                     COURT OF APPEALS OF VIRGINIA


Present: Judges Benton, Elder and Overton
Argued at Richmond, Virginia


ALBEMARLE COUNTY SCHOOL BOARD, ET AL.
                                          MEMORANDUM OPINION * BY
v.          Record No. 0075-97-2           JUDGE LARRY G. ELDER
                                               JUNE 17, 1997
VIRGIE IRENE MORRIS, ETC.


          FROM THE VIRGINIA WORKERS' COMPENSATION COMMISSION

            Patricia C. Karppi (McGuire, Woods, Battle &
            Boothe, L.L.P., on brief), for appellants.
            Michael T. Hemenway (Dygert & Hemenway, on
            brief), for appellee.



     Albemarle County School Board and School Systems of

Virginia, self-insured association, (appellants) appeal an order

of the Workers' Compensation Commission (commission) awarding

temporary total disability benefits, death benefits, medical

benefits, and burial expenses to the widow of Elson C. Morris,

(claimant).    Appellants contend that the evidence was

insufficient to support the commission's conclusion that

claimant's disability following the discovery of a heart ailment

in July, 1993 and eventual death due to heart failure on

November 15, 1993 were causally related to his work-related

accident on March 19, 1993.    For the reasons that follow, we

affirm.

     "In order to recover on a workers' compensation claim, a
     *
      Pursuant to Code § 17-116.010 this opinion is not
designated for publication.
claimant must prove: (1) an injury by accident, (2) arising out

of and (3) in the course of his employment."   Kane Plumbing, Inc.

v. Small, 7 Va. App. 132, 135, 371 S.E.2d 828, 830 (1988)

(citations omitted); see Code § 65.2-101.   An "injury by

accident" requires proof of "(1) an identifiable incident; (2)

that occurs at some reasonably definite time; (3) an obvious

sudden mechanical or structural change in the body; and (4) a

causal connection between the incident and the bodily change."
Chesterfield County v. Dunn, 9 Va. App. 475, 476, 389 S.E.2d 180,

181 (1990) (citing Lane Co. v. Saunders, 229 Va. 196, 199, 326

S.E.2d 702, 703 (1985)).   Under Code § 65.2-512, "a claimant for

death benefits . . . is required to prove a causal connection

between the accident and the subsequent death by a preponderance

of the evidence."   Lilly v. Shenandoah's Pride Dairy, 218 Va.

481, 483, 237 S.E.2d 786, 787 (1977).
               When it is established that an accident
          to an employee activates an undeveloped and
          dangerous physical condition with mortal
          consequences, such accident is properly
          considered the proximate cause of the
          fatality. Causal connection is established
          when it is shown that the employee has
          received a compensable injury which
          materially aggravates or accelerates the
          pre-existing latent disease which becomes the
          direct cause of death.

Rogers v. Williams, 196 Va. 39, 42, 82 S.E.2d 601, 602-03 (1954).
          [W]here a claimant has suffered a heart
          attack which arose out of and in the course
          of his employment and which is determined to
          have been a producing or contributing factor
          in a second fatal heart attack, regardless of



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          whether the second incident itself is
          compensable, death benefits are available to
          the dependent distributees . . . .

     Appellants concede that claimant was involved in an

identifiable incident at a reasonably definite time -- his car

accident on March 19 -- and that this accident arose out of and

occurred in the course of his employment.    In addition,

appellants do not contest the commission's finding that claimant

suffered a heart attack prior to November 15 that directly

contributed to his death from heart failure on that date.

Instead, appellants argue that credible evidence does not support

the commission's finding that claimant's heart attack occurred at

the time of his accident on March 19.
     "Decisions of the commission as to questions of fact, if

supported by credible evidence, are conclusive and binding on

this Court."   Manassas Ice & Fuel Co. v. Farrar, 13 Va. App. 227,

229, 409 S.E.2d 824, 826 (1991); see Code § 65.2-706(A).     On

appeal, we view the evidence in the light most favorable to the

prevailing party below.   R.G. Moore Bldg. Corp. v. Mullins, 10
Va. App. 211, 212, 390 S.E.2d 788, 788 (1990).   Whether or not an

injury has occurred is a question of fact.

     We hold that the commission's finding that claimant suffered

a heart attack at the time of his accident on March 19 is

supported by credible evidence.    In reaching its conclusion, the

commission relied solely upon the expert medical opinion of Dr.

Bergin, who testified that claimant suffered a heart attack at



                                  -3-
the time of his accident.   Dr. Bergin's opinion constituted

credible evidence of the timing of claimant's initial heart

attack.

     In order to possess relevant evidential value, a doctor's

expert medical opinion must not be speculative.    See Gilbert v.

Summers, 240 Va. 155, 160, 393 S.E.2d 213, 215 (1990); Spruill v.

Commonwealth, 221 Va. 475, 479, 271 S.E.2d 419, 421 (1980).      A

doctor's expert medical opinion is not speculative if it is based

on an accurate understanding of the relevant facts and if it is

based on a reasonable probability and not a mere possibility.
See Gilbert, 240 Va. at 160, 393 S.E.2d at 215 (stating that an

expert's opinion is speculative if not based upon facts within

his knowledge or established by other evidence); Clinchfield Coal

Co. v. Bowman, 229 Va. 249, 252, 329 S.E.2d 15, 16 (1985)

(holding that a doctor's medical opinion was not credible when

based upon a faulty premise); Spruill, 221 Va. at 479, 271 S.E.2d

at 421 (stating that a medical opinion is speculative if based on

a "possibility" and admissible if based on a "reasonable

probability").

     Dr. Bergin's opinion possessed evidential value because it

was based on his expert knowledge and an accurate understanding

of claimant's case and because it was not based on a mere

possibility.   First, Dr. Bergin's opinion was based on the facts

of claimant's case.   Dr. Bergin was qualified as an expert in

medicine and cardiology.    He testified that he had reviewed



                                 -4-
claimant's medical records from the Central Virginia Community

Health Center, the University of Virginia emergency room on the

date of claimant's accident, Dr. Caughron, which dated back to

1990, as well as his own records of claimant's treatment.   He

expressly testified that his opinion that claimant suffered a

heart attack on March 19 was based on both his professional

knowledge and his knowledge of claimant's case.   The record does

not indicate that Dr. Bergin's medical opinion was based on

either a faulty premise or misinformation.    See Clinchfield Coal

Co., 229 Va. at 252, 239 S.E.2d at 16; Sneed v. Morengo, Inc., 19

Va. App. 199, 205, 450 S.E.2d 167, 171 (1994).

     In addition, Dr. Bergin's opinion was based on a reasonable

probability, not a mere possibility.   He testified that the

occurrence of claimant's heart attack at the time of his accident

on March 19 was "more than likely."    He also had the following

exchange with claimant's lawyer:
          Q.   Based on your review of his medical
          records and the history you obtained from Mr.
          Morris' family, and also from Dr. Caughron,
          and based on your training and experience, do
          you have an opinion, within a reasonable
          degree of medical certainty, as to whether or
          not he suffered a heart attack in the
          accident which occurred on March 19, 1993?

          A.   Yes, I do think he suffered a heart
          attack at the accident.

     Because Dr. Bergin's medical opinion possessed relevant

evidential value, we cannot say that the commission's factual

finding based on this opinion that claimant suffered a heart


                               -5-
attack at the time of his accident was not supported by credible

evidence.

     For the foregoing reasons, we affirm the commission's award.

                                                        Affirmed.




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