- Does the heart literally stop when someone has a heart attack?
- I have read that there is a seasonal change in risk of heart disease, with winter being the most dangerous season. Is this true and is there anything I can do to reduce my risk?
- My GP recently suggested to me that I take a combination tablet that contains two medications, rather than the two tablets that I currently take individually. Will this be as effective as what I am currently taking?
- I recently read that calcium supplements might increase the risk of heart attack. I have been taking calcium for some years. Should I now be concerned?
- I have atrial fibrillation and have been taking warafin to prevent blood clots. I've heard there may be a drug alternative that doesn't require regular blood checks.
- Is dark chocolate good for you?
- When is a good time to start thinking about my heart health?
- I recently had a cardiac ultrasound because I was short of breath. Should I be concerned?
Q. Does the heart literally stop when someone has a heart attack?
Although “heart attack” is a term that is used often, it can lead to confusion because it overlaps with two conditions; myocardial infarction and sudden cardiac death.
Myocardial infarction more scientifically means that there is damage to the heart muscle. The damage is usually due to a blocked coronary artery that prevents adequate blood supply and oxygen to the affected part of the heart muscle.
On the other hand, sudden cardiac death occurs when a severe abnormal heart rhythm results in the heart being unable to pump blood adequately to sustain life. The two most common heart rhythms resulting in sudden death are ventricular fibrillation (a very fast, quivering motion of the heart) and asystole (when the heart really does stop beating). If not rapidly treated with a shock from a defibrillator, the ventricular fibrillation will eventually change to asystole. Both conditions require urgent resuscitation.
You have probably heard the expression – “time is muscle”. This refers to the observation that the quicker a blocked artery can be opened up, the less heart muscle damage occurs. So a rapid telephone call to the ambulance to get a patient to hospital, ideally within an hour of symptoms, to have the artery opened up, can greatly limit the amount of damage. Another important advantage of having an ambulance come rapidly is that the risk of sudden cardiac death due to an abnormal heart rhythm is greatest in the first hour. This can be prevented by having a defibrillator in the ambulance. Also, the placement of defibrillators in public places can help in allowing rapid defibrillation.
While a myocardial infarction due to a blocked artery usually occurs without sudden cardiac death, and an abnormal heart rhythm leading to sudden cardiac death can occur in the absence of a myocardial infarction, the two certainly can occur together.
Despite possible confusion, the term “heart attack” correctly conveys the urgency and danger of the situation – and is still a useful one. It is also a reminder of the need to recognise and seek medical help for any warning signs for a heart attack (such as chest tightness, new shortness of breath or fatigue), and not ignore them. People on medication for blood pressure and cholesterol, or on aspirin and plavix after a stent, also need to be fastidious in taking their medication; and not, as one of my recent patients said, take a “drug holiday”.
Q. I have read that there is a seasonal change in risk of heart disease, with winter being the most dangerous season. Is this true and is there anything that I can do to reduce my risk?
While heart disease occurs throughout the year, you are quite correct that there is a seasonal change in risk, with winter being associated with up to 60% greater risk than summer. This variation occurs for heart attacks, heart failure and rhythm problems as well as stroke.
There are probably several reasons for the winter peak in heart disease, which emergency departments and hospital administrators are also well aware of. These reasons include more respiratory infections puttin strain on the heart. People also tend to have higher blood pressure, higher cholesterol levels, weigh more and do less exercise in winter.
In an analysis, I found that clotting factors were also higher in the winter than summer. In some countries, winter is associated with more depressive symptoms, possibly related in part to less sunlight, while the relaxation of holidays might also be beneficial in summer. Cold temperatures may also contribute, although a seasonal variation has also been found in areas close to the equator.
What to do? Firstly, and annual flu shot amd being up to date with the Pneumovax injection is worthwhile to help combat respiratory infection, if you don't have any allergies to the vaccination. Also try to steer clear of others who have the flu, and don't be hesitant to see your doctor about taking antibiotics if need be.
Find ways to be active and keep the weight down. Be aware that many of the tinned soups have high salt content – try to avoid those.
If you do feel more short of breath than normal, or have other symptoms like swollen ankles or chest tightness, be proactive about getting medical attention.
If all else fails, one comic has suggested that you avoid winter by keeping travelling from northern to southern hemispheres.
Q. My GP recently suggested to me that I take a combination tablet that contains two medications, rather than the two tablets that I currently take individually. Will this be as effective as what I am currently taking?
You are reflecting something that is being increasingly seen in practice and makes a lot of sense. Hypertension is an area where combinations were initially seen, largely because it was recognised that many patients obtain better blood pressure control if they are on a low to moderate dose of two medications rather than a higher dose of one medication. Two medications can have an additive blood pressure lowering effect by working at different sites in the body. For instance, a diuretic may work on the kidneys while an angiotensin converting enzyme inhibitor or calcium channel blocker can affect blood vessel function. Side effects such as ankle swelling may also be minimised.
When patients are initially started on medications, especially in hospital, there is often a benefit in using individual tablets to arrive at the best combination of doses. Once that is achieved, it may be possible to find a combination tablet that will be effective in the long term.
Other benefits can include a lower cost. There is also a greater likelihood of people taking their tablets regularly, as one tablet is easier to remember than two. The combinations have been well tested and you should feel confident to go along with your doctor's suggestion.
Q. I recently read that calcium supplements might increase the risk of heart attack. I have been taking calcium for some years. Should I now be concerned?
Firstly, let me summarise my understanding of the report. A recent analysis of several studies (July 2010, British Medical Journal) reported a 30% increase in risk of heart attack in people taking calcium supplements, although no significant increase in death rate or stroke was found.
The heart attack risk was more apparent among those who had a normal or high dietary calcium intake, compared to those with low dietary calcium where there was no increased risk. The analysis did not include people who were also taking
vitamin D.
To get further advice, I spoke with Philip Sambrook, Professor of Rheumatology from Royal North Shore Hospital. He felt that the link between calcium supplements and heart risk was not proven, and pointed to a similar analysis earlier in the year that found no increased heart attack risk, and another study in elderly women finding no increased risk.
My conclusion is that it is important for you to maintain adequate calcium in the diet, and interestingly, sardines and almonds are also good sources of calcium in addition to milk and dairy. Your doctor can evaluate your intake with you.
According to the Bone and Mineral Society, if adequate dietary intake is not possible, and your doctor believes calcium supplements are needed to reduce bone fracture risk, calcium supplements in doses of 500-1,000mg could be considered.
You might use this opportunity to chat to your doctor about the risks and benefits of ongoing treatment for you, including other options.
Q. I have atrial fibrillation, and for many years have been taking warfarin to prevent blood clots. I have recently heard that there may be a drug alternative that doesn't require regular blood checks.
Atrial fibrillation is a common irregularity of the heart rhythm. If the left atrium doesn't vigorously empty its blood, a blood clot may form there, or next to it in the left atrial appendage, with the possibility of a stroke.
It is more likely to occur with old age, and in association with some other heart conditions.
Depending on a variety of factors, your doctor usually chooses to reduce the risk with aspirin or warfarin. Those who take warfarin need a regular blood test to see that the dose is within a safe and effective range. The effect can be altered by a variety of dietary and medication factors, including by some herbal supplements.
Recent studies have compared warfarin with a new twice-a-day tablet, called dabigatran (the trade name is Pradaxa). It doesn't require regular blood test monitoring.
Although Pradaxa is not yet available in Australia for treatment of atrial fibrillation, the study's results are very encouraging – it reduced stroke rate to the same extent as warfarin, and with less bleeding side effects.
While this is very promising, doctors have more experience with warfarin. Also, Pradaxa is more expensive and will have its own challenges, including drug interactions and side effects.
My suggestion would be that since you have been doing well with the warfarin, you should continue as you are. Just be aware that this new medication may soon be available as an alternative for people being newly considered for warfarin for atrial fibrillation. It is currently a treatment option to prevent deep vein thrombosis after hip or knee surgery.
Q. Is dark chocolate good for you?
Since chocolate is a common additive to food, and heart disease is so prevalent in our society, it is inevitable that the association has been studied.
Researchers have shown that cocoa contains a subgroup of flavenoids called flavenols which can help in endothelial function (blood vessel lining) and blood flow in several ways, including the release of nitric oxide.
The cocoa flavenols also have beneficial antioxidant effects and reduce tendency for blood platelets to clot. Chocolate also contains phenylethylamine which releases endorphins in the brain and can elevate mood.
While all cocoa is rich in flavenols, the particular processing of the bitter tasting flavenols into cocoa powder or confectionary chocolate determines the flavenol content of then final product - not the final colour of the chocolate. Nonetheless, dark chocolate tends to have the highest cocoa content, suggesting this may be the one to choose.
However, even if dark chocolate may be good for the heart, its calorie content (e.g 480 calories per 100-gram bar, means that weight gain may offset any potential benefit). Also, bear in mind that other foods such as tea, red wine apples, vegetables and grains are also high in flavenols.
Final proof of benefit from dark chocolate will require a large randomised study, for which there will probably be many volunteers. This topic is best summarised by a quote from my grandmother (and probably yours) of 'everything in moderation', and finally – Mum: 'Fred, there were two chocolate cakes in the pantry yesterday, and now there's only one. Why?'
Fred: 'I don't know. It must have been dark so I didn't see the other one.'
Q. When is a good time to start thinking about my heart health?
For everyone, 'now' is the best time to start thinking about improving your heart health. The first goal is to prevent heart disease before it has become evident, and the second is to prevent any further problems, such as a heart attack after a stent is placed in a narrowed artery.
Even if atherosclerosis or artery narrowing remains present, there is ample evidence that lowering cholesterol and blood pressure, by lessening the tendency for blood clotting, can help reduce the chance of a heart attack. A marked reduction in cholesterol has been shown to even reverse the severity of atherosclerosis, and the risk for smokers who quit, immediately lessens.
Additionally, it is recognised that early changes of atherosclerosis begin in some children by the age of ten. Steps to prevent the development of risk factors such as high blood pressure and cholesterol are important, even in the young. As we all know, obesity in children as well as adults is a major problem, pointing to the need for daily fun physical exercise, less time in front of the TV or computer, avoiding exposure to second-hand cigarette smoke, and healthy food habits.
Q. I recently had a cardiac ultrasound because I was short of breath. My doctor said the ultrasound was normal, but the report said I had ‘trivial mitral regurgitation'. Should I be concerned?
It is quite common for small leaks (regurgitation) to occur through a heart valve, such that when the valve opens and shuts, it doesn't fully seal. Although valves are very impressive in their general function and reliability, they are not machine-made. Fortunately, in contrast to severe forms, trivial regurgitation will not cause any extra strain on the heart, and is most unlikely to get worse.
The ultrasound, which is a very useful test, can look closely at the appearance of the valves as well as heart function, and the doctor's assessment is reassuring. However, the ultrasound is just one test, and the doctor will need to factor that into the assessment of why you are short of breath.
Disclaimer: While due care is taken in the preparation of these questions and answers, the information contained on this website is not intended as specific medical advice, and should be used as a guide only. Consult your doctor or healthcare professional before following any advice.
