Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
Extracorporeal Membrane Oxygenation, Impella, and Other Circulatory Mechanical Support
Acknowledgment
Stephen N. Palmer, PhD, ELS, contributed to the editing of the manuscript.
Mechanical Circulatory Support
Mechanical circulatory support (MCS) refers to nonpharmacologic cardiac assist systems that provide hemodynamic support in the treatment of patients with cardiogenic shock. Temporary MCS is used as a bridge to myocardial recovery, durable MCS, and heart transplantation or to provide time for clinical decision making. Despite having been in use for more than 40 years, the most common form of MCS remains the intraaortic balloon pump (IABP) (Getinge). More contemporary MCS includes intracardiac systems that can be implanted percutaneously (Impella, ABIOMED; the TandemHeart, CardiacAssist), peripheral or central extracorporeal membrane oxygenation (ECMO), and centrally inserted (via sternotomy) temporary ventricular assist systems.
At this time, no specific form of MCS has demonstrated clear superiority in the management of cardiogenic shock. Each MCS method has unique hemodynamic and mechanical characteristics that affect its clinical use and peri-implantation echocardiographic evaluation. As a result, cardiologist and echocardiographer exposure to MCS devices is heterogenous and based on patient- and center-specific parameters. This chapter reviews the most prevalent types of MCS, with a focus on echocardiographic assessment ( Table 176.1 ). Of note, in all patients being considered for MCS, baseline echocardiographic assessment should include assessing biventricular function, presence of severe valvular disease, intracardiac thrombus, and identification of alternative pathophysiologic mechanism for hemodynamic shock.
TABLE 176.1
Peri-implant Echocardiographic Assessment and Monitoring of Mechanical Circulatory Support Devices a
| MCS System | Preimplant Contraindications | Insertion Guidance | Postimplant Complications |
|---|---|---|---|
| ECMO | None | Often TTE/TEE; TEE for dual-lumen VV-ECMO | VV-ECMO: recirculation from adjacent cannulas VA-ECMO: LV pressure loading and reduced LV ejection |
| Impella | Severe AR, mechanical aortic valve, aortic dissection, LV thrombus | Fluoroscopy TTE to confirm postimplant position |
Malpositioning (incorrect depth or interference with MV function) Suction event from LV decompression or malpositioning |
| IABP | Severe AR, aortic dissection | Fluoroscopy | Malpositioning |
| TandemHeart RV Support | Left atrial thrombus, severe pulmonic regurgitation or stenosis, severe tricuspid stenosis | Fluoroscopy, TEE, or both Fluoroscopy and often TEE |
Suction events from LA decompression Pulmonic regurgitation Malpositioning |
AR, Aortic regurgitation; ECMO, extracorporeal membrane oxygenation; IABP, intraaortic balloon pump; MV, mitral valve; TEE, transesophageal echocardiography; TTE, transthoracic echocardiography; VA, venoarterial; VV, venovenous.
a Preimplantation assessment for all types of percutaneous mechanical circulatory support (MCS) should include left ventricular (LV) and right ventricular (RV) function, LV and RV size, severe valvular stenosis and regurgitation, ventricular septal defect, and peripheral vascular disease.
You're Reading a Preview
Become a Clinical Tree membership for Full access and enjoy Unlimited articles
If you are a member. Log in here