[Electromechanical dissociation in myocardial infarction. Anatomical-clincal study of 82 cases]. / Dissociazione elettromeccanica nell'infarto miocardico. Studio anatomo-clinico di 82 casi.

UNLABELLED: In our experience electromechanical dissociation (EMD) is the most common mechanism of fatal cardiac arrest in patients with acute myocardial infarction (AMI). METHODS: We reviewed retrospectively 82 autopsy cases of AMI in whom the medical record documented EMD as terminal cardiac arrest in order to outline the clinical and pathologic features of different subgroups: 26 cases with external cardiac rupture (CR) were compared with 56 cases without CR. In turn, inside the latter series, 16 cases of sudden EMD were compared with 40 cases of EMD occurring in the terminal phase of cardiac shock. RESULTS: In comparison with those without CR, patients with CR showed at multiple regression analysis less evidence of left ventricular failure (p < 0.05); less extended infarct areas (p < 0.01); more frequent sudden EMD (p < 0.05). Most patients with CR had massive pericardial effusion; cardiac rhythm at the onset of EMD was seldom slow in those cases. In the group without CR no discriminant characteristics were found in cases of sudden EMD vs cases preceded by cardiac shock. CONCLUSIONS: In case of CR EMD occurs in less extensively damaged hearts and is generally sudden; in AMI without CR EMD may affect patients with severe depression of pump performance, but not necessarily in shock. EMD after an AMI may result from several factors: cardiac tamponade is prevalent in the presence of CR; in cases without CR our data don't permit to conjecture a distinct pathogenesis for sudden EMD in comparison with cases preceded by shock.

[Heart arrest in acute pulmonary embolism. An anatomo-clinical study]. / L'arresto cardiaco nell'embolia polmonare acuta. Studio anatomo-clinico.

The Authors describe the modalities and mechanisms of cardiac arrest (CA) in the course of acute pulmonary embolism (PE). Clinical data refer to 39 CA episodes occurred in 28 patients with massive or submassive PE; autopsy data are from 26 of 28 patients of the same series. One-third of 39 CAs proved at least momentarily reversible; two-thirds were irreversible. Data analysis showed that most CA episodes, reversible or otherwise, seen in the course of PE were due to electromechanical dissociation (EMD). In fact, EMD was responsible for 12 of 13 reversible CAs and 22 of 26 irreversible arrests. EMD usually follows shock, but may occur unheralded. When EMD-induced CA is at least temporarily reversible, the heart rate is often normal or high and QRS complexes are narrow. In most cases the sudden rise of right ventricular afterload came on top of a pre-existing myocardial damage, for the most part of ischemic, sometimes necrotic, origin. In this series, therefore, it seems quite difficult to tell "primary" from "secondary" forms of EMD. External cardiac massage continued for as long as 40 minutes was associated in some cases with a bolus fibrinolytic infusion within minutes from occurrence of CA. Five of 7 patients so treated made a temporary recovery and two survived; at autopsy, none of the 5 patients who died showed any evidence of bleeding attributable to local injury.

[External post-infarction rupture of the heart. Retrospective anatomo-clinical analysis of 70 cases]. / Rottura di cuore, esterna, post-infartuale. Analisi anatomo-clinica retrospettiva di 70 casi.

A retrospective comparison was made between the clinical and pathological findings pertaining to: a) 70 cases of rupture of the ventricular free wall following myocardial infarction (RC group), b) 70 cases of acute myocardial infarction (AMI) where death intervened in the absence of cardiac rupture (NR group) and c) 70 cases (clinical findings only) of patients with AMI admitted to the hospital (IM group). The history of the RC group disclosed a considerably lower percentage of previous myocardial infarctions (p less than 0,005) as compared to the control groups. In the same group systemic hypertension after myocardial infarction was more frequent (p less than 0,025) than in the others. Shock, heart failure, bundle branch blocks were significantly less common in the RC group than in the NR group, and severe arrhythmias were found in a significantly lower percentage than in both the control groups. An electrocardiographic pattern of anterior AMI was more frequent in the RC group than in the IM group (p less than 0,05). Death was preceded by sudden loss of consciousness in 83% of the RC cases and in 51% of the NR cases (p less than 0,005), by severe chest pain respectively in 19% and 9% of the two groups (p less than 0,05). More than 25% of the patients of both RC and NR groups died within the first 24 hours, almost half within the third day after the onset of AMI. On autopsy the AMI was anterior and/or lateral in 77% of the cases in the RC group and in 44% of the NR group (p less than 0,005). In all the cases except one rupture had occurred in the area of the infarction. The site of rupture was anterior in 64% of the cases, posterior in 16%, lateral in 11%, and apical in 9%. Scars larger than 5 mm were noted in 17% of the cases in the RC group as compared to 37% in the NR group (p less than 0,01). Left ventricular hypertrophy was present in 16% of the RC cases and in 31% of the NR group (p less than 0,05). Finally the characteristics of patients at risk of cardiac rupture following myocardial infarction seem to be: absence of previous infarctions, anterior localization of AMI, sustained hypertension after myocardial infarction, absence of serious hemodynamic and arrhythmic complications.