I’ve read many opinions over time about which EKG leads we should be monitoring and I’d concluded that my best 3 to monitor are II, aVL & aVF as the 3 that give the best all around picture of what’s going on. I’ve seen many medics that have their lifepak 12 set to monitor II, III and aVF which basically only gives you an inferior wall view, probably not a good thing to work with a blind spot like this. Along comes this article in JEMS and now I think I may have found the elusive perfect lead. Although it’s been around quite a while, its use in the prehospital setting seems to be virtually unheard of. I quote the important stuff below:

A New Lead
The modified lead MCL-1 (originally called CL1) was introduced in 1968 – To run this lead, you keep the limb leads RA and LA in their standard position and place the LL electrode on the V1 position (the fourth intercostal space just at the right sternal border.) Select lead III on the monitor, and you’re now viewing lead MCL-1.

This configuration of leads gives a clear chest for cardioversion and defibrillation, and chest auscultation will also be easy. Lead MCL-1 closely resembles V1, so it offers many diagnostic advantages over lead II:

• MCL-1 is the best lead for differentiating V-tach from SVT with bundle branch blocks.
• You can immediately tell right from left ventricular ectopy.
• In most cases, right and left BBB can be recognized.
• Sometimes, P waves can be seen better.
• See the rest here

I have a Philips MRx 12 Lead monitor and the 3 lead cable has a 5th cable marked V. This allows me to monitor any V lead including v4r if I’m so inclined