Signs of sinoatrial blockade on ECG - SA-blockade

Signs of sinoatrial blockade on ECG – SA-blockade

Signs of sinoatrial blockade on ECG – SA-blockade

Grade I SA blockade: indistinguishable on a surface ECG.
CA blockade II degree:
• Type I: the gradual shortening of the PR interval leading to the loss of the P wave and the QRS complex
• Type II: repeated loss of P teeth and QRS complexes

CA-blockade of III degree: consistent loss of several P-waves and QRS complexes at once

Sinoatrial blockade is a relatively rare arrhythmia. It is characterized by a violation of the conduction between the sinus node and the atrium. As in the case of the AV-blockade, there are 3 types of SA-blockade.

I. SA blockade of I degree

The time of excitation from the sinus node to the atria is extended. However, this elongation on the surface ECG is not visible, and the blockade itself has no clinical significance.

Ii. SA-blockade of the II degree SA-blockade of the II degree, type I (SA-periodics of Wenckebach). Rarely observed. Similar to AV-blockade of the II degree (Wenkebach period), as the time of sinoatrial conduction increases gradually, the heart complex (P wave and QRS complex) falls out. The pause that arises is shorter than the double PP interval.

CA blockade of the II degree, type II. Characterized by occasional loss of sinoatrial conduction. On an electrocardiogram it is shown by loss of a tooth P and the QRS complex corresponding to it.

Sinoatrial blockade of the II degree (type II) is sometimes combined with another rhythm disorder, in particular, with sinus arrhythmia, which complicates the interpretation of the ECG. With a significant reduction in the frequency of ventricular contractions, it is necessary to discuss the issue of implantation of a pacemaker.

Leave a Reply

Your email address will not be published. Required fields are marked *