Question

Ramkumar, a 70 year old hypertensive male, was admitted to the intensive care unit with transmural anterolateral myocardial infarction. His condition was stable till the 5th day of admission, when he developed a pericardial friction rub and pleuritic chest pain which persisted despite narcotic and steroid therapy. On the 7th morning he suddenly developed marked hypotension. On examination, there was distension of jugular veins, accompanied by electromechanical dissociation. Most likely, the patient had developed:

• A. Severe acute mitral regurgitation
• B. Ventricular septal rupture
• C. Right ventricular rupture
• D. External (free wall) cardiac rupture

Hint:

Pericarditis after a transmural MI followed by sudden hypotension, distended neck veins, and electromechanical dissociation on day 5 to 7 points to free wall cardiac rupture with tamponade.

Answer 1

The Correct Option is D

Step 1: Note the timing and setting.
The patient is elderly, hypertensive, and had a large transmural anterolateral infarction, which means the full thickness of the heart wall died in that area. His sudden collapse happened on day 7, and free wall rupture of the heart classically occurs between day 3 and day 7 after a transmural infarction, exactly this window.

Step 2: Read the warning sign that came before collapse.
The pericardial friction rub and pleuritic pain on day 5 point to pericarditis over the area of dead muscle. This kind of pericarditis over a transmural infarct is a known warning sign that the wall in that area is weak and at risk of tearing.

Step 3: Read the signs at the moment of collapse.
Sudden hypotension with distended jugular veins and electromechanical dissociation, where the heart's electrical activity continues but it fails to pump, is the classic picture of cardiac tamponade caused by blood suddenly filling the pericardial sac. This happens when the free wall of the heart tears and blood escapes from inside the ventricle into the sac around the heart.

Step 4: Rule out severe acute mitral regurgitation.
This is caused by rupture of a papillary muscle and presents with a new loud murmur and sudden pulmonary edema, not with distended neck veins and electromechanical dissociation as the leading picture.

Step 5: Rule out ventricular septal rupture.
This produces a new harsh pansystolic murmur at the left sternal border along with signs of a shunt between the ventricles, and while it does cause cardiogenic shock, it does not classically present as sudden electromechanical dissociation with tamponade physiology the way free wall rupture does.

Step 6: Rule out right ventricular rupture as a separate entity.
Free wall rupture after a transmural infarct most often involves the left ventricular free wall, and the sudden tamponade and electromechanical dissociation picture described here matches that mechanism, not an isolated right ventricular event.

Step 7: Final answer.
The clinical course fits external, or free wall, rupture of the heart leading to cardiac tamponade and electromechanical dissociation.
\[ \boxed{\text{External (free wall) cardiac rupture}} \]