March 18, 2003

Note to our users: This interactive feature is in no way a substitute for the examination and advice of a physician. You are responsible for all actions you take after reading material on this site. Always seek the advice of a doctor for concerns about your health or a specific condition.

Heart1: Welcome to tonight's discussion with Dr. Chim Lang.

Heart1: Dr. Lang is a Professor of Cardiology and the Deputy Dean of Research at the University of Malaysia, as well as the director of Clinical Investigation at the University of Malaya Medical Center.

Heart1: He is the winner of numerous prestigious awards, including a Fulbright Scholarship, two Pfizer Academic Awards, and Fellowships from the American College of Cardiology, the Royal College of Physicians of Edinburgh, and the Royal College of Physicians of London. Dr. Lang currently researches and practices in his native Malaysia. He is Heart1's first international Hero.

Heart1: We welcome your questions!

Heart1: Dr. Lang, why don't we start by having you briefly tell us how you got started in cardiology?

Dr. Lang: At the end of my internal medicine residency at Dundee in Scotland, I was approached Professor Allan Struthers to join him in his laboratory as a British Heart Foundation research fellow. Professor Struthers is a clinical cardiovascular pharmacologist with an interest in the clinical physiology and pharmacology of neuro-hormones in heart failure. He motivated my interest in the syndrome of heart failure, which is fast becoming a public health problem worldwide. Everything snow balled thereafter, with further training in a number of cardiovascular research labs notably those at Vanderbilt University (where I worked with Dr Alastair Wood, Dr Dan Roden and Dr John Wilson) and Columbia University (where I worked with Dr Milton Packer and Dr Donna Mancini).

maybaby : Hi Dr. Lang. I am a 25 year-old healthy female in good shape and eat well. On the weekends I will have a few drinks (3-4) socially, but do not generally overindulge. Sometimes I notice after a drink or two that my heart will POUND quickly and violently for a few minutes. Is this normal? Maybe I'm just having some strange, benign reaction? Or is this indicative of a more serious problem?

Dr. Lang: Hello from sunny Kuala Lumpur! Alcohol can cause vasodilatation (opening of blood vessels), which can lower your blood pressure and consequently your heart may respond by beating somewhat faster. However, if your "pounding heart" is associated with symptoms of dizziness, sweating and chest discomfort, you should consult your physician.

jack: How can one tell the difference between angina and a heart attack? Are there any noticeable traits that can distinguish one from the other?

Dr. Lang: Hi Jack. Generally the chest pain during a heart attack is more intense and prolonged and is associated with symptoms of heavy sweat, nausea and vomiting, shortness of breath and even collapse. However, it should be noted that angina can become "unstable" which may represent an impending heart attack. A sign of this trait includes angina at rest or with minimal exertion, increased frequency of attacks or an otherwise different pattern from your stable angina i.e., angina not relieved by your sublingual nitrates. Under these circumstances, one should seek urgent medical care.

Heart1: Dr. Lang, what should a patient do if he or she realized they are experiencing a heart attack? What immediate action should be taken?

Dr. Lang: The patient should chew on any available aspirin (dose of 325 mg) and take some GTN sublingually (underneath the tongue) and go to the nearest emergency room.

jlim@mba2001.hbs.edu : Dr. Chim, I've been reading recently about a novel technology to remove peripheral and coronary occlusive disease more effectively. A technology known as Omniwave, has received CE mark in Europe and has just been approved for sale in the EU and Australia/New Zealand for use in the peripheral vasculature. The company is undergoing clinical trials in the U.S. for this indication and also continuing trials internationally for the use of this technology for coronary applications. This technology claims to use ultrasonic (acoustic) energy in a wave platform, causing cavitation that resolves occlusive materials into particulate matter the size of red blood cells, with no damage to the vessel walls. My questions are as follows: 1) Have you heard of Omnisonics? 2) What do you make of its claim? Apparently other methods of thrombus removal have applied ultrasonic technology in "brute force" fashion, removing the occlusive material by digging away at it vertically; they claim the wave action is more effective. 3) Do you think this technology will be adopted by interventional cardiologists since it can be used in conjunction with angiolasty and stenting? Thanks very much for taking the time to answer my questions.

Dr. Lang: I do not have any personal experience with Omnisonics but the technology sounds interesting. However, as with all new interventions, well-conducted clinical trials are needed to demonstrate its efficacy and safety.

iMacDaddy : My friend has started taking Aspirin every day to reduce the chances of a stroke. I know that Aspirin is a blood thinner, but is it good for your heart (or other organs in general) to take drugs/medications so regularly?

Dr. Lang: In general, aspirin is of use in patients who are at risk of strokes and myocardial infarction as there is an established role in primary and secondary prevention. It is not advocated in otherwise healthy individuals with no risk factors. It should be noted that aspirin has side effects, which include risk of gastric bleeding.

Sammy : I have heard that catheterization is unsafe for patients with kidney problems as the dye carries a high risk of kidney failure. Is this true? And if so, what are the other diagnostic options for patients with low ejection fraction? Thank you.

Dr. Lang: In patients with kidney impairment, the contrast used in coronary angiography can cause further deterioration of the kidney function. However, there are strategies that can be employed to ameliorate this risk such as with adequate re-hydration and the use of N-acetylecysteine prior to the procedure. There are other diagnostic options which do not require contrast that is under development which includes multi-slice CT. Needless to say, you will be best advised to consult with your cardiologist on this in your decision making.

Heart1: Dr. Lang, perhaps you could tell our users a little more about ejection fraction since it came up. Can you explain ejection fraction a little more in detail? What is a low ejection fraction and what can one do to improve their ejection fraction?

Dr. Lang: Ejection fraction is a measure of your heart's pump function and can be determined by echocardiography (with an ultrasound probe) and by nuclear scanning. Depending on the lab, the normal value is greater than 55%. When the ejection is low and becomes clinically significant i.e., ejection fraction less than 40%, the patient has left ventricular systolic dysfunction. In the presence of symptoms of shortness of breath and altered effort tolerance and signs of fluid retention such as ankle swelling, then the patient has symptomatic heart failure. There are appropriate diagnostic and treatment strategies for left ventricular dysfunction so as to elucidate the cause (such as ischemic heart disease or valvular dysfunction) and to initiate drugs such as ACE inhibitors, B-blockers, diuretics and even for consideration for revascularization (i.e, angioplasty) in those with ischemic heart disease with significant demonstrable ischemia.

Julie: Dr. Lang, could you tell us a little bit more about how medicated stents work and if they are the wave of the future?

Dr. Lang: Medicated stents is now widely considered as a major revolution in interventional cardiology. These stents are coated with drugs that prevent the regrowth of tissue within the stent, a phenomenon known as re-stenosis. The available clinical trials suggest that these drug eluting stents are highly effective in preventing in-stent stenosis particularly in lesions that are susceptible to re-stenosis such as long lesions or small vessel disease. Prevailing issues regarding drug eluting stents are the type of drug and the long-term outcome.

Heart1: We're just about out of time. Dr. Lang, do you have any closing thoughts on cardiac health that you'd like to share with our users?

Dr. Lang: Cardiovascular disease is a major cause of morbidity and mortality worldwide. Here in Malaysia , it accounts for 29% of all certifiable deaths. It is fair to so that in the last decade, we have witnessed major advances in terms of cardiovascular therapeutics and development of interventional devices. However, there is no room for complacency. Indeed, there is there is still a gap between the available clinical trial evidence and prescribing to our patients. As a result, many of our patients are not always on optimal therapy and there is much work to be done to improve on this. In this era of major advances in molecular and cellular cardiology and the understanding of the pathophysiology of cardiovascular disease, there is an urgent need for research to translate all this to our bedside. Funding of cardiovascular research remains a priority.

Heart1: Thank you, Dr. Lang, for lending us your expertise and insight tonight. And thank you, users, for joining us. Stay tuned for upcoming Body1 chats! Good night.