Heart Failure III: Clinical Manifestations

Acute decompensated heart failure causes dyspnea due to pulmonary edema, where fluid accumulates in lung alveoli and interstitium. Orthopnea occurs when lying down because fluid redistributes from the legs to the lungs, increasing pressure in pulmonary vessels. Sitting upright relieves symptoms by allowing fluid to drain back to the lower extremities, improving gas exchange.

Left-sided heart failure impairs the left ventricle's ability to eject blood into the aorta, increasing left ventricular end-diastolic pressure. This backs up blood into the left atrium and pulmonary veins, forcing fluid into lung tissue and alveoli. The resulting pulmonary edema impairs gas exchange and causes crackles on auscultation and pink, frothy sputum.

Right-sided heart failure produces jugular venous distention, dependent edema in the lower extremities, hepatomegaly, and ascites. These findings result from increased venous pressure backing up into peripheral tissues and viscera. Weight gain from fluid retention and gastrointestinal symptoms like anorexia and nausea also occur due to venous engorgement.

Chronic heart failure reduces stroke volume, stimulating the sympathetic nervous system and eventually impairing organ perfusion. Decreased cerebral blood flow and oxygenation cause dizziness, lightheadedness, confusion, and syncope. Decreased renal perfusion reduces urinary output, while gastrointestinal hypoperfusion alters digestion, contributing to overall fatigue.

Paroxysmal nocturnal dyspnea is sudden, severe nighttime dyspnea that awakens patients from sleep due to fluid accumulating in pulmonary vessels and entering alveoli when supine. Orthopnea is dyspnea that occurs when lying down but is relieved by sitting upright. Both result from fluid redistribution, but PND is more acute and disruptive to sleep.

Congestive heart failure occurs when both left and right ventricular failure symptoms are present simultaneously. Left ventricular failure increases fluid pressure through the lungs, damaging the right ventricle and reducing its pumping power. Blood backs up in the venous system, causing swelling in legs, ankles, and abdomen alongside pulmonary edema.

Acute pulmonary edema causes tachypnea exceeding 30 breaths per minute, low oxygen saturation, and constant coughing with foamy, pink sputum. Skin becomes pale, cyanotic, cool, and clammy due to peripheral vasoconstriction and impaired perfusion. Progressive confusion and restlessness indicate severe hypoxemia requiring immediate intervention and heart failure classification and diagnostic evaluation.