RV. A and D are LV support configurations. C does not create an RV bypass.
Board pearl: Inlet and outlet locations define a VAD's physiology.
An RVAD drains the right atrium and returns blood to the pulmonary artery, bypassing the RV. A and D are LV support configurations. C does not create an RV bypass.
Board pearl: Inlet and outlet locations define a VAD's physiology.
Q15 / 110
After two weeks of Impella 5.5 support, LDH is 1,480 U/L, plasma-free hemoglobin is 135 mg/dL, and platelet count is falling. What should be suspected first?
Correct answer: C — Device-related hemolysis
This should first raise concern for device-related hemolysis. While plasma-free hemoglobin rise is more predictive of hemolysis than LDH, lab error can decrease fidelity, resulting in monitoring both. Risk factors for worsening hemolysis include frequent suction alarm and worsening thrombi development in the machinery of the Impella 5.5, commonly found with longer-dwelling devices. Options for treatment of worsening hemolysis primarily include removal or replacement of the primary device. Hemolysis generally results in multi-organ dysfunction.
Board pearl: While plasma-free hemoglobin rise is more predictive of hemolysis than LDH, monitoring both is reasonable, and treatment often includes device removal or replacement.
This should first raise concern for device-related hemolysis. While plasma-free hemoglobin rise is more predictive of hemolysis than LDH, lab error can decrease fidelity, resulting in monitoring both. Risk factors for worsening hemolysis include frequent suction alarm and worsening thrombi development in the machinery of the Impella 5.5, commonly found with longer-dwelling devices. Options for treatment of worsening hemolysis primarily include removal or replacement of the primary device. Hemolysis generally results in multi-organ dysfunction.
Board pearl: While plasma-free hemoglobin rise is more predictive of hemolysis than LDH, monitoring both is reasonable, and treatment often includes device removal or replacement.