CardioDynamics Announces Publication of BioZ Pacemaker Study in PACE Journal; Company Exhibits at NASPE 24th Annual Scientific Sessions, Washington, DC.

Business Editors/Health/Medical Writers

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SAN DIEGO--(BUSINESS WIRE)--May 21, 2003

CardioDynamics (Nasdaq:CDIC), the innovator and leader of Impedance Cardiography (ICG) technology and manufacturer of BioZ(R) noninvasive cardiac function monitoring systems, today announced the publication of an international clinical study demonstrating the significance of the company's ICG technology for pacemaker optimization in PACE, the foremost peer-reviewed publication in the field of electrophysiology.

The independent study, conducted by researchers at the Queen Mary Hospital (Hong Kong), University of Hong Kong, and St. Jude Medical, Sylmar, Calif., demonstrated the utility of the company's ICG technology to determine cardiac output (amount of blood the heart pumps each minute) during pacemaker optimization compared to the Echocardiography/Doppler (Echo) method. Although pacemaker optimization can significantly improve a patient's cardiac output, the vast majority of patients with dual chamber pacemakers are not optimized with Echo because it is a time-consuming, expensive and operator-dependent method. The study's investigators concluded, "Previous studies have shown that optimization of the AV (atrioventricular) interval can contribute up to 40% of the cardiac output. Therefore, it is an important step to maximize the hemodynamic benefits of cardiac pacing, especially during cardiac resynchronization therapy for congestive heart failure. This study demonstrates the feasibility and ease of use of the impedance technique to determine cardiac output during left ventricular pacing with close correlation with Doppler echo."

Michael K. Perry, Chief Executive Officer of CardioDynamics, stated, "This is an exciting application for our technology in a growing $3 billion pacemaker market. With each study and publication comes additional scientific support and invaluable exposure to the international medical community. With over 100 BioZ studies and 1.5 million patients monitored, we are building an industry that is contributing to reducing healthcare costs and improving patient care."

The company also announced it exhibited at the North American Society of Pacing and Electrophysiology (NASPE) 24th Annual Scientific Sessions held May 15-17, 2003, in Washington. The company updated and educated the cardiac pacing and electrophysiology physicians in attendance. There are 3,343 members of NASPE, 2,614 of who are from the U.S.

About CardioDynamics:

CardioDynamics (Nasdaq:CDIC), the ICG Company, is the innovator and global leader of breakthrough medical technology called Impedance Cardiography (ICG). The company's BioZ(R) Systems are being used by leading physicians around the world to help battle the number one killer of men and women -- cardiovascular disease. Partners include GE Medical Systems Information Technologies, Philips Medical Systems and Vasomedical. The worldwide market potential for BioZ products is estimated to be $5 billion and an additional $800 million in recurring annual revenue for disposables. For additional information or to request an investor package, please refer to the company's Web site at www.cdic.com.

Forward-Looking (Safe Harbor) Statement:

Note: Except for the historical and factual information contained herein, this press release contains forward-looking statements, such as estimated cardiovascular and ICG industry prospects, market size, potential, growth and penetration rates, the accuracy of which is necessarily subject to uncertainties and risks including the Company's sole dependence on the BioZ product line, and various uncertainties characteristic of early growth companies, as well as other risks detailed in the Company's filings with the SEC, including its 2002 Form 10-K. The Company does not undertake to update the disclosures contained in this press release.