A heart attack, or acute myocardial infarction, can be a frequent occurrence when there is an inadequate flow of nutrient-enriched blood and oxygenated blood; this can result in the death of a portion of the heart muscle which can lead to death of the individual. Having a heart attack is a leading killer of women and men in developed countries; estimated worldwide deaths due to coronary heart disease are 7.1 million/ year. Each year in the USA approximately 365,000 women and 555,000 men are diagnosed as having had heart attacks, according to the American Heart Association. In part because women have heart attacks at older ages than men do, women are more likely to die from an attack within a few weeks. Thus~800,000 Americans experience a heart attack every year. In 2006, 631,636 men and women died of heart disease. The cost for comprehensive diagnosis and treatment of coronary heart disease in the U.S. exceeded $156 billion in 2008 (estimated by Genetech, Inc). Also of relevance is that individuals who survive their acute heart attack have a chance of forthcoming illness and death that is 1.5 to 15 times greater than that of the general population, depending on their sex and clinical outcomes.
Another contributor to a heart attack is hypertension. It is a disorder that may occur throughout life. Hypertension is currently defined as physician office systolic blood pressure ≥140 mm Hg and diastolic pressure of ≥ 90 mm Hg; see the categories in Table 1. Hypertension has a worldwide incidence of 9–18% in the adult population. As many as 50 million Americans have elevated blood pressure. In the presence of continuing uncontrolled hypertension, there is frequently a high incidence of heart disorders. These include congestive failure, coronary heart disease, stroke, kidney disease, and/or aneurysms of the aorta.
Table1. Classification of Blood Pressure Levels
An important component of the diagnosis of the etiology of hypertension is a determination of the level of Na + excretion in relation to the plasma levels of renin and also the daily amount of aldosterone excreted in the urine. Such an analysis may provide the formulation of a rational basis of treatment, which can include the use of inhibitors of the renin–angiotensin system such as the antagonist saralasin, use of β-blocking drugs such as propanolol, or dietary restriction of salt intake. It is beyond the scope of this presentation to consider this topic in detail.
