Fatal arrhythmia associated with myocardial contusion caused by a horse kick: A forensic autopsy case.

Overview

• This study reports a forensic autopsy case of a 48-year-old man who died from a fatal heart rhythm disturbance (arrhythmia) caused by a myocardial contusion after being kicked in the chest by a horse.
• The research emphasizes that fatal arrhythmia can occur from blunt chest trauma even without major structural heart damage, underscoring its importance in forensic investigations of horse-related injuries.

Background

• Horse-related injuries typically involve high-energy blunt trauma due to the animal’s size and strength.
• When horses kick the chest, deaths are commonly caused by severe structural cardiac injuries such as cardiac rupture (tearing of the heart muscle) or cardiac tamponade (blood or fluid buildup compressing the heart).
• Lethal arrhythmias (abnormal heart rhythms) related to myocardial contusions (bruising of the heart muscle) following horse kicks are rarely documented in forensic literature.

Case Details

• The victim was a 48-year-old man hit in the left lower chest by the right hind limb of a Thoroughbred horse.
• He collapsed immediately after the trauma.
• Emergency medical services recorded ventricular fibrillation, a life-threatening arrhythmia characterized by erratic heartbeats that prevent the heart from pumping effectively.
• Multiple attempts at defibrillation—a treatment using electric shocks to restore normal heart rhythm—were made.
• Despite advanced resuscitation efforts, including open-chest cardiac massage, the man was pronounced dead.

Autopsy Findings

• External examination showed a patterned abrasion and subcutaneous hemorrhage (bleeding under the skin) on the left hypochondrial area (region below the ribs on the left side).
• Internal examination identified:
• Fracture of the left sixth rib, suggesting significant blunt force trauma.
• Epicardial hemorrhage (bleeding on the surface layer of the heart).
• Myocardial contusion, with hemorrhage extending into the anterior, lateral, and posterior walls of the left ventricle (main pumping chamber of the heart).
• No evidence of cardiac rupture or hemopericardium (blood in the pericardial sac around the heart), ruling out commonly fatal structural injuries.
• Histological (microscopic) examination further confirmed intramyocardial (within heart muscle) hemorrhage.
• Signs from the resuscitative thoracotomy (surgical opening of the chest for emergency cardiac massage) were also noted.

Conclusion and Implications

• Given the circumstances—the blunt chest trauma from a horse kick, medical evidence showing ventricular fibrillation, and autopsy findings—the cause of death was established as fatal arrhythmia caused by myocardial contusion.
• This case highlights that sudden, deadly arrhythmias can result from blunt chest injury even when there is no catastrophic structural heart damage.
• For forensic investigations, it is crucial to consider arrhythmic death as a possible cause in horse-related chest trauma fatalities.
• The study raises awareness of the need for careful examination of myocardial injury and heart rhythm disturbances during autopsies in such trauma cases.