J Carlier

Predicting the extent and location of coronary artery disease in acute myocardial infarction by echocardiography during dobutamine infusion

The feasibility, safety and usefulness of 2-dimensional echocardiography (2-D echo) during dobutamine infusion for identifying patients with multivessel coronary artery disease (CAD) after acute myocardial infarction (AMI) were evaluated in 30 patients 5 to 10 days after AMI. Patients underwent 2-D echo under basal conditions and during dobutamine infusion at each dose from 5 to a maximum of 40 micrograms/kg/min, limited multilead submaximal bicycle exercise testing and coronary and left ventricular angiography. Echocardiograms were analyzed independently by 2 observers. The test response was considered positive if abnormal wall motion and reduced myocardial thickening were observed during dobutamine infusion in vascular distributions other than the area of infarction identified during basal conditions. Exercise testing was considered positive when more than 1 mm of ST depression occurred 80 ms after the J point. Dobutamine stress testing was well tolerated; no complications and no significant arrhythmia were observed. Echocardiographic recordings were adequate in all patients during the entire test; the concordance in interpretation between the 2 observers was perfect for the prediction and location of ischemic segments during dobutamine infusion. In 15 of 17 patients without multivessel CAD, no asynergy was observed outside the infarct zone during dobutamine infusion (specificity 88%). In 11 of 13 patients with multivessel CAD, new wall motion abnormalities were identified in the segments corresponding to the arterial lesions diagnosed by angiography (sensitivity 85%).(ABSTRACT TRUNCATED AT 250 WORDS)

Prognostic significance of angina pectoris before first acute myocardial infarction

To delineate the clinical significance and prognostic importance of a history of chronic or new onset angina pectoris before acute myocardial infarction (AMI), 732 consecutive patients admitted for a first AMI were studied and divided into 3 groups. Two hundred patients (27%) had chronic angina before AMI (greater than 1 month); 247 patients (34%) had new onset angina before AMI (less than 1 month) and the 285 remaining patients (39%) never had angina before AMI. All clinical characteristics were similar in the group of patients with chronic angina and in the group of patients with new onset angina, including in-hospital mortality (10 vs 9%) and 3-year post-hospital mortality (16 vs 16%). Compared to the 285 patients without angina, the 447 patients with angina before AMI were older, more likely to be women, and had a higher frequency of anterior AMI and early post-infarction angina. Both groups had a similar in-hospital mortality (10 vs 8%, not significant), but patients with angina had a higher 3-year post-hospital mortality (16 vs 7%, p less than 0.001). In the group of patients with angina before AMI who were discharged from the hospital, the comparison of nonsurvivors and survivors showed that the patients who died were older, presented more frequently with a non-Q-wave myocardial infarct and more often had left ventricular failure and complete bundle branch block during hospital stay. Chronic and new onset angina before AMI have the same clinical characteristics and deleterious long-term prognostic significance.

Incidence and significance of pericardial effusion in acute myocardial infarction as determined by two-dimensional echocardiography

To determine the incidence and clinical significance of pericardial effusion after acute myocardial infarction, two-dimensional echocardiography was serially performed in 66 consecutive patients. Pericardial effusion was observed in 17 (26%); the effusion was small in 13 patients, moderate in 3 and large with signs of cardiac tamponade in 1. In this patient, two-dimensional echocardiography strongly suggested myocardial rupture. The observation of pericardial effusion was not associated with age, sex, previous myocardial infarction, atrial fibrillation or treatment with heparin. It was more often a complication of anterior than of inferior acute infarction. Patients with pericardial effusion had higher peak levels of creatine kinase and lactic dehydrogenase and a higher wall motion score index. More patients with pericardial effusion had congestive heart failure or ventricular arrhythmias, developed a ventricular aneurysm or died within 1 year after their infarction. In conclusion, pericardial effusion is frequently visualized by two-dimensional echocardiography after acute myocardial infarction and its presence is associated with an increased occurrence of complications and cardiac death.

Significance of precordial ST-segment depression in inferior acute myocardial infarction as determined by echocardiography

Despite numerous studies, the significance of precordial ST-segment depression in inferior wall acute myocardial infarction (AMI) remains unclear. No clinical studies have used 2-dimensional (2-D) echocardiography to compare AMI location in patients with or without so-called reciprocal ST changes. Therefore, the clinical, electrocardiographic, echocardiographic and angiographic features of 22 patients with their first transmural inferior AMI were prospectively examined. During the first day of AMI an echocardiographic mapping of the area of necrosis was obtained using all conventional views and a ventricular segmentation related to anatomic landmarks. Patients were categorized according to the presence (group I, n = 13) or absence (group II, n = 9) of precordial ST-segment depression, defined as more than 1 mm, measured 80 ms after the J point in at least 2 of the leads V1 to V4. Basal posterolateral akinesia was observed in 11 of the 13 patients in group I and in no patient in group II (p less than 0.001). Posterior right ventricular free wall akinesia was more frequent in group II (p less than 0.02). There was no difference in the prevalence of significant left anterior descending artery (LAD) narrowing (group I, 4 patients; group II, 3 patients). Posterolateral involvement should be strongly considered in the presence of precordial ST-segment depression in association with transmural inferior AMI.

Hemodynamic profile of patients with acute myocardial infarction at risk of infarct expansion.

To identify patients at risk of cardiac expansion during hospital stay for a first acute myocardial infarction (AMI), 41 patients underwent right-sided cardiac catheterization soon after admission and serial 2-dimensional echocardiography on days 1, 3 or 4 and between days 7 and 10. Infarct expansion was recognized by echocardiography in 11 patients (27%), most often on the second recording (day 3 or 4). Age, sex, time from onset of pain to catheterization, peak levels of creatine kinase and creatine kinase-MB isoenzyme, heart rate, mean pulmonary artery wedge pressure and left ventricular stroke work index were similar in the 2 groups. Patients in whom infarct expansion developed had a higher incidence of previous systemic hypertension (73% vs 27%, p less than 0.01) and anterior AMI (91% vs 30%, p less than 0.001) and a higher mortality rate at 1 year (73 vs 7%, p less than 0.001) than those who did not. They also had higher systolic (139 +/- 24 vs 126 +/- 18 mm Hg, p less than 0.05) and diastolic (91 +/- 14 vs 75 +/- 13 mm Hg, p less than 0.001) arterial pressures, lower stroke volume index (31 +/- 10 vs 40 +/- 10 ml/m2, p less than 0.01) and much higher systemic vascular resistance (SVR) values (1,713 +/- 380 vs 1,253 +/- 264 dynes s cm-5, p less than 0.0001). In the subgroups of patients with anterior AMI, differences were significant for diastolic arterial pressure, stroke volume index, SVR and mortality.(ABSTRACT TRUNCATED AT 250 WORDS)

Combined haemodynamic effects of low doses of dopamine and dobutamine in patients with acute infarction and cardiac failure

The haemodynamic effects of an optimal dose of dobutamine (DUo) (6.7 +/- 4.2 micrograms kg-1 min-1) and the combination of this optimal dose minus 2.5 micrograms kg-1 min-1 of dobutamine (DU) plus dopamine 2.5 micrograms kg-1 min-1 (DA) were studied in a first group of 12 consecutive patients with acute myocardial infarction (AMI) and cardiac failure (CF). DUo decreased pulmonary wedge pressure from 23.5 to 16 mm Hg (P less than 0.01), systemic vascular resistance from 1 774 to 1 417 dynes s cm-5 (P less than 0.01). DUo increased cardiac output from 3.21 to 4.55 litres/min (P less than 0.01) and urinary flow (UF) from 20 to 68 ml/h (P less than 0.01). Heart rate and blood pressure did not change significantly. DUo - DU + DA significantly increased UF from 68 to 107 ml/h (P less than 0.05) while the other parameters remained unchanged with respect to DUo. The positive effect of DA on UF was confirmed in a second group of 12 consecutive patients by comparing the successive effects of DA + DUo and DUo + DU : all previously described parameters remained unchanged except UF which decreased from 107 to 65 (P less than 0.01). We conclude that in patients with CF and AMI, association of DA and DUo is useful in obtaining both inotropic and diuretic effects.

The new inotropic phosphodiesterase inhibitors

Compounds with phosphodiesterase inhibitory activity stimulate myocardial contractility by increasing the intracellular cyclic AMP concentrations. They can also increase Ca2+ entry and inhibit Ca2+ sequestration by the sarcoplasmic reticulum. Xanthines produce bronchodilation with associated venous and arteriolar dilation. However, their use is limited by their positive chronotropic effect and other side effects at high plasma levels. New phosphodiesterase inhibitors have been perfected: they are more specific with little chronotropic effect. Increasing the sensitivity of the myofilaments to Ca2+, and other unclear mechanisms may be involved in the inotropic action of these drugs. These new promising active compounds are described and discussed. They augment cardiac performance and improve regional distribution of blood flow and symptoms. However, their influence on the long-term outcome of severe heart failure has yet to be determined.

Prognostic significance of a low peak serum creatine kinase level in acute myocardial infarction

To assess the prognostic significance of a low peak creatine kinase (CK) level, 723 consecutive patients admitted with acute myocardial infarction (AMI) within 16 hours after onset of symptoms were studied. Thrombolytic therapy was not attempted during the study. Patients were dichotomized according to their peak CK levels, determined from a cluster analysis of peak CK distribution among the population of patients who died within 3 years after hospital discharge. The 139 patients with low peak CK (less than or equal to 650 IU/liter) (group 1) were compared to the 584 patients with high peak CK (greater than 650 IU/liter) (group 2). Patients in group 1 were older and had a higher incidence of previous AMI, angina pectoris before AMI and non-Q-wave AMI. Despite a lower incidence of in-hospital complications and a nonsignificantly lower hospital mortality rate (4 vs 9%) the group 1 three-year posthospital mortality rate was higher (26 vs 17%; p less than 0.02), especially in the subgroup of patients with a Q-wave infarct (mortality 31% in group 1 vs 16% in group 2; p less than 0.001). Among the 491 patients who had a first Q-wave AMI, 55 had a peak CK less than or equal to 650 IU/liter. Compared to the 436 patients with a higher peak CK, these 55 patients had a higher incidence of early postinfarction angina (31 vs 14%; p less than 0.01), a similar hospital mortality (4 vs 7%) but a higher 3-year posthospital mortality (23 vs 12%; p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Old and new inotropic drugs

An ideal cardiotonic agent should improve cardiac contractility and increase the oxygen supply to various tissues without inducing tachycardia, arrhythmias, decrease in coronary blood flow or increment in oxygen requirements of the myocardium. It should also be safe and orally active and have a persistent action. The aim of this paper is to describe various positive inotropic drugs at our disposal. The hemodynamic effects and the indications of adrenaline, noradrenaline, isoprenaline, dopamine, dobutamine and cardiac glycosides are presented first. Then several new promising orally active compounds are discussed.

Diagnosis and Management of Right Ventricular Infarction

In the setting of acute myocardial infarction, the evaluation of right ventricular function (RVF), has gained significant attention since the description of the right ventricular infarction (RVI) syndrome, in 1974 [1].