Pathology of the Week – April 9th

Jervell and Lange-Nielsen syndrome. Medicalese: first described in 1957 by Anton Jervell and Fred Lange-Nielsen. Short forms: JLNS or J-LN syndrome

JLNS is the first in a weekly series of uncommon pathologies I will post. I first heard about this cardioauditory (two words not usually together) disorder from a February, 2010 Dr. Venkatesan blog post. Jervell and Lange-Nielsen syndrome (JLNS) is a genetic disorder that affects potassium channels in the heart and inner ear. This affects cellular repolarization and lengthens the cardiac action potential causing prolonged QT intervals and neural deafness. JLNS is the most severe variant of the congenital long QT disorders with over 90% of patients becoming symptomatic and 25% suffering sudden death. In a sample of 186 patients 50% had a cardiac event before age three and only 5% neared adulthood symptomless. See this Circulation article (free access) as well as this thorough review by Tranebjaerg et al.

Jonas Gustavsson Syndrome

A few months ago the Leaf’s new goaltender underwent two rounds of treatment for a “heart condition”. I was surprised to see his specific problem receive so little mention in the sports press. For you Toronto fans, of which I am not – Deeeeetroit, here is a look at what his heart condition was.

The monster’s condition was a cardiac arrythmia – a problem within the electrical conduction system of the heart. Most probably atrioventricular reentrant tachycardia (AVRT). AVRT is just a big scary medicalese acronym. I will explain first with an example of how a normal heart beat works.

Framework for thinking about tachycardia

Supraventricular tachycardia. AV non-nodal reentrant tachycardia. SV tachycardia with aberrancy such as a bundle branch block. Bundle who? Super what?

Tachycardia is guilty of committing the sin of medicalese. An overuse of lengthy latin and greek words which make the topic appear unattainable. I certainly felt this way until I came across references that view tachycardias through a system. Although there are a few of these resources that are great (i.e. Rob Theriault’s CDI) my personal favourite is Ed Wallit’s of PodMedics.

Look for me in airports/hockey arenas

New international AED sign

ILCOR has announced an official international sign for automatic external defibrillators (AEDs). ILCOR chairman and cardiologist R.W. Koster described the sign as indicating the presence of an AED within a room, a container or that an AED can be found in a certain direction. The symbol purposefully has no markings to allow for international usage.

Increasingly research is indicating that the best patient outcomes do not require advanced life support (ALS), pharmacological treatment or invasive procedures. As Dr. John Burton describes, if you want to survive a heart attack out of hospital then you will want; Someone nearby to quickly begin CPR; An AED to be very close; And to have your core body temperature dropped a few degrees. Bringing AEDs closer to cardiac arrest is one of the simplest measures that can be undertaken to improve patient outcome.

Mom was wrong – you won’t catch your death of cold

Therapeutic hypothermia is a hot topic at this year’s ILCOR conference in Dallas. The new treatment has garnered increased attention following two papers published in the New England Journal of Medicine in 2002 (Bernard et al, 2002; the HACA group, 2002). It was also depicted in the 5th season finale of House when Wilson suggests it during an ambulance transfer of comatose Amber.

Therapeutic hypothermia is an intervention for Px who have suffered from cardiac arrest and have been successfully revived as defined by spontaneous return of circulation (SROC). It is not used to treat the arrest itself but rather to reduce the secondary injuries that ensue after the Px is brought back from the clinically dead. Basically if someone has a heart attack and is then brought back to life their body is cooled down to hypothermic levels for a day to prevent their body from hurting itself.

CPR, CPR and more CPR

A short time ago an awkward adolescent Fire Medic nerd watched his hot swim instructor demonstrate how to pinch the dummy’s nose and perform mouth to mouth respirations. It seems shocking now to consider performing such an intervention without any form of PPE/BSI. Consider other relics of resuscitation procedures. One of my former Chiefs described an 80′s EMS protocol to perform one minute of CPR, move the Px to the lawn, perform an additional minute of CPR and then continue to the ambulance. After three explanatory attempts I still do not understand the compression, ventilation and vital signs check system my Mom was taught in the early 90′s.