Ventricular arrhythmias in adult aortic stenosis: prevalence, mechanisms, and clinical relevance

Impact on clinical outcome of ventricular arrhythmias in patients undergoing transcatheter aortic valve implantation

BACKGROUND

Transcatheter aortic valve implantation (TAVI) has become a largely used treatment for severe aortic stenosis. There are limited data, however, about predictors of long-term prognosis in this population. In this study, we assessed whether ventricular arrhythmias may predict clinical outcomes in patients undergoing TAVI.

METHODS AND RESULTS

We performed a 24 h ECG Holter monitoring in 267 patients who underwent TAVI for severe aortic stenosis within 30 days from a successful procedure. The occurrence of frequent premature ventricular complexes (PVCs; ≥30/h), polymorphic PVCs and nonsustained ventricular tachycardia (NSVT) was obtained for each patient. Clinical outcome was obtained for 228 patients (85%), for an average follow-up of 3.5 years (range 1.0-8.6). Cardiovascular events (CVEs; cardiovascular death or resuscitated cardiac arrest) occurred in 26 patients (11.4%) and 63 patients died (27.6%). Frequent PVCs but not polymorphic PVCs and NSVT were found to be associated with CVEs at univariate analysis. Frequent PVCs were indeed found in 12 patients with (46.2%) and 35 without (17.3%) CVEs [hazard ratio 2.30; 95% confidence interval (CI) 1.03-5.09; P  = 0.04], whereas polymorphic PVCs were found in 11 (42.3%) and 54 (26.7%) patients of the two groups, respectively (hazard ratio 1.44; 95% CI 0.64-3.25; P  = 0.38), and NSVT in 9 (34.6%) and 43 patients of the two groups, respectively (hazard ratio 1.18; 95% CI 0.48-2.87; P  = 0.72). Frequent PVCs, however, were not significantly associated with CVEs at multivariate Cox regression analysis (hazard ratio 1.53; 95% CI 0.37-6.30; P  = 0.56). Both frequent PVCs, polymorphic PVCs and NSVT showed no significant association with mortality.

CONCLUSION

In our study, the detection of frequent PVCs at Holter monitoring after TAVI was a predictor of CVEs (cardiovascular death/cardiac arrest), but this association was lost in multivariable analysis.

Syncope in Patients With Severe Aortic Stenosis Undergoing Transcatheter Aortic Valve Replacement

BACKGROUND

No data exist on the clinical and prognostic significance of syncope in patients undergoing transcatheter aortic valve replacement (TAVR) for severe aortic stenosis.

METHODS

A total of 1705 consecutive patients with severe aortic stenosis undergoing TAVR in a tertiary university centre between 2007 and 2021 were included and classified according to the presence of syncope before the TAVR procedure. Baseline, procedural, and follow-up data were collected prospectively in a dedicated database.

RESULTS

A total of 115 patients (7%) presented with syncope before the TAVR procedure. Of these, 15 patients (13%) showed arrhythmic episodes as the probable cause of the syncope, and all of them had pacemakers implanted at a median of 13 (6 to 53) days before the TAVR procedure. Patients with syncope were older (82 ± 8 years vs 80 ± 8 years, P = 0.001) and had a higher rate of pacemaker implantation before the TAVR procedure (27% vs 14%, P < 0.001), with no differences between groups regarding the severity of aortic stenosis (transvalvular gradient, valve area). There were no differences between groups in 30-day (adjusted hazard ratio [HR], 1.28; 95% confidence interval [CI], 0.46-3.60) and 1-year (adjusted HR, 0.71; 95% CI, 0.0.35-1.45) mortality following TAVR.

CONCLUSIONS

Syncope was not associated with a more advanced valvular disease and had no significant prognostic impact on patients undergoing TAVR. However, arrhythmias and conduction-system disturbances were more common in patients with previous syncope and might play a relevant role in the pathogenesis of syncope in patients with aortic stenosis.

Association of sotalol versus atenolol therapy with survival in dogs with severe subaortic stenosis

INTRODUCTION/OBJECTIVES

Dogs with severe subaortic stenosis (SAS) are at risk of dying suddenly from fatal arrhythmias. Survival is not improved when treated with pure beta-adrenergic receptor (β)-blockers; however, the effect of other antiarrhythmic drugs on survival is unknown. Sotalol is both a β-blocker and a class III antiarrhythmic drug; the combination of these differing mechanisms may provide benefit to dogs with severe SAS. The primary objective of this study was to compare survival in dogs with severe SAS that were treated with either sotalol or atenolol. The secondary objective was to evaluate the effect of pressure gradient (PG), age, breed, and aortic regurgitation on survival.

ANIMALS

Forty-three client-owned dogs.

MATERIALS AND METHODS

Retrospective cohort study. Medical records of dogs diagnosed with severe SAS (PG ≥ 80 mmHg) between 2003 and 2020 were reviewed.

RESULTS

No statistical difference was identified in survival time between dogs treated with sotalol (n = 14) and those treated with atenolol (n = 29) when evaluating all-cause mortality (p=0.172) or cardiac-related mortality (p=0.157). Of the dogs that died suddenly, survival time was significantly shorter in dogs treated with sotalol compared to those treated with atenolol (p=0.046). Multivariable analysis showed that PG (p=0.002) and treatment with sotalol (p=0.050) negatively influenced survival in the dogs that died suddenly.

CONCLUSIONS

Sotalol did not have a significant effect on survival overall but may increase the risk of sudden death in dogs with severe SAS compared to atenolol.

Application of a Novel Two-Dimensional Echocardiographic Calcium Quantification Method to Assess All Severities of Aortic Stenosis

BACKGROUND

Aortic valve (AV) calcification (AVC) is a strong predictor of aortic stenosis (AS) severity. The two-dimensional AVC (2D-AVC) ratio, a gain-independent ratio composed of the average pixel density of the AV and the aortic annulus, has previously shown strong correlations with two-dimensional (2D) echocardiographic hemodynamic parameters for severe AS and AVC by cardiac computed tomography. We hypothesize that the 2D-AVC ratio correlates with hemodynamic parameters in all severities of AS.

METHODS

A total of 285 patients with a normal AV (n = 49), aortic sclerosis (n = 75), or mild (n = 38), moderate (n = 72), or severe (n = 51) AS undergoing 2D echocardiography were retrospectively evaluated, and the 2D-AVC ratios were correlated to mean AV gradient, peak AV velocity, AV area, and dimensionless index. The 2D-AVC ratios of various AS severities were compared against each other via area under the curve (AUC) analysis.

RESULTS

The 2D-AVC ratio is strongly correlated with mean AV gradient (r = 0.79, P < .0001) and peak AV velocity (r = 0.78, P < .0001). There was moderate correlation with the AV area (r = -0.58, P < .0001) and dimensionless index (r = -0.67, P < .0001) across all AS severities. The 2D-AVC ratio also distinguished nonmoderate AS (mild AS + normal AV) from moderate or greater (moderate + severe) AS (AUC = 0.93) and moderate versus severe AS (AUC = 0.88).

CONCLUSION

The 2D-AVC ratio exhibits moderate to strong correlation with 2D echocardiographic hemodynamic parameters across all severities of AS.

Arrhythmias in Patients With Valvular Heart Disease: Gaps in Knowledge and the Way Forward

The prevalence of both organic valvular heart disease (VHD) and cardiac arrhythmias is high in the general population, and their coexistence is common. Both VHD and arrhythmias in the elderly lead to an elevated risk of hospitalization and use of health services. However, the relationships of the two conditions is not fully understood and our understanding of their coexistence in terms of contemporary management and prognosis is still limited. VHD-induced left ventricular dysfunction/hypertrophy and left atrial dilation lead to both atrial and ventricular arrhythmias. On the other hand, arrhythmias can be considered as an independent condition resulting from a coexisting ischemic or non-ischemic substrate or idiopathic ectopy. Both atrial and ventricular VHD-induced arrhythmias may contribute to clinical worsening and be a turning point in the natural history of VHD. Symptoms developed in patients with VHD are not specific and may be attributable to hemodynamical consequences of valve disease but also to other cardiac conditions including arrhythmias which are notably prevalent in this population. The issue how to distinguish symptoms related to VHD from those related to atrial fibrillation (AF) during decision making process remains challenging. Moreover, AF is a traditional limit of echocardiography and an important source of errors in assessment of the severity of VHD. Despite recent progress in understanding the pathophysiology and prognosis of postoperative AF, many questions remain regarding its prevention and management. Furthermore, life-threatening ventricular arrhythmias can predispose patients with VHD to sudden cardiac death. Evidence for a putative link between arrhythmias and outcome in VHD is growing but available data on targeted therapies for VHD-related arrhythmias, including monitoring and catheter ablation, is scarce. Despite growing evidences, more research focused on the prognosis and optimal management of VHD-related arrhythmias is still required. We aimed to review the current evidence and identify gaps in knowledge about the prevalence, prognostic considerations, and treatment of atrial and ventricular arrhythmias in common subtypes of organic VHD.

Novel markers of ventricular repolarization are associated with mortality in patients undergoing surgical aortic valve replacement for severe aortic stenosis

INTRODUCTION

Aortic stenosis (AS) is the most common degenerative valvular heart disease that can affect left ventricular functions. Tp-e interval and Tp-e/QT ratio is a novel repolarization marker which is associated with adverse cardiovascular events in several cardiovascular diseases. In our study, our aim is to investigate the prognostic effect of Tp-e interval, Tp-e/QT and Tp-e/QTc ratios on mortality in patients who underwent successful surgical aortic valve replacement (AVR).

METHODS

A total of three hundred seventy-five patients undergoing successful surgical AVR were included in this study. Then, patients were divided into two groups according to mortality as group 1 without mortality (342 patients) and group 2 with mortality (33 patients). Tp-e interval, Tp-e/QT, and Tp-e/QTc ratios were calculated for both groups.

RESULTS

Tp-e interval (71 (63.7-77); 86 (84-88), p < .001), Tp-e/QT ratio (0.19 (0.17-0.20); 0.23 (0.22-0.23), p < .001) and Tp-e/QTc ratio (0.17 ± 0.02; 0.21 ± 0.01, p < .001) were higher in group 2 compared to group 1. In multivariate logistic regression analyses Tp-e interval (odds ratio [OR]: 1.315, 95% confidence interval [CI]: 1.203-1.437, p < .001), Tp-e/QT ratio (OR: 7.334, 95% CI: 3.274-1.643, p < .001) and Tp-e/QTc ratio (OR: 2.567, 95% CI: 4.106-1.605, p < .001) were found to be independent predictors of mortality. Additionally, a Kaplan-Meier survival analysis also revealed that long term survival was found to be significantly decreased in patients with higher Tp-e/QT ratio (Log-Rank p < .001) and Tp-e/QTc ratio (Log-Rank p < .001).

CONCLUSION

Tp-e interval, Tp-e dispersion, Tp-e/QT, and Tp-e/QTc ratios are associated with worse prognosis after surgical AVR in patients with severe AS. All of them are also independent predictors of mortality.

Catheter ablation of premature ventricular contractions originating from periprosthetic aortic valve regions

BACKGROUND

Little is known about the ablation outcomes of premature ventricular contractions (PVCs) that originate from the periprosthetic aortic valve (PPAV) regions of patients with aortic valve replacement (AVR).

METHODS AND RESULTS

Our study had 11 patients who underwent catheter ablation for PVCs arising from the PPAV regions (bioprosthetic aortic valve, n = 5; mechanical aortic valve, n = 6). The PVC characteristics, procedure characteristics, and efficacy of ablation were compared with the control group (n = 33). At baseline, the PPAV group had a lower left ventricular ejection fraction (mean [SD], 41% [12%] vs. 51% [8%]; p = .002). The rate of acute ablation success was 90.9% in the PPAV group. Ablation sites were identified above the left coronary cusp (LCC) and right coronary cusp commissure (LRCC) in one PVC, below the prosthetic valve in eight PVCs (four below LCC and four below LRCC), and within the distal coronary sinus in two PVCs. The mean procedure time, fluoroscopy time, and radiation in the PPAV group were all significantly greater than those in the control group (all p < .05). However, the number of radiofrequency ablation energy deliveries was not different. The PPAV group had a long-term success rate compared with the control group (72.7% vs. 87.9%, p = .48) and an increase of left ventricular ejection fraction from 43% to 49% after successful PVC ablation at follow-up (p < .001). Echocardiography showed no significant change in valve regurgitation after ablation. No new atrioventricular block occurred.

CONCLUSION

PVCs arising from PPAV regions can be successfully ablated in patients with prior AVR, without damaging the prosthetic aortic valve and atrioventricular conduction.

Relationship Between Anemia and Sudden Cardiac Death in Patients With Severe Aortic Stenosis

Aortic stenosis (AS) is associated with significant morbidity and mortality, including sudden cardiac death (SCD). Anemia is a known risk factor for mortality in patients with AS. We sought to understand the prognostic implications between anemia and SCD in severe AS. The Mayo Clinic AS database includes 8,357 adults with severe AS (mean gradient ≥40 mm Hg, aortic valve area ≤1 cm², or peak aortic jet velocity ≥4 m/s) enrolled between January 1, 1995 and April 30, 2015. Survival and cause of death were ascertained from the National Death Index and SCD from medical records. We excluded patients with multiple valvular abnormalities, leaving 7,292 subjects. The median (interquartile range, [IQR]) age was 76 (68, 82) years with 56% male, and median (IQR) hemoglobin level was 12.9 (11.6, 14.1) g/dl. The frequency of anemia (hemoglobin <13.0g/dl for men, <12.0 g/dL for women) was 40%. During median (IQR) follow up of 4.4 (1.8, 8.1) years, 4,056 died (10-year survival 38%) including 225 with SCD (10-year cumulative incidence 5%). In a multivariate model including age, sex, body-mass index, hypertension, diabetes mellitus, myocardial infarction, estimated glomerular filtration rate, and time dependent aortic valve replacement, anemia was associated with increased all-cause mortality (hazard ratios 1.75, 95%CI 1.64, 1.87; p < 0.001) and increased SCD mortality (hazard ratios 1.42, 95%CI 1.07, 1.86; p = 0.01). In conclusions, anemia is a frequent finding in patients with severe AS and independently associated with increased all-cause mortality and SCD. Anemia may be a useful prognostic marker and a modifiable therapeutic target in managing patients with severe AS.

Management of tachyarrhythmias in pregnancy - A review

The most common arrhythmias detected during pregnancy include sinus tachycardia, sinus bradycardia, and sinus arrhythmia, identified in 0.1% of pregnancies. Isolated premature atrial or ventricular arrhythmias are observed in 0.03% of pregnancies. Arrhythmias may become more frequent during pregnancy or may manifest for the first time.

Evaluation of early electrocardiographic changes after successful percutaneous stent implantation to isolated coarctation of aorta

BACKGROUND

Coarctation of aorta (CoA) is a congenital obstructive lesion characterized by narrowing of the aorta in which concludes as increase in afterload. Percutaneous stent implantation to CoA is a treatment of choice in older children and adults. Pathology related to CoA mainly caused by increased afterload and left ventricular hypertrophy. Electrocardiographic (ECG) findings are also related to left ventricular hypertrophy (LVH). Evidence shows that, in variety of diseases, the correction of the pathology might normalize ECG findings and ventricular dysfunction related to increase in afterload. Therefore the aim of this study was to compare the pre- and postprocedural ECG findings of the patients who underwent percutaneous intervention for isolated CoA.

METHODS

After exclusion criterion was applied, 30 patients were included into study, retrospectively. ECG records before the procedure and 3 months after the procedure of the patients were evaluated. The parameters related to LVH, ventricular and atrial conduction were evaluated and compared between pre- and post-procedural ECG records.

RESULTS

The findings showed that parameters of atrial conduction including P wave maximum duration (p < 0.001) and p wave dispersion (p < 0.001) were significantly decreased after stent implantation. Additionally, ventricular repolarization parameters including QT duration (p = 0.039), Tpe interval (p < 0.001), Tpe / QT (p = 0.038) and Tpe / QTc (p = 0.003) were significantly decreased after stent implantation. Sokolow-Lyon criteria (p < 0.003) and voltage in selected leads were significantly decreased after intervention.

CONCLUSION

Percutaneous intervention to CoA might regress LVH parameters in ECG and improve atrial and ventricular repolarization in ECG, which might lead to decreased event of atrial and ventricular arrhythmias in patients with isolated CoA.

Missing Link between Molecular Aspects of Ventricular Arrhythmias and QRS Complex Morphology in Left Ventricular Hypertrophy

The aim of this opinion paper is to point out the knowledge gap between evidence on the molecular level and clinical diagnostic possibilities in left ventricular hypertrophy (LVH) regarding the prediction of ventricular arrhythmias and monitoring the effect of therapy. LVH is defined as an increase in left ventricular size and is associated with increased occurrence of ventricular arrhythmia. Hypertrophic rebuilding of myocardium comprises interrelated processes on molecular, subcellular, cellular, tissue, and organ levels affecting electrogenesis, creating a substrate for triggering and maintaining arrhythmias. The knowledge of these processes serves as a basis for developing targeted therapy to prevent and treat arrhythmias. In the clinical practice, the method for recording electrical phenomena of the heart is electrocardiography. The recognized clinical electrocardiogram (ECG) predictors of ventricular arrhythmias are related to alterations in electrical impulse propagation, such as QRS complex duration, QT interval, early repolarization, late potentials, and fragmented QRS, and they are not specific for LVH. However, the simulation studies have shown that the QRS complex patterns documented in patients with LVH are also conditioned remarkably by the alterations in impulse propagation. These QRS complex patterns in LVH could be potentially recognized for predicting ventricular arrhythmia and for monitoring the effect of therapy.

The contemporary role of echocardiography in the assessment and management of aortic stenosis

Aortic stenosis (AS) represents a major healthcare issue because of its ever-increasing prevalence, poor prognosis, and complex pathophysiology. Echocardiography plays a central role in providing a comprehensive morphological and hemodynamic evaluation of AS. The diagnosis of severe AS is currently based on three hemodynamic parameters including maximal jet velocity, mean pressure gradient (mPG) across the aortic valve, and aortic valve area (AVA). However, inconsistent grading of AS severity is common when the AVA is < 1.0 cm² but the mPG is < 40 mmHg, also known as low-gradient AS (LGAS). Special attention should be paid to patients with symptomatic LGAS with low stroke volume and/or low ejection fraction because this entity is more difficult to diagnose and has a worse prognosis. Stress echocardiography testing plays an important role in this disease entity. Elderly patients with prohibitive comorbidities for surgical aortic valve replacement (AVR) were without procedural options until the advent of transcatheter AVR (TAVR), which has dramatically changed these circumstances. Along with computed tomography, echocardiography plays a vital role in the periprocedural assessment of the aortic valve and surrounding apparatus. This review describes the evolution of the role of echocardiography in the diagnosis and management of AS, the complexity of the aortic apparatus, and the increased need for expert use of three-dimensional echocardiography.

QT Dispersion Changes after Transcatheter Aortic Valve Implantation in Patients with Aortic Stenosis

Objective

The aim of this study was to evaluate the QT dispersion and echocardiographic parameters in patients before and after transcatheter aortic valve implantation (TAVI).

Methods

One hundred and fifty-two patients with severe aortic valve stenosis (AS) were included in our study. Ninety five patients who underwent aortic valve replacement with TAVI were included in the TAVI group and 57 patients, who refused TAVI, were included in the medical treatment group. The QT interval and echocardiographic parameters of all patients were assessed before and after the procedure (first and sixth months and first year). The QT intervals were taken from the onset of the QRS to the end of the T wave.

Results

All patients had severe AS. The average mean aortic valve gradient was 46.1±12. Left ventricular internal diastolic diameter (LVIDD) and interventricular septum diastolic thickness (IVSDT) did not change significantly after TAVI (P>0.05). QT dispersion, corrected QT dispersion, and mean aortic valve gradient changed significantly six months after TAVI (P<0.05). Compared to the medical treatment group, QT dispersion and corrected QT dispersion were significantly decreased at the sixth month in the TAVI group. The incidence of malignant arrhythmias was smaller in the TAVI group than in the medical treatment group. The mortality rate was lower at the first-year follow-up in the TAVI group than in the medical treatment group.

Conclusion

Increased QT dispersion is associated with severe symptomatic AS. After TAVI, QT dispersion reduces.

Update on Bayés' syndrome: the association between an interatrial block and supraventricular arrhythmias

INTRODUCTION

The past few years have given rise to extensive research on an interatrial block and its clinical relevance, mainly its association with supraventricular arrhythmias. In 2015, the authors of this article reviewed the Bayes syndrome for the first time and after three years there has been so much evidence accumulated that it seems reasonable to rewrite an update, based fundamentally on the new findings. Focused on its relationship with cardioembolic strokes, today efforts are being targeted at understanding its pathophysiology, its diagnosis, and its prognostic implications, in order to learn if it should be treated. Areas covered: A non-systematic review of the literature was developed using the Pubmed and Cochrane databases, focusing on randomized clinical trials and large observational studies that evaluated new physiopathological and epidemiological aspects, new clinical scenarios in which it has been assessed and its association with dementia. Finally, those studies that proposed new possible treatments were reviewed. Expert commentary: Interatrial block is not only a predictor of supraventricular arrhythmias, is a subclinical disease that might be considered as a marker of risk for adverse outcomes. Although there is some evidence to suggest that early treatment may be beneficial, potential therapies have yet to be investigated.

Update in Heart Rhythm Abnormalities and Indications for Pacemaker After Transcatheter Aortic Valve Implantation

Objective: Rhythm abnormalities following transcatheter aortic valve implantation (TAVI) and indications for permanent pacemaker implantation (PPI) were reviewed, which aren't well established in the current guidelines. New left bundle branch block and atrioventricular block are the most common electrocardiographic changes after TAVI. PPI incidence ranges from 9-42% for self-expandable and 2.5-11.5% for balloon expandable devices. Not only anatomical variations in conduction system have an important role in conduction disorders, but different valve characteristics and their relationship with cardiac structures as well. Previous right bundle branch block has been confirmed as one of the most significant predictors for PPI.

Predictors of syncope in patients with severe aortic stenosis: The role of orthostatic unload test

BACKGROUND

There is a paucity of data regarding response of cerebral blood flow to the postural unloading maneuver and its impact on the risk of syncope in patients with aortic stenosis (AS). The aim of the present study was to assess effects of orthostatic stress test on changes in carotid and vertebral artery blood flow and its association with syncope in patients with severe AS.

METHODS

108 patients were enrolled (72 with and 36 patients without syncope) with severe isolated severe AS. Peak systolic blood-flow velocity (PSV) and end-diastolic velocity in the carotid arteries and vertebral arteries were measured by duplex ultrasound in the supine position and at 1-2 min after the assumption of the standing position.

RESULTS

The orthostatic stress test induced a significant decrease in carotid and vertebral arterial flow velocities in all examined arteries (p < 0.001). The median (interquartile range) of mean change in PSV for carotid arteries was higher for patients with syncope (syncope [-] vs. syncope [+]: -0.6 cm/s [-1.8, 1.0] vs. -7.3 cm/s [-9.5, -2.0]; p < 0.001) and similarly for vertebral arteries (-0.5 cm/s [-2.0, 0.5] vs. -4.8 cm/s [-6.5, -1.3]; p < 0.001, respectively). Age, aortic valve area, and mean change in PSV for carotid arteries were independently associated with syncope.

CONCLUSIONS

In patients with AS, a decrease in carotid and vertebral arterial flow velocities in the standing position was observed and was associated with syncope. The present findings may support the value of an orthostatic test in identifying patients with severe AS and a high risk of syncope.

The effect of transcatheter aortic valve implantation on Tp-e interval, Tp-e/QT and Tp-e/QTc ratios, and Tp-e dispersion in patients with severe aortic stenosis

Background

In this study, we aimed to investigate the effect of transcatheter aortic valve implantation using two types of bioprosthetic valves on novel ventricular repolarization markers including Tp-e, Tp-e/QT and Tpe/QTc ratios, and Tp-ed.

Methods

A total of 61 patients (17 males, 44 females; mean age 78.6±6.5 years; range 55 to 89 years) who underwent transcatheter aortic valve implantation with either a Medtronic CoreValve (n=40) or an Edwards SAPIEN XT valve (n=21) were retrospectively analyzed. The electrocardiographic parameters and left ventricular mass index were calculated prior to the procedure, on postoperative Day 1, and at three months after the procedure.

Results

The Tp-e interval, Tp-e/QT and Tp-e/QTc ratios, Tp-ed, and left ventricular mass index significantly reduced at three months of the procedure, compared to baseline values (p<0.01, for all). Similar findings were observed for QT, QTc, and QT dispersion (p<0.01, for all). These changes were independent from the types of bioprosthetic valves used. Before the procedure, the left ventricular mass index was positively correlated with the Tp-e (r=0.350, p=0.007), Tp-e/QT (r=0.314, p=0.015) and Tp-e/QTc ratios (r=0.285, p=0.029). In the multivariate analysis, Tp-e interval was found to be independently associated with the left ventricular mass index (b=0.350, p=0.007).

Conclusion

In the present study, the Tp-e interval, Tp-e/QT and Tp-e/QTc ratios, Tp-ed, and left ventricular mass index significantly reduced at three months after transcatheter aortic valve implantation indicating reverse left ventricular remodeling. The effects of two types of bioprosthetic valves on ventricular repolarization markers and left ventricular mass index were similar.

New-onset arrhythmias following transcatheter aortic valve implantation: a systematic review and meta-analysis

Objective

To evaluate the prevalence and clinical impact of new-onset arrhythmias in patients following transcatheter aortic valve implantation (TAVI).

Method

We systematically identified studies reporting new-onset arrhythmias after TAVI other than atrioventricular conduction disturbances. We summarised monitoring strategies, type and prevalence of arrhythmias and estimated their effect on risk of death or cerebrovascular events by using random-effects meta-analysis. The study is registered withInternational prospective register of systematic reviews (PROSPERO) (CRD42017058053).

Results

Sixty-five studies (43 506 patients) reported new-onset arrhythmias following TAVI. The method of arrhythmia detection was specified only in 31 studies (48%). New-onset atrial fibrillation (NOAF) (2641 patients), bradyarrhythmias (182 patients), supraventricular arrhythmias (29 patients), ventricular arrhythmias (28 patients) and non-specified major arrhythmias (855 patients) were reported. In most studies (52 out of 65), new-onset arrhythmia detection was limited to the first month following TAVI. The most frequently documented arrhythmia was NOAF with trend of increasing summary prevalence of 11%, 14%, 14% and 25% during inhospital, 30-day, 1-year and 2-year follow-ups, respectively (P for trend=0.011). Summary prevalence estimates of NOAF at 30-day follow-up differ significantly between studies of prospective and retrospective design (8% and 21%, respectively, P=0.002). New episodes of bradyarrhythmias were documented with a summary crude prevalence of 4% at 1-year follow-up. NOAF increased the risk of death (relative risk 1.61, 95% CI 1.35 to 1.98, I2=47%) and cerebrovascular events (1.79, 95% CI 1.24 to 2.64, I2=0%). No study commented on therapeutic modifications following the detection of new-onset arrhythmias.

Conclusions

Systematic identification of new-onset arrhythmias following TAVI may have considerable impact on subsequent therapeutic management and long-term prognosis in this patient population.

Evaluation of Tp-E Interval and Tp-E/QT Ratio in Patients with Aortic Stenosis

BACKGROUND

The risk of syncope and sudden cardiac death due to ventricular arrhythmias increased in patients with aortic stenosis (AS). Recently, it was shown that Tp-e interval, Tp-e/QT, and Tp-e/QTc ratio can be novel indicators for prediction of ventricular arrhythmias and mortality. We aimed to investigate the association between AS and ventricular repolarization using Tp-e interval and Tp-e/QT ratio.

METHODS

Totally, 105 patients with AS and 60 control subjects were enrolled to this study. The severity of AS was defined by transthoracic echocardiographic examination. Tp-e interval, Tp-e/QT, and Tp-e/QTc ratios were measured from the 12-lead electrocardiogram.

RESULTS

Tp-e interval, Tp-e/QT, and Tp-e/QTc ratios were significantly increased in parallel to the severity of AS (P < 0.001, P = 0.001, and P = 0.001, respectively). Also, it was shown that Tp-e/QTc ratio had significant positive correlation with mean aortic gradient (r = 0.192, P = 0.049). In multivariate logistic regression analysis, Tp-e/QTc ratio and left ventricular mass were found to be independent predictors of severe AS (P = 0.03 and P = 0.04, respectively).

CONCLUSIONS

Our study showed that Tp-e interval, Tp-e/QT, and Tp-e/QTc ratios were increased in patients with severe AS. Tp-e/QTc ratio and left ventricular mass were found as independent predictors of severe AS.

Arrhythmia Burden in Elderly Patients With Severe Aortic Stenosis as Determined by Continuous Electrocardiographic Recording

Background—

This study sought to evaluate the prevalence of previously undiagnosed arrhythmias in candidates for transcatheter aortic valve replacement (TAVR) and to determine the impact on therapy changes and arrhythmic events after the procedure.

Methods and Results—

A total of 435 candidates for TAVR underwent 24-hour continuous ECG monitoring the day before the procedure. Newly diagnosed arrhythmias were observed in 70 patients (16.1%) before TAVR: paroxysmal atrial fibrillation (AF)/atrial tachycardia (AT) in 28, advanced atrioventricular block or severe bradycardia in 24, nonsustained ventricular tachycardia in 26, and intermittent left bundle-branch block in 3 patients. All arrhythmic events but one were asymptomatic and led to a therapy change in 43% of patients. In patients without known AF/AT, the occurrence of AF/AT during 24-hour ECG recording was associated with a higher rate of 30-day cerebrovascular events (7.1% versus 0.4%; P =0.030). Among the 53 patients with new-onset AF/AT after TAVR, 30.2% had newly diagnosed paroxysmal AF/AT before the procedure. In patients who needed permanent pacemaker implantation after the procedure (n=35), 31.4% had newly diagnosed advanced atrioventricular block or severe bradycardia before TAVR. New-onset persistent left bundle-branch block after TAVR occurred in 37 patients, 8.1% of whom had intermittent left bundle-branch block before the procedure.

Conclusions—

Newly diagnosed arrhythmias were observed in approximately a fifth of TAVR candidates, led to a higher rate of cerebrovascular events, and accounted for a third of arrhythmic events after the procedure. This high arrhythmia burden highlights the importance of an early diagnosis of arrhythmic events in such patients to implement the appropriate therapeutic measures earlier.

Effect of transcatheter aortic valve implantation on QT dispersion in patients with aortic stenosis

Background

QT dispersion (QTd) is a predictor of ventricular arrhythmia. Ventricular arrhythmia is an important factor influencing morbidity and mortality in patients with aortic stenosis. Surgical aortic valve replacement reduced the QTd in this patients group. However, the effect of transcatheter aortic valve implantation (TAVI) on QTd in patients with aortic stenosis is unknown. The aim of this study was to investigate the effect of TAVI on QTd in patients with aortic stenosis.

Methods

Patients with severe aortic stenosis, who were not candidates for surgical aortic valve replacement due to contraindications or high surgical risk, were included in the study. All patients underwent electrocardiographic and echocardiographic evaluation before, and at the 6^th month after TAVI, computed QTd and left ventricular mass index (LVMI).

Results

A total 30 patients were admitted to the study (mean age 83.2 ± 1.0 years, female 21 and male 9, mean valve area 0.7 ± 3 mm²). Edwards SAPIEN heart valves, 23 mm (21 patients) and 26 mm (9 patients), by the transfemoral approach were used in the TAVI procedures. All TAVI procedures were successful. Both QTd and LVMI at the 6^th month after TAVI were significantly reduced compared with baseline values of QTd and LVMI before TAVI (73.8 ± 4 ms vs. 68 ± 2 ms, P = 0.001 and 198 ± 51 g/m²vs. 184 ± 40 g/m², P = 0.04, respectively). There was a significant correlation between QTd and LVMI (r = 0.646, P < 0.001).

Conclusions

QTd, which malign ventricular arrhythmia marker, and LVMI were significantly reduced after TAVI procedure. TAVI may decrease the possibility of ventricular arrhythmia in patients with aortic stenosis.

Recurrent ventricular tachycardia from severe aortic stenosis improves after percutaneous aortic balloon valvuloplasty and transcatheter aortic valve replacement

We report a case of recurrent ventricular tachycardia from severe aortic stenosis that improved after percutaneous aortic balloon valvuloplasty and transcatheter aortic valve replacement. The electrocardiographic features of the arrhythmia were compatible with ventricular tachycardia originating from the left ventricle. Myocardial ischemia and electrolyte abnormalities were ruled out. Clinicians should be aware that recurrent left ventricular tachycardia associated with severe aortic stenosis is a potentially reversible condition by transcatheter intervention. <Learning objective: Calcific aortic stenosis is a common problem in the elderly. There is a high prevalence of ventricular arrhythmias in these patients. Transcatheter aortic valve replacement is a relatively new procedure for high-risk patients with severe aortic stenosis. We report a case that illustrates for the first time resolution of recurrent ventricular tachycardia after percutaneous aortic balloon valvuloplasty and transcatheter aortic valve replacement in an elderly patient with severe aortic stenosis.>.

Sleep-disordered breathing in patients undergoing transfemoral aortic valve implantation for severe aortic stenosis

BACKGROUND

We examined the prevalence of sleep-disordered breathing (SDB) in patients with severe aortic valve stenosis (AS) and the impact of transfemoral aortic valve implantation (TAVI) on SDB.

METHODS

79 patients underwent cardiorespiratory polygraphy (PG) before TAVI (CoreValve™), 62 of them a second PG after the procedure.

RESULTS

Forty-nine (62 %) patients had obstructive sleep apnea (OSA), 25 (32 %) central sleep apnea (CSA), and 5 (6 %) presented without significant SDB (apnea-hypopnea index (AHI) < 5/h). Among the 62 patients evaluated before and after TAVI, 36 (58 %) had OSA, 22 (36 %) CSA, and 4 patients (7 %) no SDB. AHI was significantly higher in CSA patients than in OSA patients (34.5 ± 18.3 vs. 18.0 ± 12.6/h, p < 0.001). Successful TAVI had a significant impact on CSA but not on OSA: CSA patients with optimal TAVI results experienced a significant reduction in central respiratory events (AHI 39.6 ± 19.6-23.1 ± 16.0/h, p = 0.035), while no changes were detected in OSA patients (AHI 18.8 ± 13.0-20.25 ± 13.4/h, p = 0.376). In contrast, in patients who developed at least moderate periprosthetic aortic regurgitation (AR > I), CSA increased significantly (AHI 26.3 ± 13.2-39.2 ± 18.4/h, p = 0.036), whereas no acute change was seen in patients with OSA (AHI 10.5 ± 7.8-12.5 ± 5.0/h, p = 0.5).

CONCLUSION

OSA and CSA are prevalent in more than 90 % of patients undergoing TAVI for severe aortic valve stenosis. Successful TAVI had no significant impact on OSA but improved CSA. In case of an acute change from pressure overload (aortic stenosis) to acute volume overload (aortic regurgitation after TAVI), central, but not obstructive, sleep apnea deteriorated.

Torsades de pointes as a cause of sudden death in a patient with aortic stenosis and atrial fibrillation

The occurrence of sudden cardiac death during Holter monitoring in patients with aortic stenosis has been reported previously. In the majority of the reported cases, the cause of death was a malignant ventricular tachyarrhythmia. The presence of a strong association between frequency and complexity of ventricular arrhythmias and sudden death in patients with aortic stenosis has been proposed. We report the case of a 77-year-old woman with aortic stenosis and atrial fibrillation who had an episode of torsades de pointes that degenerated into ventricular fibrillation during Holter monitoring. A short-long-short sequence, but not increased ventricular ectopics, precipitated torsades de pointes and sudden death in this case which is strongly indicative of triggered activity as the underlying mechanism of the lethal arrhythmia.

Exercise related syncope, when it's not the heart

Syncope or pre-syncope in association with physical exercise may be the first indication of a dangerous underlying cardiovascular condition. Thus, the diagnostic workup of patients presenting with exercise-related syncope must include assessment of the risk for acute cardiac death. When potentially lethal conditions have been ruled out, several hypotensive syndromes that are associated with exercise should be considered. This review aims to give a concise overview of several forms of exercise- related functional hypotensive syndromes causing syncope, including the physiology of post-exercise hypotension. The focus is on underlying mechanisms, clinical considerations, and outlining treatment strategies for these syndromes.

Regression of ventricular repolarisation inhomogeneity after aortic bileaflet valve replacement in patients with aortic stenosis

BACKGROUND

Aortic valve replacement relieves mechanical outflow obstruction in patients with aortic stenosis. However, there is limited information on whether aortic valve replacement can provide regression of ventricular repolarisation inhomogeneity.

OBJECTIVES

To determine whether aortic valve replacement can provide regression of ventricular repolarisation inhomogeneity in patients with aortic stenosis after bileaflet aortic valve replacement.

METHODS

We studied the changes of electrocardiographic QT or QTc intervals and QT or QTc dispersions of 71 patients with severe aortic stenosis and angiographically insignificant coronary lesions (<50% in diameter) before and after valve replacement (6+/-3 days after operation). Seventy-one healthy control subjects, matched for age and sex, served as control subjects. Twelve-lead electrocardiograms and echocardiographic examinations were measured before and after surgery. The QT interval was corrected for heart rate using the standard Bazett formula. QT dispersion was defined as the difference between maximal and minimal QT interval measurements occurring among any of the 12 leads on a standard electrocardiogram. QTc dispersion was calculated in a manner similar to QT dispersion. No subject had fewer than nine measurable leads.

RESULTS

Left ventricular systolic blood pressure, pressure gradient across aortic valve, left ventricular mass index, and systolic wall stress were significantly reduced after valve replacement compared with before valve replacement. The QT interval significantly decreased from 425+/-38 ms to 398+/-32 ms after replacement (P<0.0001). The QTc dispersion significantly decreased from 62+/-25 ms to 32+/-13 ms after replacement (P<0.0001). The value of QT or QTc dispersion after replacement was similar to that in controls. Univariate analysis revealed that QTc dispersion was significantly only correlated with left ventricular mass index (r=0.236, P=0.05). Multivariate analysis revealed that the best predictor of QTc dispersion was sex and left ventricular mass index (P=0.008 and 0.005, respectively).

CONCLUSIONS

Our study demonstrated a favorable consequence of aortic valve replacement distinct from hemodynamic improvement. Patients with aortic stenosis before valve replacement have abnormal prolonged QT or QTc intervals and increased QT or QTc dispersions. After successful valve replacement left ventricular mass index regressed and QT or QTc intervals and QT or QTc dispersions were normalized. These findings warrant further investigation in a large trial and long-term follow-up for clinical implications.