Chronic heart failure — Questions 21–30

21. What is chronic heart failure? 

Answer: A clinical syndrome in which the heart cannot meet the body's demands, causing low cardiac output and/or raised cardiac filling pressures. 

22. List five risk factors or underlying causes of chronic heart failure. 

Answer: Hypertension, coronary artery disease, previous MI, valvular disease and arrhythmias. Advancing age is another risk factor. 

23. What is cardiac output? 

Answer: The volume of blood pumped by the heart per minute. 

24. What are the main signs and symptoms of chronic heart failure? 

Answer: Exertional breathlessness, fatigue, exercise intolerance, orthopnoea, paroxysmal nocturnal dyspnoea and peripheral oedema. 

25. What is orthopnoea? 

Answer: Breathlessness when lying flat, usually relieved by sitting upright. 

26. What is paroxysmal nocturnal dyspnoea? 

Answer: Sudden episodes of breathlessness that wake a person from sleep. 

27. Why can heart failure cause peripheral oedema? 

Answer: Raised venous pressure and fluid retention cause fluid to accumulate in the tissues, particularly the legs and ankles. 

28. Explain how the renin–angiotensin–aldosterone system (RAAS) worsens heart failure. 

Answer: RAAS activation causes vasoconstriction and sodium and water retention, increasing cardiac workload and fluid congestion. 

29. How does fluid retention increase the workload of the heart? 

Answer: Increased circulating volume raises cardiac filling pressures and forces the heart to manage a greater volume of blood. 

30. What is cardiac remodelling? 

Answer: Structural and functional changes in the heart following ongoing stress or injury, which can worsen heart failure.