**2. Determining the cause of the cardiac arrest**

In cases of cardiac arrest, the cause determines further interventions that are required. A thorough history and examination can help identify the underlying causes and subsequent interventions required to avoid an imminent threat to life. While cardiovascular disease is a common cause of cardiac arrest, there is a broad range of differential diagnosis for potential causes (**Table 1**).


#### **Table 1.**

*Common causes of cardiac arrest; H's and T's.*

#### **3. History**

Most patients will not be able to give a history of the events leading up to their cardiac arrest, so it is important to obtain relevant details about the preceding events from any individuals who can give an insight into the patients pre-existing medical condition and the event leading up to the cardiac arrest. These can include family members, friends, witnesses, emergency service personnel, etc. This can help identify the potential cause and help guide management.
