[Acute heart failure with altered ejection fraction : Electrocardiographic signs with mortality at the Abidjan cardiology institute]. / Insuffisance cardiaque aiguë à fraction d'éjection altérée : signes électrocardiographiques associés à la mortalité à l'institut de cardiologie d'Abidjan.

INTRODUCTION: Heart failure with impaired ejection fraction (HFIEF) represents the end-stage of most cardiac diseases, and is responsible for a high mortality rate. In order to identify patients at risk, numerous clinical and paraclinical prognostic factors have been proposed. The electrocardiogram (ECG), easy to perform and inexpensive, retains a powerful role in the prognostic evaluation of heart failure patients. The aim was to evaluate ECG signs associated with mortality in a retrospective cohort of patients with ICFEA. METHODOLOGY: The study was observational and analytical based on retrospective data collected from patients benefiting from a primary hospitalization for ICFEA at the Abidjan Heart Institute from January 2018 to July 2020. RESULTS: Of the 370 patients included, 197 had died by August 1, 2020, representing an overall mortality of 53%. Mortality progressed gradually up to one year, then remained unchanged up to 30 months. In multivariate Cox regression including ECG variables only, the presence of intra-ventricular conduction disorders (OR: 1.80; 95% CI [1.01-3.25]), microvoltage (OR: 1.82; 95% CI [1.05-16]), and pathological Q waves (OR: 1.70; 95% CI [1.02-2.83]), were significantly associated with overall mortality. When ECG variables and clinical, paraclinical and therapeutic demographic variables were included, only the presence of pathological Q waves (OR:1.74; 95% CI [1.01-3.01]) persisted as a risk factor for mortality. Hypertension and treatment of heart failure, in particular ACEI/ARII, beta-blockers and ARM, were protective factors. The presence of Q waves was associated with a significant reduction in survival, based on curves obtained using the Kaplan-Meier model. CONCLUSION: ICFEA is responsible for high mortality, mainly in the year following the 1st hospitalization for cardiac decompensation. The presence of pathological Q waves is the only electrocardiographic sign that remains statistically associated with a poor prognosis, after adjustment.

Prevalence of cardiac dyssynchrony and correlation with atrio-ventricular block and QRS width in dilated cardiomyopathy: an echocardiographic study.

INTRODUCTION: Cardiac dyssynchrony causes disorganised cardiac contraction, delayed wall contraction and reduced pumping efficiency. We aimed to assess the prevalence of different types of dyssynchrony in patients with dilated cardiomyopathy (DCM), and to establish the correlation between atrio-ventricular block and atrio-ventricular dyssynchrony (AVD), and between impaired intra-ventricular conduction and the existence of inter-ventricular dyssynchrony (inter-VD) and intra-left ventricular dyssynchrony (intra-LVD). METHODS: We included 40 patients in New York Heart Association stage III or IV, admitted consecutively with DCM with severe left ventricular dysfunction (left ventricular end-diastolic diameter ≥ 60 mm and/or ≥ 30 mm/m(2)) and left ventricular ejection fraction < 35%. Electrocardiographic and echocardiographic data were evaluated in all patients. Patients were divided into two groups: group 1: eight patients, with a QRS duration ≥ 120 ms, and all presented with left bundle branch block; group 2: 32 patients with a narrow QRS < 120 ms. RESULTS: Overall, the mean age was 54.7 ± 16.8 years and patients in group 1 were older (67.2 ± 13.6 vs 51.5 ± 15.8 years, p = 0.01). The prevalence of atrio-ventricular dyssynchrony (AVD), inter-VD and intra-LVD was respectively 40, 47.5 and 70%. Two patients (5%) did not exhibit dyssynchrony. AVD was present with a similar frequency in the two groups (37.5% in group 1 vs 40.6% in group 2, p = 0.8). There was no correlation of the magnitude of AVD with the duration of the PR interval (from the beginning of the P wave to the beginning of the QRS complex) (r(2) = 0.02, p = 0.37) or the QRS width (r(2) = 0.01, p = 0.38). A greater proportion of patients with inter-VD was observed in group 1 (87.5 vs 60%, p = 0.03). There was a trend towards a more important inter-ventricular mechanical delay according to QRS width (r(2) = 0.009, p = 0.06). The proportion of intra-LVD was similar in all groups, with a high prevalence (87.5% in group 1 and 65.6% in group 2, p = 0.39). CONCLUSION: The assessment of cardiac dyssynchrony is possible in our country. Intra-ventricular mechanical dyssynchrony had a high prevalence in patients with DCM, irrespective of the QRS width. These data emphasise the usefulness of echocardiography in the screening of patients.