High-degree Atrioventricular Block Research Articles

Septal versus apical pacing sites in permanent right ventricular pacing: The multicentre prospective SEPTAL-PM study

The optimal right ventricular pacing site for patients requiring pacemaker implantation for permanent atrioventricular block is a matter of debate. Long-term right ventricular apical pacing has been associated with left ventricular ejection fraction impairment and heart failure. Right ventricular septal pacing has been proposed as an alternative. The aim of this randomized prospective multicentre trial was to compare left ventricular remodelling and outcomes between right ventricular apical and septal pacing after mid-term follow-up. Patients requiring pacemaker implantation for high-degree atrioventricular block were enrolled and randomized in a 1:1 fashion to receive a right ventricular apical or septal lead. A total of 141 patients were included, 69 in the septal group and 72 in the apical group. Both groups exhibited similar left ventricular ejection fractions after 18 months of follow-up (septal 57.1±11.9% vs. apical 57.4±13.4%), and left ventricular ejection fraction variation was similar in the two groups at the end of follow-up (septal -1.5±13.2% vs. apical 0.3±13.3%). Additionally, left ventricular volume, quality of life and 6-minute walk distance were similar in the two groups. However, patients in the septal group were more likely to be asymptomatic, with a significantly lower concentration of N-terminal prohormone of brain natriuretic peptide. Lastly, lead position did not impact 18-month survival. Pacing from the right ventricular apex does not have any detrimental effect on left ventricular systolic function compared with septal pacing over an 18-month period.

Mobitz Type I as the Initial Presentation of Multisystem Inflammatory Syndrome in Children.

To The Editors: Since the emergence of the novel coronavirus SARS-CoV-2, great attention was drawn to the multisystem inflammatory syndrome in children (MIS-C) – a life-threatening complication. Although conduction disorders are uncommon in childhood, a growing number of mild cases address these abnormalities with MIS-C.1 Usually they include prolonged QTc interval, first-degree atrioventricular block (AVB), right bundle branch block, ST-segment changes and tachyarrhythmias.1 This report illustrates the importance of cardiovascular monitoring in patients with MIS-C admitted to the pediatric intensive care unit (PICU). A previously healthy 9-year-old boy presented with a high fever of 39.4°C and vomiting lasting for 4 days. He tested positive for SARS-CoV-2 by RT-PCR from a nasopharyngeal swab. On physical examination, the patient was hypotensive (blood pressure of 90/50 mm Hg) and tachycardic (heart rate of 103 beats per minute). Initial laboratory tests revealed a WBC count of 6.3 × 109/L with relative neutrophilia (85%), elevated inflammatory markers (procalcitonin of 0.949 mcg/L, C-reactive protein of 165.6 mg/L, ferritin of 280.3 mcg/L, interleukin-6 of 352.8 ng/L, fibrinogen of 7.6 g/L and D-dimers of 4.45 mg/L) and elevated cardiac markers (troponin of 0.970 mcg/L and NT-pro-BNP of 6092 ng/L). Upon sudden development of bradycardia (heart rate of 45 beats per minute), electrocardiogram (ECG) revealed Mobitz type I second-degree AVB. Echocardiography documented moderate mitral regurgitation and normal left ventricular ejection fraction without pericardial effusion. Treatment in the PICU included empiric antimicrobial therapy with ceftriaxone and clindamycin, intravenous immunoglobulins, glucocorticoids, vasopressor support and diuretics. The fever receded after 7 days. The blood cultures were negative. However, ECG raised suspicion of possible progression to more advanced blocks with a P:QRS ratio of 3:1 while the cardiac markers were still elevated (troponin of 0.062 mcg/L and NT-pro-BNP of 4110 ng/L). Serial ECG revealed spontaneous conversion to normal sinus rhythm within 3 days, confirmed by the 24-hour ECG monitoring. The patient was discharged after 14 days. At the 3- and 6-months follow-up, a 24-hour ECG recording and ergometric testing showed normal rhythm without any signs of AVB. Mobitz type I second-degree AVB secondary to MIS-C is clinically difficult to recognize due to the predominant development of hypotension and tachycardia upon admission, whereas low and irregular heart rate would be indicative of such conduction disorder in a child without MIS-C.2 Several studies explored acute cardiovascular manifestations in MIS-C where Valverde et al included 286 cases and Regan et al described serial ECGs in 63 cases with a median of 5 ECGs per patient.1,3 Neither study reported a second-degree AVB. All patients with severe MIS-C require PICU admission due to possible rapid hemodynamic deterioration. Furthermore, all patients with Mobitz type I second-degree AVB should be admitted and monitored due to possible progression to bradycardia, hypotension and/or higher degree AVB.2 In conclusion, MIS-C cases started having unique presentations, including cardiac conduction disorders. Second-degree AVB can be a presenting finding of MIS-C and high clinical suspicion must be held for patients presenting with signs of shock.

High-degree atrioventricular heart block induced by pramipexole.

High-degree atrioventricular heart block induced by pramipexole.

Early Resolution of New-Onset Left Bundle Branch Block After Transcatheter Aortic Valve Implantation With the SAPIEN 3 Valve

New-onset left bundle branch block (LBBB) is common after transcatheter aortic valve implantation (TAVI) but can resolve in the post-TAVI period. We sought to examine the incidence, predictors, and outcomes of early resolution of new-onset LBBB among TAVI recipients with a SAPIEN 3 (S3) valve. Among 1,203 S3-TAVI recipients without a pre-existing pacemaker or wide QRS complex at our institution between 2016 and 2019, we identified 143 patients who developed new-onset LBBB during TAVI and divided them according to the resolution or persistence of LBBB by the next day post-TAVI to compare high-degree atrioventricular block (HAVB) and permanent pacemaker (PPM) rates. Patients with resolved LBBB (n=74, 52%), compared with those with persistent LBBB, were more often women and had a shorter QRS duration at baseline and post-TAVI, with a smaller S3 size and a shallower implantation depth. A multivariable logistic regression model demonstrated significant associations of post-TAVI QRS duration (per 10 ms increase, odds ratio=0.60 [95% confidence interval=0.44 to 0.82]) and implantation depth (per 1-mm-depth-increase, 0.77 [0.61 to 0.97]) with a lower likelihood of LBBB resolution. No patient with resolved LBBB developed HAVB within 30 days post-TAVI. Meanwhile, 8 patients (11.6%) with persistent LBBB developed HAVB. The 2-year PPM rate was significantly higher after persistent LBBB than after resolved LBBB (30.3% vs 4.5%, log-rank p <0.001), mainly driven by higher 30-day PPM rate (18.8% vs 0.0%). In conclusion, about half of new-onset LBBBs that occurred during S3-TAVI resolved by the next day post-TAVI without HAVB. In contrast, new-onset persistent LBBB may need follow-up with ambulatory monitoring within 30 days because of the HAVB risk.

Prevalence and Clinical Characteristics of Patients with Pause-Dependent Atrioventricular Block.

Background: In patients with complete atrioventricular block (AVB), the prevalence and clinical characteristics of patients with pause-dependent AVB (PD-AVB) is not known. Our objective was to assess the prevalence of PD-AVB in a population of patients with complete (or high-grade) AVB. Methods: Twelve-lead electrocardiogram (ECG) and/or telemonitoring from patients admitted (from September 2020 to November 2021) for complete (or high-degree) AVB were prospectively collected at the University Hospital of Nice. The ECG tracings were analyzed by an electrophysiologist to determine the underlying mechanism of PD-AVB. Results: 100 patients were admitted for complete (or high-grade) AVB (men 55%; 82 ± 12 years). Arterial hypertension was present in 68% of the patients. Baseline QRS width was 117 ± 32 ms, and mean left ventricular ejection fraction was 56 ± 7%. Fourteen patients (14%) with PD-AVB were identified, and presented similar clinical characteristics in comparison with patients without PD-AVB, except for syncope (which was present in 86% versus 51% in the non-PD-AVB patients, p = 0.01). PD-AVB sequence was induced by: Premature atrial contraction (8/14), premature ventricular contraction (5/14), His extrasystole (1/14), conduction block in a branch (1/14), and atrial tachycardia termination (1/14). All patients with PD-AVB received a dual-chamber pacemaker during hospitalization. Conclusion: The prevalence of PD-AVB was 14%, and may be underestimated. PD-AVB episodes were more likely associated with syncope in comparison with patients without PD-AVB.

Left atrial strain measured on magnetic resonance imaging (MRI) in patients with cardiac amyloidosis: A new prognosis marker of rhythmic cardiac events

In recent years, studies on left atrial strain (LAS) have been increasing and have demonstrated a potential interest for the diagnosis and the prognosis of cardiomyopathies such as hypertrophic cardiomyopathies or cardiac amyloidosis (CA). On MRI, there is a lack of knowledge about the impact prognosis of LAS on patients with CA. We performed on the same day an echocardiography and a MRI to a prospective cohort of patients with confirmed CA to analyse LA volume, function and strain. We recruited 19 patients with CA (73 ± 12 years, 74% of men, all in sinusal rhythm). During a mean follow-up of 13 (range 10–17) months, 10 rhythmic cardiac events (53%) occurred: eight new supraventricular tachycardia and two pacemaker implantations for high-degree atrioventricular block. By MRI, mean left ventricular ejection fraction (LVEF) was 63 ± 11%, mean LV thickness was 20 ± 4 mm, mean LA volume index was 37 ± 12 mL/m 2 , mean LAEF was 29.1 ± 14%, mean LA peak longitudinal strain (PALS) was 11 ± 6%, mean LA peak contraction strain (PACS) was 5 ± 4%. There were no differences between the two groups (cardiac events or not) for: LVEF, LV volume, LV hypertrophy, LV strain, LA volume and LAEF on echocardiography as on MRI. PALS and PACS were not discriminant parameters on echo, while, on MRI, mean PALS, and especially, two-chambers PALS were more impaired on the cardiac rhythmic events group (7.8% versus 14.3% and 7.4% versus 16.7%; P -value < 0.03). The present study is the first to suggest a link between LA peak longitudinal strain (PALS) by MRI and the occurrence of rhythmic cardiac event on patients with a CA.

614 Implantable cardiac monitors predict arrhythmic events in post-infarction patients with mildly reduced left ventricular ejection fraction

Abstract Aims Complications of acute myocardial infarction (MI) can be life-threatening leading to sudden cardiac death. While guidelines recommend prompt revascularization and prolonged intensive care hospitalization, predictors of major adverse cardiovascular outcomes are yet poorly understood. The role of implantable cardioverter-defibrillators, even in cases of non-sustained arrhythmias is still debated. To date, it is unknown how to follow-up patients with mild cardiac dysfunction after MI. Implantable cardiac monitors (ICMs) can be helpful for stratifying patients in the early discharge period, and remote monitoring might speed up arrhythmia recognition and treatment. We investigated the role of remote monitoring of ICMs to detect arrhythmic events in post-MI patients without overt cardiac dysfunction. Methods and results We enrolled 13 patients (9 males; 69.8 years) after either ST-segment (N = 7) or non-ST-segment elevation (N = 6) MI with a left ventricular ejection fraction (LVEF) &amp;gt;35%, admitted to our coronary care unit for urgent revascularization between September 2019 and September 2021. Twelve patients underwent percutaneous myocardial revascularization, whereas one was treated with medical therapy only. All patients received an ICM during hospitalization according to echo and EKG parameters. We considered LVEF ≤ 40% as sole risk factor or LVEF between 40% and 50% in addition to either PQ length prolongation, or QRS widening, or pathologic heart rate variability, or non-sustained ventricular tachycardia/paroxysmal advanced second degree atrioventricular block. Patients with multiple revascularization procedures and several hospital admissions were excluded. Implanted ICM were frequently monitored both remotely and in-office when required. During follow-up, brady- and tachy-arrhythmias were recorded in four patients (30.8%). The remote monitoring of the ICM documented new-onset atrial fibrillation, high-degree atrioventricular block, severe bradycardia, and sustained ventricular tachycardia. Three patients required hospitalization and upgrade of the implanted device with pacemakers and cardioverter/defibrillator. For arrhythmic risk stratification, patients were divided into two subgroups; group A included patients with LVEF 40% associated with heart rate &amp;gt; 60 b.p.m., PQ length &amp;gt;160 ms and QRS width &amp;gt;86 ms (N = 4); group B included patients with EF 41%/50%, PQ length &amp;lt;159 and QRS width &amp;lt;85 ms (N = 10). First group experienced more advanced rhythm disorders than group B (P &amp;lt; 0.05). Device implantation was significantly higher in group A (P &amp;lt; 0.05%). Conclusions OFF-label implementation of ICMs coupled with remote device monitoring may be effective for early detection of serious adverse cardiac rhythm alterations in patients after MI and LVEF higher than 35%. Further monitoring is ongoing for assessing the occurrence of multiple arrhythmias or their increased occurrence.

549 The role of conventional and speckle tracking echocardiography in the evaluation of leadless endocardial pacing with Micra-AV

Abstract Aims Micra-AV pacing system is a leadless pacemaker (LP) implanted in the right ventricle which can provide atrio-ventricular (AV) synchronous pacing. Echocardiographic data assessing left ventricle contractility 24–48 h after Micra AV implantation are lacking. To evaluate via conventional echocardiography and speckle-tracking echocardiography (STE), which was the best pacing modality (VVI vs. VDD) able to ensure the most efficient hemodynamic performance assessed by left ventricle ejection fraction (LF-EF) and global longitudinal strain (GLS). Methods and results We studied nine patients with high degree AV-block, enrolled in our Institution in a range of time of 5 months. All patients had first degree AV block (PQ interval between 160 and 340 ms). They were considered suitable candidates for MICRA-AV implantation according to current guidelines. Both LF-EF and GLS were performed 24–48 h after device implantation by two experienced echocardiographic physicians. The mean age of the population was 79 ± 8 years (8 were male, 89%). Risk factors more represented were hypertension and dyslipidaemia. The maximum PQ interval was 256 ± 51 ms. VDD pacing modality allows better LV-EF values than those obtained with a VVI stimulation (with a difference that was statistically significant difference, P-value = 0.008). Similarly, we obtained better GLS values during VDD pacing as respect to VVI (P-value = 0.008). Conclusions Left ventricle ejection fraction and LV-GLS improve early after leadless MICRA-AV implantation during VDD as compared to VVI pacing modality.

Ambulatory Electrocardiographic Monitoring Following Minimalist Transcatheter Aortic Valve Replacement

The aim of this study was to determine the impact of delayed high-degree atrioventricular block (HAVB) or complete heart block (CHB) after transcatheter aortic valve replacement (TAVR) using a minimalist approach followed by ambulatory electrocardiographic (AECG) monitoring.Little is known regarding the clinical impact of HAVB or CHB in the early period after discharge following TAVR.A prospective, multicenter study was conducted, including 459 consecutive TAVR patients without permanent pacemaker who underwent continuous AECG monitoring for 14 days (median length of hospital stay 2 days; IQR: 1-3 days), using 2 devices (CardioSTAT and Zio AT). The primary endpoint was the occurrence of HAVB or CHB. Patients were divided into 3 groups: 1) no right bundle branch block (RBBB) and no electrocardiographic (ECG) changes; 2) baseline RBBB with no further changes; and 3) new-onset ECG conduction disturbances.Delayed HAVB or CHB episodes occurred in 21 patients (4.6%) (median 5 days postprocedure; IQR: 4-6 days), leading to PPM in 17 (81.0%). HAVB or CHB events were rare in group 1 (7 of 315 [2.2%]), and the incidence increased in group 2 (5 of 38 [13.2%]; P < 0.001 vs group 1) and group 3 (9 of 106 [8.5%]; P = 0.007 vs group 1; P = 0.523 vs group 2). No episodes of sudden or all-cause death occurred at 30-day follow-up.Systematic 2-week AECG monitoring following minimalist TAVR detected HAVB and CHB episodes in about 5% of cases, with no mortality at 1 month. Whereas HAVB or CHB was rare in patients without ECG changes post-TAVR, baseline RBBB and new-onset conduction disturbances determined an increased risk. These results would support tailored management using AECG monitoring and the possibility of longer hospitalization periods in patients at higher risk for delayed HAVB or CHB.

Insights in a restricted temporary pacemaker strategy in a lean transcatheter aortic valve implantation program.

ObjectivesTo study the safety and feasibility of a restrictive temporary‐RV‐pacemaker use and to evaluate the need for temporary pacemaker insertion for failed left ventricular (LV) pacing ability (no ventricular capture) or occurrence of high‐degree AV‐blocks mandating continuous pacing.BackgroundVentricular pacing remains an essential part of contemporary transcatheter aortic valve implantation (TAVI). A temporary‐right‐ventricle (RV)‐pacemaker lead is the standard approach for transient pacing during TAVI but requires central venous access.MethodsAn observational registry including 672 patients who underwent TAVI between June 2018 and December 2020. Patients received pacing on the wire when necessary, unless there was a high‐anticipated risk for conduction disturbances post‐TAVI, based on the baseline‐ECG. The follow‐up period was 30 days.ResultsA temporary‐RV‐pacemaker lead (RVP‐cohort) was inserted in 45 patients, pacing on the wire (LVP‐cohort) in 488 patients, and no pacing (NoP‐cohort) in 139 patients. A bailout temporary pacemaker was implanted in 14 patients (10.1%) in the NoP‐cohort and in 24 patients (4.9%) in the LVP‐cohort. One patient in the LVP‐cohort needed an RV‐pacemaker for incomplete ventricular capture. Procedure time was significantly longer in the RVP‐cohort (68 min [IQR 52–88.] vs. 55 min [IQR 44–72] in NoP‐cohort and 55 min [IQR 43–71] in the LVP‐cohort [p < 0.005]). Procedural high‐degree AV‐block occurred most often in the RVP‐cohort (45% vs. 14% in the LVP and 16% in the NoP‐cohort [p ≤ 0.001]). Need for new PPI occurred in 47% in the RVP‐cohort, versus 20% in the NoP‐cohort and 11% in the LVP‐cohort (p ≤ 0.001).ConclusionA restricted RV‐pacemaker strategy is safe and shortens procedure time. The majority of TAVI‐procedures do not require a temporary‐RV‐pacemaker.

Characteristics and outcomes following transcatheter aortic valve replacement in China: a report from China aortic valve transcatheter replacement registry (CARRY).

Background:The past decade has witnessed an ever-increasing momentum of transcatheter aortic valve replacement (TAVR) and a subsequent paradigm shift in the contemporary management of severe aortic stenosis (AS). We conducted a multi-centric TAVR registry based on Chinese patients (the China Aortic valve tRanscatheter Replacement registrY [CARRY]) to delineate the clinical characteristics and outcomes of Chinese patients who underwent TAVR and compare the results between different valve types in different Chinese regions.Methods:CARRY is an all-comer registry of aortic valve disease patients undergoing TAVR across China and was designed as an observational study that retrospectively included all TAVR patients at each participating site. Seven hospitals in China participated in the CARRY, and 1204 patients from April 2012 to November 2020 were included. Categorical variables were compared using the chi-squared test, and continuous variables were analyzed using a t test or analysis of variance (ANOVA) test. The Kaplan–Meier curve was used to estimate the risk of adverse events during follow-up.Results:The mean age of the patients was 73.8 ± 6.5 years and 57.2% were male. The median Society of Thoracic Surgeon-Predicted Risk of Mortality score was 6.0 (3.7–8.9). Regarding the aortic valve, the proportion of bicuspid aortic valve (BAV) was 48.5%. During the hospital stay, the stroke rate was 0.7%, and the incidence of high-degree atrioventricular block indicating permanent pacemaker implantation was 11.0%. The in-hospital all-cause mortality rate was 2.2%. After 1 year, the overall mortality rate was 4.5%. Compared to patients with tricuspid aortic valve (TAV), those with BAV had similar in-hospital complication rates, but a lower incidence of in-hospital mortality (1.4% vs. 3.3%) and 1 year mortality (2.3% vs. 5.8%).Conclusions:TAVR candidates in China were younger, higher proportion of BAV, and had lower rates of post-procedural complications and mortality than other international all-comer registries. Given the use of early generation valves in the majority of the population, patients with BAV had similar rates of complications, but lower mortality than those with TAV. These findings further propel the extension of TAVR in low-risk patients.Trial Registration:https://www.chictr.org.cn/ (No. ChiCTR2000038526).

Abstract 14587: Electrocardiogram Findings Amongst Latin American Immigrants at Risk for Chagas Disease in Florida

Introduction: Chagas disease (CD) is caused by the parasite Trypanosoma cruzi and can lead to chronic Chagas cardiomyopathy (CCC). Cardiac arrhythmias are common in CCC and include AV node pathology, intraventricular conduction disease, ventricular arrhythmias, and other abnormalities. In the U.S. there are at least 300,000 immigrants from Latin America living with CD, but it is estimated that only 1% have been diagnosed. Florida is suspected to carry the third highest burden with approximately 18,000 people living with CD. Hypothesis: The purpose of this study is to investigate the prevalence of electrocardiogram (ECG) findings amongst a Hispanic immigrant population at risk for CCC in Florida. Methods: Latin American immigrants who were either born or lived in endemic regions and now reside in Florida were enrolled in the study after informed consent. All participants completed an epidemiological survey, underwent 12-lead ECG testing, and provided a fingerstick and venous blood sample for further CD testing. ECGs were interpreted by a board-certified electrophysiologist. Results: A total of 151 individuals were enrolled with a mean age of 44 years and 58.9% being female. The most common countries of origin were Venezuela (34.4%), Mexico (18.5%), Honduras (12.6%), and Colombia (11.9%). Overall, 7.3% had an intraventricular conduction delay (LBBB 0.7% , RBBB 2.0%, LAFB 2.0%, and other IVCD 2.6%). A 1st degree AV block was found in 0.7% and no participants had a higher degree AV block. Ischemic changes were noted in 15.9% of participants, with infarct pattern in 3.3% and non-specific ST-T wave changes in 13.2%. Rhythm findings included normal sinus rhythm 77.5%, sinus bradycardia 21.2%, atrial fibrillation 0.7%, and ectopic atrial rhythm 0.7%. Other findings included borderline prolonged QTc 1.3%, prolonged QTc 2.0%, PACs 1.3% and no patients with PVCs. Conclusions: Review of this preliminary data shows a significant number of ECG abnormalities among this cohort of Latin American immigrants in Florida which can be associated with CD and CCC. Of particular interest is the high prevalence of sinus bradycardia as compared to prior population studies. A full comparative analysis of ECG findings amongst those who test positive for CD in this cohort is ongoing.

Abstract 13657: Malignant Multivessel Coronary Spasm

Objective: Management of multivessel coronary spasm is challenging. Case: A 59-year-old female with a medical history of CAD status post coronary stents presented with atypical chest pain.The following morning the patient suffered a PEA arrest, from which she was resuscitated. Retrospective review of telemetry revealed frequent episodes of transient ST segment elevations in inferior leads, lasting minutes, eventually followed by sinus bradycardia and episodes of high-degree AV block with pauses up to 20 seconds.Two weeks earlier the patient presented at another institution with similar complaints. Inferior STEMI was diagnosed, she received 2 DES, in proximal OM1 and Mid LAD. She represented 6 days later with continued symptoms and repeat catheterization revealed patent stents. She was reassured and discharged on Isosorbide Mononitrate in addition to Carvedilol. Management and Decision Making: Coronary angiography at our facility demonstrated 90% stenosis of proximal LCX and 60-70% of proximal LAD. These stenosis resolved with intracoronary nitroglycerin. The stents were patent. Therefore, she was diagnosed with coronary spasm. During her hospital stay, the patient did have four more episodes of ST elevations associated with complete heart block. Since she developed high degree AV block after a coronary spasm, a temporary pacemaker was placed. Norvasc as well as nitroglycerin drip were used to treat her coronary vasospasm. Pure B-blocker medications were avoided to prevent unbalanced alpha effect.The patient was extubated 4 days later and fully recovered neurologically. A permanent pacemaker was placed and discharged home. Conclusion: High suspicion is important for diagnosis of coronary vasospasm. Treatment with coronary vasodilators is cornerstone of management. We also avoided pure alpha agonists during resuscitation measures, as well as pure B-blocker medications after recovery.

Abstract 12205: A New Mouse Model of Myocardial Lipids, Fibrosis, Arrhythmia and Diastolic Dysfunction Induced by Hyperlipidemia and Cardiac LDLR

Background: Hyperlipidemia is a major risk factor for CVD. Patients with HF with preserved ejection fraction (HFpEF) have more myocardial lipid accumulation than patients with reduced EF (HFrEF). RNASeq data from cardiac biopsies showed downregulation of the gene for lipoprotein lipase (LPL) that degrades triglycerides, in HFpEF patients compared to healthy and HFrEF controls. Poloxamer-407 (p407) induces hyperlipidemia by blocking LPL and subsequent increase in plasma triglycerides and low-density lipoprotein (LDL) cholesterol. We hypothesized that mice treated with p407 and cardiac LDL-Receptor (LDLR) over-expression (OE) develop hyperlipidemia, myocardial lipid accumulation, and diastolic dysfunction resulting in HFpEF and arrhythmias. Methods: Baseline cardiac function was assessed by echo for male and female C57Bl6 mice (n=9) for 2 groups: 4wk biweekly i.p. p407-injections with (n=4) or without (n=3) single i.v. injection with AAV9-cTnT-LDLR. Cardiac function was assessed by echocardiography at 3 and 4 wks. Blood Pressure (BP) and Whole Body Plethysmography (WBP) were assessed during wk4. Ttest was used for statistics. PR and ORO staining and telemetry were performed at wk4. Results: At wk3, P407 and LDLR OE led to alterations in diastolic function (increased IVCT, IVRT, MV E/E’, MPI, and NFT) and increased LV wall thickness, p&lt;0.05. At wk4, there was pulmonary hypertension (increased mean pulmonary arterial pressure, decreased pulmonary acceleration time p &lt;.05).Histology showed excessive myocardial lipids and fibrosis, and telemetry showed incidents of second-degree and higher-degree AV block. The group injected solely with p407 show e d alterations in diastolic function (increased IVCT, IVRT, NFT, LVMPI, LVMPI NFT p&lt;.05 ) and decreased EDV, ESV, EDLVM, ESLVM, p&lt;.05 at wk4. All groups had preserved %EF and no abnormalities in BP or WBP. Conclusions: P407 and cardiac LDLR OE induce a drastic decline in cardiac diastolic function over a shorter period of time compared to p407 alone. Diastolic dysfunction was observed in wk3 followed by pulmonary hypertension, arrhythmia, myocardial lipid accumulation and fibrosis in wk4. This new model may allow for more rapid investigations of cardiac abnormalities seen in HFpEF patients.

Outcomes of Tricuspid Valve Detachment for Isolated Ventricular Septal Defect Closure.

Partial detachment of the septal and anterior leaflets of the tricuspid valve (TV) is a technique to visualize a perimembranous ventricular septal defect (VSD) for surgical closure in cases where the VSD is obscured by TV tissue. However, TV incision bears the risk of causing relevant postoperative TV regurgitation and higher degree atrioventricular (AV) block. A total of 40 patients were identified retrospectively in our institution who underwent isolated VSD closure between January 2013 and August 2015. Visualization of the VSD was achieved in 20 patients without and in 20 patients with additional partial detachment of the TV. The mean age of patients with partial tricuspid valve detachment (TVD) was 0.7 ± 0.1 years compared with 1 ± 0.3 years ( p = 0.22) of patients without TVD. There was no difference in cardiopulmonary bypass time between patients of both groups (123 ± 11 vs. 103 ± 5 minutes, p = 0.1). Cross-clamp time was longer if the TV was detached (69 ± 5 vs. 54 ± 4 minutes, p = 0.023). There was no perioperative mortality. Echocardiography at discharge and after 2.5 years (2 months–6 years) of follow-up showed neither a postoperative increase of tricuspid regurgitation nor any relevant residual shunt. Postoperative electrocardiograms were normal without any sign of higher degree AV block. TVD offers enhanced exposure and safe treatment of VSDs. It did not result in higher rates of TV regurgitation or relevant AV block compared with the control group.

The incidence and predictors of high-degree atrioventricular block in patients with bicuspid aortic valve receiving self-expandable transcatheter aortic valve implantation.

BACKGROUNDThe high-degree atrioventricular block (HAVB) in patients with bicuspid aortic valve (BAV) treated with transcatheter aortic valve implantation (TAVI) remains high. The study aims to explore this poorly understood subject of mechanisms and predictors for HAVB in BAV self-expandable TAVI patients.METHODSWe retrospectively included 181 BAV patients for analysis. Using computed tomography data, the curvature of ascending aorta (AAo) was quantified by the angle (AAo angle) between annulus and the cross-section at 35 mm above annulus (where the stent interacts with AAo the most). The valvular anatomy and leaflet calcification were also characterized.RESULTSThe 30-day HAVB rate was 16.0% (median time to HAVB was three days). Type-1 morphology was found in 79 patients (43.6%) (left- and right-coronary cusps fusion comprised 79.7%). Besides implantation below membrane septum, large AAo angle [odds ratio (OR) = 1.08, P = 0.016] and type-1 morphology (OR = 4.97, P = 0.001) were found as the independent predictors for HAVB. Together with baseline right bundle branch block, these predictors showed strong predictability for HAVB with area under the cure of 0.84 (sensitivity = 62.1%, specificity = 92.8%). Bent AAo and calcified raphe had a synergistic effect in facilitating high implantation, though the former is associated with at-risk deployment (device implanted above annulus + prothesis pop-out, versus straight AAo: 9.9% vs. 2.2%, P = 0.031). CONCLUSIONSAAo curvature and type-1 morphology are novel predictors for HAVB in BAV patients following self-expandable TAVI. For patients with bent AAo or calcified raphe, a progressive approach to implant the device above the lower edge of membrane septum is favored, though should be done cautiously to avoid pop-out.

Systemic immune-inflammation index as a tool for predicting the need for a permanent pacemaker in patients with drug-induced atrioventricular block.

Drug-induced atrioventricular block (AVB) is generally considered reversible and does not require a permanent pacemaker implantation (PPM). However, some studies have demonstrated a failure of AVB cessation even when the inducing agent has been discontinued. This study has investigated the use of systemic immune-inflammation index (SII) to predict irreversible drug-induced AVB after drug discontinuation. Files of patients with high-degree AVB that required a temporary pacemaker (TPM) were retrospectively analyzed. Sixty-three patients in which AVB was drug-induced were included in the study. The patients were divided into the following two groups: (1) those whose AVB reversed after discontinuation of the related drug, and (2) those in which AVB did not reverse. AVB reversed in 24 patients (38%) after the inducing agent was discontinued while in the remaining 39 patients (62%) PPM was required. The most common drugs to induce AVB were beta-blockers (n=46, 73%). Follow-up time with TPM was significantly longer in the irreversible group (2.91±1.05days vs. 4.94±2.15days, p<.001). Multivariate logistic regression analysis showed that SII (odds ratio [OR]=1.002; 95% confidence interval [CI]=1.000-1.003; p=.01) was an independent predictor of the requirement for a PPM. An SII>752.05 was found to be a predictor of irreversible AVB requiring PPM with a sensitivity of 64% and specificity of 75% (receiving-operating characteristics [ROC] area under the ROC curve [AUC]: 0.704, 95% CI=0.570-0.838, p=.007). Approximately 2/3 of drug-induced high-degree AVBs are irreversible. SII is an easily available and cheap inflammatory biomarker that can be used to predict irreversible AVB.

High-degree atrioventricular block after valve-in-valve transcatheter aortic valve implantation: incidence and predictors

Abstract Background High-degree atrioventricular (AV) block and permanent pacemaker (PPM) implantation represent major complications after transcatheter aortic valve implantation (TAVI). Data on the incidence of AV block for patients undergoing valve-in-valve (ViV) TAVI are scarce. We examined the incidence and predictors of periinterventional AV conduction disturbances in a cohort of subjects undergoing ViV TAVI compared to subjects undergoing TAVI of native aortic valves. Methods In 50 consecutive patients who underwent ViV TAVI, clinical characteristics, incidence and predictors for AV conduction disturbances as well as intrahospital outcome were assessed. Applying a matched pair approach for age, gender, type and size of transcatheter valve, these subjects were compared to 50 patients undergoing TAVI of native tricuspid aortic valves. Results Mean age in both groups was 80±6 years and 50% of subjects were male. In the ViV group, 22 patients (44%) had a stented bioprosthesis, 10 patients (20%) a stentless bioprosthesis and 18 patients (36%) a previous TAVI prosthesis (balloon-expandable: n=15, self-expandable n=3). The majority of subjects (92% in each group) were treated using balloon-expandable valves (ViV group: Sapien XT, n=20 or Sapien 3, n=26, control group: Sapien XT, n=19 or Sapien 3, n=27). Periinterventional, non-reversible 3rd degree AV-block occurred in 6 patients within each group (12%), and all of the affected patients underwent PPM implantation. Among the 32 patients who underwent ViV-TAVI of a surgically placed bioprosthesis, only 2 (6%) developed a high-degree AV block (1/22 with a stented bioprosthesis and 1/10 with a stentless bioprosthesis). In contrast, high-degree AV block occurred in 4/18 patients (22%) who underwent ViV TAVI of a prior TAVI prosthesis. There was a significant difference in the occurrence of total high-degree AV blocks requiring postinterventional PPM implantation (p=0.033) between subjects who received TAVI of stented bioprostheses and those who received re-TAVI. In logistic regression analysis, pre-existing RBBB represented a significant predictor for periinterventional 3rd degree AV block across the whole cohort (p=0.001, Exp(B)=10.667), both in ViV subjects (p=0.016, Exp(B)=12.0) and in the control group (p=0.018, Exp(B)=10.0). Conclusion Periinterventional AV block occurs infrequently in subjects undergoing ViV TAVI for treatment of degenerated surgical bioprostheses. However, patients undergoing ViV TAVI for degenerated transcatheter prostheses as well as subjects with pre-existing RBBB are at substantial risk for the occurence of AV block and require close peri-interventional monitoring. Funding Acknowledgement Type of funding sources: None.

Electrocardiographic predictors of recovery from pacemaker dependency after transcatheter aortic valve implantation: a meta-analysis

Abstract Background Transcatheter aortic valve implantation (TAVI) is a well-established alternative to surgery for the treatment of patients with severe symptomatic aortic stenosis at high and intermediate surgical risk. The occurrence of electrical conduction disturbances with the need for permanent pacemaker (PPM) implantation remains one of the most frequent complications of the procedure. But PPM dependency after TAVI is often transient and conduction abnormalities may improve over time. Purpose We performed a meta-analysis to summarize available studies that reported the incidence of new PPM after TAVI and investigated the rate and possible predictors of recovery from PPM dependency during follow-up. Methods The authors conducted a literature search in PubMed and MEDLINE databases from January of 2012 until February of 2021. Eleven observational studies (n=6794) met inclusion criteria for the final analysis. The effect size was estimated using a random-effects model with 95% confidence interval (CI). Results PPM implantation was performed in 902 patients after TAVI (13.3%), mostly due to high degree atrioventricular (AV) block (81.3%). A follow-up of 683 patients was performed after a median period of 139 days. 322 of the patients examined during follow-up (48.6%) showed recovery from PPM dependency. Regarding secondary endpoints' analysis of relative risk (RR) and mean difference (MD) predictors of PPM recovery during follow-up were female sex (RR 1.37; 95% CI 1.10–1.71; p=0.006), preexisting coronary artery disease (RR 1.12; 95% CI 0.99–1.27; p=0.08) and reduced left ventricular ejection fraction (MD −2.08%; 95% CI 0.23–3.93%; p=0.03). ECG predictors for long-term PPM dependency after TAVI appeared to be preexisting right bundle branch block (RBBB) (RR 1.84; 95% CI 1.38–2.45; p&amp;lt;0.0001), bifascicular block (RR 4.41; 95% CI 1.64–11.86; p=0.003) and prolonged QRS duration (MD 8.69 ms; 95% CI 0.11–17.28 ms; p=0.05). While postprocedural complete heart block was highly predictive for long-term PPM dependency after TAVI (RR 1.35; 95% CI 0.97–1.89; p&amp;lt;0.0001), patients with recovery of PPM dependency showed more indications other than complete heart block for PPM implantation like lower degree AV block or sick sinus syndrome (RR 2.28; 95% CI 1.53–3.38; p&amp;lt;0.0001). Especially postprocedural AV block grade I (RR 1.73; 95% CI 0.96–3.14; p=0.07) and new left bundle branch block (LBBB) (RR 1.94; 95% CI 1.22–3.08; p=0.005) turned out to be predictors of PPM recovery during follow-up. Conclusion This structured meta-analysis proved new PPM implantation in 13.3% of patients following TAVI with half of the cases (48.6%) recovering from PPM dependency during follow-up. Therefore, it should be considered to carefully reassess the indication for PPM rather than to immediately implant PPM after TAVI, especially regarding postprocedural ECG predictors for early pacemaker recovery (lower degree AV block, postprocedural LBBB). Funding Acknowledgement Type of funding sources: None.

Cardiac arrhythmias 3 months after hospitalization for COVID-19

Abstract Background The long-term frequencies of cardiac arrhythmias in hospitalized coronavirus disease 2019 (COVID-19) patients have not been thoroughly investigated. Purpose To describe the prevalence of cardiac arrhythmias, 3–4 months after hospitalization for COVID-19. Methods and results Participants with COVID-19 discharged from five large Norwegian hospitals were invited to participate in a prospective cohort study. We examined 201 participants (44% females, mean age 58.5 years) with 24-hour electrocardiogram 3–4 months after discharge. Body mass index (BMI) was 28.3±4.5 kg/m2 (mean ± SD), and obesity (BMI &amp;gt;30) was found in 70 participants (34%). Clinically significant arrhythmias were defined as; ventricular tachycardia (non-sustained or sustained), premature ventricular contractions (PVC) exceeding 200/24 h, or coupled PVC, atrial fibrillation/flutter, second-degree atrioventricular block (AV-block) type 2, complete AV-block, sinoatrial (SA) block exceeding 3 s, premature AV-nodal beats in bigeminy, supraventricular tachycardia (SVT) exceeding 30 s, and sinus bradycardia with less than 30 beats/min. High-sensitive cardiac troponin T (hs-cTnT) was measured at the 3-month follow-up. Results Cardiac arrhythmias were found in 27% (n=54) of the participants. Ventricular premature contractions and non-sustained ventricular tachycardia were the most common arrhythmias, found in 22% (n=44) of the participants. Premature ventricular contractions were the most frequent cardiac arrhythmia. More than 200 PVCs per day were observed in 37 participants (18%) with a mean of 1300 PVC/day, and in 35 (95%) of these participants, the PVCs were polymorphic. Among 10 patients experiencing NSVT, 5 participants had previous CVD, including coronary heart disease (n=1), 1 atrial fibrillation, 2 venous thromboembolism, 4 heart failure. Atrial fibrillation was found in seven patients (3%), none of them of new-onset. SA block &amp;gt;3 seconds was only observed in one patient, and no incidence of high degree AV block was discovered. Pre-existing cardiovascular disease or hypertension (CVDH) were reported in 40% (n=81) of the participants. The CVDH group had an increased amount of arrhythmia compared to the group free of CVDH (p=0.04). High PVCs showed a fair correlation with hs-cTnT levels at 3 months (ρ=0.21 p=0.048). Conclusions Three months following hospital discharge with COVID-19, cardiac arrhythmia was found in every fourth participant and was associated with a higher concentration of hs-cTnT at 3 months. The clinical implications of persistent ventricular arrhythmia following COVID-19 is not clear, but ventricular ectopy has been linked to increased risk of cardiac disease, including cardiomyopathy and sudden cardiac death. Funding Acknowledgement Type of funding sources: Public Institution(s). Main funding source(s): The National Association for Heart, Lung diseases and the Norwegian Health Association and Akershus University Hospital.