Single most likely diagnosis
- Mitral Regurgitation: This is the most common cause of a harsh holosystolic murmur, typically due to mitral valve prolapse or rheumatic heart disease. The murmur is usually loudest at the apex and radiates to the axilla.
Other Likely diagnoses
- Tricuspid Regurgitation: This condition can also cause a holosystolic murmur, often associated with signs of right heart failure. The murmur is typically loudest at the left lower sternal border.
- Ventricular Septal Defect (VSD): A VSD can produce a holosystolic murmur due to left-to-right shunting of blood. The murmur is usually loudest at the left lower sternal border.
Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Ruptured Sinus of Valsalva: Although rare, this condition can cause a harsh holosystolic murmur and is life-threatening if not promptly diagnosed and treated.
- Traumatic VSD: A VSD caused by trauma can also produce a holosystolic murmur and requires urgent attention.
Rare diagnoses
- Congenital Heart Diseases (e.g., Ebstein's anomaly, Eisenmenger's syndrome): These conditions can cause holosystolic murmurs, but are less common and often have distinctive associated features.
- Pulmonary Arteriovenous Malformation: This rare condition can cause a holosystolic murmur due to abnormal connections between pulmonary arteries and veins.