ECG Quiz – Cardiology MCQ
|
(Click on the image for an enlarged view)
ECG finding is suggestive of:
a) Myocardial infarction
b) Dilated cardiomyopathy
c) Pericardial effusion
d) None of the above
Correct Answer
No Comments
Add a Comment
You must be logged in to post a comment.
Sir,we had a case with severe lvf and electrical alternans.No effusion
Since mechanism of swinging of heart not here,kindly explain what may be the mechanism here?
Thanks in advance
Old text books describe electrical alternans in severe left ventricular failure as corresponding to the pulsus alternans (mechanical counterpart) in those cases. Technically when there is pulsus alternans, the left ventricular volume at end diastole alternates. Usually it starts off after a supraventricular ectopic beat which has a low pulse volume due to the shorter diastole, less diastolic filling and end diastolic volume. In the normal heart, the pulsus alternans after the ectopic beat normalises after a few cycles, but it remains so in left ventricular failure. It is known by the Brodie’s effect that QRS amplitude is proportional to the end diastolic volume. So if end diastolic volume alternates, we can have QRS alternans. These are the old explanations which were taught!