Biventricular pacing (BVP) may not achieve complete electrical resynchronization.
The purpose of this study was to assess whether the resynchronizing effect of BVP varies among patients depending on ...the underlying electrical substrate.
High-resolution electrocardiographic mapping with invasive measurement of the maximal rate of systolic left ventricular (LV) pressure rise (LVdP/dtmax) was performed during baseline activation and during BVP in 61 patients with heart failure with various conduction delays: 13 with narrow QRS duration (<120 ms), 22 with nonspecific intraventricular conduction disturbance, and 26 with left bundle branch block. Electrical dyssynchrony, both during baseline activation and BVP, was quantified by total and LV activation times (TAT and LVTAT) and by ventricular electrical uncoupling (VEU = mean LVTAT - mean right ventricular activation time). Response to BVP was defined as a ≥10% increase in LVdP/dtmax.
The electrical activation pattern during BVP was similar for all patient groups and, hence, not dependent on baseline conduction disturbance. During BVP, TAT, LVTAT, and VEU were similar for all groups and were either not correlated or weakly correlated with the change in LVdP/dtmax. In contrast, changes in electrical dyssynchrony correlated significantly with the change in LVdP/dtmax: r=0.71, 0.69, and 0.69 for ∆TAT, ∆LVTAT, and ∆VEU, respectively (all P < .001). Responders showed higher baseline dyssynchrony levels and BVP-induced dyssynchrony reduction than did nonresponders (all P < .001); in nonresponders, BVP worsened activation times than did baseline activation.
BVP does not eliminate electrical dyssynchrony, but rather brings it to a common level independent of the patient's underlying electrical substrate. Therefore, BVP is of benefit to patients with dyssynchrony but not to patients with insufficient electrical dyssynchrony in whom it induces an iatrogenic electropathy.
Background
Temporary transvenous pacing in critically ill patients requiring prolonged cardiac pacing is associated with a high risk of complications. We sought to evaluate the safety and efficacy of ...self‐contained intracardiac leadless pacemaker (LPM) implantation in this population.
Methods and Results
Consecutive patients implanted with a Micra LPM during the hospitalization in an intensive care unit were retrospectively included. Inclusion criteria were: more than or equal to 1 supracaval central venous line, or a ventilation tube, or intravenous antibiotic therapy for ongoing sepsis or bacteremia. Patients with a history of the previous implantation of a pacemaker were excluded. Out of 1016 patients implanted with an LPM, 99 met the inclusion criteria. Mean age was 75 years and Charlson comorbidity index 7. LPM implantation was successfully performed in 98% of cases, with a perioperative complication rate of 5%, mainly cardiac injuries. In‐hospital mortality rate was 6%. No late (>30 days) device‐related complication occurred, especially no infection.
Conclusions
LPM appears as an acceptable alternative to conventional temporary transvenous pacing in selected critically ill patients requiring prolonged cardiac pacing, especially regarding the risk of infection.
New-onset left bundle branch block (LBBB) is a specific concern of transcutaneous aortic valve implantation (TAVI) given its estimated incidence ranging from 5% to 65%. This high rate of occurrence ...is dependent on the type of device used (size and shape), implantation methods, and patient co-morbidities. The appearance of an LBBB after TAVI reflects a very proximal lesion of the left bundle branch as it exits the bundle of His. At times transient, its persistence can lead to permanent pacemaker implantation in 15% to 20% of cases, most often for high-degree atrioventricular block. The management of LBBB after TAVI is currently not defined by international societies resulting in individual centers developing their own management strategy. The potential consequences of LBBB are dysrhythmias (atrioventricular block, syncope, and sudden death) and functional (heart failure) complications. Prompt postprocedural recognition and management (permanent pacemaker implantation) of patients prevents the occurrence of potential complications and may constitute the preferred approach in this frail and elderly population despite additional costs and complications of cardiac pacing. Moreover, the expansion of future indications for TAVI necessitates better identification of the predictive factors for the development of LBBB. Indeed, long-term right ventricular pacing may potentially increase the risk of developing heart failure in this population. In conclusion, it is thus imperative to not only develop new aortic prostheses with a less-deleterious impact on the conduction system but also to prescribe appropriate pacing modes in this frail population.
Background:Spontaneous reanalyzed coronary thrombus (SRCT) has been reported in autopsy series, but little is known about SRCT, and it is potentially under-diagnosed in clinical practice.Methods and ...Results:SRCT identified on OCT were included in a French multicenter series, the Lotus Root French Registry. A total of 34 SRCT were identified on OCT in 33 patients (23 male; median age, 56 years; IQR, 52–65 years); 23/33 patients (70%) presented with angina pectoris and/or dyspnea. Three angiographic aspects were distinguished retrospectively: braided, pseudo-dissected, and hazy. Stenosis severity on quantitative coronary analysis varied between 11% and 100% (median, 45%), whereas the reduction in lumen area on OCT varied between 20% and 92% (median, 68%). A typical “lotus root” aspect was confirmed on OCT, consisting of multiple circular concave-edged channels of varying size, numbering between 3 and 12 depending on the slice, separated by smooth-edged septa of high luminosity without posterior attenuation. OCT also served to guide treatment, with stenting in 91% of cases. During the 17-month follow-up 91% of patients had excellent evolution. One death and 3 ACS events occurred.Conclusions:In this large SRCT cohort, angiography had limited diagnostic value whereas OCT could be used to define disease characteristics and guide treatment of lesions inducing angina pectoris and/or silent myocardial ischemia. OCT-guided management was associated with good prognosis.
Cardiac resynchronization therapy (CRT) is an electrical treatment of heart failure with reduced ejection fraction and wide QRS. It aims to correct the electrical dyssynchrony present in 30% to 50% ...of patients in this population. Dyssynchrony results in widening of the QRS complex on the electrocardiogram (ECG). CRT was initially developed to treat patients who had left bundle branch block (LBBB) and delayed activation of the lateral left ventricular wall. However, a large proportion of heart failure patients present with a widened QRS that is neither an LBBB nor a right bundle branch block (RBBB): nonspecific intraventricular conduction delay (NICD). Less studied than RBBB or LBBB, its pathophysiology is both complex and varied yet still reflects intramyocardial conduction delay. NICD is most often associated with cardiomyopathy (eg, ischemic or hypertensive). Conduction pathways can be either healthy or affected. Results from CRT are contradictory in this patient group, despite a seemingly neutral trend. Unfortunately, prospective studies are lacking. Guidelines recommending implantation of CRT devices in this group are based solely on analyses of subgroups with small sample sizes. A dedicated prospective study is therefore warranted for this question to be answered properly. A detailed study of the ECG and noninvasive study of ventricular electrical activation may enable clinicians to better identify patients with NICD who will respond to CRT.
Chronic heart failure (CHF) is one of the most common causes of mortality in industrialized countries despite regular therapeutic advances. Numerous factors influence mortality in CHF patients, ...including nutritional status. It is known that malnutrition is a risk factor for mortality, whereas obesity may play a protective role, a phenomenon dubbed the "obesity paradox". However, the effect of the obesity-malnutrition association on mortality has not been previously studied for CHF. Our aim was to study the effect of nutritional status on overall mortality in CHF patients.
This retrospective, multicenter study was based on a French nationwide database (PMSI). We included all CHF patients aged ≥18 years admitted to all public and private hospitals between 2012 and 2016 and performed a survival analysis over 1 to 4 years of follow-up.
Malnutrition led to a significant decrease in life expectancy in CHF patients when compared with normal nutritional status (aHR=1.16 1.14-1.18 at one year and aHR=1.04 1.004-1.08 at four years), obese, and obese-malnutrition groups. In contrast, obesity led to a significant increase in life expectancy compared with normal nutritional status (aHR=0.75 0.73-0.78 at one year and aHR=0.85 0.81-0.90 at four years), malnutrition, and obese-malnutrition groups. The mortality rate was similar in patients presenting both malnutrition and obesity and patients with normal nutritional status.
Our results indicate that the protective effect on mortality observed in obese CHF patients seems to be linked to fat massincrease. Furthermore, malnourished obese and normal nutritional status patients had similar mortality rates. Further studies should be conducted to confirm our results and to explore the physiopathological mechanisms behind these effects.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
Magnesium (Mg) is often used to manage de novo atrial fibrillation (AF) in the emergency department (ED) and intensive care unit (ICU). Point of care measurement of ionized magnesium (iMg) allows a ...rapid identification of patients with impaired magnesium status, however, unlike ionized calcium, the interpretation of iMg is not entirely understood. Thus, we evaluated iMg reference values, correlation between iMg and plasmatic magnesium (pMg), and the impact of pH and albumin variations on iMg levels. Secondary objectives were to assess the incidence of hypomagnesemia in de novo AF.
A total of 236 emergency department and intensive care unit patients with de novo AF, and 198 control patients were included. Reference values were determined in the control population. Correlation and concordance between iMg and pMg were studied using calcium (ionized and plasmatic) as a control in the whole study population. The impact of albumin and pH was assessed in the discordant iMg and pMg values. Lastly, we assessed the incidence of ionized hypomagnesemia (hypoMg) among de novo AF.
The reference range values established in our study for iMg were: 0.48-0.65 mmol/L (the manufacturers were: 0.45-0.60 mmol/L). A strong correlation was observed between pMg and iMg (r = 0.85), but, unlike for calcium values, there was no significant impact of pH and albumin in iMg/pMg interpretation. The incidence of hypoMg among de novo AF patients was 8.5% (12.7% using our ranges). When using our ranges, we found a significant link (
= 0.01) between hyopMg and hypokalemia.
We highlight the need for more accurate reference range values of iMg. Furthermore, our results suggest that blood Mg content is not identical to that of calcium. The incidence of ionized hypomagnesemia among de novo AF patients in our study is 8.5%.
Background
While prior Micra trials demonstrated a high implant success rate and favorable safety and efficacy results, changes in implant populations and safety over time is not well studied. The ...objective of this analysis was to report the performance of Micra in European and Middle Eastern patients and compare to the Micra Investigational Device Exemption (IDE) and Micra Post Approval Registry (PAR) studies.
Methods
The prospective, single‐arm Micra Acute Performance European and Middle Eastern (MAP EMEA) registry was designed to further study the performance of Micra in patients from EMEA. The primary endpoint was to characterize acute (30‐day) major complications. Electrical performance was analyzed. The major complication rate through 12 months was compared with the IDE and PAR studies.
Results
The MAP EMEA cohort (n = 928 patients) had an implant success rate of 99.9% and were followed for an average of 9.7 ± 6.5 months. Compared to prior studies, MAP EMEA patients were more likely to have undergone dialysis and have a condition which precluded the use of a transvenous pacemaker (p < .001). Within 30 days of implantation, the MAP EMEA cohort had a major complication rate of 2.59%. Mean pacing thresholds were low and stable through 12 months (0.61 ± 0.40 V at 0.24 ms at implant and 12 months). Through 12 months post‐implantation, the major complication rate for MAP EMEA was not significantly different from IDE (p = .56) or PAR (p = .79).
Conclusion
Despite patient differences over time, the Micra leadless pacemaker was implanted with a high success rate and low complication rate, in‐line with prior reports.
The MAP EMEA study has shown that implantation of the Micra leadless pacemaker continues to remain a highly effective and safe procedure. This remains the case in both a traditional cohort of patients being considered for TV‐PPM and more specialized groups, such as those with renal impairment/hemodialysis, prior CIED infection or where conditions exist that preclude the use of TV‐PPM.
Cardiac resynchronization therapy (CRT) is a recognized therapy for heart failure with altered ejection fraction and abnormal left ventricular activation time. Since the introduction of the therapy, ...a 30% rate of non-responders is observed and unchanged. The 12-lead ECG remains the only recommended tool for patient selection to CRT. The 12-lead ECG is, however, limited in its inability to provide a precise pattern of regional electrical activity. Electrocardiographic imaging (ECGi) provides a non-invasive detailed mapping of cardiac activation and therefore appears as a promising tool for CRT candidates. The non-invasive ventricular activation maps acquired by ECGi have been primarily explored for the diagnosis and guidance of therapy in patients with atrial or ventricular tachyarrhythmia. However, the accuracy of the system in this field is lacking and needs further improvement before considering a clinical application. On the other hand, its use for patient selection for CRT is encouraging. In this review, we introduce the technical considerations and we describe how ECGi can precisely characterize ventricular activation, especially in patients with left bundle branch block, thus identifying the electrical substrate responsive to CRT.
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