|Considered by McGIVERIN, C.J., and HARRIS, LARSON, SNELL, and ANDREASEN, JJ.
McGIVERIN, Chief Justice.
The main question here is whether the trial court erred in refusing to instruct the jury on the eggshell plaintiff rule in view of the fact that plaintiff's decedent, who had a history of coronary disease, died of a heart attack six days after suffering a bruised chest and fractured ankle in a motor vehicle accident caused by defendant's negligence. The court of appeals concluded that the trial court's refusal constituted reversible error. We agree with the court of appeals and reverse the judgment of the trial court and remand for a new trial.
Benn's executor sued defendant for Loras Benn's injuries and his death after defendant's vehicle rear-ended the van in which decedent was a passenger.
At trial, the estate's medical expert, Dr. James E. Davia, testified that Loras had a history of coronary disease and insulin-dependent diabetes. Loras had a heart attack in 1985 and was at risk of having another. Dr. Davia testified that he viewed the accident that Loras was in and the attendant problems that it caused in the body as the straw that broke the camels back and the cause of Loras's death. Other medical evidence indicated the accident did not cause his death.
Based on Dr. Davia's testimony, the estate requested an instruction to the jury based on the eggshell plaintiff rule, which requires the defendant to take his plaintiff as he finds him, even if that means that the defendant must compensate the plaintiff for harm an ordinary person would not have suffered. Plaintiff requested the following charge:
If Loras Benn had a prior heart condition making him more susceptible to injury than a person in normal health, then the Defendant is responsible for all injuries and damages which are experienced by Loras Benn, proximately caused by the Defendant's actions, even though the injuries claimed produced a greater injury than those which might have been experienced by a normal person under the same circumstances.
The trial judge denied that request and instead gave the following general charge:
The conduct of a party is a proximate cause of damage when it is a substantial factor in producing damage and when the damage would not have happened except for the conduct. Substantial means the party's conduct has such an effect in producing damage as to lead a reasonable person to regard it as a cause.
Special Verdict Number 4 asked the jury: ?Was the negligence of Leland Thomas a proximate cause of Loras Benn's death. The jury answered this question, No. The jury returned a verdict for $17,000 for Loras's injuries but nothing for his death. In its special verdict, the jury determined the defendant's negligence in connection with the accident did not proximately cause Loras's death. The court of appeals reversed the trial court's judgment for $17,000 and remanded the case because the charge given to the jury failed to convey the applicable law.
A tortfeasor whose act, superimposed upon a prior latent condition, results in an injury may be liable in damages for the full disability. This rule deems the injury, and not the dormant condition, the proximate cause of the plaintiff's harm.
his precept is often referred to as the ?eggshell plaintiff rule, which has its roots in cases such as Dulieu v. White & Sons,  2 K.B. 669, 679, where the court observed:
If a man is negligently run over or otherwise negligently injured in his body, it is no answer to the sufferer's claim for damages that he would have suffered less injury, or no injury at all, if he had not had an unusually thin skull or an unusually weak heart.
Defendant contends that plaintiff's proposed instruction was inappropriate because it concerned damages, not proximate cause. Although the eggshell plaintiff rule has been incorporated into the Damages section of the Iowa Uniform Civil Jury Instructions, we believe it is equally a rule of proximate cause. See Christianson v. Chicago, St. Paul, Minneapolis & Omaha Ry. Co., 69 N.W. 640, 641 (Minn.1896) Consequences which follow in unbroken sequence, without an intervening efficient cause, from the original negligent act, are natural and proximate; and for such consequences the original wrongdoer is responsible, even though he could not have foreseen the particular results which did follow.
Defendant further claims that the instructions that the court gave sufficiently conveyed the applicable law.
We agree that the jury might have found the defendant liable for Loras's death as well as his injuries under the instructions as given. But the proximate cause instruction failed to adequately convey the existing law that the jury should have applied to this case. The eggshell plaintiff rule rejects the limit of foreseeability that courts ordinarily require in the determination of proximate cause. Once the plaintiff establishes that the defendant caused some injury to the plaintiff, the rule imposes liability for the full extent of those injuries, not merely those that were foreseeable to the defendant. Restatement (Second) of Torts 461 (1965) The negligent actor is subject to liability for harm to another although a physical condition of the other makes the injury greater than that which the actor as a reasonable man should have foreseen as a probable result of his conduct.
The instruction given by the court was appropriate as to the question of whether defendant caused Loras's initial personal injuries, namely, the fractured ankle and the bruised chest. This instruction alone, however, failed to adequately convey to the jury the eggshell plaintiff rule, which the jury reasonably could have applied to the cause of Loras's death.
Defendant maintains the fact there was extensive heart disease and that Loras Benn was at risk any time is not sufficient for an instruction on the eggshell plaintiff rule. Yet the plaintiff introduced substantial medical testimony that the stresses of the accident and subsequent treatment were responsible for his heart attack and death. Although the evidence was conflicting, we believe that it was sufficient for the jury to determine whether Loras's heart attack and death were the direct result of the injury fairly chargeable to defendant Thomas' negligence.
Defendant nevertheless maintains that an eggshell plaintiff instruction would draw undue emphasis and attention to Loras's prior infirm condition. We have, however, explicitly approved such an instruction in two prior cases.
Moreover, the other jurisdictions that have addressed the issue have concluded that a court's refusal to instruct on the eggshell plaintiff rule constitutes a failure to convey the applicable law.
To deprive the plaintiff estate of the requested instruction under this record would fail to convey to the jury a central principle of tort liability.
The record in this case warranted an instruction on the eggshell plaintiff rule. We therefore affirm the decision of the court of appeals. We reverse the judgment of the district court and remand the cause to the district court for a new trial consistent with this opinion.