Symptoms of a silent heart attack
The classic symptoms of a silent heart attack are comparable to a normal heart attack. The only difference is that the typical symptom of pain is missing in a silent heart attack. Furthermore, signs such as low exercise tolerance and shortness of breath are signs of a silent heart attack.
Fatigue, malaise and listlessness are further symptoms. Typical symptoms of a silent myocardial infarction are a feeling of weakness, dizziness and fainting. Sweating can also be symptoms of a silent heart attack, as can nausea and vomiting. Classically, the existing symptoms gradually worsen. Since a silent heart attack results in injuries and cell death in the area of the heart muscle, cardiac rhythm disturbances can occur afterwards.
Diagnosis
As with the diagnosis of any illness, the medical history (i.e. the interview with the patient) is the first step in identifying a silent myocardial infarction. The symptoms experienced by the patient, such as dizziness, nausea, sweating and fainting, play a major role in this process. If a silent heart attack is suspected, an ECG should be written immediately afterwards.Electrodes are attached to various points on the chest wall (sometimes also on arms and legs) so that the electrical currents in the heart can be measured.
In contrast to the normal case, there are special characteristics that the ECG only shows in the case of a heart attack. Furthermore, blood tests can be consulted. An increase in the troponin T value plays a major role in this context.
Troponin is the leading substance in the diagnosis of mute myocardial infarction in the blood. In addition, there are other blood values which can also give indications of a silent heart attack. Myoglobin and CK-MB play an important role here.
Myoglobin is a protein contained in muscles. During a silent myocardial infarction, heart muscle cells die. This causes the substances contained in the cells to be released into the blood.
Myoglobin is classically detectable especially in the first 4 hours after a heart attack. CK-MB (creatine kinase of type MB) is specifically present in the heart muscle and is also released when its cells die. It is detectable in the blood especially 3-12 hours after a heart attack.
Troponin is a special enzyme of the heart muscle that is determined in the blood when a silent heart attack is suspected. It can be measured in higher concentrations especially 3-8 hours after a heart attack. It remains detectable in the blood for up to two weeks after the heart attack.
However, troponin T can also be falsely elevated without a heart attack being the underlying cause. This is due to functionally impaired kidneys that cannot excrete enough troponin, or extreme stress on the skeletal muscles. This is the reason for an increased troponin concentration in the blood, especially in athletes.
The ECG is a record of the electrical currents in the heart that cause the muscles to work. These currents can be measured by means of electrodes placed on the skin. Different peaks and waves stand for different times in the heart’s action.
In a silent heart attack, the distance between the S-wave and the T-wave is typically increased. The heart attack is known as a so-called “ST elevation heart attack”. In addition, during an ECG, the currents between different electrodes are reduced.
Therefore, several lines are recorded simultaneously. The differences between the lines can be used to determine which part of the heart has suffered an infarction. More about the ECG
