Breathlessness and lying flat
Breathlessness is the feeling of not getting enough air. When the heart is the cause, it usually means the left side of the heart is struggling, so blood backs up into the lungs and the lungs become stiff and wet. The tell-tale clue that this is cardiac rather than from the lungs alone is how it behaves with posture. Lying flat makes more blood return to an already-overloaded heart, so breathlessness on lying down — called orthopnea — is a strong hint of heart failure. Patients describe needing two or three pillows, or sleeping in a chair.
Palpitations and fainting
Palpitations are an awareness of your own heartbeat — a thump, a flutter, a skip, or a racing run. Most are harmless extra beats, but the pattern matters. A single ‘skipped beat’ followed by a stronger thump is usually a normal premature beat. A sudden, fast, regular racing that starts and stops abruptly suggests a rhythm disturbance. An irregularly irregular flutter may be atrial fibrillation. Helpful clues are how it starts and stops, how fast, whether regular, and whether it comes with dizziness or chest pain.
Syncope is a brief, complete loss of consciousness from a sudden drop in blood flow to the brain, followed by full recovery. A near-miss — the grey, sweaty, ‘about to go’ feeling without quite passing out — is presyncope. Most faints are benign (a vasovagal faint when standing in heat, or after standing up too fast), but fainting during exertion, or without any warning at all, can signal a dangerous heart problem and should always be investigated.
Swelling and the right heart
When the right side of the heart cannot keep up, blood backs up into the body’s veins and fluid leaks into the tissues. Gravity pulls it to the lowest point, so it gathers around the ankles and shins as peripheral edema — press a thumb in and a dent stays for a moment (‘pitting’). In someone confined to bed it collects over the lower back instead. Cardiac swelling is usually both legs equally; one swollen leg points elsewhere, such as a clot.