injuries poisoning
Blunt Cardiac Injury
Introduction
Blunt cardiac injury is blunt chest trauma that causes contusion of myocardial muscle, rupture of a cardiac chamber, or disruption of a heart valve. Sometimes a blow to the anterior chest wall causes cardiac arrest without any structural lesion (commotio cordis). (See also Overview of Thoracic Trauma .) Manifestations vary with the injury. Myocardial contusionmay be minor and asymptomatic, although tachycardia may be present. Some patients develop conduction abnormalities and/or arrhythmias. is usually rapidly fatal, but patients with smaller, particularly right-sided, lesions may survive to present with Cardiac Tamponade . Tamponade due to atrial rupture may manifest more gradually. Valve disruptionmay occur, causing a heart murmur and sometimes manifestations of heart failure (eg, dyspnea, pulmonary crackles, sometimes hypotension), which may develop rapidly. Septal rupturemay not cause symptoms initially, but patients may present later with heart failure. Commotio cordisis sudden cardiac arrest that follows a blow to the anterior chest wall in patients who do not have preexisting or traumatic structural heart disease. Typically this blow involves a fast, hard projectile (eg, baseball, hockey puck) with relatively low kinetic energy. Pathophysiology is unclear, but the timing of the blow in relation to the cardiac cycle may be important. Initial rhythm is usually ventricular fibrillation. 