Hello and welcome to the Zero to Finals podcast.

My name is Tom and in this episode I'm going to be talking to you about superventricular tachycardia.

And you can find written notes on this topic at zero tofinals.com slash SVT

or in the cardiology section of the second edition of the zero to finals medicine book. So let's get

straight into it. Superventricular tachycardia or SVT occurs when abnormal electrical signals come from

above the ventricles causing a fast heart rate.

Supra refers to above and tachycardia is a fast heart rate.

Let's talk about the pathophysiology.

Normally the electrical signals of the heart start in the sinoatrial node.

The sinoatial node is the heart's natural pacemaker, dictating when the heart beats.

It's located at the junction between the superior v. Nicaver and the right atrium.

The electrical signal generated by the sinoatrial node travels through the right and left atrium,

causing the atria to contract, then it travels through the atrioventricular node, or AV node,

which is the pathway between the upper part of the heart, the atria, and the lower part of the

heart, the ventricles. It travels through the atrial ventricular node

down to the ventricles,

where it causes the ventricles to contract.

The electrical signal in the heart

can only go in one direction,

from the atria to the ventricles.

Normally, it cannot travel from the ventricles

back up into the atria.

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