Interatrial Block Predicts Life-Threatening Arrhythmias in Dilated Cardiomyopathy

Background Interatrial block (IAB) has been associated with supraventricular arrhythmias and stroke, and even with sudden cardiac death in the general population. Whether IAB is associated with life-threatening arrhythmias (LTA) and sudden cardiac death in dilated cardiomyopathy (DCM) remains unknown. This study aimed to determine the association between IAB and LTA in ambulant patients with DCM. Methods and Results A derivation cohort (Maastricht Dilated Cardiomyopathy Registry; N=469) and an external validation cohort (Utrecht Cardiomyopathy Cohort; N=321) were used for this study. The presence of IAB (P-wave duration>120 milliseconds) or atrial fibrillation (AF) was determined using digital calipers by physicians blinded to the study data. In the derivation cohort, IAB and AF were present in 291 (62%) and 70 (15%) patients with DCM, respectively. LTA (defined as sudden cardiac death, justified shock from implantable cardioverter-defibrillator or anti-tachypacing, or hemodynamic unstable ventricular fibrillation/tachycardia) occurred in 49 patients (3 with no IAB, 35 with IAB, and 11 patients with AF, respectively; median follow-up, 4.4 years [2.1; 7.4]). The LTA-free survival distribution significantly differed between IAB or AF versus no IAB (both P<0.01), but not between IAB versus AF (P=0.999). This association remained statistically significant in the multivariable model (IAB: HR, 4.8 (1.4-16.1), P=0.013; AF: HR, 6.4 (1.7-24.0), P=0.007). In the external validation cohort, the survival distribution was also significantly worse for IAB or AF versus no IAB (P=0.037; P=0.005), but not for IAB versus AF (P=0.836). Conclusions IAB is an easy to assess, widely applicable marker associated with LTA in DCM. IAB and AF seem to confer similar risk of LTA. Further research on IAB in DCM, and on the management of IAB in DCM is warranted.

[Inflammatory markers associated with asthma and body mass index]

BACKGROUND

Obesity can be considered as a chronic inflammatory process, which is associated with many different diseases. Its relationship with asthma has been poorly evaluated. Obesity induces the production of leptin and cytokines in asthmatic patients, and it is associated with worse disease severity.

OBJECTIVE

To determine the relationship between obesity (according to body mass index, BMI), asthma severity and leptin, IL-1 beta, and IL-4 concentrations in blood.

PATIENTS AND METHOD

37 adult allergic asthmatic patients where involved in the study, each of them with different clinical disease stages, evaluated by GINA international diagnosis and treatment criteria 2004. BMI was determined and peripheral blood samples were taken to determine IL-1 beta, IL-4, and leptin concentrations.

RESULTS

BMI and asthma severity shown a moderate correlation (r = 0.528), according to Colton's criteria. BMI and leptin correlation levels were r = 0.425 with p < 0.025. Plasma leptin levels and asthma severity shown a significant difference in the groups composed of intermittent mild asthma and persistent severe asthma (p < 0.02). There was a non significant correlation between BMI and asthma severity with IL-4, and finally there was no correlation with IL-1 beta. This results suggest that asthmatic patients with a BMI3 30 have higher plasma leptin concentrations and worse disease severity, mainly in women.