"Watts, J.

Civil action for malpractice is brought by Alie C. Bradshaw, the surviving husband, as administrator of the estate of his deceased wife, Eva L. Bradshaw, against operating surgeon Max Blaine, M. D., for damages for her alleged wrongful death during surgery. Judgment with costs was rendered for plaintiff. Defendant appeals.

Decedent entered Highland Park General Hospital July 9, 1956, at 3:35 p.m. for elective, unexceptional surgery, i.e., surgery that may be performed at the convenience of the doctor, the hospital, and the patient. Decedent had an asthmatic attack which lasted from approximately midnight, July 9th, to 5 a.m. the next morning. Defendant had knowledge of the attack. Abdominal surgery was performed on the decedent July 10th at 8 a.m., and during surgery she had a sudden cardiac arrest and expired at 9:56 the same morning.

Plaintiff alleged that defendant failed to adhere to the standard of practice for physicians and surgeons in the community when he performed surgery upon the decedent and that defendant’s failure to adhere to the standard of practice for physicians and surgeons in the community constituted negligence which was the proximate cause of death of plaintiff’s decedent.

Defendant denied plaintiff’s allegations and testified that he did adhere to the standard of practice *53 for physicians and. surgeons and that the cardiac arrest may have been a result of many causes.

Dr. Henry L. Smith, an expert witness for plaintiff; Dr. William P. Chester and Dr. Eugene Isaac Pious, expert witnesses for defendant, testified that they were familiar with the standard of practice of physicians and surgeons in the community and in similar communities for surgery such as defendant performed.

Dr. Henry L. Smith, in answer to a hypothetical question based on decedent’s case history and hospital record, testified that in his opinion defendant failed to adhere to the standard of practice for physicians and surgeons in the community and that the standard of practice required defendant to delay surgery until such a time as the patient had recuperated from the asthmatic attack. He further testified that defendant’s failure to adhere to the standard of practice for physicians and surgeons in the community could have caused decedent’s cardiac arrest.

Defendant’s witnesses, Doctors Chester and Pious, in answer to a similar hypothetical question, testified that in their opinion defendant did adhere to the standard of practice for physicians and surgeons in the community, that such standard of practice did not require defendant to delay surgery, and that there are many causes which could have brought about decedent’s cardiac arrest.

It has been repeatedly held by the Michigan Supreme Court that there is an implied contract between a patient and his surgeon requiring the latter to use that degree of skill and diligence ordinarily exercised by the average members of the medical profession in the same or similar localities with due consideration to the state of the profession at the time. Miller v. Toles (1914), 183 Mich 252 (LRA 1915C, 595); Bryant v. Biggs (1951), 331 Mich 64. In the instant case it was the duty of defendant to *54 use that degree of skill and diligence customarily used in the community or in similar communities by ordinary, average practitioners of medicine and surgery. The alleged failure of defendant to exercise that degree of skill and care could only be established by testimony of expert witnesses familiar with the standard of practice of physicians and surgeons in the same or similar communities.

Doctors Henry L. Smith, Chester, and Pious were well qualified and competent to give testimony as expert witnesses. Their testimony differed materially as to what constituted the standard of practice for physicians and surgeons in the community.

Where there is a conflict in the testimony of qualified expert witnesses, a factual issue is presented for the trier of the facts.

The trial judge, sitting without a jury, made a finding of fact from the testimony. On appeal, the Court does not substitute its judgment on fact for that of the trial judge unless the evidence clearly preponderates in the opposite direction. In re Granville Estate (1956), 345 Mich 495; Hall v. Horak (1950), 329 Mich 16.

It is our opinion defendant’s determination as to decedent’s operative condition was a matter requiring the exercise of sound professional judgment in accordance with the standard of practice of physicians and surgeons in the community.

It is the claim of defendant that the trial court committed prejudicial error in overruling the objections of defendant to certain testimony of Dr. Henry L. Smith.

This Court has reviewed the testimony and finds that the trial court did not commit prejudicial error in allowing said testimony to be received. The testimony in question was proper when considered in its entirety, a proper foundation therefor having been laid.

*55 Appellant further raised the question of proximate cause. This Court finds that the evidence presented by plaintiff was sufficient to raise a question of fact which was passed upon by the trier of the facts who found negligence on the part of defendant, constituting proximate cause of death of plaintiff’s decedent.

Judgment affirmed. Costs to plaintiff-appellee.

Lesinski, C. J., and J. H. Gillis, J., concurred.