Cardiac Arrest
Cardiac arrest refers to the sudden loss of blood flow in the human body caused by the heart’s failure to pump blood. Cardiac arrest usually occurs suddenly, although in some instances, it may be accompanied by other symptoms. If suitable actions are not taken instantly, cardiac arrest can be fatal, resulting in death. Cardiac arrests are classified into two categories, namely shockable and non-shockable. Cardiac arrests that are treatable by the use of defibrillation are shockable, and they include pulseless ventricular tachycardia and ventricular fibrillation. On the other hand, non-shockable cardiac arrests cannot be treated by the use of defibrillation, and they include pulseless electrical activity and asystole. The risk factors in sudden cardiac arrest include family history, cigarette smoking, age, high cholesterol, obesity, high blood pressure, diabetes, drinking, and lack of physical exercise, among other factors (Myerburg & Goldberger, 2017).
In most cases, cardiac arrest results from the malfunction of a diseased electrical system of the heart. The malfunction results in an abnormal heart rhythm, including ventricular fibrillation or ventricular tachycardia. Cardiac arrest also occurs when the heart’s rhythm slows down significantly. Other causes of cardiac arrests include scarring of the heart tissue as a result of a previous heart attack or other causes. Another cause of cardiac arrests is cardiomyopathy, manifested by a thickened heart muscle (Myerburg & Goldberger, 2017). Cardiomyopathy refers to a damaged heart muscle resulting from heart valve disease, high blood pressure, or other causes.
Some heart medications also result in cardiac arrests under certain conditions. This occurs when antiarrhythmic drugs meant to treat arrhythmias produce ventricular arrhythmias resulting into a proarrhythmic effect. Significant changes in magnesium and potassium levels in the blood can also result in cardiac arrest and arrhythmias. Electrical abnormalities can also cause cardiac arrests. Certain electrical abnormalities such as those related to Long QT syndrome as well as Wolff-Parkinson-White syndrome, are known to have caused abrupt cardiac arrest in young people, especially children. Congenital blood vessel abnormalities are also other causes for cardiac arrest, especially when they affect the aorta and coronary arteries. When these abnormalities are present, cardiac arrest occurs when adrenaline is released when a person engages in intense physical activity (Myerburg & Goldberger, 2017). Lastly, non-cardiac causes can also result in sudden cardiac arrest. These include the use of recreational drugs, trauma, pulmonary embolism, drug overdose, drowning, and bleeding such as aortic rupture, gastrointestinal bleeding, or intracranial hemorrhage (Crowe, Bentley & Levine, 2016).
In approximately 50 percent of people, no warning symptoms precede a cardiac arrest. For people who experience symptoms, they are usually non-specific. The most prevalent symptom of sudden cardiac arrest is loss of consciousness due to a lack of blood supply to the brain. While there are no warning signs before a cardiac arrest occurs, often, a person undergoing a cardiac arrest may experience symptoms such as shortness of breath, weakness or fatigue, lightheadedness or fatigue, fainting, chest pains, and vomiting (Crowe, Bentley & Levine, 2016).
Cardiac arrest diagnosis entails electrocardiogram; imaging tests such as nuclear scan, X-ray, and echocardiogram; blood tests to check whether magnesium, potassium, hormones and other chemical levels in the body are appropriate; and other tests such as ejection fraction testing, Coronary catheterization, and electrophysiological testing and mapping. Cardiac arrest treatment entails attempts at resuscitation. Other treatment options for cardiac arrests include defibrillation and long-term treatment of medications, implantation of cardioverter-defibrillator (ICD) and surgery options, such as coronary bypass surgery, coronary angioplasty, corrective heart surgery or radiofrequency catheter ablation (Graham, McCoy & Schultz, 2015).