The Patient: This excellent teaching case was donated to the ECG Guru by our friend, Sebastian Garay (who is an ECG Guru himself). It was taken from a 33-year-old man who was complaining of chest pain and palpitations. He reported a similar episode about six months prior, but failed to follow up with cardiology. Was told by his medical care provider that he had atrial fib.
The ECG: We are able in this case to provide a 12-lead ECG with each lead recorded for the entire width of the paper. This has the advantage of producing twelve ten-second rhythm strips. Page one contains the limb leads, and page two shows us the precordial leads.
The rhythm is atrial fibrillation, with a heart rate of 133 bpm and an irregularly irregular rhythm. The QRS axis is extreme left at about -75 degrees. This has caused Leads II, III, and aVF to be negatively deflected, and aVR and aVL to be positive. Lead I is biphasic, low voltage, and mostly positive, indicating that the axis travels almost perpendicular to Lead I, but slightly toward it.
The machine mistakenly gives us a reading for PR interval and P wave axis, even though there are no P waves. The QRS is on the wide side without being abnormal at .10 seconds (100 ms). The QTc is within normal limits, although it might be considered “borderline”, with 431-450 usually considered borderline.
There appears to be very slight ST elevation in the inferior leads with no coving of the ST segment. We see the same ST appearance in Leads V3 through V6. The axis in the vertical plane, as indicated by the chest, or precordial, leads, is also unusual. It appeared the same in multiple ECGs run by different people, so lead placement is presumed to be correct. V1 and V2 are more upright than negative, which is not normal. The most common cause of upright QRS in V1 is right bundle branch block, which is not present here. Another common cause of a dominant R wave in V1 and V2 is right ventricular enlargement. V3, V4, V5, and V6 all look very much alike, with no R wave progression, also a sign of right ventricular enlargement. First glance appears to show pathological Q waves in many leads, but on closer inspection, there are small “r” waves. Other signs of right ventricular enlargement, such as the “strain pattern” (ST depression and T wave inversion in right-sided leads), are not evident here.
So, to recap, this young and symptomatic man has had intermittent bouts of atrial fibrillation and chest pain. We do not know of other symptoms, but the ECG is abnormal in many ways, especially for a young person. His symptoms also point to serious heart disease.
The Hospital Course: The patient presented to the Emergency Department in atrial fib with a rapid ventricular response at 140/min. His troponin levels were all critically high at 1.230, 1.30, 1.230, and 1.250. (Normal 0.00 – 0.40). Later that day, he converted to sinus rhythm with PACs. The next day, cardiac catheterization was performed.
Cath Findings: Marked right heart pressure variations with respirations. Mild, non-obstructive coronary artery disease in a co-dominant system. Severe non-ischemic cardiomyopathy (NICM). The left ventriculogram showed global hypokinesis, with an ejection fraction of 20-25% (normal EF is 60% or greater).
Diagnosis: Unspecified atrial fib and Type 2 M.I. This is a term now being used for M.I. due to an underlying cause other than coronary artery plaque rupture and thrombosis. In this case, loss of cardiac output due to atrial fib with RVR and NICM caused a defect in the supply-demand conditions in his heart. Even with open coronary arteries, his heart could not keep up enough cardiac output to adequately supply the coronary arteries and the myocardium. The rapid rate increased the demand side of the equation, while not enhancing the supply side.
Patient Outcome: The patient was discharged home with instructions to follow up with his primary care provider and cardiologist. Even in the absence of heart failure symptoms, he was started on medications for failure, as well as medications for the atrial fibrillation.
Our thanks to Sebastian Garay for sharing this great non-STEMI example.