Absolutely. Sudden or severe symptoms of heart failure can be life-threatening, and the NHS advises calling emergency services (999 in the UK) immediately if you notice any of the following:
Red-Flag Symptoms
Severe shortness of breath, especially at rest
Chest pain or pressure that is intense or persistent
Rapid or irregular heartbeat accompanied by dizziness or fainting
Sudden swelling of the legs, ankles, or abdomen
Extreme fatigue or confusion
