Heart Failure

Updated August 26, 2020

If the heart is damaged, it loses the ability to pump blood efficiently. This causes the blood to back up into the heart, resulting in dilatation of the chambers and, eventually, congestion of the venous system, a condition called congestive heart failure. This is usually what is meant when someone uses the term “heart failure”, though it is a progressive condition that starts before symptoms appear. Once congestion occurs, medical intervention is required.

Risk Factors

The main risk factor for congestive heart failure is pre-existing heart disease, especially a prior heart attack. Those at most risk for heart disease and ensuing heart failure are older (>65 years of age), African-American (compared to Caucasian), overweight, and male.

Causes

ConditionMechanism
HypertensionCan cause hypertrophy and damage to the heart muscle
DiabetesEffect of metabolic dysfunction on the cardiovascular system
Coronary artery diseaseBlockage damages the heart muscle (heart attack, ischemic heart disease, cardiomyopathy)
CardiomyopathyHeart muscle dysfunction
ArrythmiasHeart beat dysfunction
Heart valve diseaseIneffective pumping by the heart
COPDCan be the origin of congestion and cause right-sided failure

Mechanism of Congestive Heart Failure

Contraction of the heart is necessary for it to fulfill its function of pumping blood through the lungs and then ejecting it from the aorta out to the body. An inability to eject the blood out of the heart is called forward failure, systolic failure, or left-sided heart failure because the left side of the heart fails to contract properly during systole. This initial event results in kidney and liver problems as the circulation is compromised.

The blood remaining in the heart then backs up into the pulmonary vessels (in the lungs), leading to an accumulation of fluid in the lungs (pulmonary edema). As the congestion continues into the right side of the heart, it results in right-sided heart failure, also called backward failure. This is also often diastolic failure because the right-sided failure is caused by the left ventricle not relaxing properly.

Blood flow through the heart. Blue: deoxygenated from body to the lungs. Red: Oxygenated from the lungs to the body. Systole is when the ventricles contract and push blood out, diastole is when they relax and fill. Source

Right-sided Failure vs. Left-sided Failure

Left-sided failure is most often caused by hypertension, ischemic heart disease (often caused by a myocardial infarction), mitral or aortic valve disease, and primary myocardial diseases.

Right-sided failure is most often a result of left-sided heart failure, though it can also occur as a result of cor pulmonale, which is most often caused by chronic obstructive pulmonary disease (COPD).

Symptoms

  • Shortness of breath (called dyspnea)
  • Heart palpitations (rapid, unsteady beat)
  • Swelling in the extremeties (called edema)
  • Persistent coughing or wheezing
  • Tiredness or fatigue
  • Lack of appetite or nausea
  • Confusion or cognitive difficulty

Diagnosis

TestLooking for
Walking testDistance and shortness of breath
Medical examHeart rhythm irregularities, fluid sounds in lungs, edema in the extremities
Blood testMarkers of damage to the organs, diabetes
Blood pressureHypertension
Chest X-rayEnlarged heart, fluid in the lungs
Heart imaging (Doppler ultrasound/echo)Problems with the functioning, movement,or size of the heart muscle
Stress testIssues with heart and/or lungs during exertion
Ejection fraction (electrocardiogram, MUGA, CAT, catheterization, nuclear stress test)How well the heart is pushing blood out
Electrocardiogram (e.g., Holter monitor)Rhythm disturbances

Compensated vs. Decompensated Heart Failure

Chronic heart failure can be compensated or decompensated.

Compensated heart failure occurs when the heart can maintain the needed output despite the dilatation, usually by increasing the number (heart beat) or strength (ventricular contraction) of its beats. This may occur even before symptoms arise.

Eventually the heart can no longer meet the demand, leading to decompensated heart failure ensues and resulting in death.

For an animation of heart failure, visit the American Heart Association.

Complications

Once heart failure develops, the condition remains, referred to as chronic heart failure. The continued strain on the heart as it moves from forward (left-sided) into backward (right-sided) failure can result in complications in other parts of the body.

ComplicationTreatment
Kidney diseaseDialysis
Liver fibrosisAntifibrotics
Heart rhythm disturbancesDepends on the disturbance and symptoms
Heart valve dysfunctionDepends on which valve and symptoms, surgery

Treatment

The damage done to the heart cannot be reversed. However, there are medications available to treat congestive heart failure and maintain the cardiac output. These drugs remove excess water and salt to limit the pressure in the compromised vascular system, strengthen the heart muscle, or affect the renin-angiotensin system.

  • Beta-blockers
  • Diuretics
  • ACE inhibitors
  • Digoxin/digitalis
  • Valsartan and similar drugs

Other treatments involve dietary and lifestyle changes, such as exercise, low sodium diet (DASH diet), losing weight, stopping smoking, avoiding excessive alcohol intake, managing stress, and keeping other conditions (e.g., hypertension and diabetes) under control.

Prevention

Manage your heart disease by seeing your doctor regularly and following your treatment plan
Eat healthy (e.g., low sodium, low cholesterol)
Exercise (daily activity)
Maintain a healthy weight
Avoid smoking and excessive alcohol consumption
Manage stress

Disclaimer: This page is for informational and learning purposes only. It is not meant to diagnose or treat any medical condition and should not be used in place of speaking with a medical doctor or seeking treatment.

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