Although very common, nonspecific ST-T (NSST-T) wave changes on ECG are often misunderstood, poorly explained to patients, or prematurely dismissed by clinicians.
On initial hospital presentation, only about 50% of patients presenting with chest pain have an ECG diagnostic of acute MI. Of the remaining patients with non-diagnostic ECGs, the tracing may be normal, show clear changes of ischemia, or be consistent with NSST-T wave changes.1
When practitioners encounter patients complaining of acute chest pain in clinical practice, it is reassuring if the chest pain resolves, if risk factors for coronary heart disease (CHD) are absent or few, and if the ECG is negative for acute ischemic changes.
For some patients, specific ECG abnormalities are present that indicate or strongly suggest ischemic heart disease or acute MI. Although obviously concerning, these positive ECG findings can be reassuring regarding clarity of diagnosis, necessary interventions, or the need for specialty consultations.
Unfortunately, such diagnostic clarity and reassurance may prove more elusive in other patients whose ECG may be abnormal (i.e., NSST-T wave changes) but not classic or specific for such conditions as ischemia, infarction, or pericarditis.The challenge in such cases is twofold: (1) to determine the actual significance of the NSST-T wave changes in symptomatic patients; and (2) to convey these concerns clearly and understandably to patients who might be from culturally and educationally diverse backgrounds.
WHAT CLINICIANS SAY vs. WHAT PATIENTS HEAR
One way to meet these challenges is to acknowledge that patients do not always hear the messages and information delivered by clinicians as intended.
For example, the clinician may tell a patient with NSST-T wave changes, “While your ECG was abnormal, there were no signs of acute MI.” The patient may interpret this message as, “I did not have a heart attack! Thank goodness I’m okay.” Better and more accurate communication is critical in this situation and can be provided by avoiding complicated or confusing medical jargon. The goal should be to facilitate communication and improve patient comprehension.
A clinician must effectively convey the essence or spirit of the medical concerns to his or her patients. In addition, the clinician must be sensitive to the fact that most patients have little or no medical background, may have limited education, or may not speak English as a primary language. It is the clinician’s obligation to explain important medical knowledge and information to the patient in terms the average layperson can reasonably be expected to understand.
In the case of an individual with NSST-T wave changes on ECG, although the diagnostic possibilities may be extensive, the provider should attempt to explain to the patient that the heart tracing did not show clear signs of serious heart damage (like a heart attack), but that the tracing was not normal either. Therefore, additional testing is necessary to assess for other possible problems.
Contrast this approach with telling a patient, “While your ECG showed no signs of acute MI, there is a myriad of other diagnostic possibilities, some more serious than others, that make additional work-up necessary to rule out medical conditions such as electrolyte abnormalities, cardiomyopathy, or pulmonary embolism.”
While technically accurate, the latter approach will probably be ineffective because the clinician has used complex language that is unlikely to be clearly understood by most patients.
NSST-T WAVE CHANGES: PERHAPS NOT SO REASSURING
To speak intelligibly about NSST-T wave changes with patients, first get a firm handle on what these changes may indicate or suggest. NSST-T wave changes may be seen on a computer-generated ECG interpretation. Patients who presented to the emergency department with chest pain and had nonspecific changes on ECG (e.g., nonspecific ST segment, T-wave, or Q-wave findings) were ultimately transferred from the observation unit to the inpatient unit at higher rates than those without such ECG changes.2
Individuals with chest pain and nonspecific ECG changes also had higher rates of positive exercise stress tests and stent placement (though not statistically significant).2 It seems clear that nonspecific ECG changes are not necessarily benign.
The interpretation of NSST-T wave changes is not synonymous with “normal” or a normal variant, particularly in a symptomatic patient. Even though NSST-T wave changes may represent a benign ECG finding, other conditions that may cause or be associated with these abnormalities should be considered. Do not assume that all is well because “classic” changes of acute ischemia or MI are absent.
A POTENTIAL MISSTEP
Many clinicians fail to seriously consider the implications of NSST-T wave changes on ECG. Perhaps the “nonspecific” part of the interpretation lends itself to reassurance.
The potential complexities and underlying differential diagnosis—if the clinician is even aware of these—may lead to a poor explanation of the findings or lessen the likelihood that an explanation will be provided at all. As a result, specific workup and follow-up based on the findings of NSST-T wave changes may not occur.
Despite the nonspecific ECG findings, very specific things should be considered to more thoroughly evaluate patients and move beyond simply noting the presence or absence of classic ECG changes consistent with ischemia or acute MI.