Central Hemodynamics for Management of Arteriosclerotic Diseases

Abstract

Arteriosclerosis, particularly aortosclerosis, is the most critical risk factor associated with cardiovascular, cerebrovascular, and renal diseases. The pulsatile hemodynamics in the central aorta consists of blood pressure, flow, and stiffness and substantially differs from the peripheral hemodynamics in muscular arteries. Arteriosclerotic changes with age appear earlier in the elastic aorta, and age-dependent increases in central pulse pressure are more marked than those apparent from brachial pressure measurement. Central pressure can be affected by lifestyle habits, metabolic disorders, and endocrine and inflammatory diseases in a manner different from brachial pressure. Central pulse pressure widening due to aortic stiffening increases left ventricular afterload in systole and reduces coronary artery flow in diastole, predisposing aortosclerotic patients to myocardial hypertrophy and ischemia. The widened pulse pressure is also transmitted deep into low-impedance organs such as the brain and kidney, causing microvascular damage responsible for lacunar stroke and albuminuria. In addition, aortic stiffening increases aortic blood flow reversal, which can lead to retrograde embolic stroke and renal function deterioration. Central pressure has been shown to predict cardiovascular events in most previous studies and potentially serves as a surrogate marker for intervention. Quantitative and comprehensive evaluation of central hemodynamics is now available through various noninvasive pressure/flow measurement modalities. This review will focus on the clinical usefulness and mechanistic rationale of central hemodynamic measurements for cardiovascular risk management.

Keywords: Aorta; Arteriosclerosis; Blood flow; Blood pressure; Stiffness.

Fig. 1.

Pressure pulse waveforms of radial artery (A) and central aorta (B) AIx_A indicates aortic augmentation index; AIx_R, radial augmentation index; AMP, pulse pressure amplification; AMP_A-R, aorta-to-radial AMP ratio; AP, augmented pressure; BP, blood pressure; P1, early systolic peak pressure; P2, late systolic peak pressure; P_d, diastolic pressure; P_i, pressure at inflection point; PP, pulse pressure; and T_r, round-trip travel time. Reproduced from Hashimoto¹⁵⁾.