Coronary Artery Disease (CAD) is the leading cause of death worldwide. CAD together with Cerebrovascular Diseases (CVD) accounts for over a quarter of all deaths in the adult population globally.
Treatment modalities of CAD, commonly manifested as heart attack and angina, have undergone revolutionary evolution over the past three decades. Once the only available remedy was medicines and then came the surgery. Today we have three well established modalities for the treatment of CAD, namely the medical, surgical (Coronary Artery Bypass Surgery) and Interventional Percutaneous Transluminal.
Coronary Angioplasty (PTCA) with stenting is now called Percutaneous Coronary Intervention (PCI). The choice of each modality depends upon the patient’s clinical profile (symptoms), severity and suitability of arterial lesions, (anatomy of the lesions) availability of facilities and expertise, and the preference of the patient. All three modalities are complementary to each other and can be used alone or in combination. Pharmacotherapy and lifestyle modification, however, remains the basic ingredients in all.
It is beyond doubt that PCI has over a period of 15 years undergone tremendous advancement. It started with a simple dilation (widening) of the coronary arteries with balloons (balloon angioplasty) by applying controlled pressures through an external device. This procedure did open up the narrowed arteries but carried several complications and risks. A large number of patients after successful initial dilation of their arteries had recurrence of narrowing (restenonsis). Simple balloon angioplasty was therefore a difficult, risky and not a very successful modality.
However, the situation dramatically changed with the advent of metallic stents. Stent implantation has reduced the complications and restenosis rates significantly. This has also made the procedure technically less difficult for the operator. At the same time, it has definitely added to the cost. But looking at the results and low restenosis retes following the stent implantation, the cost can be justified. In a matter of ten years the stent technology has seen extra ordinary improvements. The newer stents are more safe, easy to deploy and have proved to be more durable. But despite all advancements there were chances of restenosis and some of the difficult and long lesion could not be operated. These problems were overcome by the advent of drug eluting stents that are suppose to minimize the chances of restenosis and are suitable for difficult and long lesions.
Drug eluting stents are three times more expensive than standard stents. The additional cost therefore remains a crucial issue limiting their wide spread use.
In addition to the improvements and innovations in balloons, stents, wires and other hardware used in PCI the advent of newer antiplatelet agents has made another remarkable impact on the overall success of interventional procedures by reducing the immediate periprocedure and long term complication.
Patelet adhesions over the angioplastied and stented surface of the artery plays a central role in clot formation and subsequent narrowing after successful dilation and stent implantation. Use of potent and quick acting antiplatelet agents, like clopidogrel and Gp.IIb IIIa inhibitors in addition to time honoured antiplatelet agent aspirin have now made difficult and emergency angioplasties much more safer and successful by inhibiting platelet aggregation and clot formation. Some of these agents are used prior to and during the procedure while aspirin and clopidogrel are used on long term basis afterwards.
With growing expertise in the field of interventional cardiology and with the advent of new stents, antiplatelet and antithrombotic agents PCI is fast becoming the most popular modality in the management of various subsets of ischaemic heart diseases throughout the world and their role is bound to expand in the future.
The immediate cost of PCI remains an important limiting factor in its growth. It is hoped that economical versions of various items in particular stents used in PCI would be introduced by the manufacturers and importers for the benefit of common man. The government can provide significant relief by making the import of these items duty free by removing other obstacles in their availability.
It is gratifying to mention that interventional cardiology has developed with remarkable speed in Pakistan. Today at least 16 centres are performing these procedures regularly all over the country, out which seven are located in Karachi alone.
With the rising incidence of IHD in our community, the interventional cardiology has to play a very important role in the years to come. The professional has to keep up-to-date with new advancements through continued medical education. The professional has a responsibility to make these procedures more safer and cost effective so that the less privileged class of patients can benefit from these very useful procedures.
Missed a beat?
Heart is the most intriguing organ in the human body. Beside having spiritual and love characteristics, it is a master piece of engineering by the Almighty. Technically speaking, it is a pump which ensures appropriate blood supply to all parts of the body (no matter how remote and insignificant) at all times throughout life. The blood supply is based on the principle of physiological demand.
The mechanical action of the heart is described as its contraction. The contraction of the heart is initiated by an electrical stimulus called impulse. The entire heart muscle is connected through electrical wires to a central station called the pacemaker. This acts as a generator which generates electrical stimuli which are then distributed to all parts of the heart through the wires. The heart contracts on receiving the impulse to perform its duty as a pump.
Each contraction is electrically represented by a beat or pulse. This is recorded on a graph in the form of Electrocardiogram (ECG). The heart beats, on an average 72 times a minute. The heart rate varies depending upon the age, physical and emotional state of the individual.
Normal heat rate, therefore varies from person to person and in the same person at different times but on average remains between 60-90 beats per minute. A heart rate of below 60 per minute is slow heart rate and is called as Bradycardia. A heart beat above 100 per minute is fast heart rate and is called Tachycardia. The heart rate may be fast but regular (normal rhythm is maintained) this is called Sinus Tachycardia. However, under pathological conditions the rhythm may be lost. This electrical phenomenon or abnormality is called Arrhythmia or Dysrhythmia. These are usually of serious nature and need to be dealt accordingly.
Slow and fast heart rates are separate subjects on their own. For the moment we will focus on the common complaint, ‘doctor, my heart misses a beat’.
Missed beats are felt and described by different individuals in different ways. The complainants are usually young individuals, mostly females. Missed beats are usually experienced when the person is at rest. Missed beats means that they were having regular beats at a normal rate, when suddenly they feel that one beat is dropped and this is followed by a forceful beat. As a matter of fact these missed beats are extra systolic or ectopic beats that can occur during the course of a regularly beating heart.
This electrical abnormality is mostly a benign phenomenon with no serious consequences. The heart, for no obvious reason produces, an abnormal beat which usually occurs before the next due beat and is followed by a compensatory pause to equal the sum of intervals between two consecutive beats.
Missed beats are seen more often in individuals who smoke, drink a lot of tea or coffee and lead a sedentary life. Emotional stress can also be a precipitating factor. Missed beats, in general, are just a source of nuisance for a strung individual and have no significance. Occasionally, however, they may represent underlying cardiac or extra cardiac diseases, especially in old age. At time they may be the result of some medication. Therefore, individuals with missed beats do need to be evaluated by a cardiologist and a minimum work up should be done to exclude any organic cause.
The advent of 24-hours ambulatory ECG monitor (Holter) has made a major breakthrough in the evaluation of these ectopics and other arrhythmias.
Holter recording entails the application of leads to the chest and connection with a pulse recorder which records 24-hour pulse in a cassette. The cassette is then scanned through the computer. Any abnormalities in the heartbeat are easily identified and documented.
The patient is supplied with a diary and whenever he or she feels a missed beat, or any other abnormality in the pulse, the person pushes a button and that event is recorded. The time of the event is noted by the patient on diary along with symptoms. The recording is done while the patient is ambulant and is performing his routine activities. The cardiologist then correlates the symptoms on diary with the electrical activity on the Holter. Infrequent and uniform extra beats or ectopics are of no significance, unless they are multiform in nature, are repeated in succession and occur frequently.
The other simple test, is to do ultra sound scan of the heart called Echo cardiography which tells us about the structure and function of the heart as a pump. Of course, routine blood test and a Thyroid function is done to exclude a metabolic cause. Another important way to evaluate these ectopics is to subject these patients to exercise. Nearly all benign ectopics will disappear on exercise. This also explains the significance of exercise to keep the heart healthy.
Most people with missed beat do fine with reassurance by the physicians, while some may require drug treatment for symptomatic relief. Exercise regimens are important to keep the heart healthy and in good shape.
Holter monitoring has played an important role in the evaluation of these patients and their subsequent management. Though mostly benign missed beats occasionally represent an underlying heart disease which needs to be fully evaluated appropriately managed.
Unblocking the artiries is now easier and safter
