Sudden Cardiac Death
According to a study published in the April issue of Heart Rhythm, black patients with hypertensionÂ 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 consciousnessÂ that occursÂ one hour after the onset of cardiac signs and symptoms. Sudden cardiac death is natural, netraumatic,Â fast and unexpected.Â The Â underlying heart disease may be or may not be known.Â SuddenÂ cardiac deathÂ may be announced by cardiac symptoms such as chest pain, dyspnea, palpitations, the clinical status change comes next, thenÂ arrhythmia, hypotension andÂ presyncope. Next event is cardiac arrest, with loss of consciousness and peripheral circulation. HoweverÂ theseÂ events precedeÂ 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 haltedÂ in the absence of any interventions. ThisÂ periodÂ may be long if followed by the application of life support measures (8 minutes) or advanced measures (16 minutes), according toÂ resuscitation protocol.
Worldwide, hypertensionÂ affects approximately 1 billion individuals, and its mortality is aboutÂ 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 affectÂ 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 deathÂ is more common in older patients and males. Risk factors for sudden cardiac death includeÂ 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. TheÂ Association betweenÂ sudden cardiacÂ deathÂ and history of coronary heart disease in first degree relatives was demonstrated.
In a study of black and nonblackÂ patients, it was demonstrated that the incidence of sudden cardiac deathÂ is more common among black people. Important to note that patients enrolled in the study had hypertension and left ventricular hypertrophy. The follow-upÂ period was five years, during which patients received treatment with losartanÂ 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 highÂ evenÂ after adjusting sociodemographic and medical variables.