We tend to take our hearts for granted. Often the only time we actually remember that we have a beating heart which is solely responsible for keeping us alive, is when we feel that flutter in our chest, which may make us gasp for breath momentarily. This is a typical Arrhythmic episode and may only last for a few seconds or minutes, and following this, we carry on with our lives as usual, with the memory of the incident quickly fading into obscurity.
What is Arrhythmia?
The definition of Arrhythmia is that it is any abnormal heart rhythm, where the heart may beat either very slowly, very fast, or with a seemingly random beating rate. The heart beats because electrical signals are sent from a natural pacemaker, also known as a Sinoatrial Node or Sinus Node, which is part of the heart. This electrical impulse is transmitted within the heart muscle through special electrical cells. The effect is to make the heart muscle contract, which is the basic mechanism which causes the blood to flow throughout the body.
However, these signals can be interrupted for a number of different reasons, and the result is an abnormal heart rhythm as a result of the delay of these electrical signals on their way through the heart. Alternatively, the electrical messages may arrive from a different part of the heart, instead of the natural pacemaker.
Symptoms of Arrhythmia, or Heart Arrhythmia
If the heart rate is very fast, very slow, or irregular, it can make it more difficult for the heart to pump blood around the body.
Some of the symptoms of Arrhythmia are as follows :-
- heart beat like a thumping sensation
- missing heart beats
- heart beat racing or beating faster than normal
- feeling of dizziness
- feeling of tiredness
- feeling out of breath
What causes Arrhythmia?
Most people have an occasional extra, or missed heartbeat, usually without noticing it. Excessive stress, lack of sleep and stimulants, such as caffeine and nicotine, increase the risk of arrhythmias, as can medications, such as decongestants and alcohol. Continue reading
Potassium and Blood Pressure
What is Potassium?
Potassium is a chemical compound, or mineral, which is found naturally occurring in certain foods, and is an important tool in the fight against high blood pressure. It is an important nutrient for maintaining good heart health, as it is necessary for smooth muscle contraction, of which the heart is possibly the most important example. It also assists with other essential body health functions such as kidney and digestive function.
The role of Potassium in the body
Potassium is critical for the normal functioning of the muscles, heart, and nerves. It plays an important role in controlling the activity of the muscles of the heart. Normal blood levels of potassium are critical for maintaining normal heart electrical rhythm. Both low blood potassium levels (hypokalemia) and high blood potassium levels (hyperkalemia) can lead to abnormal heart rhythms (arrythmias).
Natural sources of Potassium
Potassium can be found in many natural foods ranging from fruits, vegetables and legumes, and a diet which contains sufficient potassium can usually be achieved by eating a variety of foods containing potassium. Consequently, potassium deficiency is usually rare in healthy individuals who are eating a balanced diet.
Foods with high sources of potassium
The best dietary sources of potassium are fresh unprocessed foods – meats, fish, fruit and vegetables.
These include whole grains, orange juice, potatoes, bananas, avocados, tomatoes, broccoli, soybeans, brown rice, garlic and apricots, although it is also common in most fruits, vegetables and meats. The most well known potassium food from the above list however, is bananas.
High Potassium Diet Benefits
Diets high in potassium can reduce the risk of hypertension. Dietary intake is the preferred method of maintaining the correct level of potassium in the blood. The recommended daily amount according to the US Institute of Medicine is 4g or 4,000mg, although most Americans consume only half that amount on average, per person, per day.
However Supplements of potassium are not generally recommended for boosting the body’s Potassium levels. Whilst some earlier animal and human research did suggest that potassium supplements could help to lower blood pressure, more recent improved studies suggest that potassium supplements do not improve blood pressure significantly.
Excessive Potassium in the diet
Having too much potassium in the blood is called hyperkalemia, and in its mild form is a common condition, causing stomach pain, nausea and diarrhea. Extremely high levels of potassium in the blood (severe hyperkalemia) can lead to cardiac arrest and death. Incorrect diagnosis and treatment of severe hyperkalemia results in a mortality rate of about 67%.
The most important clinical effect of hyperkalemia is related to the electrical rhythm of the heart. While mild hyperkalemia usually has a limited effect on the heart, moderate hyperkalemia can produce EKG changes (EKG is an electrical reading of the heart muscles), and severe hyperkalemia can cause suppression of electrical activity of the heart and can cause the heart to stop beating.
Low Potassium or having too little Potassium in the blood is known as hypokalemia. Studies in rats have shown that a potassium deficiency combined with an inadequate level of the vitamin thyamine has produced heart disease in rats. One of the most important uses of potassium is to treat the symptoms of hypokalemia, which include weakness, lack of energy, muscle cramps, stomach disturbances, an irregular heartbeat, and an abnormal EKG (electrocardiogram, a test that measures heart function). Treatment of this condition takes place under the guidance and direction of a physician.
Potassium and High Blood Pressure
Some studies have linked low dietary potassium intake with high blood pressure. The US Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure recommends adequate amounts of potassium in the diet, along with other measures such as dietary calcium and weight loss, to prevent the development of high blood pressure. Similarly, the Dietary Approaches to Stop Hypertension (DASH) diet emphasizes eating foods rich in fruits, vegetables, and low- or non-fat dairy products to provide high intake of potassium, as well as magnesium and calcium.
Potassium and Stroke
In several population based studies evaluating very large groups of men and women over time, a diet rich in potassium was associated with a reduced risk of stroke. For men, this seems to be particularly relevant for those suffering from high blood pressure and/or those taking diuretics (blood pressure medications that help the kidneys eliminate sodium and water from the body). Potassium supplements, however, do not seem reduce the risk of stroke.
The crucial link between Potassium and Sodium (Salt)
The correct level of potassium in the body unfortunately depends on the body’s sodium intake. This means that excessive salt consumption may deplete the body’s stores of potassium.
Other conditions that can cause potassium deficiency include diarrhea, vomiting, excessive sweating, malnutrition, and use of diuretics. In addition, coffee and alcohol can increase the amount of potassium excreted in the urine. Adequate amounts of magnesium are also needed to maintain normal levels of potassium.
Because of the potential for side effects and interactions with medications, dietary potassium supplements should only be taken under the supervision of a physician or healthcare provider. This is especially important in the elderly, as they are at high risk for developing hyperkalemia due to decreased kidney function that often occurs in later years. Older people should be careful when taking medication that may further affect potassium levels in the body, such as nonsteroidal anti-inflammatories (NSAIDs) and ACE inhibitors.
Individuals suffering from kidney diseases may suffer adverse health effects from consuming large quantities of dietary potassium. End stage renal failure patients undergoing therapy by renal dialysis must observe strict dietary limits on potassium intake, since the kidneys control potassium excretion, and buildup of blood concentrations of potassium may trigger fatal cardiac arrhythmia. Acute hyperkalemia can be reduced through eating baking soda, or glucose.
Medical term for a heart attack
The medical term for a heart attack is a Myocardial infarction (MI, or AMI for acute myocardial infarction),
What is a heart attack?
A heart attack occurs when the blood supply to part of the heart tissue, or myocardium, is interrupted by a mechanical blood flow problem.
The most common cause of a heart attack is because of a blockage, also known as an occlusion, of a coronary artery following the detachment of a piece of fatty plaque from within the artery wall.
In medical terms this is known as the rupture of a atherosclerotic plaque, containing unstable lipids (which are particles related to cholesterol) and white blood cells (especially macrophages) which are normally contained within the inner wall of an artery.
The resulting reduction in the incoming supply of blood to the heart (also known as Ischemia) and oxygen shortage, can cause damage or terminal damage to the heart tissues, which is known as an infarction. This is shown in the graphic below. The problem is greatly increased if treatment is not provided urgently.
Symptoms of a heart attack
classic symptoms of a heart attack or myocardial infarction include some or all of the following :-
- sudden chest pain
- pain radiating to the left arm or left side of the neck
- shortage of breath
- heart palpitations
- anxiety or a feeling of dread
Women and Heart Attacks
When a woman suffers a heart attack, she may experience fewer symptoms than a man. The most commonly experienced symptoms of a female heart attack are shortness of breath, weakness, and a feeling of indigestion, and fatigue.
The silent Heart Attack
Approximately one quarter of all myocardial infarctions are silent, without chest pain or other symptoms. This makes them very difficult to identify, and often the sufferer may only be diagnosed after an emergency callout for a paramedic, or admission to the ER room of a hospital.
Heart attack is the most common form of death worldwide
Heart attacks are the leading cause of death for both men and women all over the world. There are many risk factors to be considered, of which the most important are listed in the following bullets :-
- Cardiovascular disease
- Previous history of heart attack or stroke
- Older age (especially men over 40 and women over 50)
- Cigarette or tobacco smoking
- High blood levels of certain lipids (triglycerides, low-density lipoprotein or “bad cholesterol”) and low levels of high density lipoprotein (HDL, “good cholesterol”)
- High blood pressure
- Chronic kidney disease
- Heart failure
- Excessive alcohol consumption
- Drug abuse – especially cocaine
- Stress, especially chronically high levels
Immediate treatment for a heart attack
A heart attack is a medical emergency, and people experiencing chest pain are advised to alert the emergency medical services, because prompt treatment is essential.
Immediate treatment for suspected acute myocardial infarction includes oxygen, aspirin, and nitroglycerin. Pain relief is also often given, usually in the form of morphine sulfate.
Follow up treatment for a heart attack
The heart attack patient will receive a number of diagnostic tests, such as an electrocardiogram (ECG, EKG), a chest X-ray and blood tests. Under the guidance of a heart specialist or surgeon, further treatment may be administered using specialist heart drugs or possibly surgical intervention.
Confusion between heart attack and sudden cardiac death
The phrase “heart attack” is sometimes used incorrectly to describe sudden cardiac death, which may or may not be the result of an acute myocardial infarction. A heart attack is different from, but can be the cause of cardiac arrest, which is the stopping of the heartbeat, and cardiac arrhythmia, an abnormal heartbeat. It is also distinct from heart failure, in which the pumping action of the heart is impaired; severe myocardial infarction may lead to heart failure, but not necessarily.
New Doubts over Aspirin for your Heart
Doubts have been raised over the value of taking Aspirin and low dose Aspirin for your heart, as scientists now believe a daily dose could do more harm than good. New research reveals that taking a daily aspirin to ward off heart attacks could do more harm than good!
What is a low dose Aspirin?
For many years we have been led to believe that taking a low dose of aspirin – typically 75mg per day, is beneficial for our heart health and in minimising the risk of developing a heart attack.
A recent study conducted by Scottish Scientists however, has cast doubt over the benefit of aspirin as a simple, cheap heart medication. A more in-depth analysis of this research though, reveals that this applies only to preventing a first heart attack, and that Aspirin is still effective at preventing a second or repeat heart attack. The study also highlighted though that taking aspirin does increase the risk of internal bleeding.
Aspirin and the Healthy Middle Aged
Many healthy middle-aged people, also known as the ‘worried well’, decide to take low dose aspirin as a precautionary measure, even though they currently have no symptoms of cardiovascular disease.
Aspirin effectiveness trial targets diabetes sufferers
The scientists’ claim follows a study of type 2 diabetes sufferers which discovered that regular daily doses of the medication apparently fails to prevent victims of type 2 diabetes suffering a first cardiac arrest. This group was chosen as Aspirin is widely prescribed to diabetics, who are at much greater risk of heart disease than the general population. However, the scientists also advised that those people already taking small daily doses of aspirin against giving it up without consulting their doctor. Professor Jill Belch, of the Institute of Cardiovascular Research at Dundee University, Scotland, said: ‘If you’re taking aspirin for secondary prevention because you’ve had a heart attack or stroke, or have a circulatory problem, then it works’. ‘But it doesn’t work if you have none of these problems, and there is also no evidence for its use by healthy middle-aged people.’ She added, however: ‘We do not want people taking aspirin prescribed by their doctor to stop taking it without seeking medical advice. They may have conditions for which it is suitable.’ Around 2.3million Britons have type 2 diabetes, which is closely linked with growing levels of obesity, and they are up to five times more at risk of heart disease than the general population.
Aspirin’s established reputation in heart attack prevention
Aspirin does have an established reputation for reducing the risk of repeat heart attacks and stroke by up to a third. However, a major study suggests that diabetics who have not had a previous heart attack gain no benefit from a daily dose. Professor Belch’s paper published recently in the British Medical Journal, involved 1,276 patients aged over 40 with diabetes and evidence of artery disease, who had not suffered a previous heart attack. It found after eight years that there was no overall benefit from either aspirin or antioxidant treatment in preventing heart attacks or death. Patients in the aspirin groups had 116 heart attacks compared with 117 in those given placebos. Professor Belch said there was widespread prescribing of aspirin in diabetes despite the lack of evidence to support it’s use. But studies show it can double the risk of stomach bleeding from an ulcer.
Side effects of Aspirin and low dose Aspirin treatments
‘Unfortunately aspirin has side effects and it’s one of the biggest reasons for admission to hospital for drug-related adverse reactions, mainly gastrointestinal bleeding. ‘Although the risk is relatively small, the numbers taking aspirin is large so it’s a major problem.’ Professor Belch said there was international opposition to the study, mainly because U.S. guidelines recommend routine use of aspirin in patients with type 2 diabetes and millions are taking it. ‘They were adamant that it was unethical to carry out this trial but I’m glad we persevered.’ She said clinical guidelines from various UK organisations recommending aspirin as primary prevention for diabetics should be changed. There has also been growing pressure for ‘blanket prescribing’ of aspirin in middle age, with a report only last month from Nottingham and Sheffield researchers suggesting most healthy men over the age of 48 and women over 57 would benefit from the drug. Research such as this has encouraged healthy middle-aged people to start taking aspirin bought over the counter without seeing a doctor – despite it not being recommended by any medical body. Aspirin is also an ingredient of the ‘ Polypill’, a single cheap multi-drug tablet being developed to slash the toll of heart attacks. But this one-size-fits-all approach might now have to be rethought, said Professor Rory Collins, of Oxford University, a pioneer of large-scale studies into the causes and treatment of heart attacks. His team is observing 10,000 diabetics who have been allocated daily aspirin or placebo, and has carried out a major analysis of existing studies. The findings show any small benefit from using aspirin in those who have not had heart attacks is outweighed by the risk of stomach bleeding, he said. ‘There has been a conflict between guidelines recommending the use of aspirin as primary prevention and the lack of evidence supporting this. ‘But a lot of GPs are following these guidelines. When we were recruiting for our study, we found practices where all diabetic patients were being prescribed aspirin. ‘The evidence is not there but the risk of bleeding is – and it goes up with age.’