What Are Cardiovascular Diseases?

Cardiovascular diseases are a broad group of disorders affecting the heart and blood vessels, encompassing conditions that impair cardiac function, vascular integrity, and circulatory capacity. They represent the leading cause of mortality worldwide, accounting for an estimated 17.9 million deaths annually according to the World Health Organization cardiovascular disease fact sheet. The category includes coronary artery disease, stroke, heart failure, peripheral arterial disease, cardiac arrhythmias, and congenital heart defects, each with distinct pathophysiological mechanisms and clinical presentations.

Cardiovascular diseases draw on knowledge from physiology, pathology, pharmacology, and biomedical engineering. Their study spans basic research into cellular and molecular mechanisms as well as translational work directed at diagnosis, intervention, and prevention. Engineering and computational approaches have become increasingly important in modeling disease progression, designing therapeutic devices, and interpreting data from physiological monitoring systems.

Atherosclerosis and Coronary Artery Disease

Atherosclerosis is a degenerative process in which plaques composed of lipids, inflammatory cells, and connective tissue accumulate within arterial walls, progressively narrowing the lumen and reducing blood flow. When atherosclerosis affects the coronary arteries supplying the myocardium, it produces coronary artery disease (CAD), the most prevalent cardiovascular condition in high-income countries. Plaque rupture can trigger acute thrombosis, resulting in myocardial infarction. The relationship between hemodynamic shear stress and endothelial cell behavior has been studied extensively, as turbulent or disturbed flow patterns promote plaque initiation at arterial bifurcations and bends.

Cardiac Rhythm Disorders

Arrhythmias are disturbances in the electrical conduction system of the heart that disrupt normal cardiac rhythm. They range from relatively benign premature beats to life-threatening ventricular fibrillation. Atrial fibrillation (AFib) is the most common sustained arrhythmia, characterized by chaotic atrial electrical activity and an irregularly irregular ventricular response. AFib substantially increases stroke risk through thrombus formation in the left atrial appendage. Detection and classification of arrhythmias have become important applications for signal processing, with electrocardiographic algorithms and deep learning approaches documented in IEEE Transactions on Biomedical Engineering enabling real-time rhythm analysis in wearable and implantable devices.

Heart Failure and Hemodynamic Dysfunction

Heart failure is a clinical syndrome in which the heart cannot pump sufficient blood to meet the body's metabolic demands. It is broadly classified by left ventricular ejection fraction into heart failure with reduced ejection fraction (HFrEF) and heart failure with preserved ejection fraction (HFpEF). Both forms involve abnormal ventricular filling or contraction, elevated filling pressures, and compensatory neurohormonal activation. Hemodynamic monitoring, including invasive pulmonary artery catheterization and noninvasive echocardiography, provides key parameters such as cardiac output, stroke volume, and filling pressures for guiding therapy. Implantable cardiac devices such as ventricular assist devices (VADs) provide mechanical circulatory support in advanced heart failure.

Stroke and Cerebrovascular Disease

Stroke occurs when blood supply to a region of the brain is interrupted, either by arterial occlusion (ischemic stroke) or rupture (hemorrhagic stroke). Ischemic stroke, which accounts for roughly 87 percent of cases, is often caused by embolism from cardiac sources or from atherosclerotic plaques in the carotid arteries or aorta. Transient ischemic attacks (TIAs) are brief episodes of focal neurological deficit with complete resolution, representing an important warning of pending stroke. Neuroimaging techniques including CT angiography and diffusion-weighted MRI are used to identify infarct territory and guide intervention decisions within narrow treatment windows.

Applications

Cardiovascular diseases have driven development and application across many engineering and clinical domains, including:

• Implantable cardiac devices such as pacemakers, defibrillators, and ventricular assist devices
• Wearable and continuous cardiac monitoring systems for arrhythmia detection
• Computational hemodynamics and finite element modeling of coronary flow for surgical planning
• Cardiac imaging modalities including echocardiography, CT angiography, and cardiac MRI
• Pharmacological and gene therapy research targeting cardiac remodeling