Heart rhythm problems (heart arrhythmias) occur when the electrical impulses that coordinate your heartbeats don't work properly, causing your heart to beat too fast, too slow or irregularly. Heart arrhythmias may feel like a fluttering or racing heart and may be harmless. However, some heart arrhythmias may cause bothersome — sometimes even life-threatening — signs and symptoms. Heart arrhythmia treatment can often control or eliminate fast, slow or irregular heartbeats. In addition, because troublesome heart arrhythmias are often made worse — or are even caused — by a weak or damaged heart, you may be able to reduce your arrhythmia risk by adopting a heart-healthy lifestyle.
What's a normal heartbeat Your heart is made up of four chambers — two upper chambers (atria) and two lower chambers (ventricles). Your heart rhythm is normally controlled by a natural pacemaker (sinus node) located in the right atrium. The sinus node produces electrical impulses that normally start each heartbeat. These impulses cause the atria muscles to contract and pump blood into the ventricles. The electrical impulses then arrive at a cluster of cells called the atrioventricular (AV) node. The AV node slows down the electrical signal before sending it to the ventricles. This slight delay allows the ventricles to fill with blood. When electrical impulses reach the muscles of the ventricles, they contract, causing them to pump blood either to the lungs or to the rest of the body. In a healthy heart, this process usually goes smoothly, resulting in a normal resting heart rate of 60 to 100 beats a minute.
Types of arrhythmias Doctors classify arrhythmias not only by where they originate (atria or ventricles) but also by the speed of heart rate they cause:
Not all tachycardias or bradycardias mean you have heart disease. For example, during exercise it's normal to develop a fast heartbeat as the heart speeds up to provide your tissues with more oxygen-rich blood. During sleep or times of deep relaxation, it's not unusual for the heartbeat to be slower.
Tachycardias in the atria Tachycardias originating in the atria include:
Tachycardias in the ventricles Tachycardias occurring in the ventricles include:
Bradycardia — A slow heartbeat
Although a heart rate below 60 beats a minute while at rest is considered bradycardia, a low resting heart rate doesn't always signal a problem. If you're physically fit, you may have an efficient heart capable of pumping an adequate supply of blood with fewer than 60 beats a minute at rest.
In addition, certain medications used to treat other conditions, such as high blood pressure, may lower your heart rate. However, if you have a slow heart rate and your heart isn't pumping enough blood, you may have one of several bradycardias, including:
Although it often feels like a skipped heartbeat, a premature heartbeat is actually an extra beat. Even though you may feel an occasional premature beat, it seldom means you have a more serious problem. Still, a premature beat can trigger a longer lasting arrhythmia — especially in people with heart disease. Frequent premature beats that last for several years may lead to a weak heart.
Premature heartbeats may occur when you're resting or may sometimes be caused by stress, strenuous exercise or stimulants, such as caffeine or nicotine.
Arrhythmias may not cause any signs or symptoms. In fact, your doctor might find you have an arrhythmia before you do, during a routine examination. Noticeable signs and symptoms don't necessarily mean you have a serious problem, however.
Noticeable arrhythmia symptoms may include:
Other symptoms may include:
[Heart Arrhythmia, Mayo Clinic website]
In medicine, monitoring is the observation of a disease, condition or one or several medical parameters over time. It can be performed by continuously measuring certain parameters by using a medical monitor (for example, by continuously measuring vital signs by a bedside monitor), and/or by repeatedly performing medical tests (such as blood glucose monitoring with a glucose meter in people with diabetes mellitus). Transmitting data from a monitor to a distant monitoring station is known as telemetry or biotelemetry.
Monitoring can be classified by the target of interest, including:
A medical monitor or physiological monitor is a medical device used for monitoring. It can consist of one or more sensors, processing components, display devices (which are sometimes in themselves called "monitors"), as well as communication links for displaying or recording the results elsewhere through a monitoring network.
The development of new techniques for monitoring is an advanced and developing field in smart medicine, biomedical-aided integrative medicine, alternative medicine, self-tailored preventive medicine and predictive medicine that emphasizes monitoring of comprehensive medical data of patients, people at risk and healthy people using advanced, smart, minimally invasive biomedical devices, biosensors, lab-on-a-chip (in the future nanomedicine devices like nanorobots) and advanced computerized medical diagnosis and early warning tools over a short clinical interview and drug prescription.
As biomedical research, nanotechnology and nutrigenomics advances, realizing the human body's self-healing capabilities and the growing awareness of the limitations of medical interventionby chemical drugs-only approach of old school medical treatment, new researches that shows the enormous damage medications can cause, researchers are working to fulfill the need for a comprehensive further study and personal continuous clinical monitoring of health conditions while keeping legacy medical intervention as a last resort.
In many medical problems, drugs offer temporary relief of symptoms while the root of a medical problem remains unknown without enough data of all our biological systems . Our body is equipped with sub-systems for the purpose of maintaining balance and self healing functions. Intervention without sufficient data might damage those healing sub systems. Monitoring medicine fills the gap to prevent diagnosis errors and can assist in future medical research by analyzing all data of many patients.
Examples and applications
Blood glucose monitoring
Mobile Health, or mHealth, describes the use of mobile and wireless communication technologies to improve healthcare delivery, outcomes, and research. mHealth is poised to play a larger role in engaging patients in self-care as smartphone ownership is rising …. globally. Advances in smartphone software and hardware coupled with rising availability of wearable devices have resulted in exponential growth in the health apps market. Recent estimates suggest that more than 259,000 mHealth apps are available on app stores today and account for approximately 3.2 billion downloads annually. The evidence base supporting the use of apps independently of other interventions remains quite thin, and this has led to skepticism among large medical organizations about the role apps may play in healthcare. Nevertheless, apps continue to displace older technologies in several domains, for example, by replacing dedicated communication devices for individuals with autism and replacing medical bands with medical identification built into smartphone lock screens. Barriers such as privacy concerns and lack of integration into the electronic health record have limited the impact of apps, but mHealth has enormous potential to reshape healthcare delivery in the future.
[Mobile Health, Karandeep Singh, Adam B. Landman, in Key Advances in Clinical Informatics, 2017]
Digital health, particularly wearables and other connected devices, have captured the attention of consumers, providers and payers as a way to improve health, outcomes and costs. One in five Americans now owns a wearable device and more than 76% of people say they would be interested in sharing this data with their healthcare
provider, if it would contribute to improving their care. And, 70% of people said they would share data if it would reduce their insurance premiums. This all according to a survey by iTriage. [FierceMarkets]
心臟血管成形術 (通波仔 Angioplasty) & 冠狀動脈支架 (Coronary Stenting)
改善後的血液循環可能會持續，但動脈通常可能再變窄，因此心臟血管成形術一般都會使用支架。使用冠狀動脈支架的血管成形術，是在動脈中阻塞的部位，植入一個可伸張的細小金屬絲網狀管子 (支架) 。
傳統的「裸機（bare metal）」冠狀動脈支架提供了機械框架，使動脈壁保持開放，防止冠狀動脈狹窄或縮小。已證明PTCA術合併施行支架置入術在病人的預後優於僅施行血管成形術，能維持動脈功能一段較長的時間間隔。較新的藥物支架（DES）是塗有藥物的傳統支架，放置在動脈時，隨着時間的推移釋放藥物。據顯示，這些類型的支架有助於防止動脈再狹窄，透過幾個不同的生理機制，抑制組織在支架上生長和局部調節人體的發炎和免疫反應。 5種藥物，Biolimus A9, Zotarolimus，sirolimus，everolimus的和紫杉醇（paclitaxel），安全性和有效性已經證明，由支架設備製造商申請對照臨床試驗。然而，2006年歐洲3次試驗似乎表明，藥物塗層支架可能受到被稱為「晚期支架血栓形成」的事件影響，支架內血栓於支架放置後一或多年發生。晚期支架血栓形成發生在0.9％的患者，當發生血栓時非常危險，約1/3案例會致命。新一代的DES產品，試圖以生物可分解性（biodegradable）外層消除此風險
冠狀動脈支架 (Coronary Stenting)