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  FDA Approves PLC Systems' Heart Laser For TMR

      - U.S.'s First Laser for New Heart Surgery -

      FRANKLIN, Mass., Aug. 20 -- PLC Systems Inc. (Amex: PLC) today announced
      that it has received approval from the U.S. Food and Drug Administration
      (FDA) for commercial use of The Heart Laser(TM) System for TMR
      (Transmyocardial Revascularization). On April 24, 1998 an independent
      advisory panel unanimously recommended that the FDA grant approval of TMR
      using The Heart Laser System.

      PLC is the first company to receive FDA approval for commercial use of a
      product for TMR, a new surgical procedure used to treat patients suffering
      from severe coronary artery disease with no treatment alternative. The
      Heart Laser System can now be marketed throughout the U.S. and used to
      treat the estimated 80,000 domestic patients each year who suffer from
      severe coronary artery disease (CAD) but can not be treated with
      conventional coronary revascularization techniques such as bypass surgery
      or angioplasty.

      "This FDA approval confirms PLC's position as the pioneer and leader in
      TMR," said William C. Dow, President and CEO of PLC. "We are the most
      experienced laser revascularization company in the world, based on our
      treatment of more than 4,000 patients and over 100 installed Heart Laser
      Systems worldwide. We intend to maintain our market leading position,
      expand our database of clinical information and seek FDA approval for
      expanded use of The Heart Laser System, including as an adjunctive therapy
      to bypass surgery."

      Analysts have estimated that the worldwide market potential for TMR could
      be as much as $1 billion annually.

      TMR using The Heart Laser System is a revolutionary new way of restoring
      blood flow to the heart. This high-energy carbon dioxide (CO2) laser is
      used by a cardiovascular surgeon to create between 20 and 40 new channels
      into the heart muscle. Clinical studies have demonstrated that the
      creation of these channels




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      allows blood to flow into the heart muscle, despite the blockage of
      arteries. The computer-controlled laser is synchronized with the patient's
      heartbeat and fires when the heart is relatively still and unresponsive to
      stimuli.

      "The Heart Laser System was developed specifically for TMR, and it can
      create a channel in the heart muscle with a single laser pulse," added
      Dow. "We believe that this feature and our synchronization technology
      provides meaningful clinical advantages to patients. Research conducted at
      The Texas Heart(TM) Institute indicates that synchronization may reduce
      the risk of harmful heart arrhythmia that has occurred when laser
      revascularization has been performed without synchronization."

      TMR using The Heart Laser System is considered less invasive heart
      surgery. The procedure generally does not necessitate a blood transfusion
      and, because it is performed on a beating heart, it does not require a
      heart- lung machine. Therefore, recovery is potentially quicker, less
      traumatic and less costly than in open-heart procedures.

      U.S. clinical studies have demonstrated the TMR procedure to be safe and
      effective in decreasing angina by two or more classes (angina is measured
      in classes from one to four, one being the least painful and four being
      the most) in nearly 75% of patients, and, in fact, eliminating all angina
      in one-third of patients.

      PLC estimates that each year approximately 120,000 patients worldwide are
      diagnosed with severe CAD which is not treatable by conventional
      revascularization techniques. CAD is a form of heart disease caused by the
      blockage of blood flow into the coronary arteries which supply oxygen-rich
      blood to the heart muscle. Typically, severe CAD patients experience
      excruciating spasmodic attacks of chest pain, or angina, and often
      shortness of breath and fatigue. No longer candidates for traditional
      surgery, these patients have been placed on maximum drug therapy.

      PLC Systems Inc. is a cardiovascular company pioneering,






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      developing and supplying the systems and components for TMR and related
      cardiac procedures. PLC Medical Systems, Inc., a wholly-owned subsidiary
      of PLC Systems Inc. developed the CO2 Heart Laser System for TMR, which
      uses PLC's patented 'heart-synchronized pulsed laser' technology. The
      company is investigating TMR as a technology with the potential to provide
      patients suffering from coronary artery disease an alternative or adjunct
      to angioplasty and coronary bypass graft surgery. PLC Systems Inc. has
      approximately 50 patents and/or patents pending worldwide for the
      company's innovative revascularization product and procedural accessories.

      NOTE: Certain of the above statements may be forward-looking statements
      that involve risks and uncertainties. Actual results could differ
      materially from those indicated by such forward-looking statements as a
      result of a variety of factors, including competitive developments,
      regulatory approval requirements, the ability to convince healthcare
      professionals and third-party payers of the medical and economic benefits
      of The Heart Laser System, and the risk factors described in the company's
      annual report, SEC form 10K for the fiscal year ended December 31, 1997,
      and the company's other SEC reports.

            CONTACT: Investor: Michele Fasano of PLC Systems Inc.,
            508-541-8800 or
            Media: Robert Borchert of Ludgate Communications,
            212-688-5144