SICK SINUS SYNDROME

I've never really understood this, but now I do. It's all about escape rhythms.

So, because the sinus node is malfunctioning, the atrium takes over and you get tachycardia - either flutter, AF or EAT.

Then, when the tachycardia finally tires and stops, there's nothing to take over. So, there's standstill ("sinus pause")...till a ventricular or a junctional escape rhythm takes over.

Other things you see are sinus bradycardia, 'cos when the sinus node does work, it doesn't work well, sinoatrial exit block 'cos when the sinus node does work, it doesn't work well, AV block and BBB because the whole conduction system tends to be shot in these patients.

A pearl for diagnosing SSS from a tachycardia is that you will not see a very fast ventricular response because of the AV node conduction disease.