Left vs Right · Systolic vs Diastolic · Cardiovascular Part 2
Heart failure means the heart cannot pump enough blood forward to meet the body's needs. Blood backs up behind the failing side. The left heart backs up into the lungs. The right heart backs up into the body. Pick a pattern below and watch where the congestion goes.
Where does the blood back up?
👆 Click a scenario below (Left / Right / Both · Systolic / Diastolic) and watch blood dam up in the chambers behind the failing pump.
Right heart / deoxygenatedLeft heart / oxygenatedBacked-up / congested
Systolic vs Diastolic: the left ventricle
Same symptoms, opposite mechanics. It comes down to the ejection fraction (EF). That is the share of the filled blood pumped out with each beat (normal ≈ 55–70%).
60%
Normal EF
The ejection fraction is normal. The ventricle fills and empties well.
Normal heartEnough blood moving forward, no congestion
What's happening now
Choose a failing side and a type below to begin.
Controls
Which side is failing?
Type (left ventricle)
Severity50%
Decompensation triggers: push a stable patient into sudden failure.
Hemodynamics
Ejection Fraction
60
%
Cardiac Output
5.2
L/min
Blood Pressure
118
mmHg sys
Pulm. wedge P
8
mmHg
Venous P / JVP
4
mmHg
Heart Rate
74
bpm
Compensation cuts both ways: RAAS and sympathetic drive prop up blood pressure and output in the short run. Over time they hold on to salt & water (more congestion), raise afterload, and thicken the heart muscle (hypertrophy). That speeds up the failure.
Signs & symptoms
Which signs show up depends on which side is congested.
◀ Left-sided (into the lungs)
Dyspnea / SOBfluid in the air sacs (alveoli) blocks gas exchange
Orthopnea / PNDworse lying flat, wakes them breathless
Crackles / ralesheard over congested lung bases
Frothy, blood-tinged sputumflash pulmonary edema
Cool, pale extremitieslittle blood moving forward
Right-sided (into the body) ▶
Peripheral edemaswollen ankles / legs
Jugular venous distentionbacked-up systemic veins
Hepatomegalycongested, enlarged liver
Ascitesfluid in the abdomen
Weight gain / fatiguethe body holds fluid, output is low
Key link: the number one cause of right heart failure is left heart failure. Long-term lung congestion raises the pressure in the lungs until the right ventricle fails too. Turn left-sided severity up and watch the right side start to congest.