Differential Diagnosis for Chronic Lightheadedness and Dizziness

Single Most Likely Diagnosis

• Aortic Stenosis: This condition, characterized by the narrowing of the aortic valve, can lead to reduced cardiac output, resulting in symptoms such as lightheadedness and dizziness, especially upon exertion. The gradual onset of symptoms aligns with the chronic nature of the complaint.

Other Likely Diagnoses

• Hypertrophic Cardiomyopathy: This condition involves thickening of the heart muscle, which can obstruct blood flow and lead to reduced cardiac output, causing symptoms like lightheadedness and dizziness.
• Mitral Valve Prolapse: Although often asymptomatic, mitral valve prolapse can lead to mitral regurgitation, potentially causing decreased cardiac output and symptoms of lightheadedness.
• Cardiac Arrhythmias: Conditions such as atrial fibrillation or other arrhythmias can lead to irregular heartbeats, affecting cardiac output and causing symptoms of dizziness and lightheadedness.

Do Not Miss Diagnoses

• Cardiac Tamponade: Although less common, cardiac tamponade is a life-threatening condition where fluid accumulates in the pericardial sac, compressing the heart and severely impairing its ability to pump blood. Early recognition is crucial.
• Pulmonary Embolism: While not exclusively a cardiac condition, pulmonary embolism can lead to sudden onset of dizziness and lightheadedness due to the blockage of blood flow to the lungs, which indirectly affects cardiac output and oxygenation.
• Aortic Dissection: This is a serious condition where there is a tear in the aorta's inner layer, potentially leading to aortic valve insufficiency, cardiac tamponade, or severe aortic regurgitation, all of which can cause dizziness and lightheadedness.

Rare Diagnoses

• Ebstein's Anomaly: A congenital heart defect involving the tricuspid valve, which can lead to right-sided heart failure and symptoms of dizziness and lightheadedness due to decreased cardiac output.
• Constrictive Pericarditis: A condition where the pericardium becomes stiff and fibrotic, restricting the heart's ability to fill with blood properly, potentially leading to reduced cardiac output and symptoms of dizziness.
• Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC): A rare heart condition where the muscle in the right ventricle is replaced by fat and scar tissue, potentially leading to life-threatening arrhythmias and symptoms of dizziness and lightheadedness.