Monitoring the cardiovascular system: Current status and future directions

Abstract

Monitoring the circulation of the patient with cardiac disease is of necessity a complex task. Decreased cardiac performance is attended by a higher incidence of undesirable perioperative outcomes. Early detection of inadequate cardiac performance is essential in minimizing complications and facilitating optimal patient care. The foundation of modern cardivascular monitoring is a thorough understanding of cardiac function and the determinants of cardiac performance-heart rate, afterload, preload, and contractility. Monitoring of these variables is the goal of current techniques including echocardiography and radionuclear studies. While the current trend is toward non-invasive acquisition of haemodynamic data, invasive techniques such as pulmonary artery catheterization remain the mainstay of sophisticated assessment. However, cardiac ultrasound with its potential for measurement of regional and global cardiac function is undergoing rapid development as an intraoperative monitor. The technique of trans-oesophageal echocardiography is well suited to the non-invasive acquisition of physiological data. The widespread application of this newer technology faces the significant, barriers of high cost and the requirement for significant training. Other important advances include continuous non-invasive blood pressure measurement. This technique, based on the plethysmographic principle, provides a wave-form which correlates with invasive gold standards for arterial pressure measurement. While present devices do not have universal applicability, this technology with refinement may make arterial cannulae unnecessary in most circumstances. Overall, the anaesthesiologist has available a variety of monitoring options to acquire the necessary information to support the surgical patient with cardiac disease during the perioperative period.