Ischemic heart disease etiology

Tudapaty 1., and Altura, B. M. (1980). Magnesium depletion produces spasms of coronary arteries Relationship to etiology of sudden death ischemic heart disease- Scj ettce 208, 198-200. 

Heart failure affects an estimated 4.9 million Americans, and approximately 400,000 new case are diagnosed each year (see Chap. 14). Cardiac transplant candidates typically are patients with end-stage heart failure who have New York Heart Association (NYHA) class III or IV symptoms despite maximal medical management and have an expected 1 -year mortality risk of 25% or greater without a transplant. Idiopathic cardiomyopathy and ischemic heart disease account for heart failure in almost 90% heart transplant recipients. Other less common etiologies include valvular disease (4%), retransplantation for graft atherosclerosis or dysfunction (2%), and congenital heart disease (1.5%). 

Sudden, unexpected death is usually classified as cardiac in etiology, assumed to be due to ischemic heart disease or an arrhythmia. Death Irom asphyxia caused by acute bronchospasm could be erroneously classified as a cardiac cause of death. In addition, exacerbations of COPD can precipitate cardiac arrhythmias or myocardial infarction in patients with significant underlying heart disease (6,42). Severe COPD is often complicated by cor pulmonale, or chronic failure of the right ventricle caused by pulmonary hypertension and hypoxemia. Deaths caused by cor pulmonale may be misclassified as primary cardiac deaths, although the precipitating event may be a pulmonary insult. 

Heart disease is the leading cause of death in the United States and is responsible for approximately 870,000 deaths per year (1). Sudden cardiac death (SCD) is responsible for almost half of these deaths, claiming 350,000 to 400,000 lives per year (2). SCD is defined by the World Health Organization as death due to any cardiac disease that occurs out of hospital, in an emergency room, or a patient who is dead on arrival to a care facility. Of note, the death must occur within one hour after the onset of symptoms. The majority of SCD is likely arrhythmic in etiology. In women, up to 88% of sudden cardiac arrests may be due to arrhythmic causes (3). Of SCD due to cardiac arrhythmias, greater than 80% of events are due to ventricular tachycardia (VT) and ventricular fibrillation (VF), with the remainder due to bradyarrhythmias and asystole (4). Coronary artery disease (CAD), manifesting acutely as ischemic ventricular arrhythmias or chronically as scar-mediated... 

The first step in the management of chronic heart failure is to determine the etiology (see Table 14—1) and/or any precipitating factors. Treatment of underlying disorders such as anemia or hyperthyroidism may obviate the need for treatment of heart failure. Patients with valvular diseases may derive significant benefit from valve replacement or repair. Revascularization or anti-ischemic therapy in patients with coronary disease may reduce heart failure symptoms. Drugs that aggravate heart failure (see Table 14—3) should be discontinued, if possible. 

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