Common signs of cardiac failure in a patient assessed for oral surgery include which of the following?

In the context of assessing a patient for oral surgery, the common signs of cardiac failure include ankle oedema and dyspnoea. Ankle oedema occurs due to fluid retention associated with heart failure, where the heart's ability to pump efficiently is compromised, leading to fluid buildup in the lower extremities. Dyspnoea, or shortness of breath, is also a hallmark symptom as the heart struggles to effectively circulate blood, which can cause fluid to accumulate in the lungs, making it difficult for the patient to breathe comfortably.

Other options present symptoms that may occur in various medical conditions, but they are not as specific or commonly associated with cardiac failure. Elevated temperature and nausea might indicate an infectious process or other systemic conditions, while palpitations and malaise can be related to various issues, including anxiety or non-cardiac-related problems. Pallor and tremor could suggest other neurological or metabolic conditions but are not classic signs of cardiac failure. Thus, the symptoms of ankle oedema and dyspnoea are more directly indicative of heart problems, making them the correct answer in this context.