Differential Diagnosis for Sudden Death in a 27-year-old with No Existing Medical Condition

Single Most Likely Diagnosis

• Hypertrophic Cardiomyopathy (HCM): This is a common cause of sudden cardiac death in young adults, often without prior symptoms. It is characterized by an abnormal thickening of the heart muscle, which can lead to arrhythmias and sudden death.

Other Likely Diagnoses

• Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC): A condition where the muscle in the right ventricle is replaced by fat and scar tissue, leading to arrhythmias and potentially sudden death.
• Long QT Syndrome: A disorder of the heart's electrical activity that can cause sudden, uncontrollable, dangerous arrhythmias.
• Brugada Syndrome: A genetic disorder characterized by abnormal electrocardiogram (ECG) findings and an increased risk of sudden cardiac death.
• Myocarditis: Inflammation of the heart muscle, often due to viral infections, which can lead to arrhythmias and sudden death.

Do Not Miss Diagnoses

• Pulmonary Embolism: Although less common in young adults without risk factors, a pulmonary embolism can be sudden and fatal. It's crucial not to miss this diagnosis due to its potential for treatment.
• Aortic Dissection: A tear in the inner layer of the aorta, which can lead to aortic rupture and death. It's more common in older adults but can occur in younger individuals, especially those with certain genetic conditions.
• Toxic Ingestions or Overdose: Accidental or intentional ingestion of substances that can lead to respiratory or cardiac arrest.

Rare Diagnoses

• Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT): A rare genetic disorder that affects the heart's electrical system, leading to life-threatening arrhythmias.
• Short QT Syndrome: A rare condition characterized by an abnormally short QT interval on the ECG, which can increase the risk of sudden cardiac death.
• Wolff-Parkinson-White Syndrome: A rare heart condition characterized by an accessory electrical pathway in the heart, leading to arrhythmias.
• Sudden Unexplained Death in Epilepsy (SUDEP): For individuals with epilepsy, there's a small risk of sudden death, often without a clear cause.

Each of these diagnoses has a different level of likelihood but considering them is crucial for a comprehensive approach to understanding sudden death in a young adult without a known medical condition.