The diastole (Greek "the expansion") is the relaxation and filling phase of the heart chambers (Ventricle). It is in contrast to systole (tension and expulsion phase of the heart) and serves to prepare it. The filling phase during diastole is followed by the expulsion phase in systole.
Structure of the diastole
In general, the diastole begins with the relaxation of the ventricular muscles and the simultaneous closure of the two pocket valves as a connection to the large arteries. So the blood from the atria cannot flow directly into the large arteries, but is first collected in the two chambers. In the EKG, diastole is the phase between the end of the T wave and the beginning of the Q wave. More precisely, the diastole is divided into 4 different phases:
- The relaxation phase, also known as isovolumetric relaxation, is the period immediately after the chambers of the heart contract. In this phase, both the sail and pocket flaps are closed. This phase is shown in the ECG between the end of the T wave and the middle of the TP segment. The relaxation phase at the end of the systolic outflow can be seen in the echocardiogram.
- This is followed by the early filling phase, which is also known as active diastole. The two heart chambers (Ventricle) suck the blood from the atria through the open leaflet valves. In the EKG, this phase is found between the middle of the TP segment and the start of the P wave. In the echocardiogram this phase is represented by the E wave.
- Diastasis is also partly counted as part of the early filling phase. In the EKG it is represented by the P wave, in the echo by the phase between the E wave and A wave.
- This is followed by the late filling phase. Here the two atria contract until they relax and the two chambers are completely filled. The leaflet valves between the atrium and ventricle close again to prevent the blood from flowing back into the atria, and the expulsion phase can begin. In the ECG this phase is represented by the P-R segment, in the echo it is the A wave. Now the two chambers are filled with blood and the ejection phase (Systole) can start.
Diastole too low
Of the lower normal value for diastole (more precisely: the diastolic blood pressure) lies by 60-65 mmHg. If the measured blood pressure value for the diastole is below this, i.e. if the diastole is too low, one speaks of Hypotension (low blood pressure).
As a rule, a low value for the diastole hardly causes any problems, because the diastolic blood pressure value for the blood flow to the organs rather subordinate role plays.
A symptom-free low blood pressure comes especially in young girls and women before, but can also be part of a eating disorder or one pregnancy occur.
This form of low blood pressure is known as primary hypotensionwhich is harmless and has no direct organic cause. It is believed that above all hereditary factors and Environmental influences play a role in primary hypotension. There is even scientific data that shows that diastole is permanently low Service life positively influenced.
In the secondary hypotension on the other hand one can organic cause find that the too low diastole is a symptom of an existing illness. Reasons for a too low diastole can e.g. Cardiovascular diseases, one Hypothyroidism, a chronic one Bleeding or certain Medication be.
A special form of too low blood pressure with too low diastole is the so-called orthostatic hypotension. It happens, for example getting up too quickly causes a large amount of blood to sink into the legscausing the brain to run out of blood for a short time. This form of diastole that is too low is expressed by a Turning black before the eyes, a headache and dizziness. Normally, this form of hypotension can be brought under control by getting up slowly and drinking a sufficient amount of water, but when it is hot and dehydrated in summer, this form of hypotension can more often lead to collapse (brief loss of consciousness).
Diastole too high
From one too high diastole (more accurate: diastolic blood pressure) one speaks when the lower blood pressure value permanently above 90mmHg is measured. This form of hypertension can occur either together with too high a systole or on its own. In the second case one speaks of one isolated diastolic hypertension. Are both the diastole and the Systole too high, is 90% of the time primary hypertension without recognizable organic causes, which of course should be stopped with medication due to the long-term consequences to be feared. If only the diastole is too high and the systole shows normal values, this can indicate a Early form of high blood pressure but can also be a reference to a secondary hypertension be that just that Symptom of an underlying disease represents. Examples of diseases that can cause excessive diastole are one Renal artery stenosis, various hormonal diseases and Connective tissue diseases.
How can I lower my diastole?
To date, little is known about the background of an isolated increase in diastolic blood pressure.
Sometimes a Hypothyroidism (Hypothyroidism) can be identified as the cause, so that checking the thyroid values as part of a blood test can be quite useful if this has not already been done.
If this is not the case, drug therapy can be applied antihypertensive drugs like drainage tablets (Diuretics), ACE inhibitors, and Beta blockers take place, as is the case with overall increased blood pressure.
The beta blocker nebivolol in particular can be helpful here, as it has a vasodilating effect.
Furthermore, it applies to diastolic high blood pressure as well as to high blood pressure in general Lifestyle change to undertake.
The first priority is weight reduction or weight normalization. Ideally, a BMI of 25kg / m² is aimed for.
Also one Diet change in the sense of low-salt and low-fat food and smoking cessation contribute a lot to normalizing diastolic blood pressure.
Finally, care should be taken to ensure that enough exercise (and endurance sports in particular). If these measures are implemented effectively, it may even be possible that drug therapy can be dispensed with.
You can find extensive information at: How best to lower your diastole