Effect on the pulse

The human heart is controlled by the so-called autonomic nervous system. Here there are two antagonists: the sympathetic nervous system and the parasympathetic nervous system. The latter is responsible for resting and digesting, whereas the sympathetic nervous system activates the body via the stress hormones adrenaline and noradrenaline.

These stress hormones cause the heart to beat faster, blood pressure is raised and the heart beats faster. This is where the beta blockers intervene. They block the docking site of the stress hormones, the so-called beta-adrenoreceptors, and thus lower not only blood pressure but also the heart rate.

Beta-blockers thus lower the pulse. There are some diseases, such as cardiac insufficiency, where a lowered pulse has a very relieving effect, because a slowed heart can be better supplied with oxygen and work more efficiently. Lowering the pulse also helps with rhythm disturbances that make the heart beat very fast.

However, if the heart rate falls below 50 beats per minute, this is known as bradycardia – it is often associated with side effects such as tiredness and listlessness. The therapy goal when taking beta blockers should therefore be above 50 beats per minute. Asthma is one of the diseases for which beta blockers should not be used.

There are also beta receptors in the lungs which, when activated by hormones such as adrenaline, cause the bronchial tubes to dilate and thus improve the flow of air. In asthma, the bronchial tubes are narrowed. If beta-blockers are taken, the airways become even narrower, so that the symptoms of the disease are intensified and even an asthma attack can be provoked.

Therefore, an alternative medication from another group of active ingredients must be used, such as a calcium channel blocker. Beta-blockers do not differentiate in their effect between the beta-receptors on the cells, which are distributed throughout the body. Since the effect of adrenaline on beta receptors also plays an important role in the development of erection in men, taking beta blockers can also lead to erectile dysfunction. This means that the penis cannot become more or at least less stiff, which is usually called impotence.

Effects on performance

As described above, beta-blockers can provide patients suffering from arrhythmia and heart failure with more efficient cardiac work with better oxygen supply – this often has a performance-enhancing effect, as patients no longer suffer from shortness of breath or dizziness as quickly. It should be noted that this is a subjective performance enhancement, i.e. the patients were previously only able to work under little stress. Even in patients who suffer from severe nervousness or anxiety, the dampening effect of beta-blockers can certainly lead to an increase in performance, as the patients can now concentrate and find their way around more easily.

However, beta-blockers are also frequently used to treat high blood pressure, which in the long term damages the entire cardiovascular system and can lead to calcification of the blood vessels. Patients who are now adjusted with beta blockers often complain about a decline in their performance at the beginning. One reason for this is that the body was used to working under high blood pressure.

If it suddenly drops, this is a change for all organ systems, as the blood circulation changes – even though the blood pressure is now in the normal range. This kink in performance is temporary, however, until the body has become accustomed to the new conditions. On the other hand, beta-blockers lower the pulse rate as already described.

This can also initially result in a drop in performance analogous to the lowering of blood pressure. Here it should only be noted that people with a generally low pulse can quickly slip into so-called bradycardia. This means that the heart makes less than 50 beats per minute. If this is then permanently the case and the performance slump is long-term, the doctor in charge should be consulted again and, if necessary, a new blood pressure medication that does not lower the heart rate any further should be selected.