Question
A 60 year old male presented with complains of palpitations ,shortness of breath and chest tightness.He has a long term history of smoking.ECG showed the following features.What can be the underlying disorder for this condition?
A. COPD.
B. Congestive heart Failure.
C. Coronary Artery disease.
D. A and B.
Show Answer
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Correct Answer » D
Explanation
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Ans: D. A and B.
ECG in the image shows:Rapid irregular rhythm > 100 bpm and at least 3 distinctive P-wave morphologies (arrows),which is suggestive of Multifocal Atrial Tachycardia.
Multifocal Atrial Tachycardia
- A rapid, irregular atrial rhythm arising from multiple ectopic foci within the atria.
- Most commonly seen in patients with severe COPD or congestive heart failure.
- It is typically a transitional rhythm between frequent premature atrial complexes (PACs) and atrial flutter / fibrillation.
ECG findings:
- Heart rate > 100 bpm (usually 100-150 bpm; may be as high as 250 bpm).
- Irregularly irregular rhythm with varying PP, PR and RR intervals.
- At least 3 distinct P-wave morphologies in the same lead.
- Isoelectric baseline between P-waves (i.e. no flutter waves).
Mechanism :
Arises due to a combination of factors that are present in hospitalised patients with acute-on-chronic respiratory failure:
- Right atrial dilatation (from cor pulmonale)
- Increased sympathetic drive
- Hypoxia and hypercarbia
- Beta-agonists
- Theophylline
- Electrolyte abnormalities: Hypokalaemia and hypomagnesaemia (e.g. secondary to diuretics / beta-agonists)
The net result is increased atrial automaticity.
