High blood pressure – hypertension, as the medical profession calls it – is the most important risk factor for stroke, heart failure and heart attack. Currently, more than 25 million people in Germany suffer from high blood pressure. Beta-blockers are used when high blood pressure needs to be treated with medication, and they are also used to treat heart failure. How beta-blockers work and what to consider when taking them, you can learn here.
High blood pressure: beta-blockers are not always necessary
According to World Health Organization (WHO) guidelines, blood pressure values of 120/80 mmHg are considered optimal and values of 130-139/85-89 mmHg are considered normal (or high-normal). Higher values, i.e. 140/90 mmHg and above, must be treated. Treatment depends on the severity of the high pressure as well as on the age of the person affected.
Mild high blood pressure does not have to be treated immediately with medication. Often it is sufficient to change the way of life:
- Aim for normal weight
- Limit the consumption of alcohol
- Replace table salt with spices and herbs
- Stop smoking
- Provide for more physical exercise
Beta-blockers: lock-and-key principle
If drug treatment of hypertension is necessary, so-called beta-blockers are used, among other things. Beta-blockers derive their name from beta receptors. These receptors can easily be thought of as “docking sites” for hormones and other “messenger substances” on the cells.
They function according to the lock-and-key principle: each receptor is a lock that can be unlocked with certain “keys,” i.e., certain hormones. The messengers epinephrine and norepinephrine, for example, which are found in greater amounts in the body during stress, increase blood pressure through two mechanisms:
- At the heart, they bind beta-1 receptors, where they cause an increase in heart rate and cardiac output. This allows the heart to pump more blood into the circulation in a shorter period of time, allowing the body to perform better in the stressful situation. This increases blood pressure briefly – when the effect of adrenaline and noradrenaline wears off, the blood pressure also drops again.
- A longer-term increase in blood pressure reach the stress hormones via beta-1 receptors on the kidney. If they bind there, certain substances are released, which lead to an increased formation of the hormone angiotensin-II. This hormone causes a constriction of the vessels and thus allows the blood pressure to rise.
Beta-blockers for high blood pressure and heart failure.
Beta-blockers block beta receptors, preventing adrenaline and noradrenaline from binding. The hormones’ lack of action causes blood pressure and heart rate to drop.
In addition to their use against high blood pressure, beta-blockers can also be used in the treatment of heart failure. In the past, it was assumed that suppressing the effect of adrenaline and noradrenaline was not useful for a weak heart. Nevertheless, beta-blockers were used in patients with heart failure as early as the 1960s. Studies have since shown that beta-blockers also lead to improvement in disease symptoms and improved cardiac performance in patients with heart failure.
How do beta-blockers work in heart failure?
The explanation for the effectiveness of beta-blockers in heart failure is that by lowering blood pressure and heart rate, the heart has to work less, giving it a chance to recover. A decrease in heart size has also been observed. As a result, the heart becomes more efficient again and can eject more blood per heartbeat. The recovery factor for the heart is so great that even patients with severe heart failure benefit.
