Heart patients and heat: cardiologist's advice for a safe summer
Cardiac patients in summer: the sweltering heat of the summer months can be unpleasant for many, and even dangerous for those suffering from cardiovascular problems
The effects of high temperatures can threaten the cardiovascular balance of those on medication to treat hypertension or suffering from ischaemic heart disease.
Dr Valentina Mantovani, a cardiologist from the Clinical Cardiology Unit at IRCCS Policlinico San Donato, explains why this is the case and what to do about it.
The effects of heat on the cardiovascular system
“Heat produces adaptations in the cardiovascular system that are normally well tolerated by young, healthy people. These adaptations essentially consist of
- peripheral vasodilation (the increase in the calibre of blood vessels)
- sometimes accompanied by a drop in blood pressure
- an increase in heart rate in response to the drop in blood pressure.
With the exception of some peculiar reactions, such as heat stroke, these are natural adjustments of the body.
In heart patients, however, these adaptations of the cardiovascular system can make the compensation framework unstable,” explains Dr Mantovani.
Low blood pressure caused by drugs and heat
“Many cardiac patients take drug therapy which also has the effect of lowering their blood pressure.
The effect of heat can make the drop in blood pressure more severe and therefore patients may complain of
- asthenia (tiredness, weakness);
- more serious episodes such as syncope, i.e. sudden and rapid loss of consciousness.
In this case, the doctor or cardiologist may have to adjust the drug therapy normally taken.
Loss of magnesium and potassium
“In cases of ischaemic heart disease and angina (the acute pain in the chest, sometimes radiating to the arm), the danger is mainly linked to the cold, which leads to an increase in episodes.
Heat is not directly linked to the event, but the risk is heat-induced excessive sweating.
This leads to the loss of liquids and mineral salts, such as lowered levels of potassium or magnesium, which can facilitate the appearance of arrhythmias in patients who are already predisposed to this type of problem.
This phenomenon occurs mainly in patients suffering from ischaemic heart disease and, in a more severe form, in those with diabetes.
In addition, it is important to underline the fact that this excessive loss of liquids is often not replenished with the right amount of water: this is especially true of the elderly, who do not feel the thirst stimulus very strongly”.
Summer heat, what attention should be paid?
“In this season it is essential to hydrate correctly. Patients suffering from dilated heart disease and severe ventricular dysfunction should refer to their doctor to find out the right amount of liquids to take.
In these cases, the amount of fluid going in and out must be well balanced. It will always be the doctor who adjusts the drug therapy in case of hypotension and syncope.
Then there are the usual, but fundamental, rules:
- go out in the cooler hours;
- use lighter, breathable clothing;
- wear headgear.
How to eat
As far as diet is concerned, it is preferable to eat often, but lightly, favouring fresh foods such as fruit and vegetables, which are rich in both liquids and mineral salts.
The consumption of supplements, based on vitamins and mineral salts, can also be useful for replenishing the elements lost through sweating.