Friday, June 22, 2012

ECG Interpretation Review #46 (Inferior - Anterior STEMI - Takotsubo - Stress Cardiomyopathy)

The ECG shown was obtained from a 74-year-old woman who presented with abrupt onset of severe renal colic but no chest pain. Based on findings seen in her ECG – acute cardiac catheterization was performed. Her coronary arteries were normal on cath. Troponins were only minimally elevated. 
  • How would you interpret her ECG? 
  • How might you explain the finding of normal coronary arteries on cardiac catheterization?
Figure 1: ECG obtained from a 74 year with renal colic but no chest pain. - NOTE - Enlarge by clicking on Figures - Right-Click to open in a separate window.
INTERPRETATION: The ECG shows sinus rhythm at a rate close to 100/minute. The PR and QRS intervals appear to be normal – but the QT is prolonged. The axis is normal (approximately +70 degrees). There is no chamber enlargement. An rSr’ complex is noted in lead V1. 
  • Assessment of Q-R-S-T Changes is remarkable for the presence of inferior Q waves – normal transition (R wave becoming taller than the S wave between leads V3-to-V4) – and ST segment coving with marked elevation in the inferior leads. This is accompanied by deep T wave inversion
  • Similar abnormal ST segment coving and elevation (albeit not as marked) is also present in leads V4,V5. Deep, symmetric T wave inversion that begins in lead V3 is seen in V4,V5. 
Despite the absence of chest pain – the impression from interpretation of this ECG was “probable acute STEMI" (ST-Elevation Myocardial Infarction) with need for immediate cardiac catheterization and probable reperfusion”. Surprisingly, cardiac catheterization revealed normal coronary arteries. Instead – the ventriculogram revealed apical ballooning with hypercontractility of the cardiac base characteristic of Takotsubo Cardiomyopathy. The patient was treated supportively with recovery of left ventricular function over the next few weeks. 
  • Takotsubo cardiomyopathy is an underappreciated cause of acute ECG abnormalities and new-onset heart failure. The entity was first described in Japan in 1990, with the name takotsubo being derived from a specially designed container used by Japanese fishermen to trap octopuses. The unusual round bottom and narrow neck design of takotsubo resembles the diagnostic picture on cardiac catheterization obtained as a result of ballooning of the cardiac apex with hypercontraction of the base. 
  • Other names attributed to this entity include “stress cardiomyopathy” and “broken-heart syndrome” – in reference to the common occurrence of severe physical or emotional stress prior to onset of the disorder. Awareness of this syndrome is important – because the initial ECG may mimic a large apical infarction (with inferior and anterior ST segment elevation). Transient heart failure is common during the initial stages, but fortunately resolves within a few weeks in most cases.
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1 comment:

  1. Very nice post, impressive. its quite different from other posts. Thanks for sharing.

    TOSHIBA PVM-375AT

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