<P> Owing to the inaccuracy in this method of diagnosis, some bodies such as the European Resuscitation Council (ERC) have de-emphasised its importance . The Resuscitation Council (UK), in line with the ERC's recommendations and those of the American Heart Association, have suggested that the technique should be used only by healthcare professionals with specific training and expertise, and even then that it should be viewed in conjunction with other indicators such as agonal respiration . </P> <P> Various other methods for detecting circulation have been proposed . Guidelines following the 2000 International Liaison Committee on Resuscitation (ILCOR) recommendations were for rescuers to look for "signs of circulation", but not specifically the pulse . These signs included coughing, gasping, colour, twitching and movement . However, in face of evidence that these guidelines were ineffective, the current recommendation of ILCOR is that cardiac arrest should be diagnosed in all casualties who are unconscious and not breathing normally . Another method is to use molecular autopsy or postmortem molecular testing which uses a set of molecular techniques to find the ion channels that are cardiac defective . </P> <P> Clinicians classify cardiac arrest into "shockable" versus "non--shockable", as determined by the ECG rhythm . This refers to whether a particular class of cardiac dysrhythmia is treatable using defibrillation . The two "shockable" rhythms are ventricular fibrillation and pulseless ventricular tachycardia while the two "non--shockable" rhythms are asystole and pulseless electrical activity . </P> <P> With positive outcomes following cardiac arrest unlikely, an effort has been spent in finding effective strategies to prevent cardiac arrest . With the prime causes of cardiac arrest being ischemic heart disease, efforts to promote a healthy diet, exercise, and smoking cessation are important . For people at risk of heart disease, measures such as blood pressure control, cholesterol lowering, and other medico - therapeutic interventions are used . A Cochrane review published in 2016 found moderate - quality evidence to show that blood pressure - lowering drugs do not appear to reduce sudden cardiac death . </P>

What are the two shockable rhythms in cardiac arrest