How does the ECG change with heart failure?
Heart failure can have a wide variety of causes and thus also different characteristics in the ECG. Often the term “rushing weakness” is equated with the term “heart failure”. A condition in which the heart cannot pump the blood to the required extent, which can lead to a “blood backlog”.
The causes can be, for example, a disturbed transmission of stimuli by the heart. This would be shown by an irregular rhythm. If the transmission of stimuli within the heart does not function properly, this is known as a thigh block.
This manifests itself in the ECG, for example, by a prolonged PQ time. Another possibility would be an unphysiological enlargement of the heart. In this case, the lead with the highest amplitude would deviate from the normal state.
Instead of the second lead, the amplitude would be highest in the fourth lead, for example. A heart attack or myocarditis can also cause cardiac insufficiency and can be detected in the ECG. In these cases, the amplitudes of the recordings diverge from the amplitudes of a healthy heart. In addition, there are also discrepancies within the excitation complexes compared to a healthy heart. A typical sign of an anterior myocardial infarction is, for example, an insufficient depression between the S- and T-wave of the excitation complex.
Exercise ECG for cardiac insufficiency
Exercise ECG is a frequently used examination technique, which is mainly used in cases of high blood pressure, coronary heart disease (CHD) or cardiac arrhythmia. Cardiovascular diseases can be diagnosed by stressing the body. Exercise ECG is usually performed on a bicycle or treadmill and measures the performance that the patient achieves at a maximum heart rate of 220 or certain blood gas levels. While cycling, an ECG is written in parallel, which the doctor evaluates on a connected monitor. Termination criteria for a stress ECG are the occurrence of signs of reduced blood flow in the heart (myocardial ischemia), which can be shown in the ECG as ST depressions or elevations or in severe chest pain radiating into the left arm, critical blood pressure or cardiac arrhythmia.
