Posts Tagged ‘Myocardial Infarction’

10 Risk Factors cause 90% of Strokes

Thursday, July 29th, 2010

Interstroke Study published in the Lancet identified that 10 risk factors caused 88-90% of all strokes (both hemorrhagic and ischemic).

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1. Hypertension

2. Current smoking

3. Low waist to hip ratio

4. Unhealthy diet

5. Lack of regular exercise

6. Moderate or high alcohol intake

7. Psychosocial stress

8. Depression

9. High ratio of apoB to apoA1 lipoprotein (i.e. high cholesterol)

10. Diabetes

Reference: Interstroke Study, Lancet

Regenerating heart muscles to treat heart failure

Saturday, April 4th, 2009

Traditional medical teaching is that humans die with the heart muscles that they are born with.

Therefore, heart muscles that die when a person has a heart attack, will never regenerate and result in permanent injury akin to formation of scar tissue on skin (although skin does have a limited capacity to regenerate which is why scars do not form after minor skin trauma).

An article published in the Journal, Science seeks to overthrow this concept.

The researchers in their article have demonstrated that there is limited regeneration of heart muscle after birth.

“We have taken advantage of the integration of carbon-14, generated by nuclear bomb tests during the Cold War, into DNA to establish the age of cardiomyocytes in humans. We report that cardiomyocytes renew, with a gradual decrease from 1% turning over annually at the age of 25 to 0.45% at the age of 75. Fewer than 50% of cardiomyocytes are exchanged during a normal life span.”

This finding opens up possibilities of targeting medications to regenerating the heart muscle that is destroyed in a heart attack, thereby preventing a host of complications including heart failure (post myocardial infarction congestive heart failure is the number one cause of heart failure in the United States and is the major contributer of morbidity & mortality after heart attack).

Reference: Science, US News

Angioplasty and Bypass Surgery education videos

Thursday, November 13th, 2008

Animated video explaining how coronary angioplasty with stent insertion is performed. Also called percutaneous coronary intervention (PCI), it is the procedure of choice for most cases of heart attack.

Coronary artery bypass grafting is performed for severe disease as in involvement of all 3 coronary vessels or left main coronary artery.

 

Toxic BPA in plastics

Tuesday, September 16th, 2008

Bisphenol A (BPA) has been suspected of being toxic since 1930 when it was found to disrupt the hormones in rats. Now 78 years later, JAMA has published a study which lends further support to the toxic effects of BPA.

The first major epidemiological study of bisphenol A, a common ingredient in baby bottles and drink containers, suggests that relatively higher doses of the chemical double the risk of diabetes and cardiovascular disease.

Reference: Science

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Bisphenol A is used extensively in epoxy resins lining food and beverage containers and as a monomer in polycarbonate plastics in many consumer products. Widespread and continuous exposure to BPA, primarily through food but also through drinking water, dental sealants, dermal exposure, and inhalation of household dusts, is evident from the presence of detectable levels of BPA in more than 90% of the US population.

Reference: JAMA

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However, the study had a small sample size with 1455 adults aged 18 to 74 of of which 79 developed heart disease. It may be argued that the study may be underpowered to be able to confidently determine the relationship of BPA exposure (and how much BPA) to toxicity. Repeating the study with a much higher sample size will give us more definite answers.

Of note: Use of Bisphenol A has been banned for use in baby bottles in Canada due to its perceived risk of toxicity.

Bisphenol A Fact Sheet

Update (September 20, 2008):

Video from The Jama Report on BPA

When to worry about chest pain?

Sunday, September 7th, 2008

Chest comes in many varieties! For the purpose of developing heart attack there are 3 criteria that need to be considered:

  1. Description – Has 2 sub criteria:-
    1. Location – Central chest pain with radiation typically to the left shoulder (although radiation may occur to the right shoulder, neck and jaw)
    2. Quality – crushing, band like around chest, heavy as if somebody is sitting on the chest
  2. Precipitating factors – Classically precipitated by activity which is reproducible (i.e. walking 2 blocks every time will result in chest pain)
  3. Relieving factors – The pain is relieved by rest or nitroglycerin (the pain goes away within 5-10 minutes after taking nitroglycerin, if it takes longer, pain relief is not due to nitroglycerin and will not be considered a relieving factor)

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(Picture taken from Home Emergency Preparedness)

Based on these three variables chest pain can be classified into 3 types:

  1. Classical (anginal) – Chest pain meeting all the above criteria i.e. appropriate description along with precipitating and relieving factors. These people are at a very high risk of developing heart attacks.
  2. Atypical – Chest pain with any one of the above variables (appropriate description or precipitating or relieving factors) is atypical and these people are at moderate risk of heart attacks.
  3. Non anginal – Chest pain that does not match any of the above criteria. These people are at low risk of heart attacks.

Comments:

  • Classical (anginal) chest pain should never be ignored and medical help should be sought immediately
  • Atypical chest pain should in most cases (in the right clinical scenario) be evaluated by a cardiac stress test.
  • Non-anginal chest pain should also be evaluated by a doctor as it may indicate some other disease that my be serious!

Bottom line: Chest pain should be evaluated in all cases. The type of chest pain will determine the urgency of the situation.