Assuming that the ECG has been read by a cardiac expert, most people who have an ECG will not require any further investigations. In some instances, the ECG may show up suspicion of a heart muscle disorder in the form of very large, what we call QRS complexes, which are these spiky bits on the ECG. If they are very large, then we perform an echocardiogram to make sure that there is no evidence of a heart muscle disorder or a cardiomyopathy.