Hemodynamic Assessment with Implantable Pacemakers How Feasible and Reliable Is It?
Hemodynamic assessment comprises the study of the two major functions of the heart: cardiac output (flow) and pressure, with a close interaction between the two governed by the peripheral resistance. Therefore, measurements related to pressure, volumes and flow are regarded as hemodynamic markers. Diagnostic sensors, such as high-fidelity catheter-tip manometers, provide accurate assessment of single-parameter cardiac function, but the intricate interaction between cardiac contractility, preload, vascular resistance and heart rate makes it very difficult for a single measurement to provide an accurate picture of heart function . For example, isolated measurements of ventricular dP/dt will be of limited value for diagnosis, since this variable is strongly modulated by preload and afterload. This problem is further compounded when the sensor is to be permanently implanted within the heart in pacemakers or ICDs. With these devices it is generally thought preferable not to incorporate additional hardware attached to the pacing/defibrillator leads, and especially within the left heart chambers, because of the risk of clot embolization. With these concepts in mind, the idea of using intracardiac impedance sensors for hemodynamic assessment becomes very appealing, since no additional hardware is required on the pacing lead.
KeywordsAdditional Hardware Pace Lead Hemodynamic Assessment Implantable Pacemaker Volume Waveform
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