Loading…
skip to main content
Logo

Left-Sided Heart Failure

ID: ANM10003
MEDICAL ANIMATION TRANSCRIPT: In left-sided heart failure, the left ventricle cannot pump an adequate amount of blood, a volume known as preload, out of the heart. This condition causes pulmonary congestion, a buildup of blood in the pulmonary vessels causes fluid in lung tissues that impedes normal respiration. Systolic left-sided heart failure describes the left ventricle's inability to contract with enough force to drive blood out of the heart against resistance called afterload to the rest of the body. After a left ventricular contraction, the blood left behind in the chamber causes blood to back up into the left atrium and pulmonary circulation, leading to pulmonary congestion. Diastolic left-sided heart failure describes the inability of the left ventricle to expand sufficiently to accommodate oxygenated blood entering from the left atrium. In this condition, the left ventricle contracts with normal force, but the blood volume that is pumped out is insufficient to meet the body's needs. Long-standing diseases, such as coronary artery disease, hypertension, and diabetes, can thicken and stiffen the ventricular muscle, making it a non-compliant, inefficient pump. As a result of reduced myocardial contractility, the unexpelled blood pools inside the left ventricle, and the chamber expands to hypertrophic size. This hypertrophy of the heart muscle results in the insufficient delivery of nutrients and oxygen to tissues. In both systolic and diastolic left-sided heart failure, the buildup of unexpelled blood increases pressure in the pulmonary circulation, causing serosanguineous fluid to seep into the alveoli and interstitium. This fluid buildup is heard as crackles and rhonchi when the lungs are auscultated. As the lungs saturate with fluid, patients may develop difficulty breathing, called dyspnea, trouble breathing while lying flat, called orthopnea, or rapid breathing, called tachypnea. The heart rate increases to compensate for the left ventricle's weakened state, which in time leads to thickening the myocardium as it labors to push blood out of the heart against the increasing pressure in the pulmonary vessels and fluid in the lungs and continuing the cycle of cardiac muscle damage. Treatment for heart failure involves changes in lifestyle, such as diet and exercise, medication, surgery, or a combination of approaches. Medications commonly prescribed for heart failure include diuretics, which reduce fluid volume and venous return by inhibiting sodium and water reabsorption along the kidney's renal tubular system; ACE inhibitors, which block hormones in the renin-angiotensin-aldosterone system, dilating vessels, lowering blood volume and venous return, decreasing the heart's workload, and halting ventricular hypertrophy; digoxin, a cardiac glycoside medication that increases the force of myocardial contractility by raising intracellular sodium and calcium concentrations; and beta-blockers, which compete with norepinephrine molecules for binding sites on cardiomyocytes, preventing norepinephrine's effects, resulting in reduced speed and strength of the contractions, which can support more efficient circulation through the body.
Variations
    (none available)

Nucleus Medical Media Disclaimer of Medical and Legal Liability

Nucleus Medical Media ("Nucleus") does not dispense medical or legal advice, and the text, illustrations, photographs, animations and other information ("Content") available on this web site is for general information purposes only. As with any medical or legal issue, it is up to you to consult a physician or attorney for professional advice. YOU SHOULD NOT DISREGARD PROFESSIONAL MEDICAL OR LEGAL ADVICE BASED ON CONTENT CONTAINED ON THIS WEB SITE, NOR SHOULD YOU RELY ON THE CONTENT ON THIS WEB SITE IN PLACE OF PROFESSIONAL MEDICAL OR LEGAL ADVICE.

NUCLEUS DISCLAIMS ALL RESPONSIBILITY AND LIABILITY FOR ANY COUNSEL, ADVICE, TREATMENT, DIAGNOSIS OR ANY MEDICAL, LEGAL OR OTHER INFORMATION, SERVICES OR PRODUCTS THAT YOU OBTAIN BASED ON VIEWING THE CONTENT OF THIS SITE. THE INFORMATION ON THIS WEB SITE SHOULD NOT BE CONSIDERED COMPLETE OR SUITABLE FOR ANY PURPOSE WHATSOEVER.

Mature Content Disclaimer: Certain Content on this web site contains graphic depictions or descriptions of medical information, which may be offensive to some viewers. Nucleus, its licensors, and its suppliers disclaim all responsibility for such materials.

close