Wednesday, 21 June 2017

ECG of the Week - 19th June 2017 - Interpretation

The following ECG's are from a 70 yr old male. He presented to the Emergency Department complaining of palpitations, fatigue, epigastric pain and dizziness. Further history revealed he had malaena for a week prior with no history of significant alcohol consumption. His only past medical history is of ischaemic cardiac disease requiring stenting 10 yrs prior. His medications included aspirin, atorvastatin and metoprolol. His ECG on presentation is below with a further ECG performed when he complained of chest pain during his assessment. His Hb on a venous blood gas is 72 g/L(115 - 155).





ECG on arrival
Pain free
Click to enlarge
Key features

  • Rate 96 bpm
  • Regular sinus rhythm
  • Normal axis 
  • ST Depression leads II, III, aVF, V5-6
  • ST Elevation lead aVR (~1mm)



ECG during episode of chest pain
Click to enlarge
Key features

  • Rate 96 bpm
  • Regular sinus rhythm
  • Normal axis
  • Compared with prior ECG
  • Progression of the ST Depression leads II, III, aVF, V5-6
  • Now including leads I, V3-4
  • Increase ST Elevation in lead aVR (1.5mm) 
  • New ST elevation in leads aVL and V1



Interpretation:

  • Diffuse and dynamic ST segment changes in the setting of acute physiological stress from acute anaemia from a likely upper GI bleed

But this is left main occlusion....

I'd highly recommend everyone read this great myth-busting post by ECG expert Dr Smith here:


What happened ?

The patients pain was treated with GTN and iv opiates with simultaneous blood transfusion. Following urgent blood transfusion the patient's pain resolved and ECG returned to pain-free baseline. Following discussion with both cardiology and gastroenterology the patient was given aspirin but further anti-coagulation was withheld. He remained pain-free during his in-patient stay and following further transfusion under went an upper GI endoscopy. This relieved a gastric antral ulcer as the source of his GI blood loss. He had a mild rise in cardiac biomarkers which was felt to be type 2 myocardial ischaemia due to his acute anaemia and he will undergo and elective myocardial perfusion study as an out-patient.

Clinical Classification of Myocardial Infarction

The 3rd Universal Definition of Myocardial Infarction (European Heart Journal (2012) 33, 2551–2567 Full Text) classified myocardial infarction into 5 categories based on pathological, clinical and prognostic differences, along with different treatment strategies:
  • Type 1: Spontaneous myocardial infarction
    • Spontaneous myocardial infarction related to atherosclerotic plaque rupture, ulceration, Assuring, erosion, or dissection with resulting intraluminal thrombus in one or more of the coronary arteries leading to decreased myocardial blood flow or distal platelet emboli with ensuing myocyte necrosis. The patient may have underlying severe CAD but on occasion non-obstructive or no CAD.
  • Type 2: Myocardial infarction secondary to an ischemic imbalance
    • In instances of myocardial injury with necrosis where a condition other than CAD contributes to an imbalance between myocardial oxygen supply and/or demand, e.g. coronary endothelial dysfunction, coronary artery spasm, coronary embolism, tachy-/brady-arrhythmias, anemia, respiratory failure, hypotension, and hypertension with or without LVH.
  • Type 3: Myocardial infarction resulting in death when biomarker values are unavailable
    • Cardiac death with symptoms suggestive of myocardial ischemia and presumed new ischemic ECG changes or new LBBB, but death occurring before blood samples could be obtained, before cardiac biomarker could rise, or in rare cases cardiac biomarkers were not collected.
  • Type 4a: Myocardial infarction related to percutaneous coronary intervention (PCI)
    • Myocardial infarction associated with PCI is arbitrarily defined by elevation of cTn values greater than 5 x 99th percentile URL in patients with normal baseline values (<99th a="" ctn="" of="" or="" percentile="" rise="" url="" values="">20% if the baseline values are elevated and are stable or falling. In addition, either (i) symptoms suggestive of myocardial ischemia, or (ii) new ischemic ECG changes or new LBBB, or (iii) angiographic loss of patency of a major coronary artery or a side branch or persistent slow- or no-flow or embolization, or (iv) imaging demonstration of new loss of viable myocardium or new regional wall motion abnormality are required.
  • Type 4b: Myocardial infarction related to stent thrombosis
    • Myocardial infarction associated with stent thrombosis is detected by coronary angiography or autopsy in the setting of myocardial ischemia and with a rise and/or fall of cardiac biomarkers values with at least one value above the 99th percentile URL.
  • Type 5: Myocardial infarction related to coronary artery bypass grafting (CABG)
    • Myocardial infarction associated with CABG is arbitrarily defined by elevation of cardiac biomarker values greater than 10 x 99th percentile URL in patients with normal baseline cTn values<99th abnormality.="" addition="" angiographic="" artery="" coronary="" documented="" either="" evidence="" font="" graft="" i="" ii="" iii="" imaging="" in="" lbbb="" loss="" motion="" myocardium="" native="" new="" occlusion="" of="" or="" pathological="" percentile="" q="" regional="" url="" viable="" wall="" waves="">
References / Further Reading

Textbook

  • Chan TC, Brady WJ, Harrigan RA, Ornato JP, Rosen P. ECG in Emergency Medicine and Acute Care. Elsevier Mosby 2005.