What is borderline ECG?
A borderline ECG refers to a reading that falls between normal and abnormal. It describes ECG findings that are atypical but also don’t confirm a specific heart condition.
Borderline ECG findings are nonconclusive and therefore need further investigation [1].
The borderline ECG does not necessarily indicate that something is wrong. In many cases, such an ECG turns out to be nonpathological [1].
However, certain conditions often present with a borderline ECG. For example, up to half of patients with long QT syndrome have a borderline ECG [2].
Because of the uncertainty, the borderline ECG has to be further investigated by a cardiologist. An expert must rule out any potentially dangerous heart conditions.
What is an ECG?
An ECG is a medical test that measures the electrical activity of the heart. It is a non-invasive method and is performed by sensing electrode leads. In a standard ECG, there are 12 leads.
The information that an ECG delivers is crucial for the assessment of heart function. It can help in the identification and diagnosis of:
- heart attack,
- arrythmias,
- heart failure [3].
The basic principle of an ECG recording is the measurement of the direction of the electric current produced by the heart. When the current goes away from the electrode, the recorded line goes down. When the electricity flows towards the sensor, the ECG line goes up.
ECG is one of the most commonly used clinical examinations [4].
Among its advantages are low risk for the patient, low cost, a short time of examination, and easy accessibility. The disadvantages are the short recording time and possible false negative results.
What can cause borderline ECG?
Conditions that can lead to a borderline ECG include:
- ventricular hypertrophy,
- pre-excitation syndrome [5],
- pericarditis [5],
- Brugada Syndrome [6],
- bundle branch block [7],
- severe hyperkalemia [8],
- coronary insufficiency [9],
- paroxysmal arrhythmia [9]
- medications, like imipramine [10],
- technical issues with an implanted device like a pacemaker [11].
Also, technical mistakes during the ECG examination can lead to a borderline ECG.
Is a borderline ECG normal?
A borderline ECG can be a normal variant of an ECG. For example, borderline ECG can be a normal variant among professional athletes [1].
It is also possible that a borderline ECG is normal in your case. However, the borderline result of an ECG has to be further examined to exclude any dangerous conditions.
Do I need to see a doctor with a borderline ECG?
When you receive a borderline ECG, you should visit a cardiologist. It is crucial to exclude any potentially dangerous conditions.
Remember that a borderline ECG can be a normal ECG. However, it can also be an indication of a lethal heart condition.
Among the tests your doctor may perform are blood tests, echocardiography, or a Holter ECG examination. Nearly all those examinations are fast and non-invasive. The only half-invasive examination that can be performed by the doctor is a transesophageal echocardiogram.