The heart does its heavy work - uninterruptedly pumps blood into the systemic circulation, almost 300 liters per hour. A power plant that is prone to malfunction - cardiovascular disease is the leading cause of death in Germany. Important for prevention and adequate therapy is the correct diagnosis. Find out more about the course of a cardiac exam here.
At the beginning of a conversation
The examination of the heart does not start with sophisticated devices, but with a conversation. Experts assume that a large part of all suspected diagnoses can be made with the language and the hands. Often, the patient's medical history is so typical that targeted diagnosis by the experienced doctor can be made and alternative diagnoses can be ruled out.
Also important are pre-existing conditions, family diseases, medications and risk factors. Added to this are the findings that the doctor gains while looking at the patient and during the physical examination. Special tests often serve to refine the diagnosis and set up the treatment concept or for treatment control. In part, they can be coupled directly with therapeutic measures. Which apparatus tests are used depends on the suspected diagnosis and the question.
The basic diagnosis
The physical examination is usually done on a sitting or lying patient with undressed upper body. Externally visible signs of disease (inspection) are eg water retention, blue lips and fingers, changes in the fingernails, pulsations, facial redness or lesions on the legs.
In palpation, the physician checks the frequency, rhythm and character of the pulse and the apex of the heart on the left chest. The vein in the neck area (jugular vein) provides important indications of the return of the blood to the right heart.
Blood pressure measurement is also an indispensable tool. It should be done on both arms and several times.
The percussion (percussion) of the rib cage can determine the approximate heart size - however, the imaging techniques are better suited for this purpose. An important examination step is auscultation, listening to the stethoscope. The experienced can thus already recognize many heart changes, especially heart defects. Be assessed:
- Heart rate: normal, too fast, too slow?
- Heart rhythm: regular, irregular, extra beats?
- Heart sounds: Are the 1st and 2nd heart sounds normal or are they altered? Are extra tones available?
- Heart noises: Are there any additional sounds? When do these occur and how do they sound?
For the four heart valves and their changes, there are various areas where they are best listened to. Therefore, the doctor places his stethoscope in different places, where the patient may take different positions and asks him to take a deep breath, then exhale or hold his breath. Since heart and blood vessels are connected, the latter are also part of the clinical examination.
Since changes in the veins are more likely to be found on the legs than on the poor, the skin color (paleness, edema, cyanosis), leg circumference, skin and visible vessels such as varicose veins are assessed. The pulses are palpated and tapped on the arms, stomach and legs. When constrictions are often flow noise. If there is a suspicion of diseases of the arteries or veins, you can connect various tests that can be carried out without great effort and resources (walking test, storage test).
Measuring the cardiac current curve (ECG) at rest is part of the basic diagnostics. If required, exercise ECG or long-term ECG follow. With a catheter examination, an ECG can be derived directly from the heart (electrophysiological examination = EPU), which is sometimes necessary in cardiac arrhythmias.
Depending on the question, different laboratory values in the blood which, however, usually only give indications of causes or risk factors. For example, blood counts, coagulation, sugars, fats, liver and kidney levels, minerals and thyroid levels may be important. Especially for heart disease or suspected heart attack
- Lactate dehydrogenase (LDH: infarction, myocarditis),
- Creatine kinase (CK: myocardial damage),
- Troponin (heart attack) and
- Brain Natriuretic Peptide (BNP: heart muscle weakness).
Increased C-reactive protein (CRP) is discussed as a prognostic parameter for the risk of heart attack.
Ultrasound is an important method of imaging the heart and blood vessels, especially since technology and image resolution have made massive advances in recent years. On the one hand, the advantage is that ultrasound does not cause radiation exposure and is painless, and secondly, that the heart can be observed and evaluated in full action.
The normal ultrasound scans are called echocardiography or casual "heart echo". Thus, the individual structures are viewed from different angles from the chest wall and the heart function is assessed. You can see the chambers, the heart valves and the main artery (aorta). It is possible to assess the size of the heart, whether the heart muscle is contracting equally well everywhere and the heart valves open and close. Also, the ejected amount of blood can be estimated and see fluid collections in the pericardium.
With an additional device, the blood stream can be made visibly and audibly visible by means of Doppler and duplex sonography. Even under stress, eg on a bicycle or after medication, ultrasound images can be taken (stress echocardiography). These may show abnormal changes that are otherwise invisible.
In addition, the ultrasound probe can also be inserted via a thin tube into the esophagus (transesophageal echocardiography = TEE) or via a small catheter directly into blood vessels (intravascular ultrasound = IVUS). With the TEE read flaps and atria better represent, with the IVUS assess calcification of the vessel walls.
Other imaging techniques
An X-ray of the chest (chest X-ray) allows statements about heart size and shape and shows possibly calcifications. However, it is quite unspecific. With magnetic resonance imaging (MRI), the heart can be displayed in three dimensions and in full function with very accurate images; Additional information about the myocardial tissue can be obtained after the administration of contrast media. However, as the process is very expensive, it is currently not being used on a large scale.
The significance of computed tomography (CT) is limited even with newer multi-layer method, as the heart movement causes blurring. Although changes in the vascular wall can be determined directly and at an early stage as well as the calcium content of the coronary arteries - the extent to which the latter correlates with the risk of heart attack ("Kalk score") is still controversial.
Coronary angiography, a combination of cardiac catheterization and x-ray, provides the most accurate coronary artery findings. It has been increasingly used in specially equipped laboratories for accurate diagnosis of suspected vascular disease as well as preparation for heart surgery.
Optionally, the procedure may be directly coupled to a balloon dilatation of the vessel (PTCA) or the insertion of a support grid (stent). In addition to calcifications and constrictions of the coronary arteries, the heart muscle function, the valves between the left atrium and the heart chamber (mitral valve) or left ventricle and aorta (aortic valve) and the filling capacity of the heart chambers can be assessed and determine whether an outpouring (aneurysm) of the heart wall or the Artery is present.
Nuclear medical examinations
With myocardial scintigraphy, the function of the heart muscle can be assessed - it is not always clear whether a bottleneck really leads to the relevant circulatory disorder. For this purpose, a radiolabelled substance is injected after exposure and observed by means of a gamma camera, as it is recorded in the heart muscle - the better the blood circulation, the higher the enrichment. The radiation dose corresponds to a conventional X-ray, the significance is comparable to MRI.
Radionuclide ventriculography makes the beating of the heart chambers directly visible with radioactive substances.