External Counterpulsation (ECP) is a procedure designed to alleviate the chest pain associated with angina pectoris. Originating from studies done in the 1960s, the ECP technique utilizes a series of pressure cuffs to force oxygen-rich blood back to the heart and in doing so, decreases the heart’s workload. Although only select patients are eligible for this procedure, it has yielded promising results in many trials to date.
Detailed Description
During ECP, oxygen-rich blood is forced back into the coronary arteries during diastole (or resting) period of the heartbeat. This process is accomplished using a series of three inflatable cuffs, much like those used to measure blood pressure, which are placed at the calves, lower thighs, and upper thighs. The cuffs are inflated sequentially during diastole starting at the calves, and then deflate during systole (the active phase). The timing of these inflations and deflations is carefully aligned with the heart’s regular activities via an electrocardiogram (ECG) monitor. The inflations and deflations occur fairly rapidly, and are usually administered for one or two hours. Cuff pressure is also gradually increased throughout this period. The current standard for ECP is a series of such treatments totaling approximately thirty-five hours.
The benefits of ECP therapy are thought to be derived from the process of forcing oxygen-rich blood back towards the heart. This influx of blood increases central aortic pressure, increasing blood pressure in the coronary arteries. Since coronary vascular resistance is minimized during diastole, the increased influx of blood to the heart effectively forces blood into areas that may have been depleted of oxygen. By the same principle, blood flow to vital organs is also increased. The benefits of ECP treatment in reducing the pain associated with angina pectoris have been shown to last up to three years. Several studies have suggested that this long term improvement may be induced by the opening of collateral channels in the coronary vascular system, effectively bypassing blocked or malfunctioning vessels.
The benefits of ECP therapy in patients suffering from angina pectoris have been well documented in several clinical trials. Generally, treatment decreased the need for anti-angina medications, reduced the occurrence and degree of chest pain, allowed an increased physical activity level, and yielded a substantial improvement in blood flow to areas of the heart receiving substandard amounts of oxygen. ECP is most effective in treating patients with one or two malfunctioning vessels, rather than three. Additionally, ECP should not be administered to individuals with uncontrolled congestive heart failure, hemorrhage, coagulopathy, thrombophlebitis, severe aortic valvular disease, uncontrolled high blood pressure, severe artery or vein disease in the legs, tendency to bleed excessively, or those who are pregnant.
Last updated: 11-Aug-03
