Cardioembolic Stroke Causes and Risk Factors

Cardioembolic stroke is primarily caused by blood clots that originate in the heart and travel to the brain, disrupting blood flow and causing damage. Among these causes, chronic atrial fibrillation (AFib) is the most common contributor. In elderly patients, conditions such as coronary artery disease can lead to arrhythmias and AFib, where the heart's atria lose their effective contraction, preventing proper blood ejection. This stagnation of blood within the atria increases the likelihood of clot formation along the heart walls. Once these clots dislodge, they can travel through the bloodstream and cause a stroke.

Other Major Cardiac Sources of Embolism

Several other heart conditions also serve as significant sources of embolism. Rheumatic heart disease and endocarditis can lead to the formation of vegetations or mural thrombi—blood clots attached to the inner heart walls—that may break off and travel to the brain. Additionally, myocardial infarction (heart attack) can damage heart tissue and promote clot formation, increasing stroke risk.

Structural Heart Conditions and Stroke Risk

Structural abnormalities such as atrial myxoma, a benign tumor in the heart, can also release debris or clots into the bloodstream. Medical procedures such as valve replacement, heart transplantation, and catheter interventions may disturb existing clots, causing them to move and potentially trigger a stroke. Conditions like mitral valve prolapse with calcification and congenital heart defects—including atrial septal defect (ASD) and ventricular septal defect (VSD)—can allow venous clots to bypass the lungs and reach the arterial system, leading to a condition known as paradoxical embolism.

Changing Trends in Stroke Demographics

While atrial fibrillation remains the leading cause of cardioembolic stroke—particularly in older adults—recent studies have shown growing awareness around stroke risks in younger populations. Conditions like patent foramen ovale (PFO), a persistent opening between the upper heart chambers, are increasingly recognized as potential culprits in cryptogenic strokes among younger individuals. This has led to more targeted screening and preventive strategies for at-risk patients.

Understanding the various cardiac origins of embolic stroke is crucial for effective prevention and treatment. Identifying and managing underlying heart conditions can significantly reduce the risk of recurrent stroke and improve long-term outcomes for patients.