12 Mar Chronic Refractory Cardiac Pain Syndrome
Chest pain is usually a concerning event warranting immediate attention. This is because it can be the key symptom of a serious cardiopulmonary event. Even when the source of pain is cardiac, not all patients are suitable for coronary revascularization (coronary artery bypass grafting or percutaneous coronary intervention). Angina pain is defined as chronic refractory if (a) it is not acute or require emergent revascularization, (b) is not controlled by optimal medical therapy, and (3) lasts for more than 3 months.
These patients with chronic refractory angina often have a history of severe angina to begin with. And the most suitable medical therapy comprises include anti-anginal medication as well as medication for secondary prevention of atherosclerosis. In addition to that, there needs to be adequate pain relief. Interventions such as spinal cord stimulation, enhanced external counterpulsation and stellate ganglion blocks have been successful in many patients in that regard.
Chronic, refractory cardiac pain is actually quite common. Complaints of this type of chest discomfort and pain a very common cause of patients seeking help in primary care.
The underlying cause of chronic refractory angina is believed to be reversible myocardial ischemia. In addition, these patients often have impaired left ventricular function, renal impairment, and diabetes.
The diagnosis of chronic chest pain starts with the history that focuses on evaluating if the the chest pain originates from CAD, risk factors for which include such as diabetes, smoking, and hyperlipidemia. A thorough physical examination will give more clues – hypertension, murmurs, and peripheral vascular disease. Additional work-up includes getting an ECG, chest radiograph as well to try and exclude more acute causes of the pain. Of course, a comprehensive cardiology work-up is done to eliminate all possibilities of it being a condition that requires coronary revascularization. Despite that, these patients need to be on anti-anginal medication (including aspirin, beta blockers, calcium channel blockers) and lipid lowering statins.
In addition to the above, these patients need adequate pain control as well. Some patients may benefit from neuromodulation by the insertion of a spinal cord stimulator (SCS). In this therapy, a small handset stimulating an electrode placed in the epidural space close to the spinal cord. A connecting lead from the electrode is subsequently passed to a pulse generator placed under the skin. This allows the patient to remotely control amplitude, frequency, pulse width, and duration of the electrical impulse to cover the area most affected by pain. This method has been shown to be effective in as many as 80% of the patients in select patient groups. It has been recommended that the suitable and motivated patients receive a temporary stimulator and if they do benefit from it then a permanent pulse generator may be implanted. While SCS therapy and other types of neuromodulation are more frequently indicated for noncardiac pain syndromes, such as low back pain, it can be very effective for the right patient with chronic cardiac pain syndrome.