Cardiology- the ABC’s of the PQRST
Heather Carter LVT, VTS (Anesthesia & Analgesia)
Introduction
Understanding cardiology can provide the anesthetist with the ability to trouble shoot and treat various problems. Knowing
when and how to treat a bradycardia versus a tachycardia can ensure a smooth anesthetic event.
Origin of the Heartbeat
http://i.pinimg.com/736x/9b/70/59/9b7059c20a452fc655a26e9e3e4b40ad.jpg
Understanding the origin of the heartbeat can help the anesthetist know when and how to identify a potential problem. An
ECG complex consists of a PQRST complex. The sinoatrial node (SA) is the pacemaker of the heart and produces the P wave.
The QRS wave is produced by the atrioventricular node (AV). The P wave in an ECG complex indicates atrial depolarization.
The QRS is responsible for ventricular depolarization and the T wave is ventricular repolarization.
If a P wave is absent there is a lack of atrial depolarization. This is also known as atrial standstill. P waves that are combined
in the QRS complexes are indicative of ventricular tachycardia or a junctional tachycardia. Present P waves that are without
a QRS are indicative of an atrial depolarization that has not been conducted through the AV node. A QRS complex without
a P wave demonstrate premature or escape beats.
Essentials
Arrhythmias can be identified with ease if several essentials are in place. ECG leads should be placed correctly:
White- Right forelimb
Black- Left forelimb
Green- Right hind limb
Red- Left hind limb
Determining the paper speed (25mm/sec vs 50mm/sec) will also help the anesthetist determine if a bradycardia or
tachycardia is present.
Heather Carter LVT, VTS (Anesthesia & Analgesia)
Introduction
Understanding cardiology can provide the anesthetist with the ability to trouble shoot and treat various problems. Knowing
when and how to treat a bradycardia versus a tachycardia can ensure a smooth anesthetic event.
Origin of the Heartbeat
http://i.pinimg.com/736x/9b/70/59/9b7059c20a452fc655a26e9e3e4b40ad.jpg
Understanding the origin of the heartbeat can help the anesthetist know when and how to identify a potential problem. An
ECG complex consists of a PQRST complex. The sinoatrial node (SA) is the pacemaker of the heart and produces the P wave.
The QRS wave is produced by the atrioventricular node (AV). The P wave in an ECG complex indicates atrial depolarization.
The QRS is responsible for ventricular depolarization and the T wave is ventricular repolarization.
If a P wave is absent there is a lack of atrial depolarization. This is also known as atrial standstill. P waves that are combined
in the QRS complexes are indicative of ventricular tachycardia or a junctional tachycardia. Present P waves that are without
a QRS are indicative of an atrial depolarization that has not been conducted through the AV node. A QRS complex without
a P wave demonstrate premature or escape beats.
Essentials
Arrhythmias can be identified with ease if several essentials are in place. ECG leads should be placed correctly:
White- Right forelimb
Black- Left forelimb
Green- Right hind limb
Red- Left hind limb
Determining the paper speed (25mm/sec vs 50mm/sec) will also help the anesthetist determine if a bradycardia or
tachycardia is present.
