Of the four seasons, acute conditions are most common during hot summers and cold winters, particularly for patients with chronic illnesses. This leads to overcrowded emergency rooms and overburdened hospital admissions. Among Earth's diverse life forms, mammals are fragile and can only survive within specific temperature ranges. For example, in humans, a body temperature below 35 degrees Celsius is considered hypothermia, and above 37.8 degrees Celsius is defined as a fever. When temperatures reach 40 degrees Celsius or more, cells begin to suffer damage that they cannot withstand.
High temperatures can significantly affect the heart and blood circulation, even potentially triggering heart failure. Symptoms include difficulty breathing, extreme fatigue, rapid heartbeat, heat exhaustion, coma, and life-threatening heatstroke. Individuals with chronic heart disease are at a higher risk of acute relapse during hot weather, so prolonged exposure to high outdoor temperatures should be avoided. In daily life, patients with chronic heart failure need to strictly control their fluid and salt intake. Both excessive and insufficient fluid intake can increase the burden on the heart, leading to a transition from chronic to acute failure, and even posing a life-threatening risk. For those in the early stages of recovery from acute heart failure, it is recommended to consume no more than 1 litre of fluid per day. Once stable, the daily limit should not exceed 1.5 litres.
There are many triggers for heart failure, such as myocardial infarction, high blood pressure, diabetes, bacterial infections, dilated cardiomyopathy, kidney failure, and so on. For example, Mr. Chow, in his sixties, has a long history of high blood pressure and diabetes, but has continued to smoke for a long time, leading to severe cardiovascular occlusion and partial myocardial necrosis. Despite several angioplasties, his heart could not recover to normal. Additionally, occasional atrial fibrillation complicated his condition, leading to multiple complex acute heart failure admissions requiring treatment, including surgery for atrial fibrillation and implantation of a cardiac resynchronisation therapy defibrillator. After discharge, he requires long-term medication to stabilise his condition. His situation has been relatively stable for several years and is currently considered good.
Ejection fraction (EF) is commonly used to diagnose heart failure, and there are several categories of heart failure. Generally, heart failure can be broadly classified into systolic and diastolic types; Zhou Bo has the more common systolic heart failure.In systolic heart failure, the EF is less than 35%; the heart is unable to contract normally, leading to problems with pumping blood. If the EF exceeds 55%, the condition is classified as diastolic heart failure, meaning that the heart muscle is unable to relax normally to store sufficient blood, which similarly results in insufficient blood supply to the body’s organs.EF stands for ejection fraction, which is an indicator of the heart’s ability to pump blood.
In recent years, the medical community has further subdivided ejection fraction (EF) values to facilitate diagnosis and the selection of more appropriate treatment modalities: values below 35% are defined as heart failure with reduced ejection fraction (HFrEF),36% to 55% is defined as heart failure with moderate ejection fraction (HFmEF), whilst 55% and above is defined as heart failure with normal ejection fraction or diastolic heart failure (HFpEF).
Furthermore, heart failure can be divided into left heart failure and right heart failure, with the former accounting for approximately 90% and the latter around 10%. For instance, individuals with pre-existing lung disease or congenital heart defects, where the right ventricle is constantly under pressure from pumping blood, can develop right heart failure. Some patients also experience genetic disorders or acute occlusion of the right coronary artery, leading to right heart failure. The triggers for left heart failure are more diverse and include myocarditis, dilated cardiomyopathy, diabetes, hypertension, smoking, and coronary artery disease leading to heart attack.
New generation drugs, more types, more potent, bringing hope to patients.
There are many traditional medications for treating heart failure, including beta-blockers, angiotensin II receptor blockers, angiotensin-converting enzyme inhibitors, digoxin, older generation aldosterone receptor blockers, diuretics, and vasodilators. New generation aldosterone receptor blockers such as Eplerenone, type 2 sodium-glucose transporter inhibitors, neutral endopeptidase inhibitors and angiotensin II receptor antagonist drugs, Ivabradine, etc., are even more effective. As many heart failure patients suffer from multiple chronic diseases, their blood pressure, kidney function, and the condition of multiple organs must be considered before prescribing medication. If kidney function is too poor, unfortunately, many new heart failure drugs cannot be used! Therefore, for the treatment of heart failure, it is best to identify the cause and treat it as early and promptly as possible, ideally when the cardiomyocytes are still in an early reversible stage. Some fortunate patients, by receiving the latest and most potent drug treatment in a timely manner, are eventually able to reverse damaged heart cells to normal function, achieve full recovery, and return to a normal life.
Regardless of the type of heart failure ultimately diagnosed, continuous medication is required to maintain a stable condition.
The above information is provided by Dr Fu Chiu Lai, Specialist in Cardiology.
Dr Fu Chiu Lai, Cardiology Specialist
Summer heat can trigger heart failure; long-term patients should be vigilant | etnet Economic and Trade News
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