ECG made easy...My version-01(for emergency setting)

Here's some short notes on some common ECG patterns...

Normal sinus rhythm
Rate of between 60-100 bpm(beats per minute)
Every QRS complex is preceded by a P wave and every P wave must be followed by a QRS.

Sinus tachycardia
Rate of more than 100 bpm in a normal adult but often it is limited below 150bpm. Results from sympathetic activation(ie due to pain, fever, hypovolemia)

Sinus bradycardia
Rate of less than 60 bpm in a normal adult. Athletes may constantly be in sinus bradycardia as they have better stroke volume.

Sinus arrhythmia
The rhythm is regularly irregular, with the rate increasing on inspiration and decreasing on expiration. This is commonly seen in children and less common in adults. Often, it is benign.

Sinus exit block/sinoatrial block
This results when the impulse from the sinoatrial(SA) node is block and does not depolarizes the atrium. Although there SA node is firing at the usual rate, the impulses are not passed on. There will be pauses equivalent to multiple P-P intervals.

Sinus pause/sinus arrest
This is resulted when the SA node fails to fire. The difference from sinus exit block is that the pause is normally not equivalent to multiple P-P intervals.
Premature atrial contraction(PAC)
PAC occurs when there is a premature firing from the SA node. This is due to increase irritability of the atria resulting in increased automaticity. Since the SA node firing is earlier, the complex comes earlier. Observe that in the strip, the P wave comes before the dissolution of the T wave. This causes the P wave to become abnormal(biphasic, raised, flattened...). A normal QRS complex(narrow QRS as it originates from the atria) follows the P wave.


Atrial Tachycardia
Often have a rate of between 170 to 230 bpm. The narrow QRS complex shows that it is supraventricular in origin and the rate differentiates it from sinus tachycardia.


Atrial fibrillation
Is a irregularly irregular rhythm. The chaotic rhythm and the absence of P wave is the hallmark of this dysrhythmia.

Atrial flutter
This results from an reentry circuit within the atria at a rate of 250-350. This dysrhythmia is recognized by the sawtooth appearance of the baseline.


Wolf-Parkinson-White(WPW) syndrome
In this condition, there will be presence of delta wave at the foot of the QRS complex. The delta wave is the hallmark of WPW.