CPCP: What Should Psychiatrists Know About Cardiac Devices?

Thomas Salter, MD

Thomas Salter, MD

Ajay Eshcol, MD

Ajay Eshcol, MD

Recently we had an outstanding Clinical Problems in Consultation Psychiatry (CPCP) presentation about the recommendation in a recent review article published in Psychosomatics that psychiatric consultants should know a great deal more about cardiovascular implantable electronic devices (CIED), which include such things as pacemakers and implantable cardioverter defibrillators (ICDs) [1].

I took issue with the authors’ conclusions, which seemed to include recommendations beyond the average consulting psychiatrist’s scope of practice. My residents, including presenters Dr. Tom Salter, MD and a Fellow from the Cardiology Department (Dr. Ajay Eshcol, MD) agreed. What follows is a powerpoint presentation that is not just a summary of the paper, but the result of putting our heads together and figuring out what is the safest and most practical thing to do for our patients in these situations.

The bottom line is in the last ten slides, specifically slide 38. Tom and Ajay patiently explained the difference between a pacemaker and an ICD, and why the latter would be more likely to protect a patient from torsades de pointes (TdP) than a pacer. They also taught me a rough and ready way to distinguish pacers from ICDs on chest radiographs, e.g., ICDs are square and have thick ICD coils going to the ventricles. I didn’t really need to be able to distinguish ICDs and pacers on EKGs, which I think is a skill a little beyond the ability and scope of practice of most consulting psychiatrists.

Some useful links found in the presentation:

http://www.crediblemeds.org/ (which seems to be the same as www.azcert.org and www.qtdrugs.org

http://www.medcalc.com/qtc.html

There is a scary looking table at the end of the paper that has a long list of items that consulting psychiatrists need to know about CIEDs and the risk for prolonged QTc intervals and psychotropic medications. Essentially, the list could be shortened to being able to evaluate baseline risk factors:

  • Age >60 years
  • Female gender
  • Low BMI or poor nutritional status
  • Cardiac history, arrhythmia-related
  • Number of current or recent medications with risk of acquired long QT syndrome or TdP
  • Electrolyte abnormalities such as K+ <4.0 mmol/L, Mg++ <2.0 mmol/L and diuretic use

And one more thing that we could know is how to identify CIED type by chest radiograph. That and including in our recommendations to consultees appropriate cautions about keeping electrolytes normal and avoiding unnecessary QT-prolonging drugs, using telemetry when indicated–and obtaining cardiology consultation.

As usual, the trainees made some excellent slides to get the point across. In order to see the picture galleries of photos or powerpoint slides, click on one of the slides, which will open up the presentation to fill the screen. Use the arrow buttons to scroll left and right through the slides or up and down to view any annotations.

Try accomplishing this kind of reflective self-improvement with Maintenance of Certification (MOC). Can’t touch this.

Reference:

1. Brojmohun, A., J. Y. Lou, et al. (2013). “Protected from Torsades de Pointes? What Psychiatrists Need to Know About Pacemakers and Defibrillators.” Psychosomatics 54(5): 407-417.

Consultation-liaison (C-L) psychiatrists are frequently asked to initiate and manage psychotropic drugs, some of which can delay cardiac repolarization, prolong the QT interval, and increase the risk of torsades de pointes (TdP). This task is complicated by the growing number of patients with cardiovascular implantable electronic devices (CIED) [i.e., permanent pacemakers (PPM), implantable cardioverter defibrillators (ICD), and cardiac resynchronization therapy devices (CRT)]. The precise protective role of CIEDs in the prevention and treatment of TdP is not well-defined. We review practical tips for assessment of the QT interval in patients with paced rhythms, as well as the basic operative principles of CIEDs. We examine the available clinical evidence for the use of CIEDs in patients at risk for TdP. Most CIEDs have a pacing function that, when utilized appropriately, can offer partial protection against TdP by prevention of bradycardia. Defibrillators deliver shocks and are reasonably effective at terminating TdP; however, recurrent shocks are common and are associated with significant physical and psychological morbidity. CIEDs are important tools in the management of drug-induced ventricular arrhythmias in spite of significant limitations. The C-L psychiatrist should remain vigilant in recognizing and managing patients at risk for TdP, and refrain from over-reliance on CIEDs regardless of type or settings. Ultimately, the presence of a CIED should serve as a marker of increased risk of TdP.

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