Sudden Cardiac Death
According to a study published in the April issue of Heart Rhythm, black patients with hypertension are at higher risk of sudden cardiac death than nonblack counterparts.
Sudden cardiac death is natural death due to heart failure, characterized by sudden loss of consciousness that occurs one hour after the onset of cardiac signs and symptoms. Sudden cardiac death is natural, netraumatic, fast and unexpected. The underlying heart disease may be or may not be known. Sudden cardiac death may be announced by cardiac symptoms such as chest pain, dyspnea, palpitations, the clinical status change comes next, then arrhythmia, hypotension and presyncope. Next event is cardiac arrest, with loss of consciousness and peripheral circulation. However these events precede biological death, characterized by the absence of mechanical and electrical activity of the heart and nervous system. Irreversible brain damage occurring after an interval of 4-6 minutes after the blood circulation is halted in the absence of any interventions. This period may be long if followed by the application of life support measures (8 minutes) or advanced measures (16 minutes), according to resuscitation protocol.
Worldwide, hypertension affects approximately 1 billion individuals, and its mortality is about 7 million deaths per year. According to WHO, through its consequences hypertension is the leading cause of mortality worldwide. High blood pressure does not only affect blood vessels (vascular remodeling, increased vascular stiffness, accelerated atherosclerosis), but also the organs. At heart, hypertension cause left ventricular hypertrophy, heart failure, heart disease and arrhythmias. In the brain can occur cerebral infarction, cerebral hemorrhage and cognitive decline.
Nearly 50% of all cardiac deaths are sudden. Some studies show that sudden cardiac death is more common in older patients and males. Risk factors for sudden cardiac death include coronary atherosclerosis, severe ventricular systolic dysfunction, diabetes mellitus. In addition to these, there are a number of factors such as low socioeconomic status, genetic factors. The Association between sudden cardiac death and history of coronary heart disease in first degree relatives was demonstrated.
In a study of black and nonblack patients, it was demonstrated that the incidence of sudden cardiac death is more common among black people. Important to note that patients enrolled in the study had hypertension and left ventricular hypertrophy. The follow-up period was five years, during which patients received treatment with losartan and atenolol. The researchers found that almost 2% of patients had CSD and the incidence was higher in black patients (3.9 vs. 1.9) Peter M. Okin, MD, from Cornell University in New York City, said that the incidence has remained high even after adjusting sociodemographic and medical variables.