Hemodynamic Monitoring Better Than Hypertensive Drugs

Noninvasive hemodynamic monitoring based on impedance cardiography is more effective than medications in guiding antihypertensive therapy, according to new findings.

In a study of uncontrolled hypertensive patients on one to three medications at 11 medical centers, conducted by researchers at Wake Forest University School of Medicine (Winston-Salem, NC, USA), 95 participants were randomized to standard therapy with empiric selection of medication and 69 to hemodynamic guidance.
All patients underwent a two-week drug washout period followed by three months of treatment.

A variety of agents were prescribed, including angiotensin converting enzyme inhibitors, angiotensin II receptor blockers, beta-blockers, calcium channel blockers, and diuretics. At the end of the study period, systolic blood pressure reductions were greater in the hemodynamic-monitoring group than those who had standard therapy. This was true compared to baseline (19 mm Hg versus 11 mm Hg), and after washout (25 mm Hg versus 19 mm Hg). A similar pattern of diastolic blood pressure reductions were seen on comparison to baseline measurements (12 mm Hg versus 5 mm Hg) and after washout (17 mm Hg versus 10 mm Hg). The results were reported in the April 2006 issue of Hypertension

"Impedance cardiography has emerged as a reliable noninvasive method to measure hemodynamics in physician offices,” said senior investigator Dr. Carlos M. Ferrario, of Wake Forest University School of Medicine. "Using the system to treat hypertension could significantly improve blood pressure control.”

The researchers used the BioZ monitor, manufactured by CardioDynamics (San Diego, CA, USA), a noninvasive hemodynamic monitor that measures thoracic impedance via four dual sensors. The monitor features proprietary DISQ (Digital Impedance Signal Quantifier) technology and an innovative algorithm that processes impedance changes and calculates hemodynamic parameters, including cardiac output, systemic vascular resistance, contractility, and fluid status.



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Wake Forest University School of Medicine
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