Selfish Heart
摘要
The heart metaphorically is the mother of organs. It feeds others first, pumping blood systemically during systole, receiving its own supply later during diastole through left ventricular suction, via peripheral pulse wave reflection, and it extracts every ounce of oxygen akin to feeding on leftovers, hence the altruistic heart. It works hard at generating ever more blood pressure culminating with hypertension, in order to maintain flow for other organs to fulfil their metabolic needs, as they age with rising resistance. The reflected hypertension to the coronary circulation causes hypertensive adaptations and raised microvascular resistance, giving rise to the latter’s dysfunction compounded by cardiac hypertrophy and diastolic dysfunction. Now the heart turns selfish; in order to perfuse itself it generates even more blood pressure to the extent of accelerating end-organ damage elsewhere. This vicious cycle ends with heart failure with preserved ejection fraction. In women, as oestrogen wanes with its cardiovascular protection in menopause, their coronary arteries are unobstructed from delayed atherosclerosis; they become rigid with increased vasoreactivity from endothelial dysfunction, giving rise to transmitted coronary hypertension precipitating angina and predispose to Takotsubo syndrome. Thus, this purported natural history of the women’s heart; selfless and resilient until it stiffens and breaks.