The impact of complete atrioventricular block on in-hospital and long-term mortality in patients treated with primary percutaneous coronary intervention

Objective: To analyze the incidence and the prognostic impact of complete AV block on in-hospital and 6-year mortality in STEMI patients treated with pPCI. Method: Study included 3044 consecutive STEMI patients. Results: Complete AV block was registered only at admission in 144 (4.73%) patients; 125 (86.8%) patients with complete AV block had inferior infarction. Temporary pacemaker was implanted in 72 (50%) patients with complete AV block. No patient underwent permanent pacemaker implantation. In-hospital mortality was significantly higher in patients with complete AV block than in patients without complete AV block: 17.9%vs3.6%, respectively, p<0.001. In patients with heart block and inferior infarction inhospital mortality was 13%, whereas in patients with heart block and anterior infarction inhospital mortality was 53%. When we analyzed patients who were discharged alive from the hospital, we also found significantly higher long-term (6-year) mortality rate in those with complete AV block vs patients without AV block: 7.8%v 3.4% respectively, p<0.001. Complete AV block was an independent predictor for in-hospital and 6-year mortality: inhospital mortality OR 2.94 95%CI 1.23-5.22; six year mortality HR 1.61, 95%CI 1.10- 2.37. When subanalysis was performed, in patients with inferior STEMI, complete AV block was an independent predictor of in-hospital and 6-year mortality, while in patients with anterior STEMI, complete AV block was an independent predictor of in-hospital mortality. Conclusion: In analyzed STEMI patients complete AV block was transitory and was registered only at hospital admission. Although transitory, complete AV block remained a strong independent predictor of in-hospital and long-term mortality.

Transpercutaneous closure of perimembranous ventricular septal defects by symmatric occluder

Background: Ventricular septal defect ( VSD ) is the most frequently occurring congenital cardiac disease, accounts nearly 15-30% of all cases. Surgery is still the corrective therapy with high success and low complication but having some problems with: cardiopulmonary bypass, anesthesia, ICU, sternalitis, chest scar, AV block... Recently many progress in cardiac intervention applied to treat congenital heart disease especially percutaneous VSD closure. Currently patients with VSD have other choice to cure safely, effectively and less complication. Objectives: To evaluate 12 months rusults from transpercutaneous closure of perimembranous VSD by modified double – disk symmatric devices ( symmatric occluder). Methods: This is the descriptive clinical trial and follow-up. Result: 41 patients selected by echocardiography, 37 patients were closed successfully (90,2% success rate). No significant complication (AVB…) and 1 patient nonsignificant shunt is 2.7% after 12 month follow-up. Conclusions: Transpercutaneous closure of perimembranous VSD by symmatric occluder is effective and safe and more, longer follow-up.

Epicardial fat volume is associated with preexisting atrioventricular conduction abnormalities and increased pacemaker implantation rate in patients undergoing transcatheter aortic valve implantation

Epicardial fat tissue (EFT) is a highly metabolically active fat depot surrounding the heart and coronary arteries that is related to early atherosclerosis and adverse cardiac events. We aimed to investigate the relationship between the amount of EFT and preexisting cardiac conduction abnormalities (CCAs) and the need for new postinterventional pacemaker in patients with severe aortic stenosis planned for transcatheter aortic valve implantation (TAVI). A total of 560 consecutive patients (54% female) scheduled for TAVI were included in this retrospective study. EFT volume was measured via a fully automated artificial intelligence software (QFAT) using computed tomography (CT) performed before TAVI. Baseline CCAs [first-degree atrioventricular (AV) block, right bundle branch block (RBBB), and left bundle branch block (LBBB)] were diagnosed according to 12-lead ECG before TAVI. Aortic valve calcification was determined by the Agatston score assessed in the pre-TAVI CT. The median EFT volume was 129.5 ml [IQR 94–170]. Baseline first-degree AV block was present in 17%, RBBB in 10.4%, and LBBB in 10.2% of the overall cohort. In adjusted logistic regression analysis, higher EFT volume was associated with first-degree AV block (OR 1.006 [95% CI 1.002–1.010]; p = 0.006) and the need for new pacemaker implantation after TAVI (OR 1.005 [95% CI 1.0–1.01]; p = 0.035) but not with the presence of RBBB or LBBB. EFT volume did not correlate with the Agatston score of the aortic valve. Greater EFT volume is associated independently with preexisting first-degree AV block and new pacemaker implantation in patients undergoing TAVI. It may play a causative role in degenerative processes and the susceptibility of the AV conduction system.

629 CPVT and complete atrio-ventricular block: two faces of the same coin?

Aims Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an electrical genetic disease characterized by induction of malignant ventricular arrhythmias during adrenergic stress in structurally normal hearts. CPVT is correlated to syncope or sudden cardiac death (SCD). Usually, it is caused by an autosomal dominant mutation in the cardiac ryanodine receptor (RyR2), an essential gene for Ca2+ homeostasis. Methods and results Our case series refers to: a man (59 years) who came to our attention for a clinical check-up 4 years after implanting bicameral pacemaker at the age of 55 years for complete AV block; and his three sons (E. female 27 years; D. male 25 years; and B. female 17 years) who had evidence of polymorphic non-sustained ventricular tachycardia (NSVT) with increasing effort during stress test. The three sons performed cardiac MRI and underwent genetic test. All three were found to be carriers of the same microdeletion of the RYR 2 gene (1q43- extended for about 49 kb) at the genetic test. They also have non-compacted myocardium at cardiac MRI. The father was also found to be a carrier of the same genetic microdeletion, while the mother was negative to the genetic test. The man was diagnosed to be a carrier of the mutation 4 years after pacemaker implantation. Conclusions Mutation of the RyR2 may have different phenotypic expressions and can be correlated to various clinical manifestations. CPVT is the most common one, and its prompt identification is crucial to prevent subjects from sport-related risks and to plan an efficient therapy. Our case series provides evidence for a careful consideration of such a genetic disorder even in presence of a major AV conduction disease in a relatively young subject. In the present case series, no major adverse events occurred. However, we can, in the aftermath, speculate that if a genetic disorder had been suspected when AV block occurred, a timely diagnosis could have been made earlier also for the sons.

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

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.

Abstract 16643: Pacemaker For First Degree AV Block Without Bradycardia: Pseudo-pacemaker Syndrome

Case Presentation: An 86 year old man underwent PCI of distal LAD for severe single vessel coronary artery disease identified after a high risk pharmacologic nuclear stress test (evaluation of exertional fatigue prior to abdominal aortic aneurysm surgical repair). ECHO was consistent with preserved LVEF (60-65%), moderate concentric LVH and mild left atrial enlargement. Less than a week after PCI, he presented to the emergency department for NYHA III dyspnea and fatigue. The patient was not taking any negative chronotropic medications. CT angiography of the chest excluded pulmonary edema, pneumonia and pulmonary embolism; repeat limited ECHO was unchanged. EKG showed first degree AV block (PR 400ms, figure 1). Severely prolonged PR interval with otherwise-unexplained exertional symptoms raised suspicion for pseudo-pacemaker syndrome. In the absence of an alternative cause of declining exertional tolerance, a dual chamber pacemaker with short programmed AV delay (<200ms) was implanted. The patient reported resolution of exertional fatigue and dyspnea on one-month followup. Discussion: Pseudo-pacemaker syndrome is a rare, infrequently reported, complication of first degree AV block with severely prolonged PR>300ms. P-wave at the end of the preceding T-wave suggests AV dyssynchrony (arrowhead, figure 1). Left atrial contraction against a closed mitral valve led to loss of atrial contribution to cardiac output, and elevated left atrial pressure. These changes, accentuated by physiologic increase in heart rate on exertion, most likely caused symptoms in this patient. It is interesting that AV dyssynchrony in pacemaker syndrome is caused by the pacemaker (VVI pacing) whereas the AV dyssynchrony in pseudo-pacemaker syndrome from severely prolonged PR interval is treated with a pacemaker. In the appropriate clinical picture, it is an indication for dual-chamber pacemaker implantation for first degree AV block without bradycardia or pauses.

Abstract 17180: Complications Of A Severe Case Of Multisystem Inflammatory Syndrome In Children

Case Presentation: A 10 year old male with prior COVID-19 exposure presented with 7 days of fever, rash, cough, vomiting, and hypotension. Laboratory evaluation was notable for SARS-CoV2 antibodies, elevated cardiac enzymes, BNP, and inflammatory markers. Initial echocardiogram showed normal cardiac function and a small LAD coronary aneurysm. He was diagnosed with Multisystemic Inflammatory Syndrome in Children (MIS-C) and given methylprednisolone and IVIG. Within 24 hours, he developed severe LV dysfunction and progressive cardiorespiratory failure requiring VA-ECMO cannulation and anticoagulation with bivalirudin. Cardiac biopsy demonstrated lymphocytic infiltration consistent with myocarditis. On VA-ECMO, he had transient periods of complete AV block. With immunomodulator treatment (anakinra, infliximab) and 5 days of plasmapheresis, inflammatory symptoms and cardiac function improved. He weaned off ECMO, and anticoagulation was transitioned to enoxaparin. He had left sided weakness 5 days later, and brain MRI revealed an MCA infarct. Ten days later, he had focal right sided weakness and repeat MRI showed multiple hemorrhagic cortical lesions, thought to be thromboembolic with hemorrhagic conversion secondary to an exaggerated inflammatory response to an MSSA bacteremia in the setting of MIS-C. Enoxaparin was discontinued. After continued recovery and a slow anakinra and steroid wean, he has normal coronary arteries, cardiac function, and baseline ECG but requires ongoing neurorehabilitation. Discussion: COVID-19 infection in children is often mild, but MIS-C is an evolving entity that can present with a wide range of features and severity. This case highlights two concepts. While first degree AV block is often reported in MIS-C, there is potential for progression to advanced AV block. Close telemetry monitoring is critical, especially if there is evidence of myocarditis. MIS-C shares features with Kawasaki disease, with a notable difference being a higher likelihood of shock and cardiac dysfunction in MIS-C. In MIS-C patients with cardiovascular collapse requiring ECMO, there is a risk for stroke. There should be a low threshold for neuroimaging and multidisciplinary effort to guide anticoagulation in these complex cases.

Simple atrioventricular (AV) dissociation or AV dissociation caused by third degree AV block?

The article's abstract is not available.

Optimizing Transesophageal Atrial Pacing in Mice to Detect Atrial Fibrillation

Mice are routinely used to investigate molecular mechanisms underlying the atrial fibrillation (AF) substrate. We sought to optimize transesophageal rapid atrial pacing (RAP) protocols for the detection of AF susceptibility in mouse models. Hypertensive and control C57Bl/6J mice were subjected to burst RAP at a fixed stimulus amplitude. The role of parasympathetic involvement in pacing-related atrioventricular (AV) block and AF was examined using an intraperitoneal injection of atropine. In a crossover study, burst and decremental RAP at twice diastolic threshold were compared for induction of AV block during pacing. The efficacy of burst and decremental RAP to elicit an AF phenotype was subsequently investigated in mice deficient in the lymphocyte adaptor protein (Lnk-/-) resulting in systemic inflammation, or the paired-like homeodomain 2 transcription factor (Pitx2+/-) as a positive control. When pacing at a fixed stimulus intensity, pacing-induced AV block with AF induction occurred frequently, so that there was no difference in AF burden between hypertensive and control mice. These effects were prevented by atropine administration, implicating parasympathetic activation due to ganglionic stimulation as the etiology. When mice with AV block during pacing were eliminated from analysis, male Lnk-/- mice displayed an AF phenotype only during burst RAP compared to controls whereas male Pitx2+/- mice showed AF susceptibility during burst and decremental RAP. Notably, Lnk-/- and Pitx2+/- females exhibited no AF phenotype. Our data support the conclusion that multiple parameters should be used to ascertain AF inducibility and facilitate reproducibility across models and studies.

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.