This decreases the ability of hemoglobin to carry oxygen to myocardial tissue.Atherosclerosis is the most common cause of stenosis (narrowing of the blood vessels) of the hearts arteries and, hence, angina pectoris. Some people with chest pain have normal or minimal narrowing of heart arteries; in these patients, vasospasm is a more likely cause for the pain, sometimes in the context of Prinzmetals angina and syndrome X.
Myocardial ischemia also can be the result of factors affecting blood composition, such as the reduced oxygen-carrying capacity of blood, as seen with severe anemia (low number of red blood cells), or long-term smoking. Pathophysiology
Angina results when there is an imbalance between the hearts oxygen demand and supply. This imbalance can result from an increase in demand (e.g., during exercise) without a proportional increase in supply (e.g., due to obstruction or atherosclerosis of the coronary arteries). However, the pathophysiology of angina in females varies significantly as compared to males. Non-obstructive coronary disease is more common in females. Diagnosis
Angina should be suspected in people presenting tight, dull, or heavy chest discomfort that is:
Retrosternal or left-sided, radiating to the left arm, neck, jaw, or back. Associated with exertion or emotional stress and relieved within several minutes by rest. Precipitated by cold weather or a meal.Some people present with atypical symptoms, including breathlessness, nausea, or epigastric discomfort, or burning. These atypical symptoms are particularly likely in older people, women, and those with diabetes.Anginal pain is not usually sharp or stabbing or influenced by respiration.
Studies, including the Womens Ischemia Syndrome Evaluation (WISE), suggest that microvascular angina is part of the pathophysiology of ischemic heart disease, perhaps explaining the higher rates of angina in women than in men, as well as their predilection towards ischemia and acute coronary syndromes in the absence of obstructive coronary artery disease. Signs and symptoms
Angina pectoris can be quite painful, but many patients with angina complain of chest discomfort rather than actual pain: the discomfort is usually described as a pressure, heaviness, tightness, squeezing, burning, or choking sensation. Apart from chest discomfort, anginal pains may also be experienced in the epigastrium (upper central abdomen), back, neck area, jaw, or shoulders. This is explained by the concept of referred pain and is because the spinal level that receives visceral sensation from the heart simultaneously receives cutaneous sensation from parts of the skin specified by that spinal nerves dermatome, without an ability to discriminate the two. Typical locations for referred pain are arms (often inner left arm), shoulders, and neck into the jaw. Angina is typically precipitated by exertion or emotional stress. It is exacerbated by having a full stomach and by cold temperatures. Pain may be accompanied by breathlessness, sweating, and nausea in some cases. In this case, the pulse rate and the blood pressure increases. Chest pain lasting only a few seconds is normally not angina (such as precordial catch syndrome).