Prevalence Of First-degree Atrioventricular Block Research Articles

MIS-C and Cardiac Conduction Abnormalities.

Multisystem inflammatory syndrome in children (MIS-C) has spread through the pediatric population during the coronavirus disease 2019 pandemic. Our objective for the study was to report the prevalence of conduction anomalies in MIS-C and identify predictive factors for the conduction abnormalities. We performed a single-center retrospective cohort study of pediatric patients <21 years of age presenting with MIS-C over a 1-month period. We collected clinical outcomes, laboratory findings, and diagnostic studies, including serial electrocardiograms, in all patients with MIS-C to identify those with first-degree atrioventricular block (AVB) during the acute phase and assess for predictive factors. Thirty-two patients met inclusion criteria. Median age at admission was 9 years. Six of 32 patients (19%) were found to have first-degree AVB, with a median longest PR interval of 225 milliseconds (interquartile range 200-302), compared with 140 milliseconds (interquartile range 80-178) in patients without first-degree AVB. The onset of AVB occurred at a median of 8 days after the initial symptoms and returned to normal 3 days thereafter. No patients developed advanced AVB, although 1 patient developed a PR interval >300 milliseconds. Another patient developed new-onset right bundle branch block, which resolved during hospitalization. Cardiac enzymes, inflammatory markers, and cardiac function were not associated with AVB development. In our population, there is a 19% prevalence of first-degree AVB in patients with MIS-C. All patients with a prolonged PR interval recovered without progression to high-degree AVB. Patients admitted with MIS-C require close electrocardiogram monitoring during the acute phase.

Prevalence of first-degree atrioventricular block and the associated risk factors: a cross-sectional study in rural Northeast China

BackgroundFirst-degree atrioventricular block (AVB) has traditionally been regarded as a benign condition but recent studies have challenged this conception. Prevalence of 1–2% have been reported in developed countries in Asia. However, no epidemiologic studies have established the prevalence of first-degree AVB in developing countries. The aim of the study was to investigate the prevalence of first-degree AVB in rural northeast China and identify the associated risk factors.MethodsThis cross-sectional study was undertaken from September 2017 to May 2018 in rural areas of Liaoning Province. It involved 10,926 participants aged ≥40 years (85.3% of those who were eligible). First-degree AVB was confirmed by at least two independent cardiologists. Risk factors were evaluated using stepwise logistic regression.ResultsThe prevalence of first-degree AVB was 3.4% (95% confidence interval [CI]: 3.0–3.8%). Males had a higher prevalence than females (5.1% vs. 2.2%, p < 0.001). The regression model involving all participants showed that age (odds ratio [OR]: 1.32; p <0.001), male sex (OR: 1.72; p = 0.001), height (OR: 1.25; p = 0.008), systolic blood pressure (SBP) (OR: 1.15; p = 0.003), triglycerides (TG) (OR: 1.10; p < 0.001), high-density lipoprotein cholesterol (HDL-C) (OR: 0.73; p < 0.001), heart rate (OR: 0.78; p < 0.001), and exercising regularly (OR: 0.73; p = 0.030) were independent risk factors.ConclusionsFirst-degree AVB is highly prevalent in rural areas of northeast China. The associated independent risk factors include being male, older, and taller, higher SBP and TG, lower HDL-C and heart rate, and lack of exercise.

One-Year Follow-Up of Conduction Abnormalities After Transcatheter Aortic Valve Implantation With the SAPIEN 3 Valve

Long-term evolution of new-onset conduction abnormalities and need of permanent pacemaker implantation (PPI) after transcatheter aortic valve implantation (TAVI) have not been extensively evaluated. We describe the incidence and time course of new conduction abnormalities and the rate of PPI with the new-generation transcatheter aortic valve prosthesis Edwards SAPIEN 3 (S3). In total, 266 patients with severe aortic stenosis who underwent TAVI were retrospectively analyzed. Twelve-lead electrocardiograms at baseline, after TAVI, at discharge, at 1-, 6-, and 12-month follow-up were evaluated to identify conduction abnormalities and PPI requirements to investigate the correlates of PPI. After TAVI, a significant increase in PR interval duration and in QRS complex width was observed. New-onset left bundle branch block was observed in 65 patients (24%) after TAVI. The number of patients with left bundle branch block was maximum at hospital discharge and decreased at 12-month follow-up (39% and 32%, respectively). Thirty-five patients (13%) required PPI during the follow-up. However, paced rhythm was only observed in 7% of the patients with a complete 12-month follow-up. Patients who underwent PPI had a higher prevalence of first-degree atrioventricular block, complete right bundle branch block, and wider QRS complex at baseline. Baseline right bundle branch block and QRS width immediately after TAVI were the only variables independently associated with PPI. In conclusion, conduction disorders have a temporary nature after TAVI and showed a trend toward stabilization during the following months. With this new-generation device, the incidence of new conduction abnormalities requiring PPI is relatively low.

Severe brady-arrhythmias in systemic lupus erythematosus: prevalence, etiology and associated factors.

Background Severe brady-arrhythmias, requiring a permanent pacemaker (PPM), have been sparsely reported in systemic lupus erythematosus (SLE). The aim of this study was to describe the characteristics of such arrhythmias in a defined lupus cohort. Patients and methods The database of the Toronto Lupus Clinic ( n = 1366) was searched for patients who received a PPM. Demographic, clinical, immunological and therapeutic variables along with electrocardiographic (ECG) and echocardiographic findings (based on the last available test prior to PPM) were analyzed. Patients with a PPM (cases) were compared with age-, sex- and disease duration-matched patients without a PPM (controls). Analysis was performed with SAS 9.0; p < 0.05 was considered significant. Results Eighteen patients were identified, 13 (0.95%) with complete atrioventricular block and 5 (0.37%) with sick sinus syndrome. Disease duration at PPM implantation was 22 ± 12 years. Compared to controls, cases had more frequently coronary artery disease, hypertension, dyslipidemia and longer antimalarial (AM) treatment duration. The prevalence of first-degree atrioventricular block, right bundle branch block, left anterior fascicular block and septal hypertrophy was also higher. AM treatment was significantly associated with brady-arrhythmias (OR = 1.128, 95% CI = 1.003-1.267, p = 0.044). Nine patients had prior heart disease and one received a PPM two years after renal transplantation. Eight patients did not have any potential risk factors; prolonged AM therapy (mean 22 years) might have been the cause. Conclusions Apart from known causes, prolonged AM treatment may be associated with severe brady-arrhythmias in SLE. Certain ECG and echocardiographic characteristics may represent indicators of an ongoing damage in the conduction system.

Heart failure in patients with arrhythmogenic right ventricular cardiomyopathy: What are the risk factors?

BackgroundWe previously demonstrated that heart failure (HF) was one of the major causes of death in arrhythmogenic right ventricular cardiomyopathy (ARVC). The purpose of this study was to elucidate the clinical impact and risk factors of HF in patients with ARVC. Methods and resultsWe evaluated cardiac adverse outcomes including HF in 113 consecutive patients with ARVC (85 men, mean age: 44±15years). During a median follow-up of 10.0years (interquartile range: 5.2 to 15.7years), 29 patients (26%) were hospitalized for progressive HF. The patients with one or more episodes of HF hospitalization had about a 10-fold increased incidence of cardiac death (14/29 [48%] vs. 4/84 [4.7%], p<0.0001). Left ventricular ejection fraction (LVEF) and right ventricular ejection fraction (RVEF) were significantly lower in the patients with HF hospitalization compared to the patients without HF hospitalization (LVEF, 45±15 vs. 54±13%, p=0.001; RVEF, 26±10 vs. 33±11%, p=0.003, respectively). Regarding the ECG findings, the prevalence of first-degree atrioventricular block (AVB, PR interval >200ms) and epsilon waves were significantly higher in patients with HF hospitalization than those without HF hospitalization (first-degree AVB, 14/29 [48%] vs. 11/84 [13%], p<0.0001; epsilon waves, 10/29 [34%] vs. 12/84 [14%], p=0.02). In multivariate analysis, first-degree AVB at baseline was the strongest independent risk factor for HF hospitalization in patients with ARVC (hazard ratio 4.24, 95% confidence interval 1.79–10.47, p=0.0011). ConclusionHF hospitalization has a significant relation with malignant clinical course in ARVC patients. First-degree AVB was an independent determinant for increased risk of HF hospitalization.

Outcomes Related to First-Degree Atrioventricular Block and Therapeutic Implications in Patients With Heart Failure.

The prevalence of first-degree atrioventricular block in the general population is approximately 4%, and it is associated with an increased risk of atrial fibrillation. Cardiac pacing for any indication in patients with first-degree heart block is associated with worse outcomes compared with patients with normal atrioventricular conduction. Among patients withheart failure, first-degree atrioventricular block is present in anywhere between 15% and 51%. Data from cardiac resynchronization therapy studies have shown that first-degree atrioventricular block is associated with an increased risk of mortality and heart failure hospitalization. Recent studies suggest that optimization of atrioventricular delay in patients with cardiac resynchronization therapy is an important target for therapy; however, the optimal method for atrioventricular resynchronization remains unknown. Understanding the role of first-degree atrioventricular block in the treatment of patients with heart failure will improve medical and device therapy.

Diagnostic precision of Doppler flow echocardiography in fetuses at risk for atrioventricular block

To investigate the diagnostic precision of three Doppler methods in their ability to predict postnatal first-degree atrioventricular (AV) block. This was a prospective, observational study carried out from December 1999 to March 2008, including 95 fetuses of anti-SSA/Ro positive mothers undergoing weekly fetal echocardiograms at 18-24 weeks' gestation. Doppler-derived AV time intervals for left ventricular inflow (MV), inflow and outflow (MV-Ao) and superior vena cava a-wave to aortic flow (SVC-Ao) were compared with the PR interval on postnatal electrocardiography. Reference values for MV intervals were established from 102 healthy fetuses, with previously published reference ranges used for the two other methods. Bayesian and receiver-operating characteristics (ROC) curve analyses were performed. The prevalence of first-degree AV block at birth was 13.8%. Using a cut-off at the upper 95% confidence limit, MV-Ao and SVC-Ao time intervals had a sensitivity of 91.7%, and negative predictive value and negative likelihood ratio of 98.4% and 0.10, respectively. The corresponding positive predictive value/positive likelihood ratio for MV-Ao and SVC-Ao were 42.3%/4.5 and 47.8%/5.7, respectively. The areas under the ROC curve (AUC) for MV-Ao and SVC-Ao were 0.87 and 0.89, respectively (both P < 0.001), with generated cut-offs for abnormal AV time intervals at 134-138 and 132-138 ms. MV time intervals using a cut-off at the upper 95% confidence limit had a sensitivity of just 50% and an AUC of 0.74 (P < 0.01). The MV-Ao and SVC-Ao Doppler methods make it possible to identify nearly all fetuses with first-degree AV block at birth and to exclude conduction disturbances in the case of a normal AV time measurement but at the cost of a positive predictive value of 50%.

Outcome of infants from mothers with anti-SSA/Ro antibodies

To evaluate the incidence of electrocardiographic and laboratory abnormalities in neonates born from mothers with connective tissue disease and positive for anti-SSA/Ro antibodies. Electrocardiogram, blood cell counts, liver and renal function tests prospectively obtained from 51 infants born from anti-SSA/Ro-positive mothers with connective tissue disease were compared with those obtained from 50 control infants born from mothers with anti-extractable nuclear antigen (ENA)-negative connective tissue disease. One infant with congenital complete heart block was excluded from analysis. No infant showed sinus bradycardia. A first-degree atrioventricular block at birth was observed in five study group and no control group infants, P=0.023. Atrioventricular blocks spontaneously reverted or remained stable during the first year of life. Mean corrected QT value of infants born from anti-SSA/Ro-positive mothers was slightly prolonged as compared with the control group (0.404+/-0.03 s vs 0.395+/-0.02 s; P=0.060). Infants exposed to anti-SSA/Ro antibodies had a significantly higher prevalence of first-degree atrioventricular block. At variance with previous studies, we observed a low frequency of hematologic abnormalities and no cases of hepatobiliary disease.

Adverse Cardiac Effects of Combined Neuroleptic Ingestion and Tricyclic Antidepressant Overdose

During a retrospective review of 70 consecutive intensive care unit admissions for tricyclic antidepressant (TCA) overdose, we identified 12 patients (17%) who had simultaneously ingested a neuroleptic agent. We then compared several clinical and laboratory features of patients who had ingested TCAs alone with those patients who had also taken a neuroleptic drug. The 12 patients in the TCA-neuroleptic group, when compared with patients in the TCA-only group, showed a markedly higher prevalence of first-degree atrioventricular block (p less than 0.001), a significantly higher prevalence of prolongation of the QRS duration (greater than 0.10 sec) (p less than 0.05), and a threefold increase in the prevalence of QTc prolongation (p less than 0.05). Our data indicate that coingestion of neuroleptics and TCAs, when compared with the ingestion of TCA alone, may significantly increase the risk of adverse cardiac consequences. We discuss the possible mechanisms for these electrocardiographic changes as well as their potential implications.

Cardiac Conduction Defects Associated with Aortic and Mitral Valve Calcification in Dialysis Patients

The prevalence of aortic valve and mitral valve or mitral annular calcification by echocardiography was studied in 66 dialysis patients and correlated with results of 24-h ambulatory and resting ECG data and 12-month survival. The well-known association of mitral valve or mitral annular calcification with cardiac conduction defects was confirmed. Those patients with mitral valve or mitral annular calcification demonstrated a higher prevalence of first-degree atrioventricular block and bundle branch block. Despite advanced age and these conduction defects, those patients with mitral valvular calcification did not show decreased survival at 12 months.