[Optimization of the management of acute heart failure. New concept of fast-track]

The acute heart failure generates a very important number of hospitalizations for a high cost. A recent reflection on optimizing its management is ongoing, based on the fastest management in the emergency department, with a distinction between which patient should remain and who returns at home, and under what conditions, allowing to limit the number of hospitalizations. It will require a reorganization of emergency department and updating of decision algorithms and new guidelines of care.

Relationship between post-treatment platelet reactivity and ischemic and bleeding events at 1-year follow-up in patients receiving prasugrel

BACKGROUND

Post-treatment platelet reactivity (PR) is associated with ischemic and bleeding events in patients receiving P2Y12 receptor antagonists.

OBJECTIVES

We aimed to study the relationship between post-treatment PR after a 60-mg loading dose (LD) of prasugrel and 1-year thrombotic and bleeding events.

METHOD

Patients were prospectively included in this multicenter study if they had a successful percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS) and received prasugrel. The platelet reactivity index (PRI) was measured using the Vasodilator-Stimulated Phosphoprotein index (VASP) after a prasugrel LD. Endpoints included the rate of thrombotic events and bleeding events at 1 year.

RESULTS

Among the 301 patients enrolled, 9 (3%) were lost to follow-up at 1 year. The rates of thrombotic and bleeding events at 1 year were of 7.5% and 6.8%, respectively. Receiver-operating curve (ROC) analysis demonstrated an optimal cut-off value of 53.5% of PRI to predict thrombotic events at 1 year. Using this cut-off value we observed that patients exhibiting high on-treatment platelet reactivity (HTPR) had a higher rate of thrombotic events (22.4% vs. 2.9%; P < 0.001). In parallel the optimal cut-off value of PRI to predict bleeding was 16%. Patients with a PRI ≤ 16% had a higher rate of bleeding events compared with those with a PRI > 16% (15.6% vs. 3.3%; P < 0.001). In multivariate analysis, the PRI predicted both thrombotic and bleeding events (OR: 1.44, 95% confidence interval [CI]: 1.2-1.72; P < 0.001 and OR: 0.75, 95% CI: 0.59-0.96; P = 0.024 [respectively, per 10% increase]).

CONCLUSION

Platelet reactivity measurement after a prasugrel LD predicts both ischemic and bleeding events at 1 year follow-up for ACS patients undergoing PCI.

[Acquired long QT syndrome: a dominant problem?]

QT prolongation is essentially of pharmacologic origin. It is principally linked to a block of the outward potassium current Ikr, with as a consequence a prolongation of the repolarisation causing early after potentials and re-entry. The term "repolarisation reserve" expresses the variable risk of arrhythmia among individuals under the same drug blocking Ikr. This reserve can be altered under various pathologic or genetic conditions. A series of risk factors (bradycar-Torsades de pointes} were described in 1966 by Dessertenne. They are due to a perturbation of ventricular repolarisation causing QT prolongation on surface ECG. Acquired dia, electrolytic disorders, cardiac disease, neurologic disorders, nutrition troubles, female gender) can play a role as well as the metabolic processing of pharmacological agents by Cytochrome P450 and various inhibitors or inductors of this system which can influence the half life of drugs. The list of drugs involved is continuously increasing: antiarrhythmics, antihistamines, psychotropics, anti-infectious are the main categories involved. Risk prediction is difficult particularly for non cardiovascular drugs and a low risk incidence. An other risk is to exclude patients from the benefit of an efficient drug for a serious but not frequent risk, at last an industrial risk for the manufacturer when a drug is withdrawn lately when important quantities of money have already been invested for its development. The diagnosis of torsades is easy on standard ECG although QT measurement and its heart rate variation remain uneasy. The treatment of the arrhythmias is based on heart rate acceleration by Isoprenaline or intravenous pacing and on intravenous administration of magnesium.

[Aneurysm of a saphenous vein bypass graft to coronary artery: a case report discovered as an incidental finding]

We report a case of aortocoronary bypass graft aneurysm revealed by exertional dyspnea and presenting as an anterior mediastinal mass at the unenhanced computed tomography scan. The diagnosis has been established using combined contrast-enhanced CT scan which specified the vascular nature of the mass and coronary angiography which connected it to the aorto-marginal branch saphenous vein graft. This case illustrates the frequently asymptomatic expression of aneurysm and the importance of combined imaging modalities for the diagnosis.

[Cardiac resynchronization in congestive heart failure: role of Doppler echocardiography in patient selection]

Cardiac echodoppler is an efficient tool to analyse cardiac mechanic loop. Diastolic and systolic desynchronisation criteria are analysed. It should allow a more efficient selection of patients who could take benefit of resynchronization therapy, but also to choose resynchronization system, to program optimal atrioventricular delay, interventricular delay and to evaluate resynchronization efficiency. However, this tool should be evaluated in large studies in order to compare it to electrocardiogram.

[Resynchronization of the failing heart by pacing]

Cardiac pacing has been proposed for patients with advanced heart failure refractory to optimal drug treatment and having conduction disorders to resynchronize mechanical activity of the heart. Activation asynchronism as caused by bundle branch block results in alteration of systolic function and arrhythmias. A too short or too long atrio-ventricular delay can also affect diastolic ventricular filling. Early clinical studies showed a benefit of very long atrioventricular delays shortening, not confirmed by further studies. Direct stimulation of the left ventricle was beneficial in acute hemodynamic studies. Three controlled clinical studies now completed, PATH-CHF, MYSTIC and MIRACLE have showed a functional benefit. Other studies (COMPANION, CARE-HF) are currently in process to evaluate the effect on survival and the interest to associate an automatic defibrillator. Technical aspects are also under investigation: optimal lead placement in the coronary venous system, types of leads, special pacing devices. This paper reports the experience of the first 50 patients treated with multisite pacing in Aix-en-Provence general hospital, 33 men and 17 women, 71 years of mean age, on NYHA class III or IV, and showing QRS width above 120 ms. During the follow-up (mean duration 16 months) 15 deaths (30%) happened. The benefit on NYHA class was 1.34; rehospitalization rate was low. Coronary sinus access was successful in 100% of cases. Sixteen per cent had a reintervention for lead displacement or threshold elevation. Left atrioventricular crosstalk, observed in six patients, supports the use of devices with three independent channels. Echocardiography is of interest for responders identification, optimal device programming and follow-up.

A mathematical approach to the connectivity between the cortical visual areas of the macaque monkey

The visual cortex of the macaque monkey is divided into many distinct visual information processing areas. In many cases, anatomical and physiological results allow one to determine the presence or the absence of neuronal connections from one area to another. We have approached the topology of this neuronal network within the mathematical framework of graph theory. At first, we studied the unknown part of the network, i.e. the part where anatomical and physiological results are lacking. Relying on a specific topological property of the network established on the known part, we developed an interpolation algorithm for reducing the level of uncertainty concerning the unknown part. From these results, we then constructed a connectional model of the neuronal network for the entire cortical visual system. Subsequently, a topological analysis of this model, with the help of factorial analysis and clustering technics, shows its structural properties and singular vertices. This analysis suggests the existence of two distinct classes of areas, one in the parietal part of the cortex and the other in the temporal part, which are connected to each other via relay areas, especially involving the frontal eye field. These results may help to understand the functional role of particular cortical areas in vision and, more generally, to explore how visual information flows within the visual cortex.

[Intrinsic sinus node dysfunction in adolescence during anorexia nervosa]

A seventeen year old girl with anorexia nervosa (32 kg; 165 cm) was admitted as an emergency after syncope with severe bradycardia resistant to atropine monitored over a one week period. Autonomic blockade confirmed the intrinsic character of the sinus node dysfunction with chronotropic incompetence on exercise. Secondarily, a Mobitz I second degree AVB was observed. A DDDR pacemaker was implanted with an excellent functional result. With a one year follow-up, the bradycardia persists but body weight has increased. The authors discuss the physiopathology of this case: in the literature, the classical bradycardia of anorexia nervosa is sensitive to vagolytic drugs and only exceptionally as intense as in this patient. Sinus node dysfunction is very rare in the young in the absence of congenital heart disease. It is possible that the bradycardia had become chronic in this case.

[Radiofrequency treatment of permanent tachycardia caused by reciprocating rhythm]

Permanent tachycardia by reciprocal rhythm is an arrhythmia due to macro-reentry using the normal conduction pathways in anterograde direction and an accessory atrioventricular pathway, most often posteroseptal, in retrograde direction. It is sometimes worrying because of its chronicity and the deterioration in left ventricular function with which it may be associated. A case is reported of permanent tachycardia by reciprocating rhythm treated by radiofrequency. The diagnostic value, already shown by other authors, of stimulation of the upper part of the interventricular septum to confirm the participation of an accessory atrioventricular pathway in the tachycardia circuit is mentioned, and the need for extensive mapping, because of the recent description of non-postero-septal accessory pathways, is stressed.

Correction of attenuation in SPECT with an attenuation coefficient map: a new method

Attenuation coefficient (mu) maps, measured from transmission scan, are now becoming available. A simple method of attenuation correction is needed for routine implementation, however. Significant attenuation compensation can be mathematically obtained by dividing each actual pixel value of emission projections by the average of all the attenuation factors [exp (-sigma mu)] of all voxels along the same projection ray. This simple method, compatible with filtered back projection algorithms, was tested on simulations of cardiac and cerebral transaxial images on a Vax computer using the RECLBL library. In the models, the different structures received different activity and mu values. Three types of emission projections were generated: the ideal projections obtained by summation of the activity along each projection ray, the corresponding attenuated projections, and the projections corrected for attenuation. Comparison of projections on a pixel by pixel basis showed differences of less than 20% between the corrected and ideal projections. After reconstruction, both absolute and relative quantification were greatly improved by the correction of attenuation. Further validation of the method is in progress with actual patient data.

[Coronary angioplasty in patients aged 70 and over. Immediate results and later outcome]

One hundred and ninety one consecutive patients over 70 years of age (127 men and 64 women, average age 75.6 years) underwent percutaneous transluminal coronary angioplasty (PTCA) between January 1986 and February 1989. One hundred and sixty patients had severe angina (20 Class III and 140 Class IV), 72 patients had previous myocardial infarction, 36 of which were recent (less than 1 month), and 6 patients had previously undergone coronary bypass surgery. The coronary lesions affected one vessel in 67 patients and more than one vessel in 124 patients. The left ventricular ejection fraction was less than 50% in 15 patients. Angioplasty was attempted on 245 lesions (228 stenoses and 17 occlusions): 1 lesion in 141 patients, 2 lesions in 46 patients, 3 lesions in 4 patients, with a primary success rate of 81% in stenotic and 41% in occluded arteries. There were 9 deaths (4.7%) 6 of which occurred in patients with multivessel disease and unstable angina; there were 6 Q-wave infarctions (3.1%), 8 non Q-wave infarctions (4.2%) and 3 emergency coronary bypass operations (1.6%). The first 123 patients of this series were followed up for an average of 18.8 months (7 to 37 months). Follow-up of the 100 patients successfully dilated (4 lost to follow-up) showed that 55 remained improved (53 asymptomatic), 25 had recurrent angina after the initial improvement due to restenosis in 19, progression of coronary athero-sclerosis in 3, restenosis and an evolution of coronary atherosclerosis in 1 and a lesion which had been neglected in 2 cases.(ABSTRACT TRUNCATED AT 250 WORDS)

[Complex ventricular extrasystole. Value of programmed electric stimulation for evaluating the risk of sudden death]

A prospective study was carried out from May 1984 to July 1987 to determine the prognostic value of the results of programmed electrical stimulation (PES) in patients with complex ventricular ectopy. The study population comprised 118 patients, 80 with and 38 without apparent underlying cardiac disease. The PES consisted in at most 3 extrastimuli delivered to the right ventricular apex during 2 imposed basal rhythms. Two groups of patients were identified: Group I (n = 35; 29.6%) in which a significant ventricular arrhythmia was induced (sustained ventricular tachycardia (11 cases), non-sustained VT (21 cases) and ventricular fibrillation (3 cases); and Group II (n = 83; 70.3%) in which no significant arrhythmia could be induced. During follow-up (average 28.7 +/- 11.7 months, range 6 to 48 months) there were 10 cardiac deaths, 8 of which occurred suddenly. Sudden death only occurred in patients with cardiac disease and usually with LV ejection fraction of less than 0.40; the prevalence of sudden death in Group I (11.5%) was higher than in Group II (4.8%) but the difference was not statistically significant. The prognosis of patients in Group II was the same as that of the general population. The results of this study suggest that PES enables identification of a subgroup of patients with complex ventricular ectopy in which ventricular tachyarrhythmias cannot be induced and the risk of sudden death is low; the management of patients with inducible ventricular tachyarrhythmias and normal LV function has to be determined case by case.

[Post-traumatic fistula of the left anterior descending coronary artery and left ventricle. Apropos of a new case]

The authors report the case of a 23 year old man who presented with a continuous murmur five years after closed chest trauma. The electrocardiographic and echocardiographic findings indicated previous apical myocardial infarction. The underlying diagnosis was first suggested by continuous wave Doppler which showed systolo-diastolic flow in the septo-apical region directed towards the left ventricle (LV) in diastole. Color Doppler flow studies showed a mosaic pattern opposite a dilated left anterior descending (LAD) artery. These signs of LAD-LV fistula with a single orific were confirmed at coronary arteriography. The patient's previous history was in favour of a traumatic etiology. In the absence of left ventricular failure and myocardial ischaemia by coronary steal, surgery was deferred; Doppler echocardiography would seem to be a good method of following up the fistula and its consequences on left ventricular function. A traumatic left coronary to left ventricular fistula is an extremely rare condition and merits publication. The authors review the literature and describe the physiopathology, diagnosis and therapeutic indications of these fistulae.

MIBG scintigraphic assessment of cardiac adrenergic activity in response to altitude hypoxia

High altitude hypoxia induces a decrease in the cardiac chronotropic function at maximal exercise or in response to isoproterenol infusion, suggesting an alteration in the cardiac sympathetic activation. Iodine-123 metaiodobenzylguanidine [( 123I]MIBG) was used to map scintigraphically the cardiac sympathetic neuronal function in six male subjects (aged 32 +/- 7 yr) after an exposure to high altitude that created hypoxic conditions. Results obtained just after return to sea level (RSL) were compared with the normal values obtained after 2 or 3 mo of normoxia (N). A static image was created as the sum of the 16-EKG gated images recorded for 10 min in the anterior view of the chest at 20, 60, 120, and 240 min after injection. Regions of interest were located over the heart (H), lungs (L), and mediastinum (M) regions. There was a significant decrease in the H/M and the L/M ratios in RSL compared to N condition. Plasma norepinephrine concentration was elevated during the stay at altitude but not significantly different in RSL compared to N. In conclusion, cardiac [123I]MIBG uptake is reduced after an exposure to altitude hypoxia, supporting the hypothesis of an hypoxia-induced reduction of adrenergic neurotransmitter reserve in the myocardium. Furthermore, the observed significant decrease in pulmonary MIBG uptake suggests an alteration of endothelial cell function after exposure to chronic hypoxia.

[Acute occlusion of the renal artery caused by an embolism of cardiac origin. Treatment by in situ thrombolysis]

An intra-arterial infusion of streptokinase successfully dissolved a large thrombus of the renal artery in a 54-year old male patient with old-standing mitral stenosis. This case illustrates the effectiveness of fibrinolysis in situ. This method provides complete arterial recanalization and preserves the renal function, thus enabling surgical embolectomy to be performed.

[Septal rupture repaired in the acute stage of myocardial infarction. Clinical, hemodynamic and angio-coronarography findings in the evaluation of surgical risk]

Between 1977 and 1987, 27 consecutive patients (16 men, 11 women, mean age 66 years, range 54 to 75 years) with ventricular septal rupture complicating acute myocardial infarction underwent surgical repair. The purpose of this retrospective study was to analyse the post-operative mortality factors from clinical, haemodynamic and operative data in all patients and also from coronary angiographic data in 23/27 patients whose haemodynamic status allowed this type of exploration. Seventeen patients (63 p. 100) died during the first post-operative month, 10 survived and were discharged. Factors that influenced the prognosis were: (1) inferiorly-located necrosis associated with a 75 p. 100 mortality rate (9 out of 12 patients), as opposed to 53 p. 100 (8 out of 15 patients) with anterior necrosis; (2) right ventricular dysfunction, observed in 83 p. 100 of patients with inferior necrosis and 53 p. 100 with anterior necrosis, which was responsible for 7 out of 9 deaths in the inferior necrosis subgroup and contributed to 3 out of 8 deaths in the anterior necrosis subgroup; this established a cause-effect relationship between right ventricular function and the overmortality of patients with inferior necrosis; (3) independently of the haemodynamic status, two- and three-vessel lesions (56 p. 100 of all lesions) which had an 84 p. 100 mortality rate as opposed to 40 p. 100 with one-vessel lesions; (4) the presence of a state of shock which was associated with a 78 p. 100 mortality rate as opposed to 55 p. 100 in patients without shock. We conclude that when permitted by the patient's haemodynamic status coronary angiography should be part of the pre-operative evaluation to assess the operative risk and guide the surgical procedure.