Medical Treatment Of Coronary Artery Disease and Thrombolysis

Treatment of angina

A major medication used for angina is nitroglycerine. It dilates small coronary blood vessels, allowing more blood to get through. Nitroglycerine pellets are not swallowed but are placed under the tongue, where they are quickly absorbed by blood vessels there and sped to the heart; discomfort passes in minutes. Nitroglycerin is also available in a sprayable form. Often anginal attacks can be headed off by taking the tablets or spray before activities likely to bring on an attack. Some people experience temporary, mild headaches as a side effect of taking nitroglycerin.

Still other drugs have been found to relieve angina pains. One group, called the beta-blockers, slows down the heart’s action and thus its need for oxygen. Widely used to treat high blood pressure as well as heart disease, the beta-blockers may cause shortness of breath. For that reason, physicians usually prescribe other medications for persons with asthma.

The first of the beta-blockers to come into use was propranolol. But at least five chemically related drugs may be prescribed: atenolol, timolol, metoprolol, nadolol, and pindalol. Physicians generally try to fit one of these drugs to the problems of the individual patient. There is some evidence that propranolol and nitroglycerine taken together may increase the effectiveness of therapy.

A second group of drugs for angina is known as the calcium channel blockers. These drugs prevent coronary spasms, one cause of angina chest pains, by blocking the flow of calcium ions to the heart and thus dilating the arteries and increasing blood flow to the heart. The heart demand for oxygen is lessened, and blood pressure is lowered. Three chemically different calcium channel blockers in use are verapamil, nifedipine, and diltiazem.

Angina does not mean a heart attack is inevitable. Many angina patients never have one, whether the result of collateral circulation, treatment with medication, or lifestyle changes. Should attacks of angina begin to worsen in spite of these, however, angioplasty or coronary bypass surgery may be necessary.

Treatment of heart attack

Knowing the warning signals and taking proper steps may make the difference between life and death. Call a physician or get to a hospital as soon as possible. Time is crucial. Most deaths occur in the initial hours after attack. About 40 percent, for example, die within one hour after onset of a major heart attack. Often, death is not due to any wide spread damage to the heart muscle but rather to a disruption in the electric spark initiating heart muscle contraction, the same spark measured by the electrocardiogram. These killer rhythms, including complete heart stoppage or cardiac arrest, are often reversible with prompt treatment.

For patients whose heart attack is the result of a blood clot (thrombus) the administration of thrombolytic drugs, which dissolve the clot and thus limit the extent of damage to the heart, increase the survival rate by 50 percent. The most common clot-dissolving drug is tPA (tissue plasminogen activator). During the first ninety minutes, this drug will dissolve the clot that is blocking the coronary in about 75 percent of patients, restoring blood flow to the heart and limiting the amount of heart damage. Because this is a very potent drug that dissolves clots anywhere in the body, bleeding is one possible side effect of tPA. Therefore, patients must be carefully selected to have minimal risk for bleeding. It cannot be used in patients who have had a recent stroke, in patients with severe high blood pressure, or in patients with bleeding stomach ulcers. However, when it is given to carefully selected patients in the first six to twelve hours after the onset of a heart attack, it can definitely improve their outcome.

Other drugs used to treat the heart include antiarrhythmics which restore a regular beat to an irregularly beating heart, and vasopressors or inotropic agents that stimulate the heart and enhance heart function.

Among the many cardiostimulants, or inotropic drugs, is a large group called partial beta 1 agonists that accelerate the rehabilitation process and increase exercise tolerance.

Of two other classes of therapeutic drugs, calcium and beta channel blockers are used to slow the heart rate, while angiotensin converting enzyme (ACE) inhibitors increase blood flow to the kidneys. The ACE inhibitors also block an enzyme that raises blood pressure.

Among the diuretics is furosemide, marketed as Lasix. Both help to prevent fluid accumulation in the lrmgs.

Because most heart attacks are the result of reduced blood flow due to clots or buildup of deposits on arterial walls, following a heart attack the problem arteries must be identified

This is done in a procedure called coronary angiography (cardiac catheterization), where blocked arteries are identified by X-ray "movies" taken of an injected opaque dye. Another technique, nuclear magnetic resonance, uses magnetic forces to scan the heart and identify specific problems in specific areas of the heart and its arteries.

Once clogged arteries are identitied, they must be cleared. This is most commonly done by percutaneous translurninal coronary angioplasty  (PTCA). In balloon angioplasty, a catheter is pushed through an artery in the leg or shoulder and maneuvered into a coronary artery that has been narrowed by the build up of cholesterol, minerals, cell debris, and other material (plaque), which cuts off the flow of blood. A balloon attached to the catheter is then inflated, forcing open the affected artery by cracking and crushing the plaque against the arterial walls, compressing it but not removing it. The catheter and balloon are then removed. One problem with angioplasty is restenosis which occurs within six months in 30 percent of coronary arteries.

In cases where the blocked section of the artery is too long, difficult to reach, or located at a tortuous area or branch point of the artery, coronary artery bypass surgery  must be performed.

Coronary Care Units

Special hospital centers called coronary care units (CCUs) have been created to provide care for heart attack victims. Headed by a cardiologist and staffed by highly trained nurses, the CCU provides around-the-clock electronic devices that keep watch over each patient’s vital functions, particularly the heart’s electrical activity.

The critical period is the first 72 hours, when up to 90 percent of heart attack patients experience some type of electrical disturbance or arrhythmia

Patient rooms in the CCU are designed to ensure privacy and a tranquil, cheerful environment. Rooms may be separated from one another by curtains or partial or full walls. Beds usually stand in a space adequate for movement of heavy equipment such as the portable X-ray apparatus.

Each patient is connected via electrodes attached to the skin to a heart monitor, winch records the rhythm and rate of the heartbeat and the blood pressure, enabling nurses to check on a patient’s condition without leaving the nurse’s station. An alarm system on the monitor notifies the nurse when a major change is taking place in the patient’s condition.

Other CCU equipment includes defibrillators for treatment of the condition called ventricular fibrillation, intravenous pacemakers, and a crash cart stocked with such items as the drugs needed for emergency cardiac care and endotracheal tubes.