[Primary coronary angioplasty as a choice treatment in the 1st 6 hours following acute myocardial infarction]. / Angioplastía coronaria primaria como tratamiento de elección en las primeras 6 horas del infarto de miocardio.

Primary coronary angioplasty as treatment of acute myocardial infarction preserves more myocardium and has a lower mortality than thrombolysis. Aiming to assess the feasibility of its use in Chile, we studied 64 patients aged 59 +/- 2 years old, 27 with an anterior wall and 37 with an infero-lateral wall acute myocardial infarction of 118 +/- 62 min of evolution. Coronary angiography, performed 98 +/- 47 min after diagnosis, showed non significant disease in one, one vessel disease in 26 (40%), two vessel disease in 17 (27%) and three vessel disease in 20 (31%) patients. Responsible arteries for infarction were the anterior descending in 26 (40%), circumflex in 9 (14%), right in 27 (42%), a saphenous bridge in one and left main disease in one patient. In one patient with an obstruction over 50% and in two patients with left main disease, angioplasty was not attempted. The procedure was successful (defined as a residual lesion of less than 50%) in 56 of 61 patients (92%) and failed in four. One patient was re-perfused with intracoronary streptokinase. The delay in reperfusion was lower during working than non-working hours (89 +/- 48 vs 113 +/- 39 min). Four patients (6%) died during hospitalization, two had a reinfarction, two had a new vessel occlusion and three had a spontaneous ischemia. Eleven patients were operated during hospitalization and in two this was an emergency procedure. After 1993, mortality was lower (one of 55 patients) than before (three of nine). It is concluded that early coronary angioplasty in acute myocardial infarction is feasible in Chile, with a high degree of success.

Coronary angiography and left ventriculography in survivors of transmural and nontransmural myocardial infarction.

Recent studies have suggested a similar prognosis for patients with transmural myocardial infarction and nontransmural myocardial infarction despite a smaller infarct size in the latter patients estimated by creatine phosphokinase (CPK). Thirty-one patients with transmural myocardial infarction and 17 patients with nontransmural myocardial infarction as defined by electrocardiographic criteria underwent coronary angiography and left ventriculography from 10 to 24 days after they had an acute myocardial infarction. Forty-three of these 48 patients were asymptomatic following their myocardial infarction. When compared to patients with nontransmural myocardial infarction, those with transmural myocardial infarction had greater peak CPK levels, 1,090 +/- 210 versus 290 +/- 60 IU (p less than 0.01). There was no difference in prevalence of single, double or triple vessel coronary artery disease, mean number of coronary arteries 50 per cent narrowed (2.0 +/- 0.2 versus 2.0 +/- 0.2), near total or total occlusions, coronary score (Friesinger) (7.9 +/- 0.6 versus 8.2 +/- 0.7), left ventricular ejection fraction (48 +/- 2 versus 53 +/- 4), or per cent of akinetic-dyskinetic myocardial segments (66 of 242 [27 per cent] versus 32 of 132 [24 per cent]) between two groups. The similar extent of coronary artery narrowing and degree of left ventricular dysfunction may explain the similar prognosis for patients with transmural myocardial infarction and those with nontransmural myocardial infarction despite differences in enzymatically estimated acute infarct size.

Left ventricular and coronary angiographic anatomy. Relationship to ventricular irritability in the late hospital phase of acute myocardial infarction.

Late hospital phase ventricular arrhythmias in acute myocardial infarction (MI) have been associated with a high incidence of sudden death following hospital discharge. Thirty-eight patients were studied 10-24 days following onset of symptoms of MI. Each patient had a 24-hour ambulatory ECG tape recording and left ventricular and coronary angiography performed. Patients with complicated ventricular arrhythmias (multiform, coupled, R on T VPCs or ventricular tachycardia), when compared to those with uncomplicated ventricular arrhythmias (unifocal or no VPCs), had a greater number of proximally narrowed major coronary arteries (P less than 0.001), a higher coronary "score" (P less than 0.001), a greater incidence of previous myocardial infarction (P less than 0.005), a greater percentage of abnormal left ventricular segments 86% vs 69% (P less than 0.001) and lower ejection fractions. These data suggest that late hospital phase survivors of MI with complicated ventricular arrhythmias have more extensive coronary artery disease with greater left ventricular dysfunction than survivors with uncomplicated ventricular arrhythmias. This more extensive disease may result in increased areas of ischemic myocardium and may help explain the refractoriness of these arrhythmias to pharmacologic therapy.

Influence of coronary artery anatomy on survival following resection of left ventricular aneurysms and chronic infarcts.

Left ventricular (LV) aneurysms were resected in 27 patients for treatment of congestive heart failure and in five patients for treatment of ventricular arrhythmia. There were eight early (25 per cent) and five late (15 per cent) deaths. Preoperative hemodynamics including analysis of left ventriculograms in the right anterior oblique position did not consistently predict survival. In contrast, coronary artery anatomy appeared to influence the mortality rate strikingly in patients with congestive heart failure. The hospital mortality rate was 6 per cent and the late mortality rate was 13 per cent for 16 patients with one-or two-vessel coronary artery disease, but with unobstructed LV lateral wall blood supply. All but one of the survivors obtained a good late result. In nine patients with two-and three-vessel coronary artery disease and obstructed LV lateral wall blood supply there were six hospital deaths and two late deaths. It is concluded that the presence or absence of occlusive disease in the arteries supplying the LV lateral wall is an important determinant of the mortality rate associated with resection of anterior apical LV aneurysms in patients with severe congestive heart failure.