January 22, 2004(1)

FOR: ZOLL Medical Corporation

INVESTOR CONTACT: A. Ernest Whiton
Chief Financial Officer
ZOLL Medical Corporation
(978) 421-9655

PRESS CONTACT: Robert Minicucci
Corporate Communications Manager
ZOLL Medical Corporation
+1 (978) 421-9832
rminicucci@zoll.com

FOR IMMEDIATE RELEASE

Out-of-Hospital Resuscitation Rate Improves with ZOLL Rectilinear Biphasic Waveform

Thursday, January 22, 2004 – CHELMSFORD, MASS.—ZOLL Medical Corporation (NASDAQ: ZOLL), a manufacturer of non-invasive cardiac resuscitation devices, announced study results that show its Rectilinear Biphasic™ waveform (RBW) improves the resuscitation of out-of-hospital cardiac arrest patients. These results were presented by Joseph C. Stothert, M.D., Ph.D., and Medical Director, EMS Bureau of the City of Omaha Fire Department at the 2004 National Association of EMS Physicians (NAEMSP) Conference in Tucson, Arizona. The study was a retrospective analysis, which covered two years of pre-hospital cardiac arrest data. There were a total of 294 patients in the study.

The ZOLL RBW defibrillated patients at significantly better rates—and at lower energy settings—than a monophasic damped sine (MDS) waveform. The ZOLL RBW, at an energy of only 120 Joules (J), was able to terminate ventricular fibrillation (VF) in a greater number of patients on the first shock than the MDS waveform at an energy setting of 200 J (67% versus 48%). In addition, results showed that the ZOLL RBW was able to convert more patients into rhythms resulting in a return of spontaneous circulation than an MDS waveform (35% versus 26%).

“These results are further evidence showing the benefit of the ZOLL RBW in an
out-of-hospital setting,” said Richard A. Packer, President and Chief Executive Officer of ZOLL. “The ZOLL RBW, with a maximum energy of 200 J, improved first-shock efficacy in this study, while reducing the risks associated with higher energy settings and high peak currents.”

Study Methodology
ZOLL M Series™ defibrillators with the ZOLL RBW were installed on all frontline emergency equipment of the Omaha Fire Department. They were used to deliver a shock sequence of 120 J, 150 J, and maximum energy setting of 200 J. The ZOLL RBW defibrillators were used on 141 adult patients who were in VF during the year. The MDS defibrillators, studied the previous year, delivered a shock sequence of 200 J, 300 J, and 360 J. There were 153 adult patients during the year that MDS defibrillators were used. The results observed from these two years were then compared. Defibrillation was defined as termination of VF at least five seconds after a shock.

About ZOLL
ZOLL Medical Corporation (NASDAQ: ZOLL), with worldwide headquarters in Chelmsford, Massachusetts, designs, manufactures, and markets resuscitation solutions. Pacing and defibrillation devices, including ZOLL’s M Series™ and AED Plus™, and LIFECOR, Inc.’s LifeVest™ Wearable Defibrillator; and circulatory assist devices such as Advanced Circulatory Systems, Inc.’s ResQPOD™ Circulatory Enhancer and Revivant Corporation’s AutoPulse™; are used by health care professionals, emergency medical service providers, and first responders to diagnose and treat cardiac arrest wherever it may occur. ZOLL also designs and markets software that automates the collection and management of both clinical and non-clinical data. ZOLL has operations in the United States, Canada, the United Kingdom, Germany, France, the Netherlands, and Australia, and business partners in all of the world’s major markets. For more information about ZOLL, its products and partners, visit www.zoll.com or call 978-421-9655.

Certain statements contained in this press release, including statements regarding the anticipated development of the Company’s business, and other statements contained herein regarding matters that are not historical facts, are “forward-looking” statements (as defined in the Private Securities Litigation Reform Act of 1995). Because such statements are subject to risks and uncertainties, actual results may differ materially from those expressed or implied by such forward-looking statements. Factors that could cause actual results to differ materially from those expressed or implied by such forward-looking statements include, but are not limited to, those factors discussed in the section entitled “Risk Factors” in the Company’s Annual Report on Form 10-K filed with the SEC on December 19, 2003, including the future performance of the direct sales operations, as well as uncertainties regarding the market acceptance and profitability of the ZOLL AED Plus, the length and severity of the current economic slowdown and its impact on capital spending budgets, the reduction in overall capital equipment expenditures in the hospital and pre-hospital markets, the impact of governmental budget restraints on the purchase of capital equipment, the continued war in the Middle East, the impact of the war on terrorism, the potential disruption in the transportation industry on the Company’s supply chain and product distribution channels, and the desire or ability of other parties to purchase the Company’s products.

# # #

Copyright © 2004 ZOLL Medical Corporation. All rights reserved. 269 Mill Road, Chelmsford, MA 01824-4105. Rectilinear Biphasic, AED Plus, and M Series are trademarks of ZOLL Medical Corporation. The LifeVest System is a trademark of LIFECOR, Inc. The ResQPOD is a trademark of Advanced Circulatory Systems, Inc. The AutoPulse Resuscitation System is a trademark of Revivant Corporation. ZOLL is a registered trademark of ZOLL Medical Corporation. All trademarks are property of their respective owners.

News Room Resources

January 22, 2004(1)