Second-degree AV Block, Type II?
This ECG is taken from an elderly woman who complains of feeling weak and tired. We have no other clinical information, unfortunately.
There is an obvious bradycardia, with more P waves than QRS complexes. Here is what we see:
* Atrial rate is around 115/min. and P waves are regular and all alike.
* Ventricular rate is around 35/min. and QRS complexes are regular and all alike.
* PR intervals, when they occur, are all the same at 162 ms.
* QRS duration is wide at 122 ms.
* QTc interval is prolonged at 549 ms.
What does this mean? There is sinus tachycardia with second-degree AV block because the atrial rate is over 100/min, but not all P waves are conducted. The AV block looks like a Type II (Mobitz II) block because the PR intervals are all the same. This is a reliable indicator of conduction. (Not third-degree AVB). The wide QRS complexes are due to right bundle branch block. The ECG signs of RBBB are: 1) wide QRS; 2) supraventricular rhythm; and 3) rSR’ pattern in V1 and Rs, with a wide little s wave, in Leads I and V6.