A stroke occurs when the brain is deprived of sufficient blood flow, interrupting the delivery of necessary oxygen and nutrients. 

Structural heart disease describes any abnormality within the chambers and/or valves of the heart. While these conditions are often congenital, or present at birth, some people develop the disease later in life because of wear and tear on the heart, infections, aging, or other underlying conditions. 

Sudden cardiac arrest causes the heart to suddenly stop beating.

Superior sulcus (Pancoast) tumors arise in the pulmonary apex of the chest.

Syncope occurs when a temporary drop in blood flow to the brain causes someone to pass out.

Tachycardia is a cardiovascular condition characterized by an abnormally fast heart rate.