Wednesday, April 11, 2018

Huge Precordial ST Elevation in an ED Patient

This was sent bTwitike Nthakomwa, a medical officer from Malawi who knows a lot about ECGs.

Here is a 50-something patient who presented without symptoms of MI (simply a cough).  Because a murmur was heard, an ECG was recorded.

But this patient could easily develop reflux with chest pain, or chest wall pain, or any number of reasons for non-ischemic chest pain, so it is important to know the range of normal in ECGs.

Here is the ECG:
There is huge ST elevation, about 5 mm in V2 at the J-point (maybe more).
There is also a lot of voltage and this may represent LVH or a thin athletic black male
As you can see, the physician calculated the 3-variable formula
STE at 60 ms after the J-point in lead V3 is 4 mm
QTc is 424 ms
R-wave amplitude in V4 = 37 mm
I estimate the QRS in V2 as 18 mm.
3-variable formula value = 17.74 (very low, far less than cutoff of 23.4)
4-variable formula = 13.66 (very low, far less than cutoff of 18.2)

Thus, this is early repolarization (normal variant ST elevation) and NOT ischemic STE

See here for 3- and 4-variable formulas:

12 Cases of Use of 3- and 4-variable formulas to differentiate normal STE from subtle LAD occlusion

They did a bedside echo:
This does show LVH and also a small amount of mitral regurgitation.

The patient underwent a stress test:
 Notice almost all the ST elevation is resolved.

This is a well known phenomenon: the ST elevation of early repolarization often resolves with stress.

Other features are highlighted in the papers referenced below:
1. Disappearance over time in 18% of patients
2. Intermittent ST elevation in many other patients (it is not necessarily stable over time!)

References

1. Mahaveer C. Mehta, MD.  Abnash C. Jain, MD.  Early Repolarization on Scalar Electrocardiogram. The American Journal of the Medical Sciences. June 1995; 309(6):305–311.

ABSTRACT

Sixty thousand electrocardiograms were analyzed for 5 years. Six hundred (1%) revealed early repolarization (ER). Features of ER were compared with race-, age-, and sex-matched controls (93.5% were Caucasians, 77% were males, 78.3% were younger than 50 years, and only 3.5% were older than 70). Those with ER had elevated, concave, ST segments in all electrocardiograms (1—5 mv), which were located most commonly in precordial leads (73%), with reciprocal ST depression (50%) in aVR, and notch and slur on R wave (56%). Other results included sinus bradycardia in 22%, shorter and depressed PR interval in 38%, slightly asymmetrical T waves in 96.7%, and U waves in 50%. Sixty patients exercised normalized ST segment and shortened QT interval (83%). In another 60 patients, serial studies for 10 years showed disappearance of ER in 18%, and was seen intermittently in the rest of the patients. The authors conclude that in these patients with ER: 1) male preponderance was found; 2) incidence in Caucasians was as common as in blacks; 3) patients often were younger than 50 years; 4) sinus bradycardia was the most common arrhythmia; 5) the PR interval was short and depressed; 6) the T wave was slightly asymmetrical; 7) exercise normalized ST segment; 8) incidence and degree of ST elevation reduced as age advanced; 9) possible mechanisms of ER are vagotonia, sympathetic stimulation, early repolarization of sub-epicardium, and difference in monophasic action potential observed on the endocardium and epicardium.

2. Here is a good review of early repolarization by Mehta:

1 comment:

1. very cool.
it is reassuring to me, from a societal-global-optimism aspect, that your formula to help differentiate STEMI from BER is known and used by smart providers like Dr. Nthakomwa in Malawi. and that your blogs are disseminating widely.
maybe i should be less resistant and less lazy about using it in california.

six months ago , out of ignorance, this EKG would have frightened me. now i can eye-ball the huge R in V4, and the "normalcy" of the j-point into the healthy appearing T wave in V3, and predict its BER. just need to get used to using the formula.
thank you, Steve.