Search

Background Several studies have evaluated the role of QRS duration (QRSd) or QRS narrowing as predictor of response to cardiac resynchronization therapy (CRT) in order to reduce non–responders. However, their results have been conflicting. In our study we analyzed retrospectively a cohort of patients from three centers to better correlate the association between the relative change in QRS narrowing index (QI) and clinical outcome and prognosis in patients who underwent CRT implantation. Methods We included 398 patients in whom a CRT device was implanted in accordance with current guidelines in our three centres. Baseline clinical variables, echocardiographic parameters and pharmacological therapies were included. QRS duration before and after CRT implantation and QI [(pre implant QRS duration – QRS duration during CRT)/pre implant QRS duration × 100] were measured. Results Respect to echocardiographic follow up at 6 months, a significant improvement in all parameters (EF, LVEDV, LVESV) was observed. In 68% of patients, LVESV decreased by 10% or more. QI was significantly related to reverse remodelling (r = + 0.22; 95% CI: 0.11 to 0.32, p = 0.001). The cut–off value of QI that predicted best LV reverse remodelling after 6 months of CRT was 12.25% (sensitivity 65,49%, specificity 75%, area under the curve 0.7, p = 0.001). Regarding clinical outcomes at 12 mounths, a statistically significant difference was found between patients with a QI < 12.25%, and those with a QI > 12.25%, in terms of NYHA class worsening (p 0,04). Another statistically significant difference was found analyzing the relation between QI and the causes of deaths, the mean of the QI of patients who died from cardiovascular causes was lower than patients who died of other causes. (p 0,0179). Conclusions Therefore decrease in QRSd after CRT initiation was related to greater echocardiographic reverse remodelling and better outcome from death or cardiovascular hospitalization. Even if larger studies are needed, QI seems to be an easy–to– measure variable that could be used or evaluated to predict CRT response.

he right ventricular apex (RVA) has always been the most used pacing site, because it is easily accessible and provides a stable lead position with a low dislodgment rate. However, it is well-known that long-term right ventricular apical pacing may have deleterious effects on left ventricular function by inducing a iatrogenic left bundle branch block, which can have strong influences on the left ventricle hemodynamic performances. More specifically, RVA pacing causes abnormal contraction patterns and the consequent dyssynchrony may cause myocardial perfusion defects, histopathological alterations, left ventricular dilation and both systolic and diastolic left ventricular dysfunction. All these long-term changes could account for the higher morbidity and mortality rates observe in patients with chronic RVA pacing compared with atrial pacing. This observation led to the reassessment of traditional approaches and to the research of alternative pacing sites, in order to get to more physiological pattern of ventricular activation and to avoid deleterious effects. Then, attempts were made with: right ventricular outflow tract (RVOT) pacing, direct His bundle pacing (DHBP), parahisian pacing (PHP) and bifocal (RVA + RVOT) pacing. For example, RVOT pacing, especially in its septal portion, is superior to the RVA pacing and it would determine a contraction pattern very similar to the spontaneous one, not only because the septal portions are the first parts to became depolarized, but also for the proximity to the normal conduction system. RVOT is preferable in terms of safety too. DHBP is an attractive alternative to RVA pacing because it leads to a synchronous depolarization of myocardial cells and, therefore, to an efficient ventricular contraction. So it would be the best technique, however the procedure requires longer average implant times and dedicated instruments and it cannot be carried out in patients affected by His bundle pathologies; furthermore, due to the His bundle fibrous area, higher pacing thresholds are required, causing accelerated battery depletion. For all these reasons, PHP could be considered an important alternative to DHBP, to be used on a large scale. Finally, bifocal pacing in CRT candidates, provides better acute hemodynamic performance than RVA pacing, derived from a minor intra- and interventricular dyssynchrony, expressed also by the QRS shortening. Then, bifocal pacing could be taken into account when RVA pacing is likely to be the origin of serious mechanical and electrical dyssynchrony or when CRT is contraindicated or technically impossible. So, whatever chosen as selective pacing site, you must look also at safety, effectiveness and necessary equipment for an optimal pacing site.

In adults the oblique vein of Marshall is usually absent or very thin, and it is hard to be found. In this case report we describe a case of persistence observed during pacemaker implantation.

The aim of the study was to evaluate the prevalence of carotid atherosclerosis and endothelial dysfunction in 45 young patients (38 mens and 7 females) with myocardial infarction (MI), age 29-45, mean age 42+/-3 years, to verify its possible role as a marker of coronary atherosclerosis.Vascular echography was performed to verify the presence of carotid atherosclerosis and/or endothelial dysfunction in 45 young patients with MI and in 45 healthy control subjects well matched for age and sex.We observed a normal intima media thickness (IMT) only in 30% of patients with juvenile myocardial infarction (JMI) compared with 66% in the control group (P0.0001) and 34% of patients showed an increased IMT compared with 24% of healthy subjects (P0.0001). Compared with control subjects, patients with JMI had lower flow-mediated reactivity of the brachial arteries (P0.05). There was a negative linear relationship between flow-mediated dilation and IMT (P0.001). The severity of coronary artery disease (CAD) was correlated with increased IMT and with a lower flow-mediated dilation. Finally, multiple regression analysis, demonstrated that both brachial-artery reactivity and carotid IMT were significantly and independently correlated with severity of CAD.Structural (carotid atherosclerosis) and functional changes (endothelial dysfunction) were present at an early age in the arteries of persons with history of JMI.

Cardiac involvement represents a critical prognostic factor in amyloidosis, as it represents a leading cause of morbidity and mortality, in primary light chain amyloidosis, in hereditary and also in wild-type transthyretin amyloidosis. A 54-year-old male was admitted to Emergency Room with complaints of dyspnea, palpitations and diaphoresis.