There are a number of causes of congestive heart failure, where the heart fails to pump blood to other body organs. If the heart becomes so badly damaged that life is threatened major surgery may be the only option for survival. However, gene therapy could improve congestive heart failure outlook.
Signs of Heart Failure
Heart failure does not mean that the heart has suddenly stopped beating. It refers to a heart that is failing to work as well as it should in pumping blood around the body. It's still there pumping away, just not as efficiently as normal. There are many signs of heart failure including: -
- Shortness of breath
- Persistent Coughing
- Chest Pain
- Lack of Appetite
- Swelling in the legs
- Heart palpitations
By themselves these symptoms may not indicate heart failure, but if experienced together a visit to the doctor's surgery is recommended.
What causes heart failure?
There are a wide variety of causes and these can include: -
Infection such as viral myocarditis
- Narrowed arteries
- High blood pressure
- Diseases of the heart muscle such as dilated cardiomyopathy
Possible New Treatments for Congestive Heart Failure?
There are many treatments for congestive heart failure, but sometimes the heart degrades until it is in such a bad way that surgery or transplant may be the only viable long term solution.
Some types of heart surgery (of course) are major league operations that require the chest cavity to be opened. Gene therapy studies on the other hand may help medicine to take giant leaps toward the goal of one day having "closed heart surgery," with the added bonus of cutting down on the cocktail of drugs that all heart failure patients need. Although it is early days, there are some encouraging signs coming from the laboratory.
- In 2007 researchers from the Center for Translational Medicine at Jefferson Medical College used gene therapy to reverse heart failure in rats. They used a gene called S100A1 which is believed to play a role in contraction of the heart muscle, and they put it inside an adenovirus and sent it into rat bodies The gene was only expressed inside heart cells and none of the other organs. The result was that when rats were followed up some weeks after the procedure those that had gene therapy had vastly improved heart function compared to those rats that did not receive any treatment. In addition the scientists observed that this gene therapy approach had a controlling effect on the size of the heart. During heart failure it increases, but the S100A1 treatment slowed down this increase and actually reversed it. The treatment also produced a better heart failure outlook in this animal model than the application of beta-blockers.
- In October 2009 scientists from the Universities of Michigan and Minnesota published a report that showed how they had used gene therapy to help heart muscle cells from the failing hearts of humans and rabbits to heal themselves. The cells were treated with an adenovirus that had been modified to carry a gene that expressed the fast molecular motor protein - which helps heart cells to contract normally - or an adenovirus that carried a gene that expressed the slow molecular protein - that is believed to help hearts cope during failure episodes. The cells treated with the former recovered much better than those treated with the latter.
The gene therapy research is still at such an early stage, but anything that can reduce the number of drugs given to heart failure patients and/or heart surgery procedures will be a major advance.
Todd J. Herron et al. Ca2+-independent positive molecular inotropy for failing rabbit and human cardiac muscle by alpha-myosin motor gene transfer. FASEB J. doi:10.1096/fj.09-140566
Thomas Jefferson University