EKGs are a simple, cheap modality that can give an emergency physician quite a bit of information. Sometimes, in a busy ER, this information can be very subtle and almost overlooked without a second thought. A perfect example of this is a New Tall T-wave in lead V1 (NTTV1). This finding can be a normal variant, but can also be a precursor to badness.
What is a NTTV1?
- While a normal EKG has a flat or inverted T-wave in lead V1, a NTTV1 can be an early sign of an ischemic hyperacute T-wave
- Upright T-wave in lead V1 is abnormal if:
- Height of upright T-wave in V1 taller than T-wave in V6, or
- A NEW, upright T-wave in V1 (compare to old EKG)
What are the causes of a NTTV1?
- Ischemia (CAD)
- High Left Ventricular Voltage (Young Athletes)
- Lead Misplacement
What is the significance of NTTV1?1
- 84.4% of patients in a series of 218 patients undergoing cardiac catheterization had severe CAD (>75% stenosis)
- In patients with one vessel disease and NTTV1 >0.15mV, the lesion was:
- Left circumflex artery disease (44%)
- Right coronary artery (22%)
- Left anterior descending artery (2%)
- In patients with two vessel disease and NTTV1 >0.15mV, the lesions were:
- Left circumflex and right coronary artery disease (69%)
- Left anterior descending and left circumflex arteries (7%)
- Left anterior descending and right coronary arteries (17%)
EKGs From: Mattu A. ECG’s for the Emergency Physician 1. 2003.
Take Home Message
Assuming a patient doesn’t have LVH or LBBB, a new, upright, tall T-wave in lead V1 or a T-wave in lead V1 taller than V6 could signify hyperacute T-waves and precede acute myocardial infarction. Remember to always compare to prior EKGs.