The Heart: An Incredible Electric Machine

A quick primer on the electrical system of the heart followed by two major breakthroughs in pacemaker technology this year.

What makes the heart beat? Learn about the conduction system, an incredible machine.

A leadless, subcutaneous defibrillator makes the list of 5 biggest medical breakthroughs of the year.

Boston Scientific has begun marketing a FIRST-OF-ITS-KIND DEFIBRILLATOR after receiving FDA approval in September. The implantable device, which protects against sudden cardiac arrest, was developed by a California firm purchased by Boston Scientific and is expected to be a financial win for the Natick-based company. Unlike others on the market, the S-ICD does not touch the heart, instead sending electrical pulses to correct abnormal rhythms through wires implanted just beneath the skin.

http://bostonglobe.com/magazine/2012/10/27/biggest-medical-breakthroughs-year/pLJDenlFAN3XFwwsxfU7CI/story.html

No More Batteries: Piezoelectric Pacemaker Powered By The Heart

An experimental device converts kinetic energy from beating hearts into electricitythan can power a pacemaker, meaning the chance for no more batteries in the future, according to a talk at the American Heart Association’s Scientific Sessions 2012.

The study is preliminary but a piezoelectric approach is promising for pacemakers because they require only small amounts of power to operate. Batteries must be replaced every five to seven years, which is costly and inconvenient.  Piezoelectricity might also power other implantable cardiac devices like defibrillators, which also have minimal energy needs.

“Many of the patients are children who live with pacemakers for many years,” said M. Amin Karami, Ph.D., lead author of the study and research fellow in the Department of Aerospace Engineering at the University of Michigan in Ann Arbor. “You can imagine how many operations they are spared if this new technology is implemented.”

Researchers measured heartbeat-induced vibrations in the chest. Then, they used a “shaker” to reproduce the vibrations in the laboratory and connected it to a prototype cardiac energy harvester they developed. Measurements of the prototype’s performance, based on sets of 100 simulated heartbeats at various heart rates, showed the energy harvester performed as the scientists had predicted — generating more than 10 times the power than modern pacemakers require. The next step will be implanting the energy harvester, which is about half the size of batteries now used in pacemakers, Karami said. Researchers hope to integrate their technology into commercial pacemakers.

Two types of energy harvesters can power a typical pacemaker: linear and nonlinear. Linear harvesters work well only at a specific heart rate, so heart rate changes prevent them from harvesting enough power.

In contrast, a nonlinear harvester, the type used in the study, uses magnets to enhance power production and make the harvester less sensitive to heart rate changes. The nonlinear harvester generated enough power from heartbeats ranging from 20 to 600 beats per minute to continuously power a pacemaker. Devices such as cell phones or microwave ovens would not affect the nonlinear device, Karami said.

http://www.science20.com/news_articles/no_more_batteries_piezoelectric_pacemaker_powered_heart-96003

 

Chest Pain after having Stent

Chest pain following successful balloon angioplasty or stent is a common problem. Although the development of chest pain after coronary interventions may be not a problem, it is disturbing to patients, relatives and hospital staff.

Possible Causes of Pain:

  • acute coronary artery closure,
  • coronary artery spasm
  • heart attack,
  •  local coronary artery trauma

The distinction between these causes of chest pain is crucial in selecting optimal care.  Early intervention can limit the damage. Management of these patients may involve repeat hospitalization for  coronary angiography and/or additional intervention.

Commonly, repeat coronary angiography following Angioplasty (PTCA) in patients with chest pain demonstrates  lesion to be widely patent/open  suggesting that the pain was due to

  1. coronary artery spasm,
  2. coronary arterial wall stretching
  3.  non-cardiac 

 Coronary arterial wall stretching is common and occurs significantly more often after stent implantation than after PTCA or coronary angiography alone. This may be a result of the overdilation and stretching of the artery caused by the stent implantation and the consecutively high degree of stretching and the elastic recoil is minimized. Kind of like a deflated balloon, the artery doesn’t go back to original circumference.

sciencedirect.com

After getting out of the hospital every little ache and pain makes you think  “Is my heart giving me problems?” It is really difficult not to panic.

Here are some tips that should be of help you to know when to seek emergency care:

  •  Is the discomfort you are feeling the same  or similar to the discomfort that brought you to the hospital? If so, this could be a problem. It is more likely to be a problem if it is similar…don’t wait until it is bad to seek treatment. Time is muscle and we don’t want  you to lose any muscle.
  •  Does the discomfort also have other symptoms that pair up with it? These symptoms might include shortness of breath, profuse sweating, nausea, radiating discomfort into neck, jaw, arms or back.  If there are multiple symptoms you should call 911.
  •  Can you reproduce the pain or discomfort with touch or movement of body. It is less likely to be a heart symptom if you can make it hurt through touch. This is usually muscle or skeletal origin or what is referred to as non cardiac chest pain.
  •  The 4 E test…does the discomfort come on with Emotional stress,  Exercise, after Eating, or with a cold Environment? If so these are common triggers of heart symptoms. If you rest and they go away it probably isn’t emergent but you should notify your doctor as soon as possible. Keep a log of the frequency of these symptoms..when they come on, how frequently, what were you doing when they occurred, how intense was it, and what made them go away.
  • Unstable Angina….this is angina or heart pains that are coming on more frequent, occurs at rest or wakes you from sleep, or you need more nitro than usual to relieve discomfort.                                                                                                                                                                                       

If your symptoms are that of unstable angina you contact your doctor  - call 911

If you suspect you are having a heart attack chew up an adult strength aspirin and call 911.

Do not drive yourself to the emergency room. The ambulance crew is your first line of medical treatment, they will provide you with emergency medications, alert the hospital to your condition so they can manage your care quickly and efficiently. Time is muscle don’t waste any time.

Chew the aspirin even if you take an aspirin a day as regular medicine. The extra one helps more than it hurts. Only chew one not a handful that could causes more problems.

Antiplatelet effect of chewed, swallowed, and dissolved aspirinChewing aspirin hastens its antiplatelet effect, as measured by the reduction in blood thromboxane B2 levels. It took only 5 minutes for patients who chewed aspirin to achieve a 50% reduction in baseline levels, versus almost 8 minutes after they took it in a solution and 12 minutes after they swallowed it whole.Source: American Journal of Cardiology Vol. 84, p. 404.

May 2005 Update

It is best not to lie down. Try to stay calm, do some relaxation deep breathing – think belly breathes – make belly go out when you breath in. Avoid short shallow chest breathing. Focus on staying calm. If you think you are going to pass out try coughing or bearing down like you are having a bowel movement.

If you have Nitroglycerin tablets or spray that were prescribed by your doctor use them.  I can’t tell you how many people forget about their nitro when they need it the most. Place one under your tongue, do not chew it. It should make you have a headache, or cause a flushing feeling, or tingle under your tongue. These are indications that your nitro is fresh. If you suspect your nitro is old (over one year if bottle unopened, or greater than 6 months since bottle was opened) find a fresh bottle. Nitro is a very volatile compound and breaks down rapidly if in contact with air, heat, light, or plastic.

Cardiac Rehabilitation – Did you attend?

Only 30 % of patients who have an eligible diagnosis for cardiac rehabilitation services actually attend. Of those that do attend there is a very solid trend in the United States that 70% are male, and 30% are female. Minorities are even less likely to attend. 

There are many factors that contribute to the above statistics.

  • Were you referred to cardiac rehabilitation?
  • Do you have insurance that covers it?
  • Is the co-pay too high to attend?
  • Is the distance to the nearest facility too far a drive, or the cost of gas to expensive?
  • Transportation issues – such as being able to safely drive yourself, or not having transportation?
  • Do you feel like you are too young to attend or too old?

The lack of referral is an issue where it may be the physician has a pre percieved perception of what the services are. I ran into this issue frequently. Many healthcare providers percieve cardiac rehabiitation as a place for their patients to go and exercise. They often don’t realize the education that occurs. Exercise is important, but how about working with patients on learning a healthy diet, overcoming barriers to healthy lifestyles, tobacco cessation, support, risk factor education, stress management as a few examples of what one recieves in the rehabilitation setting. If your physician didn’t recommend it, it is ok to ask for a referral.

Insurance limits many, either they have a diagnosis that doesn’t cover it or the co-pays are exorbitant. I have seen co-pays of $100 per session. The programs can last up to 36 session so that can mean a pretty hefty out of pocket cost.  Most patients won’t  attend if their out of pocket for  co pays are greater than $30 per session. Yes you get a lot from attending, but add that into the co-pays from the hospital, the physician bills, the medication costs, the lost work, the laboratory costs and it is a hefty out of pocket cost to have a heart event. Many patients experience complications requiring further testing, physician visits, medications making the cost even higher. It isn’t unusual for a patient to come to rehabilitation and tell me they received their bill for open heart surgery and it was $150,000, or a stent costing $30,000. The usually have a second episode of chest pain when they see the first bill. 

How about travel? If you just had open heart surgery you probably are restricted from driving for 4 weeks, and then may not even feel healthy enough to drive self. Then you must rely on others two to three times per week to bring you to and from. Many rural areas do not have a public transport system that is reliable. Our bussing system might require you to spend 4-6 hours for transportation that is really only a 40 minute drive from the facility. Medicare will not cover telemed programs.

Why don’t women attend? Do they not feel comfortable thinking it is a gym? Do they have too many things on their plate to take care of themselves? Do they physicians not refer them, feeling they are already aware of what changes should be made or don’t think they would benefit?

                                                            

There is no set age. In fact the younger the patient is the better in terms of making lifestyle changes and learning to cope with living with a chronic disease. Elderly people seem to benefit the most from the strength and conditioning as well as the social interactions. Our programs see people from ages 20- through their 90′s.

I think our Cardiac Rehabilitation programs do a poor job of catering to minority populations. When we study ethnically diverse regions we continue to note the same trends, it is primarily the white males that attend. Is this because we have few minorities staffing the programs. We teach with a cookbook approach, everyone is taught the same diet, the same stress management and lifestyle changes. Recently I was speaking to a group of Native Americans and they informed me that when we teach to a family it usually take seven generations for changes to take place. We certainly don’t address the spiritual needs or cultural differences. Do we teach how to modify the Arabic diet, or the African American diet? Can we effectively teach stress management if we don’t understand the family dynamics of different cultures? Nope most program don’t unfortunately. 

I would love to hear from those of you with heart disease why you may have chose not to attend.

If you are considering attending here are a couple of valuable links to check out:

Cardiac Rehabilitation Fact Sheets

http://www.aacvpr.org/Portals/0/resources/patients/CRFactSheet112.pdf 

 or for a Spanish version http://www.aacvpr.org/Portals/0/resources/patients/CRFactSheet_Spanishversion04.12.pdf 

To find a program near you or to find patient resources:

  http://www.aacvpr.org/ 

 

Cardiovascular Risk – Not the same old info


I have to laugh when I hear people talk about it is the big pharmacy and  the medical community who are preventing us from curing diseases like heart disease and cancer. When they state there are simple cures, or that the companies don’t want to risk losing their profits and  are withhold lifesaving cures, I have to walk away. The human body is so complicated, and we are just learning how much we don’t know. It isn’t just about cholesterol, obesity, lack of exercise and smoking. There are so many factors that contribute to disease processes and we are only now beginning to understand them much less be able to manage them.

The comic link below shows many of the current lines of research of the contributing factors of heart disease. We continue to learn about the various issues which can cause the disease, then study to see if there is a way to modify these factors through pharmaceuticals or biotechnology. We certainly cannot use a one size fits all approach and care for patients as if the disease process is the same in each individual. Having worked in Cardiac Rehabilitation for a couple of decades, patients came in all shapes and sizes, some with perfect health habits, and others with every risk factor in the book. Lowering cholesterol and blood pressure helped some, but certainly not all. Many had great cholesterol numbers, and yet had severe heart disease. For some it’s genetics, but there is more to the story. How can one person get all the bad genes and the others miss out. One man I worked with who came from a family of 18 was alive in his late 70′s yet had lost 12 siblings before they were 40. They were raised on the same food, in the same environment. What caused his disease to present so much later than his siblings?

I have included an excerpt/link from The Fat Nurse whose blog can be found on WordPress at http://thefatnurse.wordpress.com/author/thefatnurse/

Her information is credible and every heart patient should be able to talk intelligently about their disease including being able to ask their health care provider if there are other tests, or risk factors that should or could be evaluated. Health care providers might seem taken aback at first, but they are responsible to keeping up with the research. Sometimes it takes the patient to drive the clinician to learn more. Here are some of the cardiovascular risk factors that are discussed in the link below these include:

  • CRP
  • Apo B
  • Ldl – c
  • Ldl – P
  • Lp (a)
  • Lp-pla2

This comic goes over other measurements that are emerging on cardiovascular risk other than the conventional LDL HDL cholesterol measurements. A condensed simplified comic, but it may drive your curiosity to investigate more! 

http://thefatnurse.files.wordpress.com/2012/06/cvmforallages.pdf