Angina pectoris is a result of an imbalance between the oxygen supply to the heart and the demand. When the oxygen demand is greater than the supply, chest pain occurs. The pain is caused by an insufficient blood supply to the heart, causing a myocardium's temporary ischemia (inadequate oxygen for the myocardium to meet its metabolic needs). The coronary arteries are unable to provide enough oxygen-carrying blood to meet the heart muscle's oxygen requirements.
Dramatic lifestyle changes often accompany the onset of angina in a person's life. Treatment options for angina, particularly angina that is cardiac ischemic in origin, play an essential role in the dialog between clients and health professionals. We will discuss five methods for increasing the supply of needed oxygen to the heart's muscle itself.
The first, increasing the concentrations of oxygen present in the carrying medium, is mostly of aid on an acute basis. A small number of angina sufferers use oxygen routinely as part of their treatment regimen. Oxygen administration is undoubtedly a valid complementary treatment for the most challenging angina cases associated with ischemia, whether it is the cardiac or noncardiac origin.
The second method of increasing oxygen flow to the heart muscle is using medications to increase flow availability by the carrying medium. One way of speaking, the goal of pharmacologic intervention here is to convert unstable angina into stable, predictable angina. The following are medications commonly used in the treatment of angina.
Medications Used in Treatment of Angina Pectoris
|Anti-anginal and Anti-ischemic drugs |
- Aspirin - Aspirin inhibits blood clotting, helping to maintain blood flow through narrowed heart arteries. Frequently given when presenting with angina, especially during a suspected heart attack, aspirin can decrease death rates by 25 percent, and its antiplatelet effect can last as long as seven days. Chewing the aspirin hastens its absorption.
- Clopidogrel (Plavix®) - Selectively inhibits ADP binding to platelet receptor, thereby inhibiting platelet aggregation. Consider use in patients with contraindication to aspirin.
- Nitroglycerine - This medication for treating angina temporarily opens narrowed blood vessels, improving blood flow to and from your heart. It comes in a small sublingual pill or sublingual spray form and a long-acting form (Isosorbide).
- Beta-adrenergic blockers - Slow the heart rate and decrease overall oxygen demands.
- Angiotensin-converting enzyme (ACE) inhibitors - These drugs allow blood to flow from the heart more easily. For instance, a doctor may prescribe ACE inhibitors if a person has had a moderate to severe heart attack, reducing the heart's overall pumping capacity.
- Calcium channel blockers - When treating coronary artery spasms, heart medications such as calcium channel blockers work to relax the coronary arteries and prevent the spasms. They can also aid in Prinzmetal angina (vasospastic angina).
- Ranolazine (Ranexa®) - Cardio selective anti-ischemic agent (piperazine derivative) partially inhibits fatty acid oxidation. They are indicated for chronic angina unresponsive to other antianginal treatments. Unlike beta-blockers, calcium channel blockers, and nitrates, ranolazine does not reduce blood pressure or heart rate.
The third choice for promoting increased oxygen flow to the heart tissue is that of revascularization procedures. These invasive procedures have the goal of opening partially occluded blood vessels or replacing completely blocked vessels. Coronary Artery Bypass Graft surgery (CABG) is a surgical procedure that involves the removal of a portion of a healthy blood vessel, such as a vein from the leg or the internal mammary artery (located in the chest), and using it to bypass the blockage(s) that are present in the coronary arteries.
Another revascularization procedure is Directional Coronary Atherectomy (DCA). This is the insertion of a specialized catheter into a compromised coronary artery, similar to an angioplasty, except that plaque is mechanically removed to decrease vessel blockage.
Another revascularization procedure is balloon angioplasty with or without stents placement to hold open a diseased cardiac artery.
An angioplasty is a procedure performed on patients with blocked or clogged coronary arteries. The technique is similar to a cardiac catheterization. A special catheter with a small balloon is inserted into the blockage and inflated to compress the plaque and open the artery. The uninflated balloon catheter is advanced to the area of blockage. The balloon is inflated and deflated several times until the blockage is compressed and the artery is widened. When using a stent, a fine wire mesh designed to expand and hold open the lumen of an artery is placed using a special catheter. These stents are springy, durable bundles that help provide renewed blood flow to ischemic tissue. Often angioplasty and stent placement occur during the same procedure, though either can certainly be done independently. These procedures have proven effective in the revascularization of ischemic cardiac tissues.
A fourth option is that of TMR. Transmyocardial laser revascularization is available for clients with persistent angina, considered inoperable or poor risks for the more traditional revascularization procedures. In this procedure, a surgeon exposes the heart's muscles. Using a special high-energy computerized CO2 laser creates between twenty and forty, one-millimeter wide channels (think of the width of a pinhead) in the muscle of the left heart ventricle. Body responses to these perforations close the outside of the channels. Yet, the cardiac muscle's unique characteristics allow the channels inside to remain open, providing new blood flow to ischemic tissue (Alaeddini, 2018).
The mechanism by which this works is not entirely understood even by those specialists who perform TMR. Evidence that has been gathered suggests that coronary blood flow is improved, however, and it may be that the procedure promotes angiogenesis, the growth of new, very small blood vessels that contribute to improved oxygenation of the heart.
A fifth and somewhat exciting option increasingly available for achieving improved oxygenation to the myocardium in cardiac ischemic angina sufferers is enhanced External Counter Pulsation (EECP). EECP is a noninvasive treatment using carefully timed, sequential inflations of pressure cuffs placed onto the client's calves, thighs, and buttocks. Inflation and deflation of these cuffs are timed to the patient's ECG, and the effectiveness is observed by noninvasive arterial pressure waveform monitoring.
The overall hemodynamic effect of EECP compressions is to:
- Provide diastolic augmentation and thus increase coronary perfusion pressure
- Unload systolic cardiac workload volumes and therefore decrease myocardial oxygen demand
- Increase venous return and, subsequently, cardiac output.
This pressure shift sequence works to displace the pressure of flowing blood backward into the coronary arteries during heart diastole when the cardiac tissue is in a state of relaxation. Resistance to backpressure in the coronary arteries is at its lowest point.
Remarkably, coronary collateral vessel development appears to be stimulated by this noninvasive increase in artery perfusion pressures. With time, a noticeable increase in perfusion capacities can be seen in both the new and pre-existing coronary arteries. Currently, this therapy is gaining favor as an exciting adjunct to the traditional treatment of cardiac ischemic-related angina. The investigation is being done concerning EECP's strong potential for treating other severe cardiac pathologies (Caceres, 2021).
|The FDA approved EECP to treat angina in 1995 and later to treat congestive heart failure in 2002. Current treatment regimens vary, however for many clients who suffer from angina resistance to conventional approaches, a series of around 35 daily one-hour sessions of EECP appears to promote growth in the collateral coronary artery circulation with reduction of ischemic angina symptoms.|