Monday, March 2, 2015

A 50-something male with Dyspnea

A middle-aged male presented with dyspnea.  An ECG was recorded.
What is going on?  See below.

There is sinus rhythm.  There is notable ST depression in V1-V4, maximal in V2 and V3.  At first glance, it appears to be a posterior STEMI.

But one must always read ST and T-wave abnormalities in the context of the QRS.  There is a large R-wave in V1-V3.  One can see a large R-wave in posterior MI, and so one feels as if one's first impression is confirmed.

However, Right ventricular hypertrophy (RVH) also results in large right precordial R-waves and secondary ST and T-wave abnormalities that mimic ischemia.

One should always look for an S-wave in lead I.  And there it is.   There is right axis deviation.  All this is strongly suggestive of RV hypertrophy.

So a cardiac ultrasound was done:

--Pulmonary hypertension: The estimated pulmonary artery systolic pressure is 72 mmHg + RA pressure.
--Right ventricular enlargement .
--Decreased right ventricular systolic performance .
--Right atrial enlargement but the inferior vena cava is small in size.
--Left ventricular hypertrophy concentric .
--The estimated left ventricular ejection fraction is 75 %

--There is no left ventricular wall motion abnormality identified.

The patient ruled out for MI.

Also, the the workup for PE was done and was negative.  Etiology was airway disease.  McGinn (S1Q3T3) is present here but is a very soft sign of PE.  In a large group of dyspneic patients worked up for PE, those without PE had a 3% incidence of S1Q3T3 and those with PE had an incidence of 8%, for very low positive and negative predictive values.  Also, PE does not give large R-waves in right precordial leads. 

Learning Point:

1.  Abnormal ST elevation and/or depression, and/or T-wave inversion (abnormal repolarization), may be primary (due to ischemia, for instance), or these may be secondary to abnormal depolarization (an abnormal QRS, such as LVH, RVH, LBBB, RBBB, and others).

Thus, one must always closely examine the QRS to be certain that it does not harbor abnormalities that explain the repolarization abnormalities.

2.  Right ventricular hypertrophy often results in right precordial ST depression and T-wave inversion that mimics ischemia.  In particular, it mimics posterior STEMI.

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