WARRANT

Exhibit 4.5

WARRANT

THE SECURITIES REPRESENTED BY THIS WARRANT HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR APPLICABLE STATE SECURITIES LAWS. THE SECURITIES HAVE BEEN ACQUIRED FOR INVESTMENT AND MAY NOT BE OFFERED FOR SALE, SOLD, TRANSFERRED OR ASSIGNED IN THE ABSENCE OF AN EFFECTIVE REGISTRATION STATEMENT FOR THE SECURITIES UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR APPLICABLE STATE SECURITIES LAWS, OR AN OPINION OF COUNSEL IN A FORM REASONABLY SATISFACTORY TO THE ISSUER THAT REGISTRATION IS NOT REQUIRED UNDER SAID ACT OR APPLICABLE STATE SECURITIES LAWS OR UNLESS SOLD PURSUANT TO RULE 144 UNDER SAID ACT. NOTWITHSTANDING THE FOREGOING, THIS WARRANT MAY BE PLEDGED IN CONNECTION WITH A BONA FIDE MARGIN ACCOUNT.

WARRANT TO PURCHASE PREFERRED STOCK

SynCardiaSystems, Inc., a Delaware corporation (the “Company”), hereby certifies that, for [    ] United States Dollars ($[        ]) and other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, [                    ] (the “Holder”), the registered Holder hereof or its permitted assigns, is entitled, subject to the terms set forth below, to purchase from the Company upon surrender of this Warrant, at any time or times on or after the date hereof (the “Effective Date”), but not after 11:59 P.M. Eastern Time on the Expiration Date (as defined herein) the number of fully paid and nonassessable shares of the Preferred Stock (as defined herein) of the Company (the “Warrant Shares”) set forth above at the exercise price per share provided in Section 1(a)(xii) below or as subsequently adjusted. For purposes of this Warrant, in determining the number of outstanding shares of Preferred Stock, a Holder may rely on the number of outstanding shares of Preferred Stock as reflected in (1) the Company’s most recent Form 10-QSB or Form 10-KSB, if any, (2) a more recent public announcement by the Company or (3) any other notice by the Company or its transfer agent setting forth the number of shares of Preferred Stock outstanding. Upon the written request of the Holder, the Company shall promptly, but in no event later than two (2) Business Day following the receipt of such notice, confirm in writing to any such Holder the number of shares of Preferred Stock then outstanding. In any case, the number of outstanding shares of Preferred Stock shall be determined after giving effect to the exercise of Warrants (as defined below) by such Holder and its affiliates since the date as of which such number of outstanding shares of Preferred Stock was reported. The Holder and the Company agree that notwithstanding any terms to the contrary contained herein, the Holder shall have no right to exercise this Warrant until the Effective Date. This Warrant is being issued to Holder as an inducement to Holder

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agreeing, subject to the conditions set forth in that certain [                    ] Agreement of even date herewith between Holder and the Company (the “[                    ] Agreement”), to make available to the Company up to $[        ] in [                    ] financing pursuant to the terms and conditions of the [                    ] Agreement. In the event the Company does not execute an [                    ] under the [                    ] Agreement, this Warrant shall be void.

Section 1.

(a) Definitions. The following words and terms as used in this Warrant shall have the following meanings:

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Section 2. Exercise of Warrant.

(a) Subject to the terms and conditions hereof, this Warrant may be exercised by the Holder hereof then registered on the books of the Company, pro rata as hereinafter provided, at any time on any Business Day on or after the opening of business on such Business Day, commencing with the Effective Date, and prior to 11:59 P.M. Eastern Time on the Expiration Date, by (i) delivery of a written notice, in the form of the subscription notice attached as Exhibit A hereto (the “Exercise Notice”), of such Holder’s election to exercise this Warrant, which notice shall specify the number of Warrant Shares to be purchased, (ii) payment to the Company of an amount equal to the Warrant Exercise Price(s) applicable to the Warrant Shares being purchased, multiplied by the number of Warrant Shares (at the applicable Warrant Exercise Price) as to which this Warrant is being exercised (plus any applicable issue or transfer taxes) (the “Aggregate Exercise Price”) in cash or wire transfer of immediately available funds and (iii) the surrender of this Warrant (or an indemnification undertaking with respect to this Warrant in the case of its loss, theft or destruction) to a common carrier for overnight delivery to the Company as soon as practicable following such date. In the event of any exercise of the rights represented by this Warrant in compliance with this Section 2, the Company shall on the fifth (5th) Business Day following the date of receipt of the Exercise Notice, the Aggregate Exercise Price and this Warrant (or an indemnification undertaking with respect to this Warrant in the case of its loss, theft or destruction) and the receipt of the representations of the Holder specified in Section 6 hereof, if requested by the Company (the “Exercise Delivery Documents”), issue and surrender to a common carrier for overnight delivery to the address specified in the Exercise Notice, a certificate, registered in the name of the Holder, for the number of shares of Preferred Stock to which the Holder shall be entitled pursuant to such request. Upon delivery of the Exercise Notice and Aggregate Exercise Price referred to in clause (ii) above the Holder of this Warrant shall be deemed for all corporate purposes to have become the Holder of record of the Warrant Shares with respect to which this Warrant has been exercised. Notwithstanding any provisions herein to the contrary, if the fair market value of one Warrant Share is greater than the Exercise Price (at the date of calculation as set forth below), in lieu of exercising this Warrant by payment of cash, the Holder may elect to receive shares equal to the value (as determined below) of this Warrant (or the portion thereof being canceled) by surrender of this Warrant at the principal office of the Company together with the properly endorsed Notice of Exercise in which event the Company shall issue to the Holder a number of Warrant Shares computed using the following formula:

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For purposes of the above calculation, the fair market value of one Warrant Share shall be determined by the Company’s Board of Directors in good faith; provided, however, that in the event that this Warrant is exercised pursuant to this Section 2 in connection with the Company’s initial public offering of its Common Stock, the fair market value per share shall be the product of (i) the per share offering price to the public of the Company’s Common Stock in the initial public offering, and (ii) the number of shares of Common Stock into which each Warrant Share is convertible at the time of such exercise.

Section 3. Covenants as to Preferred Stock. The Company hereby covenants and agrees as follows:

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Section 4. Taxes. The Company will pay all taxes (other than taxes based upon income) and other governmental charges that may be imposed with respect to the issuance or delivery of shares of Preferred Stock upon exercise of this Warrant, other than any tax or other charge imposed in connection with any transfer involved in the issue and delivery of shares of Preferred Stock in a name other than that of the Holder.

Section 5. Warrant Holder Not Deemed a Stockholder. Except as otherwise specifically provided herein, no Holder, as such, of this Warrant shall be entitled to vote or receive dividends or be deemed the holder of shares of capital stock of the Company for any purpose, nor shall anything contained in this Warrant be construed to confer upon the Holder hereof, as such, any of the rights of a stockholder of the Company or any right to vote, give or withhold consent to any corporate action (whether any reorganization, issue of stock, reclassification of stock, consolidation, merger, conveyance or otherwise), receive notice of meetings, receive dividends or subscription rights, or otherwise, prior to the issuance to the Holder of the Warrant Shares which he or she is then entitled to receive upon the due exercise of this Warrant. In addition, nothing contained in this Warrant shall be construed as imposing any liabilities on such Holder to purchase any securities (upon exercise of this Warrant or otherwise) or as a stockholder of the Company, whether such liabilities are asserted by the Company or by creditors of the Company. Notwithstanding this Section 5, the Company will provide the Holder of this Warrant with copies of the same notices and other information given to the other holders of Preferred Stock contemporaneously with the giving thereof to such holders.

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Section 6. Representations of Holder. The Holder of this Warrant, by the acceptance hereof, represents that it is acquiring this Warrant and the Warrant Shares for its own account for investment only and not with a view towards, or for resale in connection with, the public sale or distribution of this Warrant or the Warrant Shares, except pursuant to sales registered or exempted under the Securities Act; provided, however, that by making the representations herein, the Holder does not agree to hold this Warrant or any of the Warrant Shares for any minimum or other specific term and reserves the right to dispose of this Warrant and the Warrant Shares at any time in accordance with or pursuant to a registration statement or an exemption under the Securities Act and other applicable securities laws. The Holder of this Warrant further represents, by acceptance hereof, that, as of this date, such Holder is an “accredited investor” as such term is defined in Rule 501(a)(1) of Regulation D promulgated by the Securities and Exchange Commission under the Securities Act (an “Accredited Investor”). Upon exercise of this Warrant the Holder shall, if requested by the Company, confirm in writing, in a form satisfactory to the Company, that the Warrant Shares so purchased are being acquired solely for the Holder’s own account and not as a nominee for any other party, for investment, and not with a view toward distribution or resale and that such Holder is an Accredited Investor. If such Holder cannot make such representations because they would be factually incorrect, it shall be a condition to such Holder’s exercise of this Warrant that the Company receive such other representations as the Company considers reasonably necessary to assure the Company that the issuance of its securities upon exercise of this Warrant shall not violate any United States or state securities laws.

Section 7. Ownership and Transfer.

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(i) there is then in effect a registration statement under the Securities Act covering such proposed disposition and such disposition is made in accordance with such registration statement; or

(ii) the Holder shall have notified the Company of the proposed disposition and shall have furnished the Company with a reasonably detailed statement of the circumstances surrounding the proposed disposition, and if reasonably requested by the Company, the Holder shall have furnished the Company with an opinion of counsel, reasonably satisfactory to the Company, that such disposition will not require registration of such shares under the Securities Act (it is agreed that the Company will not require opinions of counsel for transactions made pursuant to Rule 144 except in extraordinary circumstances).

Section 8. Adjustment of Warrant Exercise Price and Number of Shares. The Warrant Exercise Price and the number of shares of Preferred Stock issuable upon exercise of this Warrant shall be adjusted from time to time as follows:

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(c) Issuance of Preferred Stock. If at any time or from time to time, the Company shall issue or sell Preferred Stock or rights, options, warrants or other securities convertible into Preferred Stock, excluding those rights, options, warrants or other securities convertible into Preferred Stock outstanding as of the date hereof, at a price per share (the “Sale Price”) that is lower than the then current Warrant Exercise Price (a “Series D Preferred Issuance”), then the Warrant Exercise Price shall thereupon be reduced to the Sale Price and the holder of this Warrant shall thereafter, on the exercise hereof as provided in Section 2, be entitled to receive that number of shares of Preferred Stock determined by multiplying the number of shares of Preferred Stock that would otherwise (but for the provisions of this Section 8(c)) be issuable on such exercise, by a fraction of which (i) the numerator is the Warrant Exercise Price that would otherwise (but for the provisions of this Section 8(c)) be in effect, and (ii) the denominator is the Warrant Exercise Price as adjusted pursuant to this Section 8(c). Such adjustment shall be made upon each Series D Preferred Issuance, and shall become effective immediately and retroactive to the record date for the determination of stockholders issued the Preferred Stock or entitled to receive such rights, options, warrants or convertible securities in connection with such Preferred Issuance.

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If there is an adjustment to the Warrant Exercise Price pursuant to the immediately preceding paragraph as a result of the issuance of rights, options, warrants or other securities convertible into Preferred Stock, then upon the termination of the right to convert or exchange such securities or the right to acquire Preferred Stock, the Warrant Exercise Price shall be readjusted to such Warrant Exercise Price as would have been obtained had the adjustments made upon the issuance of such convertible or exchangeable securities been made upon the basis of the delivery of only the number of shares of Preferred Stock actually delivered upon conversion or exchange of such securities or the exercise of the options or warrants and upon the basis of the consideration actually received by the Company (determined as provided in paragraph (d) immediately below) for such securities. Such a readjustment shall not affect the number of shares issued upon the exercise of any Warrants prior to the date the readjustment is made.

(d) Valuation of consideration. For purposes of any computation respecting consideration received pursuant to paragraph (c) hereof, the following shall apply:

(i) in the case of the issuance of shares of Preferred Stock for cash, the consideration shall be the amount of such cash, provided that in no case shall any deductions be made for any commissions, discounts or other expenses incurred by the Company for any underwriting of the issue or otherwise in connection therewith;

(ii) in the case of the issuance of shares of Preferred Stock for a consideration in whole or in part other than cash, the consideration other than cash shall be deemed to be the fair market value thereof as determined by the Company’s Board of Directors in good faith; and (iii) in the case of the issuance of securities convertible into or exchangeable for shares of Preferred Stock, the aggregate consideration received therefor shall be deemed to be the consideration received by the Company for the issuance of such securities plus the additional minimum consideration, if any, to be received by the Company upon the conversion or exchange thereof (the consideration in each case to be determined in the same manner as provided in clauses (i) and (ii) of this paragraph (d)).

(e) Definition of shares of Preferred Stock. For the purposes of this Section 8, the term “shares of Preferred Stock” shall mean (i) the class of stock designated as the Preferred Stock of the Company at the date of this Agreement as defined in Section 1(a)(x) hereof or (ii) any other class of stock resulting from changes or reclassifications of such shares consisting solely of changes in par value, or from par value to no par value, or from no par value to par value. In the event that at any time, as a result of an adjustment made pursuant to paragraph (b) above, the Holders shall become entitled to purchase any shares of the Company other than shares of Preferred Stock, thereafter the number of such other shares so purchasable upon exercise of each Warrant and the Warrant Exercise Price of such shares shall be subject to adjustment from time to time in a manner and on terms as nearly equivalent as practicable to the provisions with respect to the Warrant Shares contained in Section 8 as they would have been applied to the Warrant Shares.

(f) Minimum adjustment. No adjustment in the number of shares purchasable hereunder shall be required unless such adjustment would require an increase, or

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decrease of at least one half (1/2) of one percent (1%) in the number of shares purchasable upon the exercise of each Warrant; provided, however, that any adjustments which by reason of this paragraph (f) are not required to be made shall be carried forward and taken into account in any subsequent adjustment or upon any exercise of a Warrant.

Section 9. Purchase Rights; Reorganization, Reclassification, Consolidation, Merger or Sale.

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Section 10. Mutilated or Destroyed Warrant. If this Warrant is lost, stolen, mutilated or destroyed, the Company shall promptly, on receipt of an indemnification undertaking (or, in the case of a mutilated Warrant, the Warrant), issue a new Warrant of like denomination and tenor as this Warrant so lost, stolen, mutilated or destroyed.

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Section 11. Notice. Any notices, consents, waivers or other communications required or permitted to be given under the terms of this Warrant must be in writing and will be deemed to have been delivered: (i) upon receipt, when delivered personally; (ii) upon receipt, when sent by facsimile (provided confirmation of receipt is received by the sending party transmission is mechanically or electronically generated and kept on file by the sending party); or (iii) one Business Day after deposit with a nationally recognized overnight delivery service, in each case properly addressed to the party to receive the same. The addresses and facsimile numbers for such communications shall be:

If to a Holder of this Warrant, to it at the address and facsimile number set forth on Exhibit C hereto, with copies to such Holder’s representatives as set forth on Exhibit C, or at such other address and facsimile as shall be delivered to the Company upon the issuance or transfer of this Warrant. Each party shall provide five days’ prior written notice to the other party of any change in address or facsimile number. Written confirmation of receipt (A) given by the recipient of such notice, consent, facsimile, waiver or other communication, or (B) provided by a nationally recognized overnight delivery service shall be rebuttable evidence of personal service, receipt by facsimile or receipt from a nationally recognized overnight delivery service in accordance with clause (i), (ii) or (iii) above, respectively.

Section 12. Date. The date of this Warrant is set forth on page 1 hereof. This Warrant, in all events, shall be wholly void and of no effect after the close of business on the Expiration Date.

Section 13. Amendment and Waiver. Except as otherwise provided herein, the provisions of the Warrants may be amended and the Company may take any action herein prohibited, or omit to perform any act herein required to be performed by it, only if the Company

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has obtained the written consent of the Requisite Holders; provided that, except for Sections 8(a) and 8(d), no such action may increase the Warrant Exercise Price or decrease the number of shares or class of stock obtainable upon exercise of any Warrant without the written consent of the Holder of such Warrant.

Section 14. Descriptive Headings; Governing Law. The descriptive headings of the several sections and paragraphs of this Warrant are inserted for convenience only and do not constitute a part of this Warrant. All questions concerning the construction, validity, enforcement and interpretation of this Agreement shall be governed by the internal laws of the State of Arizona, without giving effect to any choice of law or conflict of law provision or rule (whether of the State of Arizona or any other jurisdictions) that would cause the application of the laws of any jurisdictions other than the State of Arizona. Each party hereby irrevocably submits to the exclusive jurisdiction of the state and federal courts sitting in Arizona, for the adjudication of any dispute hereunder or in connection herewith or therewith, or with any transaction contemplated hereby or discussed herein, and hereby irrevocably waives, and agrees not to assert in any suit, action or proceeding, any claim that it is not personally subject to the jurisdiction of any such court, that such suit, action or proceeding is brought in an inconvenient forum or that the venue of such suit, action or proceeding is improper. Each party hereby irrevocably waives personal service of process and consents to process being served in any such suit, action or proceeding by mailing a copy thereof to such party at the address for such notices to it under this Agreement and agrees that such service shall constitute good and sufficient service of process and notice thereof. Nothing contained herein shall be deemed to limit in any way any right to serve process in any manner permitted by law.

Section 15. Waiver of Jury Trial. AS A MATERIAL INDUCEMENT FOR EACH PARTY HERETO TO ENTER INTO THIS WARRANT, THE PARTIES HERETO HEREBY WAIVE ANY RIGHT TO TRIAL BY JURY IN ANY LEGAL PROCEEDING RELATED IN ANY WAY TO THIS WARRANT AND/OR ANY AND ALL OF THE OTHER DOCUMENTS ASSOCIATED WITH THIS TRANSACTION.

Section 16. Option. In the event after the date of the issuance of this Warrant, the Company raises additional capital through the sale of any capital stock of the Company (the “Offered Stock”), the Company shall grant to the Holder the right to purchase at the same price and on the same terms as the Offered Stock is to be sold to the other purchasers thereof that number of shares of the Offered Stock determined as follows: the greater of (a) that number of shares of the Offered Stock determined by multiplying the total number of shares of the Offered Stock times the Holder’s percentage ownership of the Preferred Stock on a fully diluted, as if exercised basis or (b) that number of shares of the Offered Stock determined by dividing [                                        ] by the price at which the Offered Stock is sold by the Company.

(signature page follows)

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IN WITNESS WHEREOF, the Company has caused this Warrant to be signed as of the date first set forth above.

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EXHIBIT A TO WARRANT

EXERCISE NOTICE

TO BE EXECUTED

BY THE REGISTERED HOLDER TO EXERCISE THIS WARRANT

The undersigned Holder hereby exercises the right to purchase                      of the shares of                  Preferred Stock (“Warrant Shares”) of SynCardiaSystems, Inc., a Delaware corporation (the “Company”), evidenced by the attached Warrant (the “Warrant”). Capitalized terms used herein and not otherwise defined shall have the respective meanings set forth in the Warrant.

1. Form of Warrant Exercise Price. The Holder intends that payment of the Warrant Exercise Price shall be made as a “Cash Exercise” with respect to                      Warrant Shares.

2. Payment of Warrant Exercise Price. The Holder shall pay the sum of $         to the Company in accordance with the terms of the Warrant.

3. Delivery of Warrant Shares. The Company shall deliver to the Holder Warrant Shares in accordance with the terms of the Warrant.

Date:                  ,         

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EXHIBIT B TO WARRANT

FORM OF WARRANT POWER

FOR VALUE RECEIVED, the undersigned does hereby assign and transfer to                     , Federal Identification No.     , a warrant to purchase                  shares of the capital stock of SynCardiaSystems, Inc., a Delaware corporation, represented by warrant certificate no.     , standing in the name of the undersigned on the books of said corporation. The undersigned does hereby irrevocably constitute and appoint                     , attorney to transfer the warrants of said corporation, with full power of substitution in the premises.

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