Hypertension is a risk factor for cardiac mortality, and it is associated with angina. For the latter, the mechanisms can be diverse. In the absence of obstructive coronary artery disease, these can range from endothelial dysfunction predisposing to coronary vasospasm, as well as vascular and left ventricular remodelling giving rise to coronary microvascular dysfunction and left ventricular hypertrophy respectively, and collectively they produce structural and electrical abnormalities in the hypertensive heart. This chapter presents three illustrative cases within hypertension’s natural history, involving coronary thermodilution and acetylcholine provocation. Left ventricular diastolic dysfunction and raised coronary microvascular resistance are early common denominators responsible for exercise intolerance, leading to heart failure with preserved ejection fraction.