1.3 Cardiac Injuries

Cardiomyocytes can be damaged throughout the lifespan, which, as you now know, poses a problem for humans since they are not typically capable of regeneration.

Cardiovascular Diseases (CVD) are the underlying cause of more deaths in the North America than Cancer and Respiratory combined (American Heart Association). The risk factors of these diseases will be touched on later in the chapter, in Section 3.1, however, some examples of cardiac injuries that lead to irreparable damage include:

CHD: Coronary Heart Disease (CHD) is a general umbrella term for cardiovascular diseases that arise as a result of a blocked coronary artery (Silverthorn et al). The coronary arteries are responsible for supplying the heart with oxygenated blood, however, a blockage in the artery by plaque buildup or blood clots can result in reduced flow to the myocardium. Myocardial infarction, also known as a heart attack, is a common outcome of CHD in which the blood flow to the heart is blocked off and causes ischemia and necrosis of the cardiac tissue, as shown in Figure 5. Subsequently, inflammatory processes begin that lead to the production of scar tissue (Dickhout et al.).

IRI: Once the blockage is cleared by medical intervention, such as a stent or coronary bypass, ischemia-reperfusion injury (IRI) may ensue (Hausenloy and Yellon). This injury may lead to contractile dysfunction, apoptosis of cardiomyocytes, and capillary damage that obstructs the microvasculature, and ventricular arrhythmia, which is an irregular beating of the ventricles (Swaminathan et al.)