Ventricular septal rupture, secondary to myocardial infarction

Correlates of survival in patients with postinfarction ventricular septal defect

Prognostic indicators of survival in 42 consecutive patients (21 men and 21 women) with postinfarction ventricular septal defect were reviewed. Infarct location was anterior in 57%, inferior in 33%, and combined in 10%. The hospital mortality among 9 patients not receiving surgical therapy was 100%. Of the 33 surgically treated patients, 19 (58%) survived. Time from diagnosis to operation, ventricular function, and presence or absence of shock were analyzed in a logistic regression model to determine which factors carried independent prognostic value. Shock was independently predictive of operative mortality (p less than 0.01). Of additional variables examined, nonsurvivors were characterized by a shorter time from postinfarction ventricular septal defect to operation, a relatively higher incidence of inferior infarction, moderate right ventricular dysfunction and mild left ventricular dysfunction, and a lower right ventricular systolic pressure. Results of postmortem examination were available for 15 nonsurvivors. Quantitative analysis of percent ventricle infarcted revealed that in patients with inferior infarctions, a mean of 31% of the right ventricle was infarcted compared with 10% in patients with anterior infarction (p = 0.059). Kaplan-Meier survival estimates revealed 1-year survival of 70%, 5-year survival of 55%, and 10-year survival of 20%. Seventy percent of survivors were in New York Heart Association class I or II. These data show that, irrespective of ventricular function or timing of operation, the development of shock is the most important predictor of survival in postinfarction ventricular septal defect. The higher mortality in patients with inferior infarction may be associated with a greater degree of right ventricular infarction and consequent dysfunction. Finally, long-term survival and excellent functional recovery can be achieved in patients undergoing operation.

Management of ventricular septal rupture in acute myocardial infarction

Four patients with rupture of the interventricular septum after myocardial infarction are described. This condition carries a grave prognosis. Surgical repair of the septum is almost always urgently required if the left-to-right shunt is large (QP/WS > 3). Results are better if surgery can be deferred for six weeks to allow the infarcted area to heal and the tissues to be come firmer. This delay may be achieved by using a combination of agents to reduce afterload and to exert a positive inotropic effect. The timing of surgical intervention was an important factor in the survival of three of the four patients.

Perforation of the interventricular septum complicating myocardial infarction

The presentation and management of 21 patients with postinfarction ventricular septal defect (VSD) in whom surgical treatment was considered or performed since 1970 have been analysed and reviewed. An acute group of 11 patients, each of whom developed cardiogenic shock, 9 of whom came to surgery within one week from the onset of their VSD, had a poor outlook, only 27% becoming long-term survivors. Six patients were classified as subacute because their surgery was precipitated by worsening congestive cardiac failure in all, and by pulmonary oedema at the time of surgery in three patients. Four chronic patients were operated upon electively. The results in the subacute and chronic groups were excellent, and all are long-term survivors. Operative closure of the defect is best achieved by the use of a patch. Infarctectomy and aneurysmectomy are necessary in more than half of the cases. Left ventricular assistance by the intra-aortic balloon counterpulsation catheter has been disappointing and did not contribute to long-term survival. The major factor determining survival is the integrity of the closure, and the function of the remaining viable myocardium. Reoperation for reopening of the defect should always be considered.

Balloon-induced right ventricular outflow obstruction: a new approach to control of acute interventricular shunting after myocardial infarction in canines and swine

Current management of ventricular septal defect (VSD) after myocardial infarction (MI) is aimed at improving left ventricular (LV) performance by afterload reduction as a means of hemodynamic stabilization or shunt control. The current investigation was undertaken to determine whether primary manipulation of right venticular (RV) performance by afterload enhancement was an effective means of reducing MI-VSD shunting. In five open-chest dogs an external LV-RV shunt was created with pulmonary-systemic flow ratios (Qp/Qs) averaging 2.26:1. Inflation of a balloon-tipped catheter in the main pulmonary artery (PA) reduced average QP/Qs to 1.28:1 and shunt flow from 783 to 343 ml/min. However, this increase in RV afterload caused further significant increases in RV systolic and end-diastolic pressure and suggested that deterioration of RV function might be limiting the usefulness of this technique. To investigate whether inotropic support for the RV would overcome this limitation, a similar shunt was created in 11 open-chest swine. We then investigated the effects of dopamine, infused at 24, 60, and 120 mug/min, on QP/QS and other hemodynamic variables both with and without PA balloon inflation. Optimal shunt control was obtained when effects of dopamine were added to those of PA balloon inflation. Shunt flow that had been 1,633 ml/min was reduced to 892 ml/min with the PA balloon and reduced further to 757 ml/min with dopamine, which also lowered RV and LV end-diastolic pressure and reduced total systemic vascular resistance. In four other swine with left anterior descending ligations, PA balloon inflation and dopamine infusion again favorably affected hemodynamics. Epicardial mapping in these swine showed an increase in S-T segment displacement, suggesting that the cumulative effect of these interventions allowed hemodynamic improvement at the expense of enhanced ischemic injury. These data indicate that acute RV outflow obstruction with a balloon catheter is an effective means of temporarily reducing acute ventricular shunting and that dopamine may be a useful pharmacological agent to use with RV afterload manipulation to stabilize a patient prior to transfer to a medical center for more definitive therapy.

Echocardiographic findings of ventricular septal rupture in acute myocardial infarction

Echocardiograms were recorded both before and after the clinical appearance of an autopsy-confirmed interventricular septal rupture in a patient with an acute myocardial infarction. The major findings were related to the upper portion of the interventricular septum. Before rupture, this portion of the septum was relatively akinetic with a slight anterior motion during systole, whereas after rupture there was a marked increase in the amplitude of septal motion with abrupt posterior motion occurring with the onset of ventricular diastole.