It achieves this by generating mechanical power in its heart cells (cardiomyocytes) by converting chemical energy into mechanical energy. The unidirectional flow of blood from the left side of the heart to the body and its return to the right side of the heart, its subsequent journey through the lungs to exchange oxygen and expel carbon dioxide is made possible by the work of four valves – two on the right and two on the left side of the heart. The heart itself is powered by blood that flows through arteries called the coronary arteries.
If our heart stops working and no treatment is available we would die in a matter of minutes.
Our heart could, for a variety of reasons, stop suddenly (the commonest reason is a massive heart attack). This is called acute heart failure. More commonly, it loses its function slowly over a period of time. This can happen as a result of a single heart attack, or repeated mild heart attacks, valves not working well and leaking blood back into the wrong chamber (regurgitation) or becoming tight (stenosis) and not allowing blood to enter a chamber or a combination of both (mixed valve disease), an inability of the heart cell to generate enough power (cardiomyopathy). The latter condition can be the result of infections (especially viral), genetic or medicines (e.g. some cancer drugs).
When the heart starts to lose its power, the circulation slows down. the result is that fluid backs up in the tissues. When there is a build up of fluid in the lungs it can lead to breathlessness. The fluid can also build up in the abdomen and around the ankles – these are signs of heart failure. The rising incidence of coronary artery disease in young patients will reflect in time as an increase in the number of patients with ischemic cardiomyopathy.
Difference between heart attack and heart failure
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Dr Paul Ramesh Thangaraj
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The reduction of blood flow in the blood vessels of the heart (coronary artery) can deprive the heart cells of oxygen (ischemia) and cause damage to the heart muscle – this is termed as a heart attack. The damage can announce itself as chest pain (angina) or may be silent.
The damage can sometimes (not always) result in death to part of the heart muscle (myocardial infarction). When a lot of muscle is damaged the pump function of the heart suffers – this is heart failure.
Heart failure is the inability of the heart to maintain the circulation of the blood in step with the needs of the body.
Initially, its symptoms may be present only during strenuous work or exercise, later even during rest. Our body has a huge reserve and the ability to adapt and compensate for loss of heart function. This implies that when symptoms appear these reserves are overcome. When symptoms appear at rest it indicates advanced heart failure.
Heart failure can be treated initially with medicines, sometimes with conventional management techniques like valve and coronary bypass surgery or stents. If the heart failure is being worsened by a rhythm problem, specialised pacemakers can help. However, when these options are exhausted then heart transplant remains the best option.
Heart transplants are the gold standard for the treatment of end stage heart failure. It has come a long way since its introduction in December 1967 and is currently associated with excellent results.
The advances made in the field of transplantation in general and heart transplant in specific have been due to better management of donors, surveillance, prevention and early management of both rejection and infection.
One of the most important principles that underpin any transplant programme is ensuring that the right person gets the organ at the right time.
In the course of their disease, patients transit from a point where their own organ although damaged, can support them (too well to transplant) to a point where the disease has rendered other organ systems dysfunctional and has resulted in the patient becoming exceptionally high risk for a transplant (too sick to transplant). The time interval between these two points is sometimes referred to as the ‘transplant window.’
Unfortunately, heart and lung failure patients in India are referred very late for consideration of transplants.
The potential recipient undergoes a variety of tests to determine their suitability for transplant.
The data are summarised in risk scores (eg. Seattle Heart Failure Score) and objective assessment rather than a guess at whether the patient has a better chance with a transplant or not.
These scores can be validated in Indian populations only if an effort is made to streamline patients with heart failure into dedicated heart failure clinics with an interdisciplinary mindset. They should consist of general physician, cardiologist and cardiac surgeons with nurses and rehabilitation personnel to assess, and quantify quality of life issues at all stages of heart failure. Few hospitals in India have such dedicated teams.
Heart transplant is associated with excellent outcomes. Our programme has a one year survival of 86 per cent. In terms of quality of life, I can illustrate it with examples of two of my own patients.
One of them was 65 years old, breathless on mild exertion, previous coronary bypass, stents placed in the coronary arteries and with cardiac resynchronisation therapy done. None of the above had helped and he had progressive heart failure. He is now four years post transplant and lives life to the fullest, working at his business and runs 10-15 km a day.
The second is a young boy, 19 years of age, with restrictive cardiomyopathy. He was bed bound with breathlessness and advanced heart failure. Today, three years post transplant, he has passed his CA exams and leads a normal life.
| Difference between heart attack and heart failure |
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When a lot of muscle is damaged, pump function of the heart suffers – this is heart failure. It is the inability of the heart to maintain the circulation of the blood in step with the needs of the body |
Heart transplant in India
Prof PK Sen is said to have done a heart transplant in India in 1968, soon after Christian Barnard’s maiden attempt in December 1967. The first recorded heart transplant was done in AIIMS in August 1994 soon after the Organ Transplant Act was passed in the parliament. After an initial flurry of activity, enthusiasm waned. A second wave in mid-2000s, especially in Tamil Nadu, led to a resurgence of activity. Tamil Nadu in particular has had empathic state support in the form of Tamil Nadu Organ Sharing (TNOS), an initiative by the state government to streamline organ sharing in the entire state.
Although in Tamil Nadu the government sector has recorded heart transplants, the majority of heart transplants are still performed in the private sector.
No specific registry exists to collate information. A combination of published material, media reports and web-based data indicate that less than 150 heart transplants have been done to date. AIIMS has done 33, TNOS data shows that 88 heart transplants have been performed in Tamil Nadu. Occasional cases have been reported mainly in the media from Kerala, Andhra Pradesh and Chandigarh as well.
The reluctance to refer early (in the transplant window), hesitation on the part of patients to see it as valid therapy, cost and logistics have all been factors that have hindered widespread application of heart transplant in the management of heart failure in India.
Early referral does not mean early transplant, it will ensure that the patient is optimised and the transplant window is ascertained. It also means that the transplant is not done as an emergency or salvage procedure which in turn limits outcomes.
Future of heart transplant
Current medical management, advanced pacemaker options and mechanical hearts have all helped to palliate this difficult clinical problem. Their overall impact has however been variable. Left ventricular assists devices are useful as bridge to transplants and also as an alternative in patients who are not eligible for transplants. When both ventricles are supported it is termed a ‘Total Artificial Heart’. The problems are development of thrombus, strokes, infection and the high costs involved.
Increasing miniaturisation of mechanical devices and stem cell therapy are potential therapies that hold promise for the future. They will have to show an equivalence in achieving similar outcomes to heart transplant. Until that happens heart transplantation will remain an important mode of treatment for patients with end stage heart failure.