Sunday, July 10, 2011

Tandem Heart

The purpose of this blog is to educate critical care nurses on the Tandem Heart, a percutaneously inserted ventricular assist device that can be used as temporary resuscitation after an acute myocardial infarction or a long term bridge to heart transplant for patients with severe cardiomyopathy.  One major advantage of using a blog to educate nurses regarding this fairly new device is that this medium will allow me to add links to the Tandem Heart website which has several pictures and videos of the device and how it works to enable those that learn better visually.  Another advantage to using a blog is that this education material can be seen by nurses and other healthcare providers throughout the world via the web, and not just those nurses in my unit.  One disadvantage is not being able to address questions in a timely manner.  In an in-person inservice, questions can be answered on the spot.  When using a blog, it may take the writer several days to respond to questions. 

The Tandem Heart device can be implanted in the CVOR or the Cath Lab by a cardiothoracic surgeon or an interventional cardiologist.  Indications for use of the Tandem Heart include, but are not limited to, AMI, cardiogenic shock, RV infarct, decompensated HF, acute myocarditis, post-cardiotomy pump failure, high risk coronary interventions and cardiac arrest (http://www.cardiacassist.com/).

The system has three major components: the pump, escort controller and the cannula.  The heart pump is a dual chamber device that allows for adequate blood inflow/outflow by using a powerful impeller.  The escort controller is the "brains" behind the device that gives easy to follow instructions on set-up and trouble shooting.  The cannula, that comes in two lengths, may be inserted percutaneously or transseptally.  The cannula has a built in dilator to help dilate the septum.  Pictures of these devices may be found at http://www.cardiacassist.com/.

Before the invention of the Tandem Heart, the IABP (intra-aortic balloon pump) was used more frequently for patients in need of ventricular support.  However, new studies have shown that the IABP only decreases the LV workload by 10-15% and still requires the patient to have higher doses of inotropic support.  The Tandem heart, inserted percutaneously or transseptally, allows the chest to be closed giving a flow of 5-8 LPM.  This gives the patient a less likely chance of aquiring an infection (http://www.cardiacassist.com/).

The patient on the Tandem Heart must be monitered continuously and very closely.  This monitoring includes EKG, Art line, PAP, CVP, Cardiac output, SVO2 and a peripheral circulatory assessment.  The patient should be assessed for signs of decreased perfusion, especially in the lower extremities and the left upper extremity.  The patient should also be monitered for compartment syndrome. 

Though this device gives patients better outcomes than the standard IABP, it also comes with it's risks and complications.  Complications include:  bleeding, right sided circulartory failure, exposure to high doses of heparin, coagulopathy, platelet dysfunction, hemodilution and cannula dislocation.  Considerations to include in the plan of care are maintaining fluid balance, managing arrhythmias, insertion site care, distal pulse assessments and decreased patient mobility. 

The Tandem Heart may be removed by physician only in the CVOR, Cath Lab or at bedside.  Continuous monitering should be available. 

In an online article in The Journal of Invasive Cardiology, it states "use of the TandemHeart pVAD may improve the morbidity and mortality rates associated with high-risk PCI. In addition, by increasing the amount of time available in which to deploy the stent safely, the pVAD may allow more accurate stent placement, thereby improving long-term vascular patency. This application may broaden the treatment options for patients at high risk for both surgical and percutaneous revascularization" (2006).

"Patients with heart failure and profound cardiogenic shock, who are unresponsive to vasopressors and intra-aortic balloon pump insertion, have few options except for mechanical cardiac support with a ventricular assist device" (Bruckner, Frazier, Gregoric, Jacob, Kar, La Francesca & Myers, 2009).

References (using APA format, 6th edition)

http://www.cardiacassist.com/  Retrieved July, 10, 2011

Civitello, A., Delgado, R., Forrester, M., Gemmato, C., Kar, B., Loyalka, P., & Myers, T.  (2006, March).  Use of the TandemHeart Percutaneous Ventricular Assist Device to Support Patients Undergoing High-Risk Percutaneous Coronary Intervention.  The Journal of Invasive Cardiology.  Retrieved from http://www.invasivecardiology.com/article/5270

Bruckner, B., Frazier, O.H., Gregoric, I., Jacob, L., Kar, B., La Francesca, S., & Myers, T.  (2009, May/June).  Techniques and Complications of TandemHeart Ventricular Assist Device Insertion During Cardiac Procedures.  ASAIO Journal, 55(3), 251-254.  doi: 10.1097/MAT.0b013e31819644b3 
Retrieved from http://www.asaiojournal.com/