Cardiac rupture--challenge in diagnosis and management

Predictors of late hospital death in acute myocardial infarction

Although death from ischemic heart disease occurs in the majority of cases within 24 hr of a new clinical event, study of patients selected by admission to hospital shows a mortality pattern in which most deaths from myocardial infarction happen after the first day. In one hospital, over the last 2 yr, 46% of deaths from infarction have happened from the fourth day onwards. Introduction of a coronary-care unit in this hospital has reduced hospital mortality in patients under 70 yr of age from approximately 21% in 1966-1967 to 13% in 1977-1979, mainly because of improved treatment of arrhythmias. With the decline of cardiac arrhythmias as a mode of dying in hospitals, mechanical complications of shock and cardiac failure now account for up to two-thirds of hospital deaths, with cardiac rupture probably next in importance, accounting for 15%-20% of deaths. Of these 3 mechanisms, death from cardiac failure is most likely to be "late" (from the fourth day onwards). Shock and cardiac failure are directly related to massive destruction of left ventricular myocardium. Therefore, major efforts aimed at reduction of late hospital mortality should be directed towards therapeutic measures, initiated very early after the onset of infarction, which might protect the threatened myocardial tissue and restrict infarct size.

Acute myocardial infarction in hospitalized patients over age 70

The history and clinical course of 175 patients aged 70 and older (Group A) with acute myocardial infarction (MI) was studied to determine the hospital mortality rate in this population group and to determine the clinical factors that influenced the hospital mortality rate. The mortality rate of a second group of 772 patients below age 70 years (Group B) admitted during the same time period was determined for comparison with the mortality rate of Group A. The hospital mortality rate in Group A (32%) was 3.9 times the hospital mortality rate in Group B (8.2%). Advanced age was associated with a significantly higher mortality rate, even when so called "good risk" patients from Group A were compared with patients in Group B. The major causes of death in this hospitalized group of patients aged 70 and older were shock (33.9%) and cardiac rupture (28.6%). Factors that significantly influenced hospital mortality rate in the elderly group were the development of shock, pulmonary edema on chest x-ray, a clinical diagnosis of congestive heart failure, and the development of complete heart block or new bundle branch block during the hospital course.

Echocardiography and rupture of the heart

In four patients with rupture of the free wall of the left ventricle, the diagnosis was made at the bedside using a portable cross-sectional echocardiograph; this was confirmed at necropsy in two patients and by paracentesis in the other two. Weak ventricular contractions were seen after each QRS complex of the electrocardiogram, contradicting a widespread belief that cardiac rupture immediately produces electromechanical dissociation. In one patient aspiration of 100 ml blood from the pericardium allowed resumption of cardiac pump function; this patient survived for three days but was allowed to die because of cerebral damage sustained during resuscitation.

Myocardial rupture: III. Chamber pressure, rate of distention, and ventricular disruption in isolated hearts

We have developed an in vitro technique for producing myocardial rupture in lamb hearts, which relates tensile strength to a variety of conditions which can prevail in normal and infarcted human hearts. Retrograde perfusion of saline solution and inflation of the left ventricle was used to apply progressive stress to the left ventricular wall. Three separate sites of myocardial rupture were observed and occurred with the frequency of 54% at the papillary muscle, 30% at the interventricular septum, and 16% at the free wall of the left ventricle. The distribution and configuration of the experimental ruptures were similar to those usually noted as complications of human myocardial infarction. The mean rupturing pressure was 526 mm Hg in normal lamb hearts. Application of these techniques should ultimately provide data relevant to the diagnosis, prevention, and treatment of myocardial rupture.

Left ventricular false aneurysm after coronary bypass surgery: radionuclide diagnosis and surgical resection

A patient with left ventricular pseudoaneurysm formation resulting from myocardial infarction 4 years after coronary bypass surgery is described. The pseudoaneurysm was diagnosed with gated cardiac blood pool imaging and was subsequently successfully surgically repaired. Postoperative pericardial abnormalities predisposing to the possible development of a false aneurysm are discussed. Also, clinical situations in which pseudoaneurysm should be suspected are described, and appropriate diagnostic approaches are outlined.