Third-degree block [keywords]
- Complete heart block in pregnancy: case report, analysis, and review of anesthetic management. [Journal Article]
- J Clin Anesth 2016 Sep.:58-61.
Maternal complete heart block can pose significant challenges for the anesthesiologist in the antepartum, peripartum, and postpartum periods. Some patients may present for the first time in the puerperium with dizziness, weakness, syncope, or congestive heart failure as a result of the additional hemodynamic burden that accompanies pregnancy. Although there is an increase in permanent pacemaker placement in young symptomatic patients before pregnancy, prophylactic placement of pacemakers in asymptomatic parturients is not always indicated. The need for temporary or permanent pacemakers in asymptomatic women should be assessed on a case-by-case basis; many of these patients may be safely managed during labor and delivery without pacing. The parturient with complete heart block must be followed vigilantly during pregnancy and post delivery, as the need for pacemaker insertion can also arise in the postpartum period. We present a case of third-degree heart block in a 26-year-old parturient.
- Identification of discrete epitopes of Ro52p200 and association with fetal cardiac conduction system manifestations in a rodent model. [JOURNAL ARTICLE]
- Clin Exp Immunol 2016 Aug 22.
Congenital heart block (CHB) is a potentially lethal condition characterized by a third-degree atrioventricular block (AVB). Despite anti-Ro52 antibodies being detected in nearly 90% of mothers of affected children, CHB occurs in only 1-2% of anti-Ro/SSA autoantibody-positive pregnancies. Maternal antibodies have been suggested to bind molecules crucial to fetal cardiac function, however it remains unknown whether a single antibody profile associates with CHB or whether several specificities and cross-reactive targets exist. Here, we aimed to further define the reactivity profile of CHB-associated antibodies towards Ro52p200 (amino-acid 200-239). We first analyzed reactivity of a monoclonal anti-Ro52 antibody shown to induce AVB in rats (7.8C7) and of sera from anti-Ro52p200 antibody-positive mothers of children with CHB towards a panel of modified Ro52p200 peptides, and subsequently evaluated their potential to induce AVB in rats upon transfer during gestation. We observed that CHB maternal sera displayed a homogenous reactivity profile preferentially targeting the C-terminal part of Ro52p200, in contrast to 7.8C7 that specifically bound the p200 N-terminal end. In particular, amino acid D233 appeared crucial to maternal antibody reactivity towards p200. Despite low to absent reactivity towards rat p200 and different binding profiles towards mutated rat peptides indicating recognition of different epitopes within Ro52p200, IgG purified from two mothers of children with CHB could induce AVB in rats. Our findings support the hypothesis that several fine antibody specificities and cross-targets may exist and contribute to CHB development in anti-Ro52 antibody-positive pregnancies. This article is protected by copyright. All rights reserved.
- Transfemoral aortic valve implantation with the repositionable Lotus valve for treatment of patients with symptomatic severe aortic stenosis: results from a single-centre experience. [Journal Article]
- EuroIntervention 2016 Aug 20; 12(6):760-7.
The aim of the study was to evaluate the procedural and 30-day results for the repositionable Lotus valve in patients undergoing transfemoral aortic valve implantation in a single-centre experience.We prospectively enrolled 110 patients with severe symptomatic aortic stenosis (NCT02162069). All procedures were performed without general anaesthesia by the transfemoral approach. Patients were followed for 30 days. Patients received the 23 mm (n=20), 25 mm (n=43) or 27 mm (n=47) Lotus device. Mean oversizing in relation to annulus or left ventricular outflow tract (LVOT) did not differ among groups. There was no residual moderate or severe aortic regurgitation. The rate of mild aortic regurgitation was low at 9.1%. There was no valve embolisation, no need for a second valve and no conversion to surgery. The need for a new pacemaker implantation due to complete (third degree) or type II (Mobitz) second degree atrioventricular block was 24.1%, excluding patients with previously implanted devices. Within 30 days the rates of all-cause mortality and stroke were low.In patients with severe aortic stenosis, transfemoral TAVI with the repositionable Lotus valve was associated with a high rate of device success, no moderate or severe residual aortic regurgitation, low rates of major vascular complications and mortality within 30 days.
- Conduction disorders in bradyasystolic out-of-hospital cardiac arrest. [JOURNAL ARTICLE]
- Resuscitation 2016 Jul 12.:113-119.
Bradyasystolic heart rhythms are often recorded in out-of-hospital cardiac arrest (OHCA). Atrioventricular (AV) conduction disorders might lead to OHCA, but the prevalence of AV-conduction disorders and other bradyasystolic rhythms in OHCA is unknown. These patients might benefit from pre-hospital pacing. We aimed to determine the prevalence of different types of bradyasystolic heart rhythms in OHCA, including third degree AV-block, and document survival rates.We used data from the ARREST-registry of OHCA in the Netherlands. Patients with bradyasystolic OHCA in 2006-2012 were included. ECGs were classified according to the presence of P-waves and QRS complexes in five rhythm groups. Differences in survival to discharge in relation to resuscitation characteristics, rhythm and pacing were tested using Chi-Square test and multivariate regression analysis.We included 2333 patients with a bradyasystolic rhythm; 371 patients (16%) presented with a third degree AV-block. In total 45 patients (1.9%, 95%-CI 1.4-2.5%) survived. A third degree AV-block (adjusted OR 0.86, 95%-CI 0.38-1.96) or pacing (adjusted OR 0.89, 95%-CI 0.21-3.78) was not associated with survival. Pacing was initiated in 110 patients (4.7%), after a long delay (median 18.7min). The strongest association with survival was found for the presence of a bradycardia (vs. asystole) (adjusted OR 4.20, 95%-CI 1.79-9.83), bystander witnessed (OR 4.13, 95%-CI 1.45-11.8) and EMS witnessed collapse (OR 5.18, 95%-CI 2.77-9.67).In bradyasystolic OHCA, 16% of all patients present with third degree AV-block, but survival for these and other bradyasystolic patients remains poor. Pacing is seldom initiated, often delayed, and rarely beneficial.
- Left Bundle Branch Block and Complete Heart Block Complicating Inferior Myocardial Infarction. [CASE REPORTS]
- Ann Noninvasive Electrocardiol 2016 Jul 13.
Left bundle branch block following inferior myocardial infarction remains uncommon and scarcely reported in the literature. We describe a rare presentation of a 58-year-old male patient who developed left bundle branch block and third degree atrioventricular block after inferior myocardial infarction requiring permanent pacemaker placement. Pathophysiology, impact on mortality, and management options are discussed.
- Heart block following stage 1 palliation of hypoplastic left heart syndrome. [Journal Article]
- J Thorac Cardiovasc Surg 2016 Jul; 152(1):189-94.
Publicly available data from the Pediatric Heart Network's Single Ventricle Reconstruction Trial was analyzed to determine the prevalence, timing, risk factors for, and impact of second- and third-degree heart block (HB) on outcomes in patients who underwent stage 1 palliation (S1P) for hypoplastic left heart syndrome (HLHS).The presence and date of onset of post-S1P HB occurring within the first year of life, potential risk factors for HB, and factors known to predict poor outcomes after S1P were extracted. Multivariable logistic and Cox regression analyses were performed to identify risk factors for HB and to determine the effect of HB on 3-year transplantation-free survival.Among the 549 patients in the cohort, 33 (6%) developed HB after S1P. The median interval between S1P and HB was 8 days (interquartile range, 0-133 days). Regression analysis showed that tricuspid valve repair during S1P and obstruction of pulmonary venous drainage requiring pre-S1P intervention were independently associated with HB (adjusted odds ratio [aOR], 11.6, 95% confidence interval [CI] 3.3-40; P < .001 and aOR, 5.1; 95% CI, 1.3-20.6; P = .02, respectively). Transplantation-free survival at 3 years was lower for those with HB (39% vs 65%; P = .004). HB remained associated with transplantation-free survival after controlling for known risk factors (adjusted hazard ratio, 3.1; 95% CI, 1.9-5.0; P < .001). Nine children (27%) had a pacemaker implanted, and 7 of these children (78%) died or underwent heart transplantation.HB after S1P is rare but heralds a poor outcome. Careful monitoring of these patients is recommended given their significantly increased risks of death and heart transplantation.
- Electrophysiological Mechanisms of Bayés Syndrome: Insights from Clinical and Mouse Studies. [Journal Article, Review]
- Front Physiol 2016.:188.
Bayés syndrome is an under-recognized clinical condition characterized by inter-atrial block (IAB). This is defined electrocardiographically as P-wave duration > 120 ms and can be categorized into first, second and third degree IAB. It can be caused by inflammatory conditions such as systemic sclerosis and rheumatoid arthritis, abnormal protein deposition in cardiac amyloidosis, or neoplastic processes invading the inter-atrial conduction system, such as primary cardiac lymphoma. It may arise transiently during volume overload, autonomic dysfunction or electrolyte disturbances from vomiting. In other patients without an obvious cause, the predisposing factors are diabetes mellitus, hypertensive heart disease, and hypercholesterolemia. IAB has a strong association with atrial arrhythmogenesis, left atrial enlargement (LAE), and electro-mechanical discordance, increasing the risk of cerebrovascular accidents as well as myocardial and mesenteric ischemia. The aim of this review article is to synthesize experimental evidence on the pathogenesis of IAB and its underlying molecular mechanisms. Current medical therapies include anti-fibrotic, anti-arrhythmic and anti-coagulation agents, whereas interventional options include atrial resynchronization therapy by single or multisite pacing. Future studies will be needed to elucidate the significance of the link between IAB and atrial tachyarrhythmias in patients with different underlying etiologies and optimize the management options in these populations.
- Differential Clinical Implications of High-Degree Atrioventricular Block Complicating ST-Segment Elevation Myocardial Infarction according to the Location of Infarction in the Era of Primary Percutaneous Coronary Intervention. [Journal Article]
- Korean Circ J 2016 May; 46(3):315-23.
The clinical implication of high-degree (second- and third-degree) atrioventricular block (HAVB) complicating ST-segment elevation myocardial infarction (STEMI) is ripe for investigation in this era of primary percutaneous coronary intervention (PCI). We sought to address the incidence, predictors and prognosis of HAVB according to the location of infarct in STEMI patients treated with primary PCI.A total of 16536 STEMI patients (anterior infarction: n=9354, inferior infarction: n=7692) treated with primary PCI were enrolled from a multicenter registry. We compared in-hospital mortality between patients with HAVB and those without HAVB with anterior or inferior infarction, separately. Multivariate analyses were performed to unearth predictors of HAVB and to identify whether HAVB is independently associated with in-hospital mortality.STEMI patients with HAVB showed higher in-hospital mortality than those without HAVB in both anterior (hazard ratio [HR]=9.821, 95% confidence interval [CI]: 4.946-19.503, p<0.001) and inferior infarction (HR=2.819, 95% CI: 2.076-3.827, p<0.001). In multivariate analyses, HAVB was associated with increased in-hospital mortality in anterior myocardial infarction (HR=19.264, 95% CI: 5.804-63.936, p<0.001). However, HAVB in inferior infarction was not an independent predictor of increased in-hospital mortality (HR=1.014, 95% CI: 0.547-1.985, p=0.901).In this era of primary PCI, the prognostic impact of HAVB is different according to the location of infarction. Because of recent improvements in reperfusion strategy, the negative prognostic impact of HAVB in inferior STEMI is no longer prominent.
- Interaction between Macrophages and Fibroblasts during Wound Healing of Burn Injuries in Rats. [Journal Article]
- Kurume Med J 2016; 62(3-4):59-66.
Analysis of the structural changes and cell-to-cell interactions occurring during wound healing of burn injuries is essential to elucidate the morphological characteristics of the reconstitution of tissue architecture. However, conventional approaches do not provide sufficient information with respect to cell-to-cell interactions during wound healing. The aim of this study was to evaluate the interaction between bone marrow-derived cells and resident stromal cells throughout the wound healing of burn injuries, using immunohistochemistry and focused ion beam/scanning electron microscope tomography. We induced third-degree burn injuries on the backs of Wistar rats with a heated cylindrical aluminum block (2.0 cm in diameter). At 7 and 14 days after the burn injuries, the burned skin was immunostained with anti-Iba1 and anti-HSP47 antibodies for visualization of bone marrow-derived cells/macrophages and resident stromal cells/fibroblasts, respectively. Normal skin tissue was used as a control. Double-staining immunohistochemistry revealed frequent contacts between macrophages and fibroblasts and a higher contact ratio in the 3 normal skin compared with burned skin, particularly in the areas of granuloma. Three-dimensional ultrastructural analysis with focused ion beam/scanning electron microscope tomography revealed that macrophages and fibroblasts were located closer together in the normal skin than in the burned skin, confirming the analysis by light microscopic observations and ultrastructural analysis from single sections. These results highlight the importance of contact between macrophages and fibroblasts in the maintenance of skin tissue structure and during wound healing.
- A case of reversible third-degree AV block due to Lyme carditis. [Journal Article]
- J Electrocardiol 2016 Jul-Aug; 49(4):519-21.
The most common manifestation of Lyme carditis is a varying degree of atrioventricular (AV) conduction block. This case describes a 45-year-old male with third-degree AV block due to Lyme carditis. Treatment with intravenous antibiotics resulted in complete normalization of AV conduction, thereby averting permanent pacemaker implantation.