Ownership Submission
FORM 3
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
  MIDDLETON FRED A
2. Date of Event Requiring Statement (Month/Day/Year)
03/18/2008
3. Issuer Name and Ticker or Trading Symbol
CARDIONET INC [BEAT]
(Last)
(First)
(Middle)
400 SOUTH EL CAMINO REAL, SUITE 1200
4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ Director __X__ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
5. If Amendment, Date Original Filed(Month/Day/Year)
(Street)

SAN MATEO, CA 94402
6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Beneficially Owned
1.Title of Security
(Instr. 4)
2. Amount of Securities Beneficially Owned
(Instr. 4)
3. Ownership Form: Direct (D) or Indirect (I)
(Instr. 5)
4. Nature of Indirect Beneficial Ownership
(Instr. 5)
Common Stock 4,695
I
See footnotes (1)
Common Stock 16,475
I
See footnotes (2)
Common Stock 16,510
I
See footnotes (3)
Common Stock 45,000
I
See footnotes (4)
Common Stock 42,319
I
See footnotes (5)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly. SEC 1473 (7-02)
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Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 4)
2. Date Exercisable and Expiration Date
(Month/Day/Year)
3. Title and Amount of Securities Underlying Derivative Security
(Instr. 4)
4. Conversion or Exercise Price of Derivative Security 5. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 5)
6. Nature of Indirect Beneficial Ownership
(Instr. 5)
Date Exercisable Expiration Date Title Amount or Number of Shares
Stock Option (right to buy)   (6) 09/24/2017 Common Stock 7,500 $ 7.2 D  
Stock Option (right to buy)   (6) 09/24/2017 Common Stock 15,000 $ 7.2 D  
Series B Convertible Preferred Stock   (7)   (7) Common Stock 97,819 $ (7) I See footnotes (1)
Series B Convertible Preferred Stock   (7)   (7) Common Stock 343,223 $ (7) I See footnotes (2)
Series B Convertible Preferred Stock   (7)   (7) Common Stock 343,957 $ (7) I See footnotes (3)
Series B Convertible Preferred Stock   (7)   (7) Common Stock 34,014 $ (7) I See footnotes (4)
Series B Convertible Preferred Stock   (7)   (7) Common Stock 881,655 $ (7) I See footnotes (5)
Series C Convertible Preferred Stock   (8)   (8) Common Stock 9,370 $ (8) I See footnotes (1)
Series C Convertible Preferred Stock   (8)   (8) Common Stock 655,261 $ (8) I See footnotes (9)
Series C Convertible Preferred Stock   (8)   (8) Common Stock 32,877 $ (8) I See footnotes (2)
Series C Convertible Preferred Stock   (8)   (8) Common Stock 32,948 $ (8) I See footnotes (3)
Series C Convertible Preferred Stock   (8)   (8) Common Stock 351 $ (8) I See footnotes (4)
Series C Convertible Preferred Stock   (8)   (8) Common Stock 53,721 $ (8) I See footnotes (10)
Series C Convertible Preferred Stock   (8)   (8) Common Stock 223,839 $ (8) I See footnotes (11)
Series C Convertible Preferred Stock   (8)   (8) Common Stock 60,374 $ (8) I See footnotes (12)
Series C Convertible Preferred Stock   (8)   (8) Common Stock 327,596 $ (8) I See footnotes (13)
Series C Convertible Preferred Stock   (8)   (8) Common Stock 84,454 $ (8) I See footnotes (5)
Series C Convertible Preferred Stock   (8)   (8) Common Stock 369,209 $ (8) I See footnotes (14)
Series C Convertible Preferred Stock   (8)   (8) Common Stock 7,143 $ (8) I See footnotes (15)
Series D Convertible Preferred Stock   (16)   (16) Common Stock 11,281 $ (16) I See footnotes (10)
Series D Convertible Preferred Stock   (16)   (16) Common Stock 47,006 $ (16) I See footnotes (11)
Series D Convertible Preferred Stock   (16)   (16) Common Stock 12,679 $ (16) I See footnotes (12)
Series D Convertible Preferred Stock   (16)   (16) Common Stock 77,534 $ (16) I See footnotes (14)
Series D Convertible Preferred Stock   (16)   (16) Common Stock 1,500 $ (16) I See footnotes (15)

Reporting Owners

Reporting Owner Name / Address Relationships
Director 10% Owner Officer Other
MIDDLETON FRED A
400 SOUTH EL CAMINO REAL
SUITE 1200
SAN MATEO, CA 94402
  X   X    

Signatures

/s/ Fred A. Middleton 03/17/2008
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 5(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) By Sanderling [Feri Trust] Venture Partners IV, L.P. Fred Middleton, a member of the Issuer's board of directors is a general partner of Middleton-McNeil Investment Partners IV, L.P. the sole general partner of Sanderling [Feri Trust] Venture Partners IV, L.P. and has voting and investment power over the shares held by Sanderling [Feri Trust] Venture Partners IV, L.P. Mr. Middleton disclaims beneficial ownership of these shares except to the extent of his pecuniary interest therein.
(2) By Sanderling IV Biomedical, L.P. Fred Middleton, a member of the Issuer's board of directors is a managing director of Middleton, McNeil & Mills Associates IV, LLC the sole general partner of Sanderling IV Biomedical, L.P. and has voting and investment power over the shares held by Sanderling IV Biomedical, L.P. Mr. Middleton disclaims beneficial ownership of these shares except to the extent of his pecuniary interest therein.
(3) By Sanderling IV Limited Partnership. Fred Middleton, a member of the Issuer's board of directors is a general partner of Middleton-McNeil IV, L.P. the sole general partner of Sanderling IV Limited Partnership and has voting and investment power over the shares held by Sanderling IV Limited Partnership. Mr. Middleton disclaims beneficial ownership of these shares except to the extent of his pecuniary interest therein.
(4) By Sanderling Ventures Management IV. Fred Middleton, a member of the Issuer's board of directors is an owner of Sanderling Ventures Management IV and has voting and investment power over the shares held by Sanderling Ventures Management IV. Mr. Middleton disclaims beneficial ownership of these shares except to the extent of his pecuniary interest therein.
(5) By Sanderling Venture Partners IV, L.P. Fred Middleton, a member of the Issuer's board of directors is a general partner of Middleton-McNeil Associates IV, L.P. the sole general partner of Sanderling Venture Partners IV, L.P. and has voting and investment power over the shares held by Sanderling Venture Partners IV, L.P. Mr. Middleton disclaims beneficial ownership of these shares except to the extent of his pecuniary interest therein.
(6) 33 1/3 % of the shares subject to the option shall vest on the first anniversary of the vesting start date of 9/24/07; 1/24th shall vest on each monthly anniversary thereafter. The options may be early exercised prior to vesting but any exercised and unvested shares are subject to a right of repurchase on behalf of the Issuer.
(7) Series B Preferred Stock has no expiration date and is convertible at any time at the option of the holder and will automatically convert upon the closing of the Issuer's initial public offering, at a conversion ratio of one share of Common Stock for every two shares of Series B Preferred Stock, for no additional consideration.
(8) Series C Preferred Stock has no expiration date and is convertible at any time at the option of the holder and will automatically convert upon the closing of the Issuer's initial public offering, at a conversion ratio of one share of Common Stock for every two shares of Series C Preferred Stock, for no additional consideration.
(9) By Sanderling IV Biomedical Co-Investment Fund, L.P. Fred Middleton, a member of the Issuer's board of directors is a managing director of Middleton, McNeil & Mills Associates IV, LLC the sole general partner of Sanderling IV Biomedical Co-Investment Fund, L.P. and has voting and investment power over the shares held by Sanderling IV Biomedical Co-Investment Fund, L.P. Mr. Middleton disclaims beneficial ownership of these shares except to the extent of his pecuniary interest therein.
(10) By Sanderling V Beteilingungs GmbH & Co KG. Fred Middleton, a member of the Issuer's board of directors is a managing director of Middleton, McNeil & Mills Associates V, LLC the sole general partner of Sanderling V Beteilingungs GmbH & Co KG and has voting and investment power over the shares held by Sanderling V Beteilingungs GmbH & Co KG. Mr. Middleton disclaims beneficial ownership of these shares except to the extent of his pecuniary interest therein.
(11) By Sanderling V Biomedical Co-Investment Fund L.P. Fred Middleton, a member of the Issuer's board of directors is a managing director of Middleton, McNeil & Mills Associates V, LLC the sole general partner of Sanderling V Biomedical Co-Investment Fund L.P and has voting and investment power over the shares held by Sanderling V Biomedical Co-Investment Fund L.P. Mr. Middleton disclaims beneficial ownership of these shares except to the extent of his pecuniary interest therein.
(12) By Sanderling V Limited Partnership. Fred Middleton, a member of the Issuer's board of directors is a managing director of Middleton, McNeil & Mills Associates V, LLC the sole general partner of Sanderling V Limited Partnership and has voting and investment power over the shares held by Sanderling V Limited Partnership. Mr. Middleton disclaims beneficial ownership of these shares except to the extent of his pecuniary interest therein.
(13) By Sanderling Venture Partners IV Co-Investment Fund, L.P. Fred Middleton, a member of the Issuer's board of directors is a managing director of Middleton, McNeil & Mills Associates IV, LLC the sole general partner of Sanderling Venture Partners IV Co-Investment Fund, L.P and has voting and investment power over the shares held by Sanderling Venture Partners IV Co-Investment Fund, L.P. Mr. Middleton disclaims beneficial ownership of these shares except to the extent of his pecuniary interest therein.
(14) By Sanderling Venture Partners V Co-Investment Fund, L.P. Fred Middleton, a member of the Issuer's board of directors is a managing director of Middleton, McNeil & Mills Associates V, LLC the sole general partner of Sanderling Venture Partners V Co-Investment Fund, L.P and has voting and investment power over the shares held by Sanderling Venture Partners V Co-Investment Fund, L.P. Mr. Middleton disclaims beneficial ownership of these shares except to the extent of his pecuniary interest therein.
(15) By Sanderling Ventures Management V. Fred Middleton, a member of the Issuer's board of directors is an owner of Sanderling Ventures Management V and has voting and investment power over the shares held by Sanderling Ventures Management V. Mr. Middleton disclaims beneficial ownership of these shares except to the extent of his pecuniary interest therein.
(16) Series D Preferred Stock has no expiration date and is convertible at any time at the option of the holder and will automatically convert upon the closing of the Issuer's initial public offering, at a conversion ratio of one share of Common Stock for every two shares of Series D Preferred Stock, for no additional consideration.

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