Case Presentation

A 67-year-old man presented to our hospital in cardiogenic shock with a history of intermittent epigastric discomfort in the previous 3 days. His medical history was pertinent for hypertension and diabetes, treated with nifedipine, ramipril, and metformin.

On arrival, the patient was pale and diaphoretic. Blood pressure was 60/40 mm Hg, heart rate was 80 beats/min, and a 2-3/6 holosystolic murmur was audible at the cardiac apex. Jugular venous pressure was elevated. Electrocardiography revealed high-degree atrioventricular block and inferior ST-segment elevation with inverted T waves in the inferior and lateral leads. Troponin T, creatine kinase, and creatine kinase-MB levels peaked at 20.35 μg/L, 1,372 U/L, and 140.4 μg/L, respectively. Biochemistry showed acute renal failure, hepatic cytolysis and lactic acidosis. Chest x-ray displayed pulmonary edema.

Treatment of cardiogenic shock was initiated immediately. Transthoracic echocardiography was performed <2 hours after presentation and established inferior wall motion abnormalities and a 17 × 24 mm ventricular septal rupture (VSR) of the basal and mid inferoseptal wall ( Video 1A , Figure 1 top) with massive left-to-right shunting on color Doppler ( Video 1B , Figure 1 bottom). The left ventricular ejection fraction was measured at 43%. The right ventricle was dilated and severely hypokinetic. Moderate tricuspid regurgitation was present, and systolic pulmonary artery pressure was 70 mm Hg. Coronary angiography demonstrated occlusion of the distal right coronary artery as well as intermediate lesions on the proximal left anterior descending and circumflex coronary arteries.

Parasternal short-axis view showing the RVFW dissection (small arrow) in the continuity of a large VSR of the basal to mid inferoseptal wall (large arrow) . Color Doppler (bottom) shows a significant left-to-right shunt.

The patient was stabilized after volemic resuscitation, positive inotropic support, and the placement of an intra-aortic counterpulsation pump. Emergency coronary artery bypass grafting of the left anterior descending coronary artery and posterior interventricular artery was performed, and the septal rupture was repaired with a pericardial patch a few hours after admission. Transesophageal echocardiography (TEE) during surgery unveiled an intramyocardial dissection of the right ventricular inferior wall at the site of the VSR ( Video 2 , Figure 2 ). The right ventricular free wall (RVFW) dissection was left uncorrected.

Transesophageal echocardiogram showing large intramyocardial dissection of the RVFW from the apex to almost the tricuspid annular level (arrow) .

The postoperative evolution was favorable, with normalization of pulmonary artery pressure and hemodynamic parameters. The patient was dismissed 6 days after admission. At follow-up 1 month later, he was symptom free. Control TEE performed 6 weeks after discharge revealed a thrombosis of the RVFW dissection and a repaired VSR with no residual shunt ( Videos 3A and 3B , Figure 3 ).

Transesophageal echocardiogram at 4-week follow-up showing intramyocardial thrombosis of the RVFW (arrow) . Color Doppler shows no residual flow (bottom) .

Discussion

VSR with accompanying intramyocardial dissection of the RVFW is an extremely rare complication in patients with inferior myocardial infarction (MI) and was first described in 1977 in postmortem studies. We reviewed the 5 cases reported in the literature since this initial description. Two management strategies are possible for intramyocardial dissection, medical treatment only and surgical repair.

Although spontaneous closure of left ventricular intramyocardial dissection with subsequent survival has been reported in patients after anterior MI without VSR, mortality in patients with VSR and RVFW dissection after inferior MI is 100% if treated medically. Surgical repair of VSR after MI improves survival, although mortality rates remain high. However, the optimal surgical strategy in patients with RVFW dissection complicating VSR has not yet been established.

Tighe et al reported two patients who developed VSR and RVFW dissection after inferior MI and underwent emergent repair of both VSR and RVFW. Postoperative evolution was favorable, and both patients were well at follow-up. Another patient, treated in the same manner, died of hemorrhagic complications after surgery, possibly related to thrombolysis administered at admission for inferior MI.

In our patient, transthoracic echocardiography was suggestive of RVFW dissection. TEE has been shown to have 100% sensitivity and in our case confirmed the diagnosis. At the surgeon’s discretion, only repair of the VSR was performed, without reconstruction of the RVFW. At 4-week follow-up, the patient was symptom free. Control TEE showed a repaired ventricular septum without residual intracardiac shunt and partial thrombosis of the RVFW dissection. Only one other case treated in the same way has been reported in the literature, with a comparable outcome at 6-month follow-up.

Given the very limited published data on this rare clinical entity, the value of the different surgical options is difficult to assess. Repair of VSR is mandatory and significantly improves the outcome of post-MI septal rupture, but the importance of RVFW reconstruction remains debatable. Patients have fared well with and without that intervention, and one must weigh the risks of prolonging the surgical procedure and extracorporeal circulation exposure against the benefits of repairing the RVFW.

We conclude that in patients with VSR complicated by RVFW dissection following inferior MI, rapid diagnosis by echocardiography is key to proper management, and TEE is an important diagnostic adjunct if findings on transthoracic echocardiography are inconclusive. Repair of VSR is mandatory, but the value of RVFW reconstruction remains elusive.