BackgroundThe mechanisms associated with the cardiovascular consequences of obstructive
sleep apnea include abrupt changes in autonomic tone, which can trigger cardiac
arrhythmias. The authors hypothesized that nocturnal cardiac arrhythmia occurs
more frequently in patients with obstructive sleep apnea.ObjectiveTo analyze the relationship between obstructive sleep apnea and abnormal heart
rhythm during sleep in a population sample.MethodsCross-sectional study with 1,101 volunteers, who form a representative sample of
the city of São Paulo. The overnight polysomnography was performed using an EMBLA®
S7000 digital system during the regular sleep schedule of the individual. The
electrocardiogram channel was extracted, duplicated, and then analyzed using a
Holter (Cardio Smart®) system.ResultsA total of 767 participants (461 men) with a mean age of 42.00 ± 0.53 years, were
included in the analysis. At least one type of nocturnal cardiac rhythm
disturbance (atrial/ventricular arrhythmia or beat) was observed in 62.7% of the
sample. The occurrence of nocturnal cardiac arrhythmias was more frequent with
increased disease severity. Rhythm disturbance was observed in 53.3% of the sample
without breathing sleep disorders, whereas 92.3% of patients with severe
obstructive sleep apnea showed cardiac arrhythmia. Isolated atrial and ventricular
ectopy was more frequent in patients with moderate/severe obstructive sleep apnea
when compared to controls (p < 0.001). After controlling for potential
confounding factors, age, sex and apnea-hypopnea index were associated with
nocturnal cardiac arrhythmia.ConclusionNocturnal cardiac arrhythmia occurs more frequently in patients with obstructive
sleep apnea and the prevalence increases with disease severity. Age, sex, and the
Apnea-hypopnea index were predictors of arrhythmia in this sample.
BackgroundLeft atrial volume (LAV) is a predictor of prognosis in patients with heart
failure.ObjectiveWe aimed to evaluate the determinants of LAV in patients with dilated
cardiomyopathy (DCM).MethodsNinety patients with DCM and left ventricular (LV) ejection fraction ≤ 0.50 were
included. LAV was measured with real-time three-dimensional echocardiography
(eco3D). The variables evaluated were heart rate, systolic blood pressure, LV
end-diastolic volume and end-systolic volume and ejection fraction (eco3D), mitral
inflow E wave, tissue Doppler e´ wave, E/e´ ratio, intraventricular dyssynchrony,
3D dyssynchrony index and mitral regurgitation vena contracta. Pearson´s
coefficient was used to identify the correlation of the LAV with the assessed
variables. A multiple linear regression model was developed that included LAV as
the dependent variable and the variables correlated with it as the predictive
variables.ResultsMean age was 52 ± 11 years-old, LV ejection fraction: 31.5 ± 8.0% (16-50%) and
LAV: 39.2±15.7 ml/m2. The variables that correlated with the LAV were
LV end-diastolic volume (r = 0.38; p < 0.01), LV end-systolic volume (r = 0.43;
p < 0.001), LV ejection fraction (r = -0.36; p < 0.01), E wave (r = 0.50; p
< 0.01), E/e´ ratio (r = 0.51; p < 0.01) and mitral regurgitation (r = 0.53;
p < 0.01). A multivariate analysis identified the E/e´ ratio (p = 0.02) and
mitral regurgitation (p = 0.02) as the only independent variables associated with
LAV increase.ConclusionThe LAV is independently determined by LV filling pressures (E/e´ ratio) and
mitral regurgitation in DCM.
Heart failure (HF) is associated with morbidity and mortality. Real-time three-dimensional echocardiography (RT3DE) may offer additional prognostic data in patients with HF. The study aimed to evaluate the prognostic value of real-time three-dimensional echocardiography (RT3DE). This is a prospective study that included 89 patients with HF and left ventricular ejection fraction (LVEF) < 0.50 who were followed for 48 months. Left atrium and ventricular volumes and functions were evaluated by RT3DE. TDI and two-dimensional echocardiography parameters were also obtained. The endpoint was a composite of death, heart transplantation and hospitalization for acute decompensated HF. The mean age was 55 ± 11 years, and the LVEF was 0.32 ± 0.10. The composite endpoint occurred in 49 patients (18 deaths, 30 hospitalizations, one heart transplant). Patients with outcomes had greater left atrial volume (40 ± 16 vs. 32 ± 12 mL/m; p < 0.01) and right ventricle diameter (41 ± 9 vs. 37 ± 8 mm, p = 0.01), worse total emptying fraction of the left atrium (36 ± 13% vs. 41 ± 11%; p = 0.03), LVEF (0.30 ± 0.09 vs. 0.34 ± 0.11; p = 0.02), right ventricle fractional area change (34.8 ± 12.1% vs. 39.2 ± 11.3%; p = 0.04), and greater E/e' ratio (19 ± 9 vs. 16 ± 8; p = 0.04) and systolic pulmonary artery pressure (SPAP) (50 ± 15 vs. 36 ± 11 mmHg; p < 0.01). In multivariate analysis, LVEF (OR 4.6; CI 95% 1.2-17.6; p < 0.01) and SPAP (OR 12.5; CI 95% 1.8-86.9; p < 0.01) were independent predictors of patient outcomes. LVEF and the SPAP were independent predictors of outcomes in patients with HF.
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