The employee appeals from the compensation judge’s denial of his claim for payment of medical expenses related to surgery for the implantation of a cardiac pacemaker.  We affirm.

Donald Vold began working for the employer, Pepsi-Cola of Ortonville, in 2003.  He worked as a delivery driver and also stocked store shelves with Pepsi-Cola products after delivery.

On September 28, 2009, the employee was on a step-stool counting the cases of product that had been loaded on his truck.  As he was climbing down off the stool, his foot missed a step and he fell backwards, landing on a concrete floor.  He was unable to move his left arm and was taken by ambulance to the emergency room at the Ortonville Hospital.  He was seen by Dr. Allan Ross and x-rays revealed a displaced midshaft fracture of the left humerus.

Attempts were made to realign the bone using gravity and pulling on the arm.  A portable X-ray machine was used to determine whether the procedure was working.  X-rays showed the fracture was improved but still displaced.  During the procedure, the employee “felt light-headed and nauseated” and then had a brief syncopal episode.^[1]  A heart monitor showed bradycardia and there was an episode of ventricular fibrillation lasting about 45 seconds followed by asystole, or stoppage of the heart for perhaps 15-20 seconds.  His heart rhythm then spontaneously returned to normal and he regained consciousness.

Because the Ortonville hospital had no cardiologist on duty, the employee was transferred by helicopter to the Sanford Medical Center in Sioux Falls, South Dakota.  He was seen there by Dr. Tomasz Stys, who found the employee to be asymptomatic and hemodynamically stable.  Dr. Stys reviewed the employee’s heart rhythm data sent from Ortonville and concluded that the employee had experienced a severe vasovagal event.  He recommended that the employee undergo cardiac catheterization for definite diagnosis of his coronary anatomy, and that he have an electrocardiogram and be seen for an electrophysiology consultation by Dr. Scott Pham with regard to a possible pacemaker implantation.  Dr. Stys also referred the employee to orthopedic services for the further management of his left humeral fracture.

Later the same day, the employee underwent left heart catheterization, a left ventriculogram, and a coronary angiogram.  The diagnostic impression from these tests was of 99 percent ostial second diagonal medium-sized branch disease, and mild major epicardial disease was otherwise noted.

Dr. Pham also saw the employee that day, September 28, 2009.  He agreed that the episode of syncope the employee had experienced at the Ortonville hospital was likely vasovagal syncope, but because of the profound atrial asystole, he recommended that the employee undergo pacemaker implantation, in part because it would allow him to sit down before any future syncopal episodes.  The employee agreed with this recommendation.  The employee underwent the implantation of a pacemaker on the following day, September 29, 2009.

On September 30, 2009, the employee underwent open reduction internal fixation of his left humeral fracture while at Sanford Hospital.

The employee returned to work with the employer on November 19, 2009, initially under restrictions, and then without restriction after December 17, 2009.  He has not had further syncopal episodes.

The employer and insurer paid the employee temporary total disability compensation and for the medical expenses the employee incurred for treatment of his fracture.  By the date of hearing, they had also agreed to pay for medical treatment for the employee’s vasovagal episode at Ortonville, for his transportation to the Sanford Hospital, and for the coronary evaluations and testing performed at Sanford.  However, they denied liability for the surgical expenses of the pacemaker surgery, contending that the work injury was not a substantial contributing cause of the need for that procedure.  That issue came on for hearing before a compensation judge of the Office of Administrative Hearings on May 12, 2011.  Following the hearing, the judge found that the employee’s injury did not substantially contribute to his need for the pacemaker implantation and denied reimbursement for that portion of the employee’s medical expenses.  The employee appeals.

Pursuant to Minn. Stat. § 176.135, subd. 1, an employer is obligated to furnish any medical care that is reasonably required to cure and relieve an injured worker from the effects of a work injury.  It is also well settled that injuries are compensable if the employment is a substantial contributing factor not only in causing a new condition but also in aggravating or accelerating a preexisting condition.  Wallace v. Hanson Silo Co., 305 Minn. 395, 235 N.W.2d 363, 28 W.C.D. 79 (1975).

The sole question presented in this case is whether substantial evidence supports the judge’s finding that the work injury was not a substantial contributing cause of the need for the pacemaker implantation surgery.

Both parties offered expert medical opinion evidence bearing on this question.  The employee relied on letter opinions from Dr. Stys, Dr. Ross and Dr. Phan.  The employer and insurer relied on the medical reports of Dr. David Berman, who examined the employee on their behalf.

Dr. Stys, Dr. Ross and Dr. Berman all agreed that the work injury was a substantial contributing factor to the employee’s episode of bradycardia, syncope and asystole while in the emergency room at the Ortonville Hospital.  Dr. Stys and Dr. Berman further agreed that the employee had a predisposition to vasovagal episodes with a propensity to atrial asystole and syncope.^[2]  The question, however, was not whether the vasovagal and syncopal episode in the Ortonville Hospital was causally related to the work injury, but whether the injury was also a substantial contributing cause of a need for a pacemaker.

Dr. Stys, in two letter opinions, extended the causal connection between the work injury and the episode of asystole to the pacemaker surgery by explaining that the episode at the Ortonville Hospital “resulted in a subsequent diagnosis” of the employee’s vasovagal syndrome and propensity to asystole, and it was this diagnosis, in turn, which led to the decision to implant the pacemaker.  Dr. Ross’ opinion similarly noted that the recommendation for a pacemaker would not have been made but for the accident and the ensuing vasovagal reaction.  This seems to be the sole rationale provided by these physicians to support a causal connection between the work injury and the pacemaker implantation.

Dr. Berman, on the other hand, specifically stated that the pacemaker implantation was medically unrelated to the work injury.  He considered the cardiac episode in the Ortonville Hospital emergency room to have been related to the effects of the work injury, but noted that this episode had resolved by the time of the decision to implant the pacemaker.  He further saw no evidence of any injury to the heart or any heart disease due to the work injury or from the subsequent cardiac episode.  In his opinion neither the work injury nor the subsequent cardiac episode precipitated or aggravated any heart condition, nor had they aggravated or accelerated the employee’s pre-existing tendency for a vasovagal response and risk for asystole.  Since the medical necessity for the pacemaker was to prevent further episodes of asystole, Dr. Berman considered that procedure to have been necessitated solely by the employee’s pre-existing condition.

The compensation judge found that the employee’s injury did not substantially contribute to the need for pacemaker implantation.  Rather, the judge concluded that “the cardiac reaction to the injury helped to diagnose an underlying and pre-existing condition that required treatment” with a pacemaker.  In reaching her findings, the judge expressly relied upon the expert medical opinion of Dr. Berman.

As a general rule, if there is a disagreement between one or more medical experts, it is the job of the compensation judge to review the differing opinions and to choose which opinions appear most credible and most consistent with the evidence as a whole.  The opinion of a medical expert, where adopted by the compensation judge, may serve as the basis for her decision, so long as the expert had a sufficient factual basis or foundation for the opinion from an examination of the employee and review of the employee’s medical records.  See, e.g., Heitland v. R.O. Drywall, No. WC04-263 (W.C.C.A. Apr. 5, 2005).

We note that the evidence as a whole is consistent with the stated basis for Dr. Berman’s opinion.  First, the employee’s cardiac examination after arrival at Sanford Hospital showed him to be asymptomatic, chest pain free, and hemodynamically stable.  The tests performed there did not show any obvious recent damage to his heart.  None of the medical experts offered the opinion that the work injury or the subsequent cardiac episode at the Ortonville Hospital had caused a new cardiac problem or had accelerated or aggravated an underlying condition.  The medical records recommending the pacemaker implantation were phrased in terms of alleviating the risks which would be associated with any future episodes of vasovagal syncope, independent of the previous episode which was related to the injury.

The employee argues that, as a matter of law, the judge should have found a causal nexus between the work injury and the cardiac pacemaker implantation, on the basis that the work injury made the underlying tendency toward vasovagal syncope and potential asystole symptomatic.  While we agree that treatment for a condition made symptomatic by a work injury may be compensable, the symptoms of the underlying condition in this case had returned to the asymptomatic state by the time the employee was evaluated at the Sanford Hospital, and the evidence reasonably supports the judge’s finding that the reason for the implantation of the pacemaker was to reduce future risks associated with that underlying condition and not to treat or relieve the effects of the work injury.

The situation presented in this case is somewhat unusual, but this court has previously considered a somewhat analogous situation in Astren v. Ad Art Advertising, Inc., No. WC05-210 (W.C.C.A. Nov. 17, 2005).^[3]  In Astren, we stated that “we find no authority to support the employee’s contention that compensability should extend to a non-work-related condition merely because that condition happened to be discovered during the course of treatment for a work injury.”

We conclude that substantial evidence supported the compensation judge’s finding and that the judge’s conclusions did not constitute an error of law.  We therefore affirm.