Incidence Of Complete Heart Block Research Articles

In-hospital outcomes of rotational atherectomy in relation to operator volumes: data from an asian national databank

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Studies investigating the relationship between percutaneous coronary intervention operator volumes and patient adverse events largely, but not consistently, suggest an inverse association. A recent study of rotational atherectomy (Rota-PCI) suggests lower adverse events as operator volumes increased. Purpose In this study, we aimed to use a Southeast asian national registry to investigate the relationship of Rota-PCI operator volumes to patient selection, procedural success, and in-hospital outcomes. Methods Data from a national databank was analysed for all Rota-PCI procedures performed at public hospitals from 2013 to 2019. No procedures were excluded. Operator volumes were divided into 3 tertiles and logistic regressions were performed to investigate the association to patient selection, procedural success, and in-hospital clinical outcomes. Results A total of 1,278 Rota-PCI procedures, with 37 operators performing a median volume of 23 procedures per year was included. The tertiles had median volumes of 5, 17 and 30 annually respectively. Operators at the highest tertile performed Rota-PCI in more patients with renal disease (43% vs 49% vs 53%, Tertiles 1, 2, 3 respectively; p=0.006), ACS presentations (34% vs 37% vs 41%, p=0.036), severe left ventricular dysfunction (28% vs 42% vs 44%, p<0.001), and left main disease (17% vs 24% vs 31%, p<0.001). This group also attempted more lesions (2 vs 2 vs 3, p<0.001), and utilized more circulatory support (4.2% vs 7% vs 12%, p<0.001). Intracoronary imaging was used most by the lowest tertile (29% vs 24% vs 12%, p<0.001). Operators at the highest tertile had a higher incidence of complete heart block (2.1% vs 0.8% vs 3.9%, p=0.05) but had no difference in coronary complications. There was an increase in length of stay (2 vs 3 vs 3 days, p<0.001) but otherwise no difference in in-hospital outcomes of MI, major bleed, stroke and mortality in multivariate analysis. Conclusion In summary, in-hospital outcomes were similar between all three tertiles of operator volumes. These findings may reflect our local practice where operators appropriately triage Rota-PCI cases, with the most complex cases being assigned to high volume operators.

Trends and In-Hospital Outcomes of Patients With Baseline Right Bundle Branch Block Who Underwent Transcatheter Aortic Valve Implantation

This study aimed to explore contemporary in-hospital outcomes and trends of transcatheter aortic valve implantation (TAVI) outcomes in patients with baseline right bundle branch block (RBBB) using data collected from a nationwide sample. Using the National Inpatient Sample, we identified patients hospitalized for an index TAVI procedure from 2016 to 2019. Primary outcomes included in-hospital all-cause mortality, complete heart block, and permanent pacemaker (PPM) implantation. A total of 199,895 hospitalizations for TAVI were identified. RBBB was present in 10,495 cases (5.3%). Patients with RBBB were older (median age 81 vs 80years, p <0.001) and less likely to be female (35% vs 47.4%, p <0.001). After adjusting for differences in baseline characteristics and elective versus nonelective admission, patients with RBBB had a higher incidence of complete heart block (adjusted odds ratio [aOR] 4.77, confidence interval [CI] 4.55 to 5.01, p <0.001) and PPM implantation (aOR 4.15, CI 3.95 to 4.35, p <0.001) and no difference in-hospital mortality rate (aOR 0.85, CI 0.69 to 1.05, p=0.137). Between 2016 and 2019, there was a 3.5% and 2.9% decrease in in-hospital PPM implantation in patients with and without RBBB, respectively. In conclusion, from 2016 to 2019, the rate of in-hospital PPM implantation decreased during index TAVI hospitalization in both patients with and without RBBB. However, in those with baseline RBBB, complete heart block complication rates requiring PPM implantation remain relatively high. Further research and advances are needed to continue to reduce complication rates and the need for PPM implantation.

Comparison of In-Hospital Mortality between Acute Inferior Wall STEMI Patients with and without Right Ventricular Infarction Undergoing Primary PCI

Background: Patients with acute inferior wall ST elevation myocardial infarction (STEMI) with right ventricular infarction (RVI) involvement have a worse prognosis. However, most patients in the previous studies were treated with intravenous fibrinolysis and they were in the Caucasian populations. Objective: To compare the in-hospital mortality rate of patients with acute inferior wall STEMI with and without RVI treated with primary percutaneous coronary intervention (PPCI). Materials and Methods: The present study was a retrospective descriptive study that enrolled patients with acute inferior wall STEMI treated with PPCI in King Chulalongkorn Memorial Hospital between January 1, 2007, and December 31, 2016. Results: Among 452 acute inferior wall STEMI patients treated with PPCI, 99 patients had RVI. The in-hospital mortality rate was 23.2% compared with 5.1% in patients without RVI (p&lt;0.001). Patients with RVI had a significantly higher incidence of cardiogenic shock at 48.5% versus 15.6% (p&lt;0.001), lower left ventricle ejection fraction at 51.15±17.27% versus 55.79±12.46% (p=0.037), higher incidence of complete heart block at 33.3% versus 11.9% (p&lt;0.001), and ventricular tachycardia at 15.2% versus 5.9% (p=0.003). After adjustment for age, female gender, cardiogenic shock on admission, left ventricular ejection fraction (LVEF), ventricular tachycardia, and complete heart block, the RVI had a tendency to be the poor predictor for in-hospital death (adjusted HR 1.96; 95% CI 0.73 to 5.23; p=0.18). Nevertheless, the RVI was the significant independent predictor for 1-year mortality (adjusted HR 2.12; 95% CI 1.03 to 4.36; p=0.041). Conclusion: Patients with acute inferior wall STEMI and RVI treated with PPCI had higher in-hospital mortality compared to no RVI. The RVI tended to have worse outcomes than those without RVI. Keywords: Acute inferior wall STEMI; Right ventricular infarction; Mortality

Impact of Hospital Volume on Outcomes of Septal Myectomy for Hypertrophic Cardiomyopathy

BackgroundLeft ventricular outflow tract obstruction is common among symptomatic patients with hypertrophic cardiomyopathy, yet septal reduction by surgical myectomy (septal myectomy [SM]) is performed infrequently in many centers. This study examined the possible relationship between institutional case volume and early outcomes of SM. MethodsThe Society of Thoracic Surgeons Adult Cardiac Surgery Database was queried for patients with hypertrophic cardiomyopathy who underwent SM from January 2012 to December 2019. The study defined center case volume categories as <1, 1 to 4.99, 5 to 9.99, and ≥10 cases performed on average per year. ResultsThe study population included 5935 patients at 481 centers with 933 surgeons. The range of average center volume was <1 to 138 cases per year. Overall early mortality was 2.6%, ventricular septal defect (VSD) occurred in 1.9%, and complete heart block occurred in 9.0%. Concomitant mitral valve (MV) repair was performed in 28.7%, and MV replacement was performed in 17.1%. In multivariable analysis, the lowest annual case volume (average <1 case/y) was consistently associated with greater early mortality (odds ratio [OR], 5.4; CI, 3.0-9.9; P < .001), greater risk of VSD (OR, 9.3; CI ,4.2-20.4; P < .001), increased incidence of complete heart block (OR, 2.0; CI, 1.5-2.7; P < .001), and a higher likelihood of MV replacement (OR, 9.4; CI, 7.5-11.8; P < .001). ConclusionsVolume of SM cases varies widely among institutions reporting to the Society of Thoracic Surgeons Adult Cardiac Surgery Database. There appears to be an important association between surgical experience, as reflected by institutional case volume, and early outcomes, including mortality, as well as the occurrence of VSD, heart block, and MV replacement.

Are Sutureless and Rapid-Deployment Aortic Valves a Serious Alternative to TA-TAVI? A Matched-Pairs Analysis.

Background: Transcatheter aortic valve implantation is a feasible alternative to conventional aortic valve replacement with expanding indication extending to low-risk patients. Sutureless and rapid-deployment aortic valves were developed to decrease procedural risks in conventional treatment. This paired-match analysis aims to compare patients undergoing surgical transcatheter aortic valve implantation to sutureless and rapid-deployment aortic valve implantation. Methods: Retrospective database analysis between 2010 and 2016 revealed 214 patients undergoing transcatheter aortic valve implantation procedures through surgical access (predominantly transapical) and 62 sutureless and rapid-deployment aortic valve procedures including 26 patients in need of concomitant coronary artery bypass surgery. After matching, 52 pairs of patients were included and analyzed. Results: In-hospital death (5.8% vs. 3.8%; p = 0.308) was comparable between transcatheter aortic valve implantation (mean age 77 ± 4.3 years) and sutureless and rapid-deployment aortic valve implantation groups (mean age 75 ± 4.0 years), including 32 females in each group. The logistic EuroSCORE was similar (19 ± 12 vs. 17 ± 10; p = 0.257). Postoperative renal failure (p = 0.087) and cerebrovascular accidents (p = 0.315) were without significant difference. The incidence of complete heart block requiring permanent pacemaker treatment was relatively low for both groups (1.9% vs. 7.7%; p = 0.169) for TAVI and sutureless and rapid-deployment valves respectively. Intraoperative use of blood transfusion was higher in the sutureless and rapid-deployment aortic valve implantation group (0.72 U vs. 1.46 U, p = 0.014). Estimated survival calculated no significant difference between both groups after 6 months (transcatheter aortic valve implantation: 74 ± 8% vs. sutureless and rapid-deployment aortic valve implantation: 92 ± 5%; log rank p = 0.097). Conclusion: Since sutureless and rapid-deployment aortic valve implantation is as safe and effective as transapical transcatheter aortic valve implantation, combining the advantage of standard diseased-valve removal with shorter procedural times, sutureless and rapid-deployment aortic valve replacement may be considered as an alternative for patients with elevated operative risk considered to be in the “gray zone” between transcatheter aortic valve implantation and conventional surgery, especially if concomitant myocardial revascularization is required.

Reversibility of heart block after congenital heart surgeries in pediatrics, is it predictable?

Abstract Funding Acknowledgements Type of funding sources: None. Background AV block is a serious complication of congenital heart diseases(CHD) repair surgeries.it is associated with an increased mortality and morbidity. Purpose : Identifying the incidence of Complete Heart Block (CHB) after heart surgeries for CHD, analyzing the patients` specifications and procedural data to evaluate the potential correlations that contribute the HB postoperatively. Patients and methods : We enrolled all patients who underwent CHD surgeries from September 2014 till February 2020 and identified the patients who developed postoperative CHB, those patients were divided into two groups, (a group who developed transient CHB and those who developed permanent CHB which required implantation of permanent pacemaker (PPM). We defined the transient HB as the recovery from an advanced second or third degree HB after the surgery within 10days . And the presence of advanced second or third degree HB persisting for more than 10 days after cardiac surgery is considered a permanent HB and indicated for PPM implantation according to current guidelines . Results : Our cohort includes 2377 CHD surgeries, 46 % female patients, median weight was 12.06 kg at the time of the operation, median height was 85 cm. Mean age at the time of the operation was 2.7 years in the cohort with transient HB while it was 2.6 years in the cohort who received PPM. Incidence of HB following those surgeries was 3 %(72) patients, 1.8 %of the patients (43) had transient HB and 1.2% of the patients (21 ) received a PPM. Recovery from HB was within 7days in 35 patients (82%),Two out of the 43 patients who had transient HB ended up with late onset CHB requiring pacing representing 4.6 % of that cohort, one after one month of recovery and the other one after 11 years from the surgery despite they restored their sinus rhythm within 6 days and 10 days respectively. We found the highest incidence of postoperative HB associated with VSDs surgeries either isolated or with other complex CHD diseases followed by TOF with no significant difference between transient and permanent groups according to the type of surgery. The duration of preoperative PR interval suggested the incidence of permanent CHB postoperatively with a P value of 0.005 We found that gender, age, weight and height didn`t affect the outcome, preoperative heart rate and preoperative medications didn`t alter the prognosis, the duration of CBP time and the clamping time were of no statistical significance between the 2 groups with P value of ( 0.38 and 0.33 ). Conclusion : Incidence of CHB post CHD surgeries in our center is 3 %, only 1.2 % required PPM. Various clinical data , ECG criteria , procedural time and duration of the HB except for the preoperative PR interval failed to prove a significant correlation with the incidence of CHB necessitating further investigation to identify the specific risk factors for such complication. Abstract Figure. Incidence of CHB with various surgeries

Temporal Trends and Outcomes of Transcatheter versus Surgical Aortic Valve Replacement in Patients with Prior Myocardial Infarction

ABSTRACT Background : There is a paucity of data regarding the comparative safety and effectiveness of transcatheter aortic valve replacement (TAVR) versus surgical aortic valve replacement (SAVR) in patients with prior myocardial infarction (MI). Methods : We queried the NIS database (2012–2016) to identify patients with a prior history of MI who underwent isolated AVR. We conducted a propensity matching analysis comparing patients with TAVR versus SAVR based on patient demographics, comorbidities and hospital characteristics. The primary outcome was in-hospital mortality. Results : Among 24,090 hospitalizations with prior MI undergoing isolated AVR, 58.5% underwent TAVR. Over the study period, there was an increase in the proportion of patients undergoing TAVR and a decrease in patients undergoing SAVR (Ptrend<0.001). After propensity matching, in-hospital mortality was not different between TAVR and SAVR (odds ratio 1.07; 95% confidence interval 0.85–1.33). Compared with SAVR, TAVR was associated with lower rates of cardiac arrest, cardiogenic shock, acute kidney injury, respiratory complications, postoperative bleeding, blood transfusion, acute stroke, vascular complications and shorter length of stay. TAVR was associated with a higher incidence of complete heart block and pacemaker implantation. Conclusion : In this nationwide observational study, there has been a steady increase in the number of TAVRs performed in patients with prior MI. Compared with SAVR, TAVR was associated with similar in-hospital mortality and a lower rate of complications and length of stay.

Transcatheter Closure of Perimembranous Ventricular Septal Defects Using Different Generations of Amplatzer Devices: Multicenter Experience.

Objectives To demonstrate safety and efficacy of using different generations of softer Amplatzer™ devices for ventricular septal defect (VSD) closure to avoid serious complications at follow-up. Background Transcatheter closure of perimembranous ventricular septal defects (PmVSD) is a well-established procedure; however, it is associated with unacceptable incidence of complete heart block. Great advantages have been achieved by using softer devices for VSD transcatheter closure. The first and second generation of Amplatzer™ occluders (AVP II, ADO, and ADO II) seem to offer a safe and attractive alternative for this procedure. These devices can be delivered using either an arterial (retrograde) or venous (prograde) approach. Methods and Results Patients with congenital PmVSD who underwent transcatheter closure using ADO, ADO II, and AVP II devices were included. Primary end point was to determine efficacy and safety of these generations of devices and to determine the incidence of complications at follow-up (complete AV block and aortic/tricuspid/mitral regurgitation). One hundred and nineteen patients underwent VSD closure at a median age of 5 years (8 months–54 years). During the catheterization, there were only minor complications and at follow-up of 36 ± 25.7 months (up to 99 months), the closure rate was high of 98.3% and freedom from AV block was 100%. Conclusions The use of softer Amplatzer™ devices is a good alternative to achieve PmVSD closure safely with no risk of AVB during the procedure or at midterm follow-up.

Temporal Occurrence of Arrhythmic Complications After Alcohol Septal Ablation.

The temporal occurrence of arrhythmic complications after alcohol septal ablation (ASA) is unclear. As a result, the appropriate time to monitor patients after ASA is controversial. The purpose of this study is to determine the temporal occurrence of complete heart block (CHB) and ventricular tachyarrhythmia (VT) after ASA to better understand when patients can be safely discharged. Consecutive patients treated with ASA for hypertrophic cardiomyopathy from 2003 to 2019 at a tertiary referral center were reviewed retrospectively. The incidence and timing of CHB or sustained VT within 30 days post-ASA were assessed. A total of 243 patients were included in this study. Mean maximal septal thickness was 19.0±3.9 mm, and total volume of ethanol injected was 1.7±0.6 mL. CHB occurred in 59 (24.3%) patients, including transient CHB in 33 (13.6%) and permanent in 26 (10.7%). The initial episode of CHB occurred within 24 hours post-ASA in 51 (21.0%) patients, between 24 and 48 hours in 3 (1.2%), between 48 and 72 hours in 3 (1.2%), and after 72 hours in 2 (0.8%). New permanent pacemaker was placed in 46 (18.3%). Presence of baseline bundle branch block and age ≥70 were significantly associated with CHB but not CHB presenting after 24 hours. VT occurred in 3 (1.2%) patients, including 1 (0.4%) within 24 hours, 1 (0.4%) between 24 and 48 hours, and 1 (0.4%) after 72 hours. VT required cardioversion in 2 patients and new implantable cardioverter-defibrillator placement in 2. The incidence of CHB or VT presenting after 72 hours post-ASA was low. These findings suggest that timely discharge of patients without evidence of early conduction disturbances after ASA can be considered as a potentially safe management strategy, especially in patients without preexisting conduction abnormalities.

P264 Comparison of in-hospital mortality between acute inferior wall STEMI patients with right ventricular infarction and without right ventricular infarction undergoing a primary PCI in KCMH

Abstract Background Patients with acute inferior wall ST elevation myocardial infarction, if there is a right ventricular myocardial infarction involvement, they have pretended a worse prognosis with hemodynamic and electrophysiologic complications causing higher in-hospital morbidity and mortality. However most patients in previous studies were mainly treated with intravenous fibrinolysis and also studied in the Caucasian populations. Objectives To compare the in-hospital mortality rate of patients with acute inferior wall ST elevation myocardial infarction with and without right ventricular infarction involvement, whom were treated with primary percutaneous coronary intervention (PPCI). Methods The study was a retrospective descriptive study which enrolled patients with acute inferior wall ST elevation myocardial infarction who were treated with PPCI in our hospital from 1 January 2007 - 31 December 2016. Results Among 452 acute inferior wall ST elevation myocardial infarction patients who were treated with PPCI, there were 99 patients who had right ventricular infarction involvement, the in-hospital mortality rate was 23.2%, mainly due to cardiogenic shock, compared with 5.1 % in patients who had no right ventricular infarction (p &amp;lt; 0.001). Patients with right ventricular infarction had a significantly higher incidence of cardiogenic shock (48.5% versus 15.6%, P &amp;lt; 0.001), the lower number of left ventricle ejection fraction (51.15 ± 17.27% versus 55.79 ± 12.46%, p = 0.037), the higher incidence of complete heart block (33.3% versus 11.9%, p &amp;lt; 0.001) and ventricular tachycardia (15.2% versus 5.9%, p = 0.003). After adjustment for age, female sex, diabetes, hypertension, previous myocardial infarction, cardiogenic shock on admission, left ventricular ejection fraction, ventricular tachycardia and complete heart block, the right ventricular infarction remained the independent predictor of in-hospital death (adjusted hazard ratio, 1.69; 95% confidence interval, 0.38 to 7.48; P = 0.489) and significant independent predictor for 1-year mortality (adjusted hazard ratio, 2.76; 95% confidence interval, 1.08 to 7.03; P = 0.034). Conclusion Patients with acute inferior wall STEMI whom were treated with PPCI, if there was right ventricular infarction involvement, the in-hospital death and 1-year mortality were significantly higher than who were without right ventricular infarction.

Temporal Trends and Outcomes of Transcatheter Versus Surgical Aortic Valve Replacement for Bicuspid Aortic Valve Stenosis

ObjectivesThe purpose of this study was to assess the temporal trends of transcatheter aortic valve replacement (TAVR) in patients with bicuspid aortic stenosis (AS), and to compare the outcomes between TAVR and surgical aortic valve replacement (SAVR) in this population. BackgroundRandomized trials comparing TAVR to SAVR in AS with bicuspid valve are lacking. MethodsThe study queried the National Inpatient Sample database (years 2012 to 2016) to identify hospitalizations for bicuspid AS who underwent isolated aortic valve replacement. A propensity-matched analysis was used to compare outcomes of hospitalizations for TAVR versus SAVR for bicuspid AS and TAVR for bicuspid AS versus tricuspid AS. ResultsThe analysis included 31,895 hospitalizations with bicuspid AS, of whom 1,055 (3.3%) underwent TAVR. TAVR was increasingly utilized during the study period for bicuspid AS (ptrend = 0.002). After matching, TAVR and SAVR had similar in-hospital mortality (3.1% vs. 3.1%; odds ratio: 1.00; 95% confidence interval: 0.60 to 1.67). There was no difference between TAVR and SAVR in the rates of cardiac arrest, cardiogenic shock, acute kidney injury, hemopericardium, cardiac tamponade, or acute stroke. TAVR was associated with lower rates of acute myocardial infarction, post-operative bleeding, vascular complications, and discharge to nursing facility as well as a shorter length of hospital stay. On the contrary, TAVR was associated with a higher incidence of complete heart block and permanent pacemaker insertion. TAVR for bicuspid AS was associated with similar in-hospital mortality compared with tricuspid AS. ConclusionsThis nationwide analysis showed similar in-hospital mortality for TAVR and SAVR in patients with bicuspid AS. TAVR for bicuspid AS was also associated with similar in-hospital mortality compared with tricuspid AS. Further studies are needed to evaluate long-term outcomes of TAVR for bicuspid AS.

COMPLETE HEART BLOCK AFTER TRANSCATHETER AORTIC VALVE REPLACEMENT: TRENDS IN INCIDENCE AND IN-HOSPITAL OUTCOMES

Complete heart block (CHB) is a frequent complication after transcatheter aortic valve replacement (TAVR). Trends in incidence of CHB, subsequent permanent pacemaker (PPM) implantation, and outcomes of patients with CHB after TAVR are lacking. We queried the 2012-2014 national inpatient sample

Pregnancy with Complete Heart Block.

Complete heart block is a conduction disorder characterized by a random relationship between the atrial and the ventricular activation where the atrial impulses are not conducted to the ventricle. The incidence of complete heart block (CHB) is estimated to be 1 in 15,000 to 20,000 live births [1]. It may be congenital or acquired. The acquired variety is rare during pregnancy as this type is mostly seen after 50 years of age [1]. However, the congenital variety is seen during pregnancy but that is also very rare and only few cases have been reported in the literature. Whenever encountered in a pregnant women, CHB presents a challenge for the obstetrician and calls for a multidisciplinary approach involving the cardiologist and anesthesiologist.

Cardiac Permanent Pacing after a Correction of a Congenital Heart Defect

A connection between the superior vena cava and the right pulmonary artery is known as Glenn’s shunt. Since the late 1950s, the Glenn’s shunt has been performed to improve pulmonary blood flow in patients with cyanotic congenital heart disease. Venous access to the right ventricle was complicated by the loss of continuity between the right atrium and superior vena cava consequent on the previous surgery [1]. The incidence of complete heart block following Glenn’s shunt is not known. Complete heart block may occur immediately after surgery or early in the postoperative period and also may occur many months or years after surgery. Implantation of epicardial leads was considered undesirable because of the previous thoracic surgery.

The “excluding” suture technique for surgical closure of ventricular septal defects: A retrospective study comparing the standard technique

Background:Conventional methods of closure of ventricular septal defects involve placement of sutures 4-5 mm from the posterior inferior margin. This study compares the conventional method with an alternative technique wherein sutures are placed along the edge of the defect thereby “excluding” the conduction system and the tensor apparatus of the tricuspid valve from the suture line.Materials and Methods:Between January 2013 and January 2016, 409 consecutive patients were retrospectively reviewed and divided into two matched groups. Group A (n = 174) underwent closure using the alternative technique and Group B (n = 235) with the conventional technique. Patients with isolated ventricular septal defects (VSDs) (n = 136) were separately analyzed as were infants within this subset.Results:Immediate postoperative results were similar with no statistically significant differences in either group in terms of incidence of residual defects or postoperative tricuspid regurgitation. There was however a significantly increased incidence of post operative complete heart block (CHB) among patients in the conventional group (P = 0.02). Incidence of temporary heart block that reverted to sinus rhythm was also more in the conventional method group (Group B) (P = 0.03) as was right bundle branch block (P ≤ 0.05) in all the subsets of patients analyzed.Conclusion:Surgical closure of VSDs can be accomplished by placing sutures along the margins or away with comparable results. The incidence of CHB, however, seems to be less when the “excluding” technique is employed.

Incidence and predictors of late complete heart block after alcohol septal ablation treatment of hypertrophic obstructive cardiomyopathy.

This study was designed to identify the incidence of late complete heart block (CHB) first identified at least 48 hours post alcohol septal ablation (ASA). Septal reduction with ASA is a therapeutic option for patients with symptomatic hypertrophic obstructive cardiomyopathy (HCM). CHB, resulting from the septal infarct, is a known complication with a reported incidence of 9-22%. The incidence of CHB more than 48 hours post-procedure is unknown. Consecutive patients who underwent ASA were analyzed and clinical characteristics associated with late CHB were assessed. Late CHB was defined as first identification of CHB more than 48 hours after ASA. From 2002-2013, 145 subjects underwent 168 ASA procedures and were followed for a mean of 3.2 +/- 2.3 years. The incidence of late CHB was 8.9% (15/168 ASA procedures). Heart block occurred from 48 hours to 3-years post-procedure. In a multivariable model, patients with any CHB were more likely to have had multiple ASA procedures (OR 4.14; 95% CI: 1.24, 13.9; P < 0.05) and high resting and provoked left ventricular outflow tract (LVOT) gradient assessed by catheterization (OR per 10 mmHg gradient 1.14; 95% CI: 1.0, 1.20; P < 0.05). After multivariable adjustment, only a high provokable LVOT gradient remained an independent predictor of late CHB (OR per 10 mmHg gradient 1.14 [95% CI 1.02-1.29]). Late CHB is a common complication of ASA for treatment of symptomatic HCM. Post-discharge electrocardiographic surveillance for atrioventricular conduction disease should be considered after ASA, especially for those with a high provokable LVOT gradient.

13Pulmonary hypertension leads to dysfunction and widespread ion channel remodelling within the atrioventricular node in the monocrotaline rat model

Introduction: Arrhythmias are common in pulmonary arterial hypertension (PAH) causing severe symptoms and sudden death. Atrioventricular (AV) node dysfunction is seen in PAH but the cause has not been determined. We assessed AV node function, and key ion channels, connexins and intracellular calcium handling proteins in the AV node in the moncrotaline (MCT) rat model of PAH. Methods: Male Wistar rats (200 g) were injected with either MCT (60 mg/kg) or saline (CON). Echo was performed to confirm PAH in the MCT rats. The rats were sacrificed if they showed clinical deterioration or on day 28. For whole heart experiments the heart was excised and mounted on a Langendorff perfusion column at 37°C. For right atrial (RA)/atrioventricular (AV) node experiments, a tissue preparation was superfused at 37°C. Atrio-His (AH) interval, AV effective refractory period (AVERP) and AV functional refractory period (AVFRP) were measured. A separate cohort of hearts was used to assess mRNA expression of key ion channels, connexins and intracellular calcium handling proteins in the AV node using reverse transcription quantitative polymerase chain reaction (RTqPCR). Sections of the AV node were labelled for HCN4 and connexin 43 using immunofluorescence allowing identification of the atrium, ventricle and four regions within the AV node: transitional tissue (TT), inferior nodal extension (INE), compact node (CN) and penetrating bundle (PB). Each region was microdissected and mRNA levels of 96 proteins were measured. Results: The whole heart experiments showed an increase in AVERP (87±1 ms in CON v 94±2 ms in MCT, p<0.05) and AVFRP (115±2 ms in CON v 122±2 ms in MCT, p<0.05) in the MCT rats compared with the CON rats. The isolated RA/AV node preparation demonstrated a 50% incidence of complete heart block in the MCT rats compared with 0% in the CON rats (p<0.05). The RTqPCR experiments demonstrated widespread remodelling of ion channel expression in the AV node in the MCT injected rats. In the TT, there was downregulation of phospholamban and sarcolipin; in the INE there was downregulation of HCN4, Kv2.1, minK and KChiP2, Kir2.4, phospholamban, RyR2, sarcolipin, α1 Na+/K+ ATPase and α2 Na+/K+ ATPase; in the CN there was downregulation of HCN4 and KChiP2. No significant changes were detected in the PB. Changes in HCN4 are shown. Conclusions: PAH leads to AV node dysfunction in the MCT model which is likely due to remodelling of ion channels and intracellular calcium handling proteins in the AV node. Downregulation of HCN4 is of particular interest given recent studies showing that HCN4 knockout causes heart block and suggests HCN4 may play a greater role in AV node function than has previously been realised. ![Graphic][1] Figure HCN4 expression in the AV node. The control rats show the expected distribution of HCN4 across the different regions of the AV node. Significant downregulation of HCN4 is seen in the atrium, INE and CN of the MCT rats [1]: /embed/inline-graphic-1.gif

Transcatheter closure of perimembranous ventricular septal defects with ductal occluders.

To study the feasibility and complications associated with the use of ductal occluders for closure of perimembranous ventricular septal defects. A total of 126 patients, ranging from 1 to 41 years of age (median - 8 years), underwent closure of ventricular septal defects from August 2010 to April 2013. Small- and moderate-sized defects were closed using first-generation Patent ductus arteriosus occluders or Amplatzer Duct Occluder-II. Patients were followed up for the development of complications such as heart block, aortic regurgitation, and tricuspid regurgitation. Patent ductus arteriosus occluders were used in 81 patients, and the Amplatzer Duct Occluder-II device in 45 patients. The devices were successfully deployed in 99.2% of the cases. One patient had embolisation of an Amplatzer Duct Occluder-II device soon after deployment. There was one case of transient complete heart block (0.8%) needing temporary pacing, and two cases of isoarrhythmic atrioventricular dissociation (1.6%). One patient developed late-onset complete heart block 15 months after the procedure and underwent permanent pacemaker implantation. There were no instances of new-onset aortic regurgitation. New-onset mild tricuspid regurgitation was seen in two patients. Of the patients, three had small residual shunts on follow-up, without haemolysis. Duct occluders can be used to effectively close small- and moderate-sized ventricular septal defects. The incidence of complete heart block and valvular regurgitations are much less than reported with other devices, and they are cost-effective.

Treatment of congenital non‐ductal shunt lesions with the amplatzer duct occluder II

To evaluate feasibility of use of ADO II in non-ductal positions, incidence of complete heart block (CHB), advantages and disadvantages. Out of 79 defects closed with ADO II, 61 had perimembranous, 12 apical/mid-muscular ventricular septal defects (VSD), 4 Gerbode defects, one each of coronary arterio-venous fistula and aorto-right ventricular tunnel. Age ranged from 8 months to 21 years (mean 8.9 ± 4.02 years, median 9 years). The mean fluoroscopy time was 5.2 ± 1.1 min with range 4.2-9.2 min. Complete closure was achieved in all. Three cases developed transient junctional bradycardia, treated with steroids. One patient who developed CHB (1.3%) needed temporary pacing. ADO II is a low profile device. It can be easily delivered through a 5F guiding catheter and needs very short fluoroscopic time as arteriovenous loop is not needed. The cost is 1/3 of regular ventricular septal occluders. The CHB that is a major challenge for closure of VSDs is less common with soft, specially designed ADO II, which does not compress the conducting system. Use of the ADO II in non-ductal positions can be achieved with high success and low complication rates, especially CHB; its use is also associated with significantly reduced procedure time and device cost. Device size availability restricts use of the ADO II to defects up to 6 mm in diameter. © 2013 Wiley Periodicals, Inc.

New Design of the Amplatzer Membranous VSD Occluder: A Step Forward?

Closure of perimembranous ventricular septal defects (PmVSDs) [4] with the original Amplatzer membranous VSD occluder (mVSD1) has been associated with an increased risk of complications, the most notable of which has been complete heart block. This has led to the introduction of a new device to close PmVSDs. The authors describe their experience with the new Amplatzer membranous VSD occluder (mVSD2) in two patients and critique the new device design and delivery system, comparing it with the mVSD1 occluder. Two patients underwent attempted closure of PmVSDs with the new mVSD2 device. One patient had successful closure of the defect with no residual shunt and no evidence of heart block at follow-up evaluation. Trace to mild aortic insufficiency was observed at the time of closure and at the last follow-up visit. The rhythm remained sinus. In the second patient, the device was placed but removed before release because of inability to orient the device in optimal position. Percutaneous closure of PmVSD is feasible with the new mVSD2 occluder. The change in the design may reduce the incidence of complete heart block. It remains to be seen whether the device will be suitable for smaller patients.