Does Cardiac Arrhythmia Predict Worse Outcome in Mild or Moderate Covid-19 Infection?

Covid-19 is a multisystem disease with the lungs being predominantly affected. Cardiac involvement is mostly seen as a rise in troponins, arrhythmias, and ventricular dysfunction. This study aimed to estimate the incidence of arrhythmias seen in Covid-19 infection and assess if arrhythmias predict worsening or mortality. Prospective observational study involving patients with mild to moderate Covid illness admitted in a tertiary care centre. Among the 85 patients (Mean age 45.8 + 14.1 years; 75.31% men), worsening of Covid-19 illness was seen in 29 (34.1%) patients. New onset arrhythmias were detected on Holter in 9 (10.5%) patients. Supraventricular tachycardia was seen in 7 (8.2%) patients of whom 6 showed worsening which was statistically significant (p-value-0.006). Risk factors associated with worsening on univariate analysis were male gender (OR [95%CI] = 6.93(1.49-32.31), p-value - 0.014), new onset supraventricular tachycardia (OR [95% CI] = 14.35 [1.64-125.94], p-value - 0.016) and D-dimer elevation (OR [95% CI] = 1.00(1.00-1.01), p-value - 0.02). On multivariate analysis D-dimer (OR [95% CI] = 1.00(1.00-1.01; p-value 0.046) and supraventricular arrhythmias (OR [95% CI] = 11.12 (1.22-101.14); p-value - 0.033) were independently associated with worsening. Covid-19 infection can lead to cardiac arrhythmias. The development of supraventricular tachycardia in patients with Covid-19 infection predicts higher morbidity and worsening.

Early dose of Adenosine, postRadiofrequency abLation of accessory pathwaY in determining acute procedural success (EARLY study).

INTRODUCTION: Post ablation of the accessory pathway (AP), the patient is observed in the catheterization laboratory for a variable period for resumption of pathway conduction. Aim of the study was to determine whether the administration of intravenous adenosine at 10 min after ablation of AP would have the same diagnostic accuracy as waiting for 30 min in predicting the resumption of AP conduction. METHODS: This was a prospective interventional study conducted in two centers. Post ablation of the AP, intravenous adenosine was administered at 10 min to look for dormant pathway conduction. The response was recorded as positive (presence of pathway conduction), negative (absence), or indeterminate (not able to demonstrate AV and VA block and inability to ascertain AP conduction). RESULTS: The study included 110 procedures performed in 109 patients. Adenosine administration at 10 min showed positive result in 3 cases (2.7%), negative result in 99 cases (90%) and indeterminate result in 8 cases (7.3%). Reconnection of accessory pathway at 30 min postablation was seen in 8 cases (7.3%). Of these 8 cases, 10 min adenosine administration showed positive test in 3 patients and negative test in 5 patients. Adenosine test at 10 min has a sensitivity, specificity, positive predictive value, and negative predictive value of 37.5%, 100%, 100%, and 94.9% in identifying the recurrence of accessory pathway conduction at 30 min, respectively. CONCLUSION: Absence of pathway conduction on administration of adenosine 10 min postablation does not help predict the absence of resumption of conduction thereafter.

Impact of transesophageal electrophysiological study on midterm management of pediatric tachyarrhythmias.

Background: Transesophageal electrophysiological study (TEEPS) is a minimally invasive procedure that helps in evaluating the risk of recurrence of supraventricular tachycardia based on the inducibility of the tachycardia. The purpose of this study was to evaluate the diagnostic capability, negative predictive value of noninducibility of tachycardia and safety of TEEPS among the Indian pediatric population. Methods: It is a retrospective single-center observational study of all patients who underwent TEEPS from January 01, 2014, to December 31, 2020. Results: Twenty-two TEEPS procedures were done in eighteen children with three children undergoing more than one procedure. The median duration of follow-up was 42.97 months (8.52-82.12 months). Out of the 22 procedures, four were conducted for acute tachycardia termination, two for tachycardia suppression assessment, and sixteen to assess tachycardia inducibility off medications. Tachycardia was noninducible in nine children and inducible in six children. Two children had clinical recurrence of tachycardia on follow-up. Out of these two children, one had noninducibility of tachycardia on TEEPS. The negative predictive value of TEEPS was 88.89% in this study. None of the children had any postprocedure complication. Conclusions: TEEPS is a safe procedure. It is used to assess the efficacy of medication in the suppression of arrhythmia. The noninducibility of tachycardia has a high negative predictive value and is a good indicator of nonrecurrence of clinical tachycardia on midterm follow-up.

Do the predictors of right ventricular pacing-induced cardiomyopathy add up?

OBJECTIVE: Knowledge of factors causing pacing-induced cardiomyopathy (PICM) is incomplete. We sought to estimate the incidence and predisposing factors for PICM and evaluate if the risk they portend adds up. METHODS: Single centre retrospective study where consecutive patients with preserved LVEF undergoing pacemaker (PM) implantation between 2012 and 2018 were analysed. RESULTS: A total of 749 patients (68.4 % male; mean age 59.2 ± 14.08 years) were included in the analysis. PICM developed in 74 (9.9%) patients over a median follow up of 2.2 years (IQR 1.1-3.2). Pre-implant LVEF, paced QRS duration and RV pacing burden were independent predictors of PICM. Using 90 % specificity cut-off values for LVEF and paced QRS, and the value separating lowest tertile of RV pacing from the higher tertiles, three risk factors were identified: (i) baseline LVEF < 55 %, (ii) paced QRS duration > 160 msec, and (iii) RV pacing burden > 33 %. Patients with two or more risk factors were at the highest risk (OR 11.62, 95 % CI 4.62-29.21, p-value < 0.001) for developing PICM while those with one risk factor had an intermediate risk (OR 3.89, 95 % CI 1.62-9.34, p-value 0.002) when compared to those without any risk factors. CONCLUSION: Low-normal baseline LVEF, wider paced QRS and higher RV pacing burden independently predicted the development of PICM. The presence of ≥2 factors increased the odds of PICM, twelve-fold. A narrower paced QRS, the only modifiable risk factor may help mitigate development of PICM.

Postpacing interval is shorter than tachycardia cycle length-What's the mechanism?

A 33-year-old male who underwent surgery for Tetralogy of Fallot presented with atrial flutter. Electrophysiology study revealed concealed entrainment along the mid lateral right atrium with postpacing interval shorter than the tachycardia cycle length. Ablation at this site terminated the tachycardia. The presence of shorter PPI than TCL was due to a large virtual electrode leading to downstream capture of far field tissue. This case demonstrates that sites showing PPI shorter than TCL are in a slow conducting narrow critical isthmus and hence constitute good ablation targets.

Pacemaker detected prolonged atrial high rate episodes - Incidence, predictors and implications; a retrospective observational study.

INTRODUCTION: Atrial tachyarrhythmias especially atrial fibrillation are the most commonly encountered arrhythmias in clinical practice. Most atrial tachyarrhythmia episodes are subclinical. Cardiac implantable electronic devices with atrial sensing function enable detection of atrial tachyarrhythmias through means of atrial high rate event algorithms. Prolonged atrial high rate episodes(AHRE) above a defined rate and duration threshold represent episodes of atrial fibrillation, atrial flutter, and longer atrial tachycardias that correlate strongly with risk for thromboembolic events. OBJECTIVE: 1. To examine the occurrence of prolonged AHRE in dual-chamber pacemaker recipients over the study period. 2. To examine the factors which influence the occurrence of prolonged AHRE in these patients. METHODS: In this study, we analyzed data of 398 patients without valvular heart disease or history of atrial fibrillation who underwent dual chamber permanent pacemaker implantation at our center from January 2013 to June 2018. Patient demographics, cardiovascular comorbidities, medications, echocardiographic parameters such as ejection fraction and left atrial(LA) dimension were obtained. Also, we collected pacing characteristics such as paced QRS duration(QRSd), ventricular pacing site and cumulative percentage ventricular paced beats. RESULTS: Prolonged AHRE occurred in 59 patients(14.8%). Baseline LA dimension was greater in patients with prolonged AHRE(median 35 mm, IQR 33-37 vs median 35 mm, IQR 34-38, P = 0.004) compared to those without. Paced QRSd was significantly longer in patients with prolonged AHRE (median of 147 ms, IQR 139-160 ms vs 140 ms, IQR 132-150 ms; P < 0.001). On multivariable logistic regression, paced QRSd(OR 1.04, 95%CI 1.02-1.06; P = 0.001) and baseline LA dimension(OR 1.14, 95%CI 1.03-1.27; P = 0.01) significantly co-predicted AHRE. On Kaplan Meier analysis, patients with paced QRSd≥142 ms had more likelihood of developing prolonged AHRE during follow up (HR 2.46, CI 1.40-4.3, P = 0.001). After adjusting for baseline values, patients with paced QRSd≥142 ms had significant decline in left ventricular ejection fraction (adjusted mean difference -1.27%; P = 0.02) and significant LA dilation (adjusted mean difference 0.62 mm; P = 0.05). CONCLUSION: In our study, paced QRSd and LA dimension were the strongest predictors for prolonged AHRE. The incidence of AHRE may be reduced by achieving the narrowest possible paced QRSd during device implantation.

Prognostic significance of accelerated ventricular response during radiofrequency ablation of premature ventricular complexes.

BACKGROUND: Accelerated ventricular response is frequently observed during radiofrequency ablation (RFA) of premature ventricular complexes (PVCs). We hypothesized that acceleration indicates an appropriate site and adequate injury to the arrhythmogenic tissue, and sought to investigate its value in predicting the outcome. METHODS: We retrospectively analyzed RFA procedures performed for PVCs in our institution from 2011 to 2019. RESULTS: Fifty-eight patients (29 male; age 42.7 ± 15.6 years) underwent 62 RFA procedures. The most common site was the right ventricular outflow tract (67.7%). Acute success was seen in 88.7%. Accelerated ventricular response was observed in 60.0% of the successful procedures. After a median follow-up of 14.0 months (IQR: 6.0-26.6 months), 16 patients had a recurrence. Recurrence was significantly lower in the group with acceleration than in the group without acceleration (12.5% vs. 57.1%; log-rank P < 0.001). The 1-year recurrence rate was 6.5% in the acceleration group and 41.6% in the group without acceleration. On multivariable analysis the adjusted hazard ratio was 0.17 (95% CI, 0.04-0.64; Cox regression P = 0.009). The sensitivity, specificity, positive predictive, and negative predictive values of accelerated response to predict long-term success were 75.7%, 75.0%, 87.5%, and 57.2%, respectively. CONCLUSIONS: The recurrence after PVC ablation is significantly lower when an accelerated response was observed at the successful location during RFA. This can be an additional useful marker of long-term success.

Cardiovascular implantable electronic device lead removal in a resource-constrained setting: A single-center experience from India.

BACKGROUND: Data from large-volume centers in developed countries, using dedicated tools, show a high success rate with a good safety record for the percutaneous lead removal procedure. However, there are constraints to replicate the results in a resource-poor setting and there is limited data from India. METHODS: We retrospectively analyzed lead removal procedures performed in our institution from 2008 to 2019. RESULTS: Seventy-five patients underwent percutaneous removal of 138 leads. Of these, 44 procedures and 80 leads qualified as extraction with a median dwell time of 52.1 (IQR 28.2-117.2) months. Overall, 33/44 (75.0%) procedures were successful and 65/80 (81.2%) leads were successfully extracted. Manual traction was successful in the extraction of 44/57 (77.2%) leads. All leads implanted less than 2.7 years could be removed with manual traction alone. Specialized tools were used in 23 leads and 21 (91.3%) of those could be successfully extracted. Inability to use dedicated tools was an independent predictor of procedural failure (adjusted OR 14.0; 95% CI 1.8-110.2; p-value 0.012). Right-sided implant (adjusted OR 12.6; 95% CI 1.3-119.5; p-value 0.027) was also independently associated with failure. There was 1 death (1.3%) and minor complications occurred in 6 (8.0%) patients. CONCLUSIONS: In a resource-limited setting, percutaneous lead extraction of predominantly pacemaker leads by manual traction methods achieved success in extracting about three-fourths of the leads. Inability to use specialized tools was the main factor limiting success. The complication rate was low.

Percutaneous Carillon Mitral Contour System Deployment Followed by CRT-D Implantation: First Case Report from Oman.

Mitral valve regurgitation (MR) is a common problem in patients with cardiac issues especially those with dilated cardiomyopathy (DCM) due to mitral annular dilatation and malcoaptation of the mitral valve leaflets. Although DCM is associated with high mortality rates, there has been no global agreement about the best method of treatment. Treatment of MR in such cases can be done by surgery, which has many limitations due to high-risk concerns. MR may also be managed by other alternatives such as mitral-clip and transcoronary venous mitral annuloplasty using the Carillon® Mitral Contour System®. Combined therapy with a cardiac resynchronization therapy defibrillator (CRT-D) and mitral contour can be used in such cases with valuable improvement in general condition in many patients. In our case, we used the Carillon Mitral Contour System for treatment of severe MR in a 64-year-old patient with severely impaired systolic function after implantation of a CRT-D.

The Affordable Care Act's Impact on Small Business.

Issue: Small-business owners have seen significant gains in health care coverage for themselves and their employees thanks to the Affordable Care Act. Though efforts to repeal the law failed in 2017, the current administration continues to take steps that undermine the law's progress. In recent months, new rules have been announced that allow more groups to establish association health plans and extend the length of short-term health insurance plans. These changes are likely to impact the stability of the marketplaces and coverage rates for the small-business community. Goal: Examine the Affordable Care Act's impact on small businesses, solo entrepreneurs, and small-business employees. Methods: Analysis of ACA small-business enrollment data from established sources, including federal agencies and nonpartisan health care research foundations, supplemented by analysis of U.S. Census data. Findings and Conclusions: Because of the creation of the individual marketplaces and the expansion of Medicaid, more entrepreneurs and small-business employees have health coverage than before the ACA was implemented. Indeed, the uninsured rate for small-business employees fell by almost 10 percentage points post-ACA. The ACA also has helped stabilize health costs for many small businesses that provide coverage, with the rate of small-business premium increases falling by half following implementation of the law.

Three-dimensional echocardiography with left ventricular strain analyses helps earlier prediction of right ventricular pacing-induced cardiomyopathy.

BACKGROUND AND OBJECTIVES: Right ventricular (RV) pacing can lead to progressive ventricular dysfunction over a certain period. This pacemaker-induced cardiomyopathy (PiCMP) may be more common than previously reported. Speckle tracking imaging is a recent development in echocardiography that can identify left ventricular (LV) dysfunction even before the LV ejection fraction (LVEF) value decreases. Three-dimensional (3D) echocardiography has made more accurate assessment of LVEF possible. The objectives of this study are to study the incidence of RV PiCMP using 3D echocardiography and LV strain analysis over a follow-up of 6 months, and to identify its predictors. METHODS: This is an observational study of consecutive patients without structural heart disease and with a baseline EF of more than 45% who received a permanent pacemaker. They were observed over a 6-month period. PiCMP was defined as a decrease in LVEF by 10 percentage points or a decrease in LV strain by 15% from baseline in the absence of other known causes of cardiomyopathy. PiCMP incidence and its associations were analyzed over a 6-month period. RESULTS: The incidence of PiCMP was not only significant over a period of 6 months but also at 24 hours. Significant drops in 3D EF were noted in one (2.8%) patient at 24 hours and in another four (11.1%) patients at 6 months. A significant decrease in LV global longitudinal strain was noted in 23 (63.9%) patients by 6 months. In seven of these patients, there was significant decrease in global longitudinal strain 24 hours after implantation. In analyzing longitudinal strain, the parameter significantly influencing a decrease was a pacing percentage of ≥20% (p = 0.023). CONCLUSIONS: PiCMP is not uncommon in patients undergoing pacemaker implantation and is associated with RV pacing. PiCMP was associated with a ventricular pacing percentage of ≥20%. 3D echocardiography with LV strain analysis plays a vital role in identifying LV dysfunction at an earlier stage compared to EF. PiCMP, if picked up and intervened upon early, can help impede its progression.

Influence of ethnic background on left atrial markers of inflammation, endothelial function and tissue remodelling.

BACKGROUND: It has been suggested that ethnicity can make a significant difference to the likelihood of thromboembolic stroke related to atrial fibrillation. Ethnic differences have been shown to alter inflammatory and haemostatic factors; however, this may all be confounded by differences in cardiovascular risk factors between different ethnicity. The impact of different ethnicities on the thrombogenic profile is not known. The aim of this study was to investigate differences in markers of inflammation, endothelial function and tissue remodelling between Caucasian and Indian populations with supraventricular tachycardia (SVT). METHODS: Patients with structurally normal hearts undergoing catheter ablation for SVT were studied. This study included 23 Australian (Caucasian) patients from the Royal Adelaide Hospital, Adelaide, Australia and 24 Indian (Indian) patients from the Christian Medical College, Vellore, India. Blood samples were collected from the femoral vein, and right and left atria. Blood samples were analysed for the markers of endothelial function (ADMA, ET-1), inflammation (CD40L, VCAM-1, ICAM-1), and tissue remodelling (MMP-9, TIMP-1) using ELISA. RESULTS: The study populations were well matched for cardiovascular risk factors and the absence of structural heart disease. No difference in the echocardiographic measurements between the two ethnicities was found. In this context, there was no difference in markers of inflammation, endothelial function or tissue remodelling between the two SVT populations. CONCLUSION: Caucasian and Indian populations demonstrate similar inflammatory, endothelial function or tissue remodelling profiles. This study suggests a lack of an impact of different ethnicity in these populations in terms of thrombogenic risk.

A new magnetic resonance-based technique for high-resolution quantification of amorphous and quasi-amorphous structures.

We present a novel, high-resolution magnetic resonance technique, fine structure analysis (FSA) for the quantification and analysis of amorphous and quasi-amorphous biological structures. The one-dimensional technique is introduced mathematically and then applied to one simulated phantom, two physical phantoms and a set of ex vivo biological samples, scanned with interpoint spacings of 0.0038-0.195 mm and cross-sectional sizes of 3 × 3 or 5 × 5 mm. The simulated phantom and one of the physical phantoms consists of randomly arranged beads of known size in two and three dimensions, respectively. The second physical phantom was constructed by etching lines on Perspex. The ex vivo samples are human bone specimens. We show that for all three phantoms, the FSA technique is able to elucidate the average spacing of the structures present within each sample using structural spectroscopy, the smallest of which was 180 µm in size. We further show that in samples of trabecular bone, FSA is able to produce comparable results to micro-computed tomography, the current gold standard for measuring bone microstructure, but without the need for ionizing radiation. Many biological structures are too small to be captured by conventional, clinically deployed medical imaging techniques. FSA has the potential for use in the analysis of pathologies where such small-scale repeating structures are disrupted or their size, and spacing is otherwise altered.