AMENDED AND RESTATED INVESTORS' RIGHTS AGREEMENT

Exhibit 4.2

CRYOCOR, INC.

AMENDED AND RESTATED

INVESTORS’ RIGHTS AGREEMENT

June 4, 2003

TABLE OF CONTENTS

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TABLE OF CONTENTS

(continued)

SCHEDULE A - Schedule of Prior Investors

SCHEDULE B - Schedule of Investors

AMENDED AND RESTATED

INVESTORS’ RIGHTS AGREEMENT

THIS AMENDED AND RESTATED INVESTORS’ RIGHTS AGREEMENT (this " Agreement ") is made as of the 4th day of June, 2003, by and between CryoCor, Inc., a Delaware corporation (the "Company "), the parties listed on Schedule A hereto (the "Prior Investors" ) and the investors listed on Schedule B hereto, each an " Investor " and collectively the "Investors" .

RECITALS

WHEREAS , the Company and the Investors (the "Series D Investors ") are parties to the Series D Preferred Stock Purchase Agreement of even date herewith (the " Series D Purchase Agreement "), providing for the sale and issuance by the Company of its Series D Preferred Stock (the " Series D Preferred Stock ") to the Series D Investors;

WHEREAS , certain obligations in the Series D Purchase Agreement are conditioned upon the execution and delivery of this Agreement;

WHEREAS , certain of the Investors are holders of the Company’s Series A Preferred Stock (the "Series A Investors " and the " Series A Preferred Stock ", respectively) and/or holders of the Company’s Series B Preferred Stock (the " Series B Investors " and the " Series B Preferred Stock ", respectively) and/or holders of the Company’s Series C Preferred Stock (the " Series C Investors " and the " Series C Preferred Stock ", respectively);

WHEREAS , the Prior Investors and the Company are parties to an Amended and Restated Investors’ Rights Agreement, dated January 23, 2002 (the " Prior Agreement ");

WHEREAS , the parties to the Prior Agreement desire to terminate the Prior Agreement and terminate all the rights and covenants afforded them under the Prior Agreement;

WHEREAS, upon amendment and restatement of the Prior Agreement in accordance with Section 3.11 of this Agreement, the Prior Investors shall no longer be a party to this Agreement unless such Prior Investors are listed as Investors on Schedule B hereto; and

WHEREAS , in connection with the consummation of the Series D Purchase Agreement, the Company and the Investors have agreed to the registration rights, information rights, and other rights as set forth below.

NOW, THEREFORE , in consideration of these premises and for other good and valid consideration, the receipt and sufficiency of which are hereby acknowledged, the parties hereto agree as follows:

1. Registration Rights . The Company covenants and agrees as follows:

1.1. Definitions . For purposes of this Section 1:

(a) The term " Act " means the Securities Act of 1933, as amended.

(b) The term " Form S-3 " means such form under the Act as in effect on the date hereof or any registration form under the Act subsequently adopted by the SEC which permits inclusion or incorporation of substantial information by reference to other documents filed by the Company with the SEC.

(c) The term " Holder " means any person owning or having the right to acquire Registrable Securities or any assignee thereof in accordance with Section 1.13 hereof.

(d) The term " 1934 Act " shall mean the Securities Exchange Act of 1934, as amended.

(e) The terms " register ", " registered ," and " registration " refer to a registration effected by preparing and filing a registration statement or similar document in compliance with the Act, and the declaration or ordering of effectiveness of such registration statement or document.

(f) The term " Registrable Securities " means (i) the Common Stock of the Company (the "Common Stock" ) issuable or issued upon conversion of the Series A Preferred Stock, the Series B Preferred Stock, the Series C Preferred Stock and the Series D Preferred Stock; (ii) Common Stock of the Company issuable upon the exercise of warrants to purchase up to 4,684,431 shares of Common Stock of the Company held by certain of the Series B Investors and Series C Investors; and (iii) any Common Stock of the Company issued as (or issuable upon the conversion or exercise of any warrant, right or other security which is issued as) a dividend or other distribution with respect to, or in exchange for or in replacement of the shares referenced in (i) and (ii) above, excluding in all cases, however, any Registrable Securities sold by a person in a transaction in which his rights under this Section 1 are not assigned.

(g) " Registrable Securities then outstanding " shall be the number of shares determined by calculating the total number of shares of the Company’s Common Stock that are Registrable Securities that either (A) are then issued and outstanding or (B) are issuable pursuant to then exercisable or convertible securities.

(h) The term " SEC " shall mean the Securities and Exchange Commission.

1.2. Request for Registration .

(a) If the Company shall receive at any time after the earlier of (i) June 4, 2006, or (ii) one hundred eighty (180) days after the effective date of the first registration statement for a public offering of securities of the Company (other than a registration statement relating either to the sale of securities to employees of the Company pursuant to a stock option, stock purchase or similar plan or a SEC Rule 145 transaction), (A) a written request from the Holders of a majority of the Registrable Securities then outstanding that the Company

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file a registration statement under the Act covering the registration of at least thirty percent (30%) of the Registrable Securities then outstanding or (B) a written request from the Holders of a majority of the Series D Preferred Stock Registrable Securities then outstanding that the Company file a registration statement under the Act covering the registration of at least thirty percent (30%) of the Series D Preferred Stock Registrable Securities then outstanding (or, in each case, a lesser percent if the anticipated aggregate offering price, net of underwriting discounts and commissions, would exceed $10,000,000), then the Company shall:

(i) within fifteen (15) days of the receipt thereof, give written notice of such request to all Holders of the Company’s intention to file a registration statement under the Act for all Registrable Securities which the Holders request to be registered, subject to the limitations of subsection 1.2(b) ; and

(ii) file, as soon as reasonably possible (but in any event not later than sixty (60) days after the fifteenth (15 ^th ) day following the notice to all Holders), and effect as soon as reasonably possible thereafter, a registration statement under the Act covering all Registrable Securities which the Holders request to be registered, subject to the limitations of subsection 1.2(b).

(b) If the Holders initiating the registration request hereunder (the " Initiating Holders ") intend to distribute the Registrable Securities covered by their request by means of an underwriting, they shall so advise the Company as a part of their request made pursuant to subsection 1.2(a) and the Company shall include such information in the written notice referred to in subsection 1.2(a). The underwriter will be selected by the Company and shall be reasonably acceptable to a majority in interest of the Initiating Holders. In such event, the right of any Holder to include his Registrable Securities in such registration shall be conditioned upon such Holder’s participation in such underwriting and the inclusion of such Holder’s Registrable Securities in the underwriting (unless otherwise mutually agreed by a majority in interest of the Initiating Holders and such Holder) to the extent provided herein. All Holders proposing to distribute their securities through such underwriting shall (together with the Company as provided in subsection 1.4(e)) enter into an underwriting agreement in customary form with the underwriter or underwriters selected for such underwriting. Notwithstanding any other provision of this Section 1.2, if the underwriter advises the Initiating Holders in writing that marketing factors require a limitation of the number of shares to be underwritten, then the Initiating Holders shall so advise all Holders of Registrable Securities which would otherwise be underwritten pursuant hereto, and the number of shares of Registrable Securities that may be included in the underwriting shall be allocated among all Holders thereof, including the Initiating Holders, in proportion (as nearly as practicable) to the amount of Registrable Securities of the Company owned by each Holder; provided, however , that the number of shares of Registrable Securities to be included in such underwriting shall not be reduced unless all other securities are first entirely excluded from the underwriting.

(c) Notwithstanding the foregoing, if the Company shall furnish to Holders requesting a registration statement pursuant to this Section 1.2, within fifteen (15) days of receiving such request, a certificate signed by the Chief Executive Officer of the Company stating that in the good faith judgment of the Board of Directors of the Company, it would be seriously detrimental to the Company and its stockholders for such registration

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statement to be filed and it is therefore essential to defer the filing of such registration statement, the Company shall have the right to defer taking action with respect to such filing for a period of not more than one hundred eighty (180) days after receipt of the request of the Initiating Holders; provided, however , that the Company may not utilize this right more than once in any twelve-month period.

(d) In addition, the Company shall not be obligated to effect, or to take any action to effect, any registration pursuant to this Section 1.2:

(i) after the Company has effected two registrations authorized pursuant to this Section 1.2 by the Holders of a majority of the Registrable Securities then outstanding and two registrations authorized pursuant to this Section 1.2 by the Holders of a majority of the Series D Preferred Stock Registrable Securities then outstanding and such registrations have been declared or ordered effective;

(ii) during the period starting with the date sixty (60) days prior to the Company’s good faith estimate of the date of filing of, and ending on a date one hundred eighty (180) days after the effective date of, a registration subject to Section 1.3 hereof; provided that the Company is actively employing in good faith all reasonable efforts to cause such registration statement to become effective;

(iii) if the Initiating Holders propose to dispose of shares of Registrable Securities that may be immediately registered on Form S-3 pursuant to a request made pursuant to Section 1.12 below;

(iv) if within thirty (30) days of receipt of a written request from the Initiating Holders pursuant to Section 1.2(a), the Company gives notice to the Holders of the Company’s intention, as evidenced by the approval of such intention by a majority of the Board of Directors of the Company, to file a registration statement pursuant to Section 1.3 within sixty (60) days; or

(v) in any particular jurisdiction in which the Company would be required to qualify to do business or to execute a general consent to service of process in effecting such registration, qualification or compliance.

1.3. Company Registration . If (but without any obligation to do so) the Company proposes to register (including for this purpose a registration effected by the Company for stockholders other than the Holders) any of its stock or other securities under the Act in connection with the public offering of such securities solely for cash (other than a registration relating solely to the sale of securities to participants in a Company stock plan, or a registration relating to a corporate reorganization or other transaction under Rule 145, or a registration on any form which does not include substantially the same information as would be required to be included in a registration statement covering the sale of the Registrable Securities), the Company shall, at such time, promptly give each Holder written notice of such registration. Upon the written request of each Holder given within twenty (20) days after mailing of such notice by the Company in accordance with Section 3.5, the Company shall, subject to the provisions of Section 1.8, cause to be registered under the Act all of the Registrable Securities that each such Holder has requested to be registered.

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1.4. Obligations of the Company . Whenever required under this Section 1 to effect the registration of any Registrable Securities, the Company shall, as expeditiously as reasonably possible:

(a) Prepare and file with the SEC a registration statement with respect to such Registrable Securities and use its best efforts to cause such registration statement to become effective, and, upon the request of the Holders of a majority of the Registrable Securities registered thereunder, keep such registration statement effective for a period of up to one hundred twenty (120) days or until the distribution contemplated in the Registration Statement has been completed; provided, however , that (i) such one hundred twenty (120) day period shall be extended for a period of time equal to the period the Holder refrains from selling any securities included in such registration at the request of an underwriter of Common Stock (or other securities) of the Company; and (ii) in the case of any registration of Registrable Securities on Form S-3 which are intended to be offered on a continuous or delayed basis, such one hundred twenty (120) day period shall be extended, if necessary, to keep the registration statement effective until all such Registrable Securities are sold, provided that Rule 415, or any successor rule under the Act, permits an offering on a continuous or delayed basis, and provided further that applicable rules under the Act governing the obligation to file a post-effective amendment permit, in lieu of filing a post-effective amendment which (I) includes any prospectus required by Section 10(a)(3) of the Act or (II) reflects facts or events representing a material or fundamental change in the information set forth in the registration statement, the incorporation by reference of information required to be included in (I) and (II) above to be contained in periodic reports filed pursuant to Section 13 or 15(d) of the 1934 Act in the registration statement.

(b) Prepare and file with the SEC such amendments and supplements to such registration statement and the prospectus used in connection with such registration statement as may be necessary to comply with the provisions of the Act with respect to the disposition of all securities covered by such registration statement for the period set forth in (a) above.

(c) Furnish to the Holders such numbers of copies of a prospectus, including a preliminary prospectus, in conformity with the requirements of the Act, and such other documents as they may reasonably request in order to facilitate the disposition of Registrable Securities owned by them.

(d) Use its best efforts to register and qualify the securities covered by such registration statement under such other securities or Blue Sky laws of such jurisdictions as shall be reasonably requested by the Holders; provided that the Company shall not be required in connection therewith or as a condition thereto to qualify to do business or to file a general consent to service of process in any such states or jurisdictions.

(e) In the event of any underwritten public offering, enter into and perform its obligations under an underwriting agreement, in usual and customary form, with the managing underwriter of such offering. Each Holder participating in such underwriting shall also enter into and perform its obligations under such an agreement.

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(f) Notify each Holder of Registrable Securities covered by such registration statement at any time when a prospectus relating thereto is required to be delivered under the Act of the happening of any event as a result of which the prospectus included in such registration statement, as then in effect, includes an untrue statement of a material fact or omits to state a material fact required to be stated therein or necessary to make the statements therein not misleading in the light of the circumstances then existing.

(g) Cause all such Registrable Securities registered pursuant hereunder to be listed on each securities exchange on which similar securities issued by the Company are then listed or qualify such Registrable Securities for inclusion on Nasdaq if the Company does not have a class of equity securities listed on a national securities exchange.

(h) Provide a transfer agent and registrar for all Registrable Securities registered pursuant hereunder and a CUSIP number for all such Registrable Securities, in each case not later than the effective date of such registration.

(i) Use its best efforts to furnish, at the request of any Holder requesting registration of Registrable Securities pursuant to this Section 1, on the date that such Registrable Securities are delivered to the underwriters for sale in connection with a registration pursuant to this Section 1, if such securities are being sold through underwriters, or, if such securities are not being sold through underwriters, on the date that the registration statement with respect to such securities becomes effective, (i) an opinion, dated such date, of the counsel representing the Company for the purposes of such registration, in form and substance as is customarily given to underwriters in an underwritten public offering, addressed to the underwriters, if any, and to the Holders requesting registration of Registrable Securities and (ii) a letter dated such date, from the independent certified public accountants of the Company, in form and substance as is customarily given by independent certified public accountants to underwriters in an underwritten public offering, addressed to the underwriters, if any, and to the Holders requesting registration of Registrable Securities.

1.5. Furnish Information .

(a) It shall be a condition precedent to the obligations of the Company to take any action pursuant to this Section 1 with respect to the Registrable Securities of any selling Holder that such Holder shall furnish to the Company such information regarding itself, the Registrable Securities held by it, and the intended method of disposition of such securities as shall be required to effect the registration of such Holder’s Registrable Securities as the Company may reasonably request in writing.

(b) The Company shall have no obligation with respect to any registration requested pursuant to Section 1.2 or Section 1.12 if, due to the operation of subsection 1.2(b), the number of shares or the anticipated aggregate offering price of the Registrable Securities to be included in the registration does not equal or exceed the number of shares or the anticipated aggregate offering price required to originally trigger the Company’s obligation to initiate such registration as specified in subsection 1.2(a) or subsection 1.12(b)(2), whichever is applicable.

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1.6. Expenses of Demand Registration . All expenses, other than underwriting discounts and commissions, incurred in connection with registrations, filings or qualifications pursuant to Section 1.2, including (without limitation) all registration, filing and qualification fees, printers’ and accounting fees, fees and disbursements of counsel for the Company and the reasonable fees and disbursements of one counsel for the selling Holders, shall be borne by the Company; provided, however , that the Company shall not be required to pay for any expenses of any registration proceeding begun pursuant to Section 1.2 if the registration request is subsequently withdrawn at the request of the Holders of a majority of the Registrable Securities to be registered (in which case all participating holders shall bear such expenses), unless the Holders of a majority of the Registrable Securities agree to forfeit their right to one demand registration pursuant to Section 1.2; provided further, that if (i) the Company fails to register and sell at least 85% of the Registrable Securities requested to be registered in such Section 1.2 request, or (ii) the Company postpones the registration for any reason and the Initiating Holders withdraw such registration request, the Company shall bear all such expenses in connection with the registration, but such registration shall not count against the number of demand registrations to which such Holders are entitled.

1.7. Expenses of Company Registration . The Company shall bear and pay all expenses incurred in connection with any registration, filing or qualification of Registrable Securities with respect to the registrations pursuant to Section 1.3 for each Holder (which right may be assigned as provided in Section 1.13), including (without limitation) all registration, filing, and qualification fees, printers and accounting fees relating or apportionable thereto and the fees and disbursements of one counsel for the selling Holders selected by them, but excluding underwriting discounts and commissions relating to Registrable Securities.

1.8. Underwriting Requirements . In connection with any offering involving an underwriting of shares of the Company’s capital stock, the Company shall not be required under Section 1.3 to include any of the Holders’ securities in such underwriting unless they accept the terms of the underwriting as agreed upon between the Company and the underwriters selected by it (or by other persons entitled to select the underwriters), and then only in such quantity as the underwriters determine in their sole discretion will not, jeopardize the success of the offering by the Company. If the total amount of securities, including Registrable Securities, requested by stockholders to be included in such offering exceeds the amount of securities sold other than by the Company that the underwriters determine in their sole discretion is compatible with the success of the offering, then the Company shall be required to include in the offering only that number of such securities, including Registrable Securities, which the underwriters determine in their sole discretion will not jeopardize the success of the offering (the securities so included to be apportioned pro rata among the selling stockholders according to the total amount of securities entitled to be included therein owned by each selling stockholder or in such other proportions as shall mutually be agreed to by such selling stockholders) but in no event shall (i) the amount of securities of the selling Holders included in the offering be reduced below forty percent (40%) of the total amount of securities included in such offering, unless such offering is the initial public offering of the Company’s securities in which case the selling stockholders may be excluded if the underwriters make the determination described above and

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no other stockholder’s securities are included or (ii) notwithstanding (i) above, any shares being sold by a stockholder exercising a demand registration right similar to that granted in Section 1.2 be excluded from such offering. For purposes of the preceding parenthetical concerning apportionment, for any selling stockholder which is a holder of Registrable Securities and which is a partnership, limited liability company or corporation, the partners, members, retired partners or members and stockholders of such holder, or the estates and family members of any such partners, members, retired partners or members and any trusts for the benefit of any of the foregoing persons shall be deemed to be a single "selling stockholder", and any pro-rata reduction with respect to such "selling stockholder" shall be based upon the aggregate amount of shares carrying registration rights owned by all entities and individuals included in such "selling stockholder", as defined in this sentence.

1.9. Delay of Registration . No Holder shall have any right to obtain or seek an injunction restraining or otherwise delaying any such registration as the result of any controversy that might arise with respect to the interpretation or implementation of this Section 1.

1.10. Indemnification . In the event any Registrable Securities are included in a registration statement under this Section 1:

(a) To the extent permitted by law, the Company will indemnify and hold harmless each Holder, any underwriter (as defined in the Act) for such Holder and each person, if any, who controls such Holder or underwriter within the meaning of the Act or the 1934 Act, against any losses, claims, damages, or liabilities (joint or several) to which they may become subject under the Act, or the 1934 Act or other federal or state law, insofar as such losses, claims, damages, or liabilities (or actions in respect thereof) arise out of or are based upon any of the following statements, omissions or violations (collectively a "Violation"): (i) any untrue statement or alleged untrue statement of a material fact contained in such registration statement, including any preliminary prospectus or final prospectus contained therein or any amendments or supplements thereto, (ii) the omission or alleged omission to state therein a material fact required to be stated therein, or necessary to make the statements therein not misleading, or (iii) any violation or alleged violation by the Company of the Act, the 1934 Act, or other federal or state laws or any rule or regulation promulgated thereunder; and the Company will pay to each such Holder, underwriter or controlling person any legal or other expenses reasonably incurred by them in connection with investigating or defending any such loss, claim, damage, liability, or action; provided, however , that the indemnity agreement contained in this subsection 1.10(a) shall not apply to amounts paid in settlement of any such loss, claim, damage, liability, or action if such settlement is effected without the consent of the Company (which consent shall not be unreasonably withheld), nor shall the Company be liable in any such case for any such loss, claim, damage, liability, or action to the extent (and only to the extent) that it arises out of or is based upon a Violation which occurs in reliance upon and in conformity with written information furnished expressly for use in connection with such registration by any such Holder, underwriter or controlling person of such Holder.

(b) To the extent permitted by law, each selling Holder will, severally and not jointly, if Registrable Securities held by such Holder are included in the registration, indemnify and hold harmless the Company, each of its directors, each of its officers

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who has signed the registration statement, each person, if any, who controls the Company within the meaning of the Act, any underwriter, any other Holder selling securities in such registration statement and any controlling person of any such underwriter or other Holder, against any losses, claims, damages, or liabilities (joint or several) to which any of the foregoing persons may become subject, under the Act, or the 1934 Act or other federal or state law insofar as such losses, clai