Incidence of carditis and predictors of pacemaker implantation in patients hospitalized with Lyme disease

Background Lyme carditis, defined as direct infection of cardiac tissue by Borrelia bacteria, affects up to 10% of patients with Lyme disease. The most frequently reported clinical manifestation of Lyme carditis is cardiac conduction system disease. The goal of this study was to identify the incidence and predictors of permanent pacemaker implantation in patients hospitalized with Lyme disease. Methods A retrospective cohort analysis of the Nationwide Inpatient sample was performed to identify patients hospitalized with Lyme disease in the US between 2003 and 2014. Patients with Lyme carditis were defined as those hospitalized with Lyme disease who also had cardiac conduction disease, acute myocarditis, or acute pericarditis. Patients who already had pacemaker implants at the time of hospitalization (N = 310) were excluded from the Lyme carditis subgroup. The primary study outcome was permanent pacemaker implantation. Secondary outcomes included temporary cardiac pacing, permanent pacemaker implant, and in-hospital mortality. Results Of the 96,140 patients hospitalized with Lyme disease during the study period, 10,465 (11%) presented with Lyme carditis. Cardiac conduction system disease was present in 9,729 (93%) of patients with Lyme carditis. Permanent pacemaker implantation was performed in 1,033 patients (1% of all Lyme hospitalizations and 11% of patients with Lyme carditis-associated conduction system disease). Predictors of permanent pacemaker implantation included older age (OR: 1.06 per 1 year; 95% CI:1.05–1.07; P<0.001), complete heart block (OR: 21.5; 95% CI: 12.9–35.7; P<0.001), and sinoatrial node dysfunction (OR: 16.8; 95% CI: 8.7–32.6; P<0.001). In-hospital mortality rate was higher in patients with Lyme carditis (1.5%) than in patients without Lyme carditis (0.5%). Conclusions Approximately 11% of patients hospitalized with Lyme disease present with carditis, primarily in the form of cardiac conduction system disease. In this 12-year study, 1% of all hospitalized patients and 11% of those with Lyme-associated cardiac conduction system disease underwent permanent pacemaker implantation.

Conduction System Disease and Atrioventricular Block in Victims of COVID-19 in Iran

Background More recently, a growing body of literature on COVID-19 has investigated the electrophysiological issues presetting as a disease manifestation of COVID-19 and highlight the spectrum of arrhythmias observed in patients with COVID-19 infection. This Study discuss the prevalence of arrhythmias and conduction system disease in patients with COVID-19. Method electrocardiographic data and comorbidity data of 432 expired COVID-19 patients admitted to Faghihi Hospital of Shiraz University of Medical Sciences from August 1st until December 1st were reviewed. Results AVB was found in 40(9.3%) patients. 28(6.5%) of the patients suffered from 1st degree AVB, and 12(2.8%) suffered from CHB. Changes in ST-T wave compatible with myocardial infarction or localized myocarditis appeared in 189(59.0%) patients. Findings compatible with myocardial injury such as fragmented QRS, and prolonged QTc were assessed with prevalence of 21.1% (91 patients), 6.5% (28 patients). In victims of COVID-19, conduction disease was not related to any underlying medical condition. Fragmented QRS, axis deviation, presence of S1Q3T3 and poor R wave progression were significantly related to conduction system disease in victims of COVID-19 (P value > 0.05, Table 3) Conclusion Our findings can serve in future studies that aim to develop a risk stratification method for susceptible COVID-19 patients. Myocardial injury appears to role significantly in COVID-19 morbidity and mortality. Consequently, we recommend health policymakers to consider separate catheterization laboratories that provide service only to COVID-19 patients.

A rare cause of familial atrioventricular block with a novel LMNA mutation (p. Ala502Val)

Mutation in LMNA accounts for 10% of Dilated Cardiomyopathy (DCM). It is characterised by progressive conduction system disease, arrhythmia and systolic impairment, lamin A/C heart disease is the most malignant gene common in DCMs especially in man. It is likely to be an under-recognised cause of this cardiomyopathy. In certain clinical scenarios, particularly familial DCM with early conduction disease, the probability of finding an LMNA mutation may be quite high.

How good is operator opinion at predicting high ventricular pacing burden among patients receiving device therapy for bradycardia?

Funding Acknowledgements Type of funding sources: None. Introduction Current guidelines indicate that pacing methods that maintain physiologic ventricular activation (biventricular pacing or His-bundle pacing) should be chosen over right ventricular pacing (Vp) among patients with EF 36-50% who are expected to Vp &gt;40% of the time. There are no guidelines to help predict which patients will receive a high burden of Vp and this is left to operator opinion. We sought to ascertain whether operator opinion is an accurate predictor of high burden of Vp. Methods This was a single-centre single-blinded observational study of patients who received pacemaker implant for treatment of bradycardia between April 2015 and 2019 and had at least 12 month follow-up data on record. Patients’ demographic, clinical, electrocardiographic and echocardiographic data were reviewed in a blinded fashion by a senior implanting physician, who estimated whether the Vp at 12 months would exceed 40%. The Vp at approximately 12 months was obtained from the pacing records and compared with the prediction. Results Some 982 patients underwent pacemaker implantation during the study period, 698 for conduction system disease (CSD), 267 for sinus node disease (SND) and 17 for other conditions. Overall, 856 had valid follow-up data. Of these, 543 (63.4%) were predicted to Vp &gt;40% , and 527(61.6%) were documented as having Vp &gt;40%. The sensitivity and specificity of operator prediction were 93.2% and 84.2%, with positive and negative predictive values of 90.4% and 88.5%. Table 1 illustrates analyses of different populations by clinical parameter. In sub-group analysis, complete heart block and PR &gt; 300ms were significant factors for accurate prediction of Vp &gt; 40%, however clinical features, such as syncope, were poor discriminators. Conclusion In this single-centre study, among patients receiving pacemaker implant for treatment of bradycardia, operator prediction of the burden of Vp &gt;40% has an acceptable degree of accuracy. Sub-group analysis suggests that certain clinical parameters could make this prediction easier. Table 1. Comparison of operator opinion SND CSD CHB SND+PR &lt; 160 PR &gt; 300 Syncope Non-syncope n 698 267 216 84 60 409 344 Sensitivity 44.4% 97.7% 100% 6.3% 100% 86.4% 87.9% Specificity 98.3% 62.0% 45.2% 97.1% 0%* 89.9% 79.6% PPV 87.0% 90.6% 91.6% 33.3% 98.3% 94.2% 92.2% NPV 87.9% 87.9% 100% 81.5% - 77.6% 70.5% * only 1 patient did not RV pace &gt;40% - this was not predicted. SND – sinus node disease; CSD – conduction system disease; CHB – complete heart block, PPV – positive predictive value; NPV – negative predictive value

The evolution of cardiac resynchronization therapy and an introduction to conduction system pacing: a conceptual review

In chronic systolic heart failure and conduction system disease, cardiac resynchronization therapy (CRT) is the only known non-pharmacologic heart failure therapy that improves cardiac function, functional capacity, and survival while decreasing cardiac workload and hospitalization rates. While conventional bi-ventricular pacing has been shown to benefit patients with heart failure and conduction system disease, there are limitations to its therapeutic success, resulting in widely variable clinical response. Limitations of conventional CRT evolve around myocardial scar, fibrosis, and inability to effectively simulate diseased tissue. Studies have shown endocardial stimulation in closer proximity to the specialized conduction system is more effective when compared with epicardial stimulation. Several observational and acute haemodynamic studies have demonstrated improved electrical resynchronization and echocardiographic response with conduction system pacing (CSP). Our objective is to provide a systematic review of the evolution of CRT, and an introduction to CSP as an intriguing, though experimental physiologic alternative to conventional CRT.

Phenotypic expression and clinical outcomes in a South Asian PRKAG2 cardiomyopathy cohort

The PRKAG2 syndrome is a rare autosomal dominant phenocopy of sarcomeric hypertrophic cardiomyopathy (HCM), characterized by ventricular pre-excitation, progressive conduction system disease and left ventricular hypertrophy. This study describes the phenotype, genotype and clinical outcomes of a South-Asian PRKAG2 cardiomyopathy cohort over a 7-year period. Clinical, electrocardiographic, echocardiographic, and cardiac MRI data from 22 individuals with PRKAG2 variants (68% men; mean age 39.5 ± 18.1 years), identified at our HCM centre were studied prospectively. At initial evaluation, all of the patients were in NYHA functional class I or II. The maximum left ventricular wall thickness was 22.9 ± 8.7 mm and left ventricular ejection fraction was 53.4 ± 6.6%. Left ventricular hypertrophy was present in 19 individuals (86%) at baseline. 17 patients had an WPW pattern (77%). After a mean follow-up period of 7 years, 2 patients had undergone accessory pathway ablation, 8 patients (36%) underwent permanent pacemaker implantation (atrio-ventricular blocks—5; sinus node disease—2), 3 patients developed atrial fibrillation, 11 patients (50%) developed progressive worsening in NYHA functional class, and 6 patients (27%) experienced sudden cardiac death or equivalent. PRKAG2 cardiomyopathy must be considered in patients with HCM and progressive conduction system disease.

No increased extracellular volume fraction or conduction time after childhood septal myectomy

OBJECTIVES The aim of this study was to assess the effect of surgical septal myectomy performed during early childhood for severe, drug-refractory hypertrophic cardiomyopathy with left ventricular outflow tract obstruction on the extent of septal myocardial extracellular volume fraction and the potential risk of developing atrioventricular cardiac conduction system disease. METHODS In this retrospective study, data from 30 patients with a confirmed diagnosis of childhood-onset hypertrophic cardiomyopathy were reviewed including cardiovascular magnetic resonance (CMR) with myocardial T1 mapping and late gadolinium enhancement, histopathology of myocardial specimens, transthoracic echocardiography, electrocardiography, 24-h Holter and cardiopulmonary exercise testing. Eighteen patients without were compared to 12 patients with prior septal myectomy performed during childhood (non-operated versus myectomy patients). RESULTS Late gadolinium enhancement on CMR as a correlate for focal myocardial fibrosis was found in 53% of patients, predominantly located in the septal region, with no difference between groups. As compared to non-operated patients, those after myectomy showed a similar amount of total and septal extracellular volume fraction, as calculated from pre- and post-contrast CMR T1 mapping, which is a correlate for diffuse interstitial myocardial fibrosis. PQ-intervals or the occurrence of higher degree conduction system disease were equal between the 2 groups. CONCLUSIONS Data from CMR and electrocardiography suggest that surgical septal myectomy performed during early childhood for severe obstructive hypertrophic cardiomyopathy does not cause an increased septal extracellular volume fraction or delayed atrioventricular conduction time on long-term follow-up.