Arrhythmia-Induced Cardiomyopathy: JACC State-of-the-Art Review

Identifying Premature Ventricular Complexes from Outflow Tracts Based on PVC Configuration: A Machine Learning Approach

BACKGROUND

Current inferences about the site of origin (SOO) of premature ventricular complexes (PVC) from the surface ECG have not been subjected to newer data analytic techniques that identify signals that are not recognized by visual inspection.

AIMS

The objective of this study was to apply data analytics to PVC characteristics.

METHODS

PVCs from 12-lead ECGs of a consecutive series of 338 individuals were examined by unsupervised machine learning cluster analysis, and indexes were compared to a composite criterion for SOO.

RESULTS

Data analytics found that V1S plus V2S ≤ 9.25 of the PVC had a LVOT origin (sensitivity 95.4%; specificity 97.5%). V1R + V2R + V3R > 15.0 (a RBBB configuration) likely had a LVOT origin. PVCs with V1S plus V2S > 12.75 (LBBB configuration) likely had a RVOT origin. PVC with V1S plus V2S > 14.25 (LBBB configuration) and all inferior leads positive likely had a RVOT origin.

CONCLUSION

Newer data analytic techniques provide a non-invasive approach to identifying PVC SOO, which should be useful for the clinician evaluating a 12-lead ECG.

Subclinical Left Ventricular Dysfunction and Ventricular Arrhythmias in Older Adults With Normal Ejection Fraction

Background Premature ventricular contractions (PVCs) and nonsustained ventricular tachycardia (NSVT) are known to be associated with reduced left ventricular (LV) ejection fraction and adverse outcomes in patients with structural heart disease. The relationship between subclinical LV dysfunction and ventricular arrhythmias in the general population is not established. Methods and Results Participants in the SAFARIS (Subclinical Atrial Fibrillation and Risk of Ischemic Stroke) study with normal left ventricular ejection fraction (n=503; mean age 77 years, 63% women) underwent 14-day electrocardiographic monitoring and 2-dimensional echocardiography. Frequent PVCs were defined as PVCs >500 per 24 hours and NSVT as ≥4 consecutive ventricular ectopic beats. Reduced LV global longitudinal strain (GLS) was used as an indicator of subclinical LV dysfunction. Seventy-six participants (15.1%) had PVCs >500/d, 117 (23.3%) had NSVT episodes. LV GLS was significantly reduced in both frequent PVCs and NSVT groups (P<0.01). In multivariable analyses, lower LV GLS was associated with frequent PVCs (adjusted odds ratio [aOR], 1.19 [95% CI, 1.09-1.30 per unit reduction]; P<0.001) and NSVT (aOR, 1.09 [95% CI, 1.01-1.17]; P=0.036) independently of established risk factors and other echocardiographic parameters. Abnormal LV GLS (>-15.8%) carried a 2-fold increase in risk of ventricular arrhythmias (aOR, 2.18, P=0.029 for PVCs; aOR, 2.09, P=0.026 for NSVT). Conclusions PVCs and NSVT episodes were frequent in this community-based elderly cohort with normal left ventricular ejection fraction and were independently associated with lower LV GLS. The association between LV dysfunction and ventricular arrhythmias is present at an early, subclinical stage, an observation that carries possible preventative implications.

How to Improve Clinical Outcomes in Patients with Tachycardia-Induced Cardiomyopathy. Comment on Katz et al. Long-Term Outcomes of Tachycardia-Induced Cardiomyopathy Compared with Idiopathic Dilated Cardiomyopathy. J. Clin. Med. 2023, 12, 1412

The clinical course of tachycardia-induced cardiomyopathy (TICM) has not yet been well studied thus far [...].

Implications of the Mitral Leaflet Coaptation Pattern on Clinical Outcomes in Patients With Functional Mitral Regurgitation

The classification of secondary mitral regurgitation (MR) is based on atrial functional MR (AFMR) or ventricular functional MR (VFMR) and volume changes, but the mitral leaflet coaptation angle also contributes to the MR mechanism. The clinical implications of the coaptation angle on cardiovascular (CV) outcomes have not been well evaluated. A total of 469 consecutive patients (265 AFMR vs 204 VFMR) with more than moderate MR were evaluated for the occurrence of heart failure, mitral valve operations, and CV death. The coaptation angle was assessed by measuring the internal angle between both leaflets at mid-systole using the apical 3-chamber view. A coaptation angle ≥130° was classified as leaflet flattening, and an angle <130° was classified as leaflet tethering. AFMR and VFMR were associated with higher frequencies of leaflet flattening and tethering, respectively. AFMR was more likely to be associated with older age, atrial fibrillation, and preserved ejection fraction, all of which were related to leaflet flattening. During a follow-up of 2.3 years, 83 patients had heart failure (17.7%), 21 patients underwent mitral valve operations (4.5%), and 34 patients died (7%). Compared with leaflet tethering, leaflet flattening was more significantly related to CV events, whereas CV event rates were less markedly different in A/VFMR. Irrespective of A/VFMR, leaflet flattening and atrial fibrillation were associated with a higher frequency of CV events. Adjusted analysis showed that leaflet flattening remained an independent predictor of CV events (hazard ratio 3.5, 95% confidence interval 1.11 to 4.88, p = 0.003), whereas A/VFMR did not. In conclusion, the leaflet coaptation angle in patients with functional MR could provide risk stratification superior to that of A/VFMR. Leaflet flattening appears to be associated with unfavorable clinical outcomes.

Alterations of sarcoplasmic reticulum-mediated Ca2+ uptake in a model of premature ventricular contraction (PVC)-induced cardiomyopathy

Premature ventricular contractions (PVCs) are the most frequent ventricular arrhythmias in the overall population. PVCs are known to acutely enhance contractility by the post-extrasystolic potentiation phenomenon, but over time persistent PVCs promote PVC-induced cardiomyopathy (PVC-CM), characterized by a reduction of the left ventricular (LV) ejection fraction. Ca2+ cycling in myocytes commands muscle contraction and in this process, SERCA2 leads the Ca2+ reuptake into the sarcoplasmic reticulum (SR) shaping cytosolic Ca2+ signal decay and muscle relaxation. Altered Ca2+ reuptake can contribute to the contractile dysfunction observed in PVC-CM. To better understand Ca2+ handling using our PVC-CM model (canines with 50% PVC burden for 12 weeks), SR-Ca2+ reuptake was investigated by measuring Ca2+ dynamics and analyzing protein expression. Kinetic analysis of Ca2+ reuptake in electrically paced myocytes showed a ~ 21 ms delay in PVC-CM compared to Sham in intact isolated myocytes, along with a ~ 13% reduction in SERCA2 activity assessed in permeabilized myocytes. Although these trends were not statistically significant between groups using hierarchical statistics, relaxation of myocytes following contraction was significantly slower in PVC-CM vs Sham myocytes. Western blot analyses indicate a 22% reduction in SERCA2 expression, a 23% increase in phospholamban (PLN) expression, and a 50% reduction in PLN phosphorylation in PVC-CM samples vs Sham. Computational analysis simulating a 20% decrease in SR-Ca2+ reuptake resulted in a ~ 22 ms delay in Ca2+ signal decay, consistent with the experimental result described above. In conclusion, SERCA2 and PLB alterations described above have a modest contribution to functional adaptations observed in PVC-CM.

Experimental drugs for supraventricular tachycardia: an analysis of early phase clinical trials

INTRODUCTION

Supraventricular tachycardias (SVT) are a diverse group of commonly encountered arrhythmias arising at or above the atrioventricular (AV) node. Conventional anti-arrhythmic medications are restricted by extensive side-effect profiles and limited efficacy. Catheter ablation has emerged as a first-line therapy for many arrhythmias but is not a suitable option for all patients. This has prompted the exploration of novel pharmacological approaches targeting specific molecular mechanisms of SVT.

AREAS COVERED

This review article aims to summarize recent advancements in pharmacological therapeutics for SVT and their clinical implications. The understanding of molecular mechanisms underlying these arrhythmias, particularly atrial fibrillation, has opened up new possibilities for targeted interventions. Beyond the manipulation of ion channels and membrane potentials, pharmacotherapy now focuses on upstream targets such as inflammation, oxidative stress, and structural remodeling. This review strives to provide a comprehensive overview of recent advancements in pharmacological therapeutics directed at the management of SVT. We begin by providing a brief summary of the mechanisms and management of commonly encountered SVT before delving into individual agents, which in turn are stratified based on their molecular treatment targets.

EXPERT OPINION

The evolving landscape of pharmacologic therapy offers hope for more personalized and tailored interventions in the management of SVT.

Right Heart Structure and Function after Electrical Cardioversion for Atrial Fibrillation

INTRODUCTION

Atrial fibrillation (AF) adversely impacts right ventricular (RV) and right atrial (RA) structure and function. There are limited data on these changes after electrical cardioversion (ECV) and the relative contribution of heart rate to evaluate the immediate (1-2 h) and short-term (4-6 weeks) changes in right cardiac chamber dimensions and RV function after ECV in patients with persistent AF.

METHODS

Right cardiac chamber dimensions and RV function were measured in 64 patients using transthoracic echocardiography 1-2 h before, immediately after, and 4-6 weeks after ECV. Associations between changes in right-heart measures and rhythm status at follow-up were assessed using linear regression models.

RESULTS

For patients who remained in sinus rhythm 4-6 weeks after ECV (n = 48), median fractional area change (FAC) at baseline, immediately after ECV, and 4-6 weeks after ECV were 39 (Q1:35, Q3:42) %, 42 (Q1:39, Q3:46) %, 46 (Q1:43, Q3:49) % (p < 0.01); median tricuspid annular plane systolic excursion (TAPSE) values at the same time points were 18 (Q1:17, Q3:20) mm, 20 (Q1:18, Q3:23) mm, and 24 (Q1:22, Q3:26) mm (p < 0.01), respectively. There was no significant difference in RV end systolic area and RA volume index before and after ECV. However, RV end systolic area and RA volume index decreased significantly after 4-6 weeks from a median of 10 (Q1:8, Q3:13) cm2 to 8 (Q1:7, Q3:10) cm2 (p < 0.01), and from a median of 30 (Q1:24, Q3:36) mL/m2 to 24 (Q1:20, Q3:27) mL/m2 (p < 0.01). Changes in TAPSE were significantly associated with sinus rhythm at follow-up (p = 0.027), changes in FAC showed a strong trend to association with sinus rhythm (p = 0.053), and this was not true for RA measures (p = 0.64).

CONCLUSIONS

Among AF patients who remained in sinus rhythm after ECV, RV function improved immediately after ECV with further improvement at 4-6 weeks following sinus rhythm restoration.

Renal denervation reverses ventricular structural and functional remodeling in failing rabbit hearts

Renal denervation (RDN) suppresses the activity of the renin-angiotensin-aldosterone system and inflammatory cytokines, leading to the prevention of cardiac remodeling. Limited studies have reported the effects of renal denervation on ventricular electrophysiology. We aimed to use optical mapping to evaluate the effect of RDN on ventricular structural and electrical remodeling in a tachycardia-induced cardiomyopathy rabbit model. Eighteen rabbits were randomized into 4 groups: sham control group (n = 5), renal denervation group receiving RDN (n = 5), heart failure group receiving rapid ventricular pacing for 1 month (n = 4), and RDN-heart failure group (n = 4). Rabbit hearts were harvested for optical mapping. Different cycle lengths were paced (400, 300, 250, 200, and 150 ms), and the results were analyzed. In optical mapping, the heart failure group had a significantly slower epicardial ventricular conduction velocity than the other three groups. The RDN-heart failure, sham control, and RDN groups had similar velocities. We then analyzed the 80% action potential duration at different pacing cycle lengths, which showed a shorter action potential duration as cycle length decreased (P for trend < 0.01), which was consistent across all groups. The heart failure group had a significantly longer action potential duration than the sham control and RDN groups. Action potential duration was shorter in the RDN-heart failure group than the heart failure group (P < 0.05). Reduction of conduction velocity and prolongation of action potential duration are significant hallmarks of heart failure, and RDN reverses these remodeling processes.

Ventricular pre-excitation in cats: 17 cases

OBJECTIVES

Atrioventricular accessory pathways are abnormal electrical connections between the atria and ventricles that predispose to ventricular pre-excitation (VPE) and tachycardias.

ANIMALS

Seventeen cats with VPE and 15 healthy matched-control cats.

MATERIAL AND METHODS

Multicenter case-control retrospective study. Clinical records were searched for cats with VPE, defined as preserved atrioventricular synchrony, reduced PQ interval, and increased QRS complex duration with a delta wave. Clinical, electrocardiography, echocardiographic, and outcome data were collated.

RESULTS

Most cats with VPE were male (16/17 cats), non-pedigree cats (11/17 cats). Median age and mean body weight were 5.4 years (0.3-11.9 years) and 4.6 ± 0.8 kg, respectively. Clinical signs at presentation included lethargy (10/17 cats), tachypnea (6/17 cats), and/or syncope (3/17 cats). In two cats, VPE was an incidental finding. Congestive heart failure was uncommon (3/17 cats). Nine (9/17) cats had tachyarrhythmias: 7/9 cats had narrow QRS complex tachycardia and 2/9 cats had wide QRS complex tachycardia. Four cats had ventricular arrhythmias. Cats with VPE had larger left (P < 0.001) and right (P < 0.001) atria and thicker interventricular septum (P = 0.019) and left ventricular free wall (P = 0.028) than controls. Three cats had hypertrophic cardiomyopathy. Treatment included different combinations of sotalol (5/17 cats), diltiazem (5/17 cats), atenolol (4/17 cats), furosemide (4/17 cats), and platelet inhibitors (4/17 cats). Five cats died, all from cardiac death (median survival time 1882 days [2-1882 days]).

CONCLUSIONS

Cats with VPE had a relatively long survival, albeit showing larger atria and thicker left ventricular walls than healthy cats.

Abnormal Conduction-Induced Cardiomyopathy: JACC Review Topic of the Week

Nonischemic cardiomyopathies are a frequent occurrence. The understanding of the mechanism(s) and triggers of these cardiomyopathies have led to improvement and even recovery of left ventricular function. Although chronic right ventricular pacing-induced cardiomyopathy has been recognized for many years, left bundle branch block and pre-excitation have been recently identified as potential reversible causes of cardiomyopathy. These cardiomyopathies share a similar abnormal ventricular propagation that can be recognized by a wide QRS duration with left bundle branch block pattern; thus, we coined the term abnormal conduction-induced cardiomyopathies. Such abnormal propagation results in an abnormal contractility that can only be recognized by cardiac imaging as ventricular dyssynchrony. Appropriate diagnosis and treatment will not only lead to improved left ventricular ejection fraction and functional class, but may also reduce morbidity and mortality. This review presents an update of the mechanisms, prevalence, incidence, and risk factors, as well as their diagnosis and management, while highlighting current gaps of knowledge.

Heart failure with reduced ejection fraction and atrial fibrillation: a Sub-Saharan African perspective

Cardiovascular diseases are a well-established cause of death in high-income countries. In the last 20 years, Sub-Saharan Africa (SSA) has seen one of the sharpest increases in cardiovascular disease-related mortality, superseding that of infectious diseases, including HIV/AIDS, in South Africa. This increase is evidenced by a growing burden of heart failure and atrial fibrillation (AF) risk factors. AF is a common comorbidity of heart failure with reduced ejection fraction (HFrEF), which predisposes to an increased risk of stroke, rehospitalizations, and mortality compared with patients in sinus rhythm. AF had the largest relative increase in cardiovascular disease burden between 1990 and 2010 in SSA and the second highest (106.4%) increase in disability-adjusted life-years (DALY) between 1990 and 2017. Over the last decade, significant advancements in the management of both HFrEF and AF have emerged. However, managing HFrEF/AF remains a clinical challenge for physicians, compounded by the suboptimal efficacy of guideline-mandated pharmacotherapy in this group of patients. There may be an essential role for racial differences and genetic influence on therapeutic outcomes of HFrEF/AF patients, further complicating our overall understanding of the disease and its pathophysiology. In SSA, the lack of accurate and up-to-date epidemiological data on this subgroup of patients presents a challenge in our quest to prevent and reduce adverse outcomes. This narrative review provides a contemporary overview of the epidemiology of HFrEF/AF in SSA. We highlight important differences in the demographic and aetiological profile and the management of this subpopulation, emphasizing what is currently known and, more importantly, what is still unknown about HFrEF/AF in SSA.

Successful treatment with ivabradine in a β-blocker-refractory patient with acute decompensated heart failure with reduced ejection fraction

Ivabradine is an established treatment for chronic heart failure with reduced ejection fraction (HFrEF); however, it is not used for acute heart failure treatment. Negative inotropic effects (NIE) often limit the up-titration of β-blockers. Contrarily, ivabradine has no NIE, and enables β-blockers usage for treating patients with acute decompensated HFrEF.

How arrhythmias weaken the ventricle: an often underestimated vicious cycle

Arrhythmia-induced cardiomyopathy (AIC) is classified as a form of dilated cardiomyopathy in which left ventricular systolic dysfunction (LVSD) is triggered by tachycardic or arrhythmic heart rates. On the one hand AIC can develop in patients without cardiac disease and on the other hand it can appear in patients with pre-existing LVSD, leading to a further reduction in left ventricular (LV) ejection fraction. A special aspect of AIC is the potential termination or partial reversibility of LVSD; thus, AIC is curatively treatable by the elimination of the underlying arrhythmia. Since arrhythmias are often seen merely as a consequence than as an underlying cause of LVSD, and due to the fact that the diagnosis of AIC can be made only after recovery of LV function, the prevalence of AIC is probably underestimated in clinical practice. Pathophysiologically, animal models have shown that continuous tachycardic pacing induces consecutive changes such as the occurrence of LVSD, increased filling pressures, LV dilatation, and decreased cardiac output. After termination of tachycardia, reversibility of the described pathologies can usually be observed. Studies in human ventricular myocardium have recently demonstrated that various cellular structural and functional mechanisms are activated even by normofrequent atrial fibrillation, which may help to explain the clinical AIC phenotype.

Long-Term Outcomes of Tachycardia-Induced Cardiomyopathy Compared with Idiopathic Dilated Cardiomyopathy

BACKGROUND

data on the natural course and prognosis of tachycardia-induced cardiomyopathy (TICMP) and comparison with idiopathic dilated cardiomyopathies (IDCM) are scarce.

OBJECTIVE

To compare the clinical presentation, comorbidities, and long-term outcomes of TICMP patients with IDCM patients.

METHODS

a retrospective cohort study of patients hospitalized with new-onset TICMP or IDCM. The primary endpoint was a composite of death, myocardial infarction, thromboembolic events, assist device, heart transplantation, and ventricular tachycardia or fibrillation (VT/VF). The secondary endpoint was recurrent hospitalization due to heart failure (HF) exacerbation.

RESULTS

the cohort was comprised of 64 TICMP and 66 IDCM patients. The primary composite endpoint and all-cause mortality were similar between the groups during a median follow-up of ~6 years (36% versus 29%, p = 0.33 and 22% versus 15%, p = 0.15, respectively). Survival analysis showed no significant difference between TICMP and IDCM groups for the composite endpoint (p = 0.75), all-cause mortality (p = 0.65), and hospitalizations due to heart failure exacerbation. Nonetheless, the incidence of recurrent hospitalization was significantly higher in TICMP patients (incidence rate ratio 1.59; p = 0.009).

CONCLUSIONS

patients with TICMP have similar long-term outcomes as those with IDCM. However, it portends a higher rate of HF readmissions, mostly due to arrhythmia recurrences.

Tachycardia-Induced Cardiomyopathy in a Young Adult: The Significance of Early Diagnosis and Treatment

Tachycardia-induced cardiomyopathy (TIC) is gradually gaining the attention it deserves as one of the most common causes of reversible cardiomyopathy. Although TIC appears common, there has been limited data, especially among young adults. Patients with tachycardia and left ventricular dysfunction should be suspected of having TIC, with or without established etiology of heart failure, because TIC can develop by itself or contribute to cardiac dysfunction. We present a case of a previously healthy 31-year-old woman with persistent nausea and vomiting, poor oral intake, fatigue, and persistent palpitations. Vital signs at presentation were significant for tachycardia of 124 beats per minute, which she reported was similar to her baseline heart rate of 120s per minute. There were no apparent signs of volume overload at the presentation. Labs were significant for microcytic anemia with hemoglobin/hematocrit of 10.1/34.4 g/dL, and mean corpuscular volume was low at 69.4 fL; other labs were unremarkable. Transthoracic echocardiography obtained at admission was significant for mild global left ventricular hypokinesis, systolic dysfunction with an estimated left ventricular ejection fraction of 45-50%, and mild tricuspid regurgitation. Persistent tachycardia was suggested as the primary cause of cardiac dysfunction. The patient was subsequently started on guideline-directed medical therapy, including beta blockers, angiotensin-converting enzyme inhibitors, and spironolactone, with eventual normalization of the heart rate. Anemia too was also treated. Follow-up transthoracic echocardiography done four weeks after was notable for significant interval improvement in left ventricular ejection fraction of 55-60%, with a heart rate of 82 beats per minute. The case illustrates the need for early identification of TIC regardless of the patient's age. It is essential that physicians consider it in the differential diagnosis of new-onset heart failure because prompt treatment leads to the resolution of symptoms and improvement of ventricular function.

Emerging concepts in heart failure management and treatment: focus on tachycardia-induced cardiomyopathy

Tachycardia-induced cardiomyopathy is an entity characterized by reversible dysfunction of the left ventricle, which can be induced by different types of arrhythmia such as atrial fibrillation, atrial flutter, incessant supraventricular tachycardia and ventricular arrhythmia (more frequent causes). Correct identification of the causative arrhythmia and normalization of the heart rate (e.g through medical treatment, electrical cardioversion, ablation) can lead to recovery of left ventricular function. Tachycardia-induced cardiomyopathy should be suspected in patients with tachycardia and left ventricular dysfunction (heart failure setting), especially when there is no history of previous heart disease. Its usual phenotype is that of non-ischaemic/non-valvular dilated cardiomyopathy and it can occur in both children (main cause: permanent junctional reciprocating tachycardia) and adults (main cause: atrial fibrillation). With proper treatment, most cases recover within a few months, though there is a risk of relapse, especially when the causal arrhythmia reappears or its control is lost. This is a narrative review that comprehensively addresses the pathophysiology, clinical manifestations, and therapeutic management of tachycardia-induced cardiomyopathy. This article is part of the Emerging concepts in heart failure management and treatment Special Issue: https://www.drugsincontext.com/special_issues/emerging-concepts-in-heart-failure-management-and-treatment.

The monocyte to high-density lipoprotein cholesterol ratio is a risk factor for frequent premature ventricular complexes: a retrospective cohort study

BACKGROUND

Little is known about the link between the monocyte to high-density lipoprotein cholesterol ratio (MHR) and frequent premature ventricular complexes (PVCs). This investigation aimed to evaluate the link between the MHR and frequent PVCs in patients, as well as their outcomes, using the axis, burden, coupling interval-ventricular tachycardia (ABC-VT) risk score (ARS).

METHODS

Two hundred patients with frequent PVCs and 70 controls were retrospectively enrolled, and their general data were gathered. The MHR and ARS were calculated. Then, patients developing frequent PVCs were classified into a medium-/high-risk subgroup and a low-risk subgroup according to ARS. The results were evaluated employing comparative statistical analyses, Spearman's correlation, logistic regression analyses, and receiver operating characteristic (ROC) curves.

RESULTS

The MHR in the controls was obviously lower than that in the frequent PVC group. In addition, the MHR was the lowest in the control group and highest in the medium-/high-risk subgroup, with that of the low-risk subgroup falling in the middle. Spearman's correlation analyses showed that the MHR was positively correlated with the ARS (ρ = 0.307, P < 0.001). Ultimately, the MHR was found to be a risk factor for frequent PVCs in the multivariate analysis. In addition, an MHR cutoff point of 254.6 featured 67.50% sensitivity and 67.14% specificity for predicting frequent PVCs, and the area under the curve (AUC) reached 0.694 (95% confidence interval: 0.623-0.766) (P < 0.001).

CONCLUSIONS

The MHR is positively and independently correlated with frequent PVCs and can be used as a practical, cost-saving and simple biomarker of inflammation owing to its value in predicting frequent PVCs. In addition, the MHR is crucial to risk stratification and prognosis, which may give it clinical value in the prevention and management of frequent PVCs.

Dyssynchronous Heart Failure: A Clinical Review

PURPOSE OF THE REVIEW

Dyssynchrony occurs when portions of the cardiac chambers contract in an uncoordinated fashion. Ventricular dyssynchrony primarily impacts the left ventricle and may result in heart failure. This entity is recognized as a major contributor to the development and progression of heart failure. A hallmark of dyssynchronous heart failure (HF_d) is left ventricular recovery after dyssynchrony is corrected. This review discusses the current understanding of pathophysiology of HF_d and provides clinical examples and current techniques for treatment.

RECENT FINDINGS

Data show that HF_d responds poorly to medical therapy. Cardiac resynchronization therapy (CRT) in the form of conventional biventricular pacing (BVP) is of proven benefit in HF_d, but is limited by a significant non-responder rate. Recently, conduction system pacing (His bundle or left bundle branch area pacing) has also shown promise in correcting HF_d. HF_d should be recognized as a distinct etiology of heart failure; HF_d responds best to CRT.

Efficacy and feasibility of cryoballoon ablation for atrial fibrillation in patients with heart failure: A large-scale multicenter study

INTRODUCTION

Data are limited regarding outcomes of cryoballoon ablation for atrial fibrillation (AF) in patients with heart failure (HF). This large-scale multicenter study aimed to evaluate the prognosis of patients with HF after cryoballoon ablation for AF.

METHODS

Among 3655 patients undergoing cryoballoon ablation at 17 institutions, 549 patients (15%) (391 with paroxysmal AF and 158 with persistent AF) diagnosed with HF preoperatively were analyzed. Clinical endpoints were recurrence, mortality, and HF hospitalization after ablation.

RESULTS

Most patients had a preserved left ventricular ejection fraction (LVEF) ≥ 50%. During a mean follow-up period of 25.7 months, recurrence, all-cause death, and HF hospitalization occurred in 29%, 4.0%, and 4.8%, respectively. Cardiac function on echocardiography and B-type natriuretic peptide (BNP) levels significantly improved postoperatively, and the effect was more pronounced in the nonrecurrence group. Major complications occurred in 33 patients (6.0%), but most complications were phrenic nerve palsy (3.6%). Although death and HF hospitalization occurred more frequently in patients with LVEF ≤ 40% (n = 73) and New York Heart Association (NYHA) class III-IV (n = 19) than other subgroups, the BNP levels, and LVEF significantly improved after ablation in all LVEF and NYHA class subgroups. High BNP levels, NHYA class, CHADS₂ score, and structural heart disease, but not postablation recurrence, independently predicted death, and HF hospitalization on multivariate analysis. The patients with tachycardia-induced cardiomyopathy had better recovery of BNP levels and LVEF after ablation than those with structural heart disease.

CONCLUSIONS

Cryoballoon ablation for AF in HF patients is feasible and leads to significantly improved cardiac function.

Clinical applications of heart rhythm monitoring tools in symptomatic patients and for screening in high-risk groups

Recent technological advances have facilitated and diversified the options available for the diagnosis of cardiac arrhythmias. Ranging from simple resting or exercise electrocardiograms to more sophisticated and expensive smartphones and implantable cardiac monitors. These tests and devices may be used for varying periods of time depending on symptom frequency. The choice of the most appropriate heart rhythm test should be guided by clinical evaluation and optimized following accurate characterization of underlying symptoms, 'red flags', risk factors, and consideration of cost-effectiveness of the different tests. This review provides evidence-based guidance for assessing suspected arrhythmia in patients who present with symptoms or in the context of screening, such as atrial fibrillation or advanced conduction disturbances following transcatheter aortic valve implantation in high-risk groups. This is intended to help clinicians choose the most appropriate diagnostic tool to facilitate the management of patients with suspected arrhythmias.

Risk factors for the development of premature ventricular complex-induced cardiomyopathy: a systematic review and meta-analysis

Background

Premature ventricular complexes (PVCs) are a potentially reversible cause of heart failure. However, the characteristics of patients most likely to develop impaired left ventricular function are unclear. Hence, the objective of this study is to systematically assess risk factors for the development of PVC-induced cardiomyopathy.

Methods

We performed a structured database search of the scientific literature for studies investigating risk factors for the development of PVC-induced cardiomyopathy (PVC-CM). We investigated the reporting of PVC-CM risk factors (RF) and assessed the comparative association of the different RF using random-effect meta-analysis.

Results

A total of 26 studies (9 prospective and 17 retrospective studies) involving 16,764,641 patients were analyzed (mean age 55 years, 58% women, mean PVC burden 17%). Eleven RF were suitable for quantitative analysis (≥ 3 occurrences in multivariable model assessing a binary change in left ventricular (LV) function). Among these, age (OR 1.02 per increase in the year of age, 95% CI [1.01, 1.02]), the presence of symptoms (OR 0.18, 95% CI [0.05, 0.64]), non-sustained ventricular tachycardias (VT) (OR 3.01, 95% CI [1.39, 6.50]), LV origin (OR 2.20, 95% CI [1.14, 4.23]), epicardial origin (OR 4.72, 95% CI [1.81, 12.34]), the presence of interpolation (OR 4.93, 95% CI [1.66, 14.69]), PVC duration (OR 1.05 per ms increase in QRS-PVC duration [1.004; 1.096]), and PVC burden (OR 1.06, 95% CI [1.04, 1.08]) were all significantly associated with PVC-CM.

Conclusions

In this meta-analysis, the most consistent risk factors for PVC-CM were age, non-sustained VT, LV, epicardial origin, interpolation, and PVC burden, whereas the presence of symptoms significantly reduced the risk. These findings help tailor stringent follow-up of patients presenting with frequent PVCs and normal LV function.

Case report: Treatment of tachycardia-induced cardiogenic shock with permanent His bundle pacing and atrioventricular node ablation

Tachycardia-induced cardiomyopathy (T-CMP) related to supraventricular arrhythmia is a rare and often unrecognized cause of refractory cardiogenic shock. When rhythm control interventions are ineffective or no longer pursued, atrioventricular node ablation (AVNA) with pacemaker implantation is indicated. Conduction system pacing provides normal synchronous activation of the ventricles after AVNA. However, there is a lack of data on pace and ablate strategy in hemodynamically unstable patients. We report on 2 patients with T-CMP presenting with refractory cardiogenic shock who were successfully treated with His bundle pacing in conjunction with AVNA.

Stroke Severity in Ischemic Stroke Patients with a History of Diastolic Blood Pressure Treated in a Telestroke Network

Background: The relationship between diastolic blood pressure (DBP), risk factors, and stroke severity in acute ischemic stroke (AIS) patients treated in a telestroke network is not fully understood. The present study aims to determine the effect of risk factors on stroke severity in AIS patients with a history of elevated DBP. Material and Methods: We retrospectively analyzed data on stroke severity for AIS patients treated between January 2014 and June 2016 treated in the PRISMA Health telestroke network. Data on the severity of stroke on admission were evaluated using NIHSS scores ≤7 for reduced, and >7 for increased, stroke severity. DBP was stratified as ≤80 mmHg for reduced DBP and >80 mmHg for elevated DBP. The study’s primary outcomes were risk factors associated with improving neurologic functions or reduced stroke severity and deteriorating neurologic functions or increased stroke severity. The associations between risk factors and stroke severity for AIS with elevated DBP were determined using multi-level logistic and regression models. Results: In the adjusted analysis, AIS patients with a DBP ≤ 80 mmHg, obesity (OR = 0.388, 95% Cl, 0.182−0.828, p = 0.014) was associated with reduced stroke severity, while an increased heart rate (OR = 1.025, 95% Cl, 1.001−1.050, p = 0.042) was associated with higher stroke severity. For AIS patients with a DBP > 80 mmHg, hypertension (OR = 3.453, 95% Cl, 1.137−10.491, p = 0.029), history of smoking (OR = 2.55, 95% Cl, 1.06−6.132, p = 0.037), and heart rate (OR = 1.036, 95% Cl, 1.009−1.064, p = 0.009) were associated with higher stroke severity. Caucasians (OR = 0.294, 95% Cl, 0.090−0.964, p = 0.002) and obesity (OR = 0.455, 95% Cl, 0.207−1.002, p = 0.05) were more likely to be associated with reduced stroke severity. Conclusions: Our findings reveal specific risk factors that can be managed to improve the care of AIS patients with elevated DBP treated in the telestroke network.

Profile of Patients with Cardiovascular Diseases during the Pandemic in a Cardiology Clinic of a COVID-19 Support Hospital

Background: During the pandemic, our hospital became a COVID support hospital and consequently the cardiology clinic had restricted activity; thus, it received only suspect and/or patients confirmed positive with the various COVID-19 strains that were associated with a chronic/flaring cardiovascular pathology. Methods: Two batches of patients admitted during a one-year period were compared in the cardiology clinic over two different periods of time: BATCH I (1 April 2019 to 31 March 2020), in a non-COVID context (BATCH I N-COV) and BATCH II (1 July 2020 to 30 June 2021) comprising patients that presented with respiratory infection of SARS-CoV-2 (BATCH II COV-2), associated with chronic and/or acute cardiovascular condition. To determine the profile of the patients admitted in our clinic, we observed the following parameters: age, type of cardiac condition, and admission mode (for the N-COV group). Results: The data obtained as absolute numbers and as percentages in relation to the total number of admissions were presented in separate tables and graphs for both of the studied groups. Conclusions: The SARS-CoV-2 pandemic, in its almost two years of evolution, has divided the medical world in two main categories: COVID and non-COVID. Admission of the patients with chronic, but non-COVID cardiac conditions, in our case, dropped to almost one-quarter when we compared the two absolute admission numbers: 1382 in the year prior to pandemic compared with only 356 in the pandemic year. We believe that the number of deaths due to SARS-CoV-2 infection was infinitely higher than the reported ones and uncountable, in as much as COVID-19 did not kill only the infected patients, but it has also yielded a very large number of collateral victims among chronic patients who had no contact with the disease, but were unable to be admitted and treated for chronic heart disease.

Tachycardia-Induced Cardiomyopathy in a Young Healthy Patient: A Case Report

Tachycardia-induced cardiomyopathy (TIC) can result in both systolic and/or diastolic ventricular dysfunction as a result of the prolonged fast heart rate which is reversible upon controlling the fast heart rate or arrhythmia. The exact heart rate that can lead to this is not clear, however, a heart rate > 100 in general needs attention. Tachycardia-induced cardiomyopathy is a well-established cause of left ventricular dysfunction which usually happens due to an increased atrial or ventricular rate. The incidence of TIC is very low although the exact incidence is unclear. It should be considered in all patients with dilated cardiomyopathy or those with no obvious explanation for dilated cardiomyopathy and in presence of tachycardia or atrial fibrillation with a rapid ventricular response. Tachycardia-induced cardiomyopathy has also been labeled as arrhythmia-induced cardiomyopathy lately. We present a case of a 50-year-old patient who presented with a fever of 39^oC, feeling generally unwell, had a sore throat, and collapsed at home after several episodes of vomiting after two days of intense exercise. He was diagnosed with suspected tonsillitis and was treated with co-amoxiclav. He was exercising over 10 hours weekly for the last two months in the gym for the Ironman triathlon in London. An echocardiogram showed severe left ventricular systolic dysfunction (LVSD) with a left ventricular ejection fraction (LVEF) of 25%. An electrocardiogram showed sinus tachycardia with a right bundle branch block (RBBB). Cardiac magnetic resonance imaging (CMR) showed normal biventricular function with an ejection fraction (EF) of 71% four months later. The patient was diagnosed with tachycardia-induced cardiomyopathy. This case is unique as the patient presented with transient severe LVSD after training for the ironman triathlon and spontaneous recovery.

Left ventricular dyssynchrony as marker of early dysfunction in premature ventricular contraction-induced cardiomyopathy

Background

Strain imaging has been suggested as a tool to detect early left ventricular (LV) dysfunction due to frequent premature ventricular contractions (PVCs) in patients with preserved LV ejection fraction (EF). However, the progression of intraventricular dyssynchrony (IVD), radial, and circumferential strain (RS, CS) in PVC-cardiomyopathy (CM) are unknown. The aim of this study was to elucidate the progression patterns of CS, IVD, and electro-mechanical latency (EML) in PVC-CM.

Methods and results

Pacemakers were implanted in 20 canines to reproduce ventricular bigeminy at 200ms (PVCs n = 11) for 12 weeks and compared to a sham group (n = 9). We obtained echocardiograms at baseline, 4-, 8- and 12-weeks. RS and CS were obtained at the LV mid-cavitary level. IVD was defined as the time between the earliest and latest peak RS. EML was defined as the time between the onset of QRS and the earliest peak RS. LVEF (62 ± 5 to 42 ± 7%, p < 0.01), CS (-18 ± 3 to -12 ± 3, p < 0.01), and EML (219 ± 37 to 283 ± 46ms, p = 0.02) changed significantly in the PVC group. Peak CS (-18 ± 3 to -14 ± 4, p = 0.02) and IVD (49 ± 31 to 122 ± 103, p = 0.05) had a significant change at 4-weeks despite preserved LVEF (51 ± 5%). IVD normalized while EML increased at weeks 8 and 12.

Conclusion

Our findings consolidate the existing theory that changes in strain precede changes in LVEF in PVC-CM. While IVD becomes abnormal early in the development of PVC-CM, it pseudo-normalizes at advanced stages due to further increases in EML suggestive of cardiac contractility remodeling. These findings are consistent with recent published data where abnormal LV mechanics could be part of a substrate that can predispose to worse outcome in PVC-Cardiomyopathy.

Bidirectional regulatory effects of Cordyceps on arrhythmia: Clinical evaluations and network pharmacology

Background: Cordyceps is a precious Chinese herbal medicine with rich bio-active ingredients and is used for regulating arrhythmia alongside routine treatments. However, the efficacy and potential mechanisms of Cordyceps on patients with arrhythmia remain unclear.

Methods: Randomized controlled trials of bradycardia treatment with Cordyceps were retrieved from diverse databases and available data. Dichotomous variables were expressed as a risk ratio (RR) with a 95% confidence interval (CI). Continuous variables were expressed as a standardized mean difference (SMD) with a 95% CI. Network pharmacology was used to identify potential targets of Cordyceps for arrhythmia. Metascape was used for gene ontology (GO) and genome (KEGG) pathway enrichment analysis.

Results: Nineteen trials included 1,805 patients with arrhythmia, of whom 918 were treated with Ningxinbao capsule plus routine drugs, and, as a control, 887 were treated with only routine drugs. Six trials reported on bradycardia and the other 13 on tachycardia. Treatment with Cordyceps significantly improved the total efficacy rate in both bradycardia (RR = 1.24; 95% CI, 1.15 to 1.35; P_z <0.00001) and tachycardia (RR = 1.27; 95% CI, 1.17 to 1.39; P_z <0.00001). Cordyceps also had beneficial secondary outcomes. No serious adverse events occurred in patients treated with Cordyceps. The results of KEGG pathway enrichment analysis were mainly connected to adrenergic signaling in cardiomyocytes and the PI3K-Akt signaling pathway. IL6, TNF, TP53, CASP3, CTNNB1, EGF, and NOS3 might be key targets for Cordyceps in the treatment of arrhythmia.

Conclusion: This study confirmed that Cordyceps has a certain positive effect on the treatment of arrhythmia and that its main mechanism may be through the regulation of adrenergic signaling in cardiomyocytes and the PI3K-Akt signaling pathway.

Qualitative Evaluation of an Artificial Intelligence–Based Clinical Decision Support System to Guide Rhythm Management of Atrial Fibrillation: Survey Study

Background

Despite the numerous studies evaluating various rhythm control strategies for atrial fibrillation (AF), determination of the optimal strategy in a single patient is often based on trial and error, with no one-size-fits-all approach based on international guidelines/recommendations. The decision, therefore, remains personal and lends itself well to help from a clinical decision support system, specifically one guided by artificial intelligence (AI). QRhythm utilizes a 2-stage machine learning (ML) model to identify the optimal rhythm management strategy in a given patient based on a set of clinical factors, in which the model first uses supervised learning to predict the actions of an expert clinician and identifies the best strategy through reinforcement learning to obtain the best clinical outcome—a composite of symptomatic recurrence, hospitalization, and stroke.

Objective

We qualitatively evaluated a novel, AI-based, clinical decision support system (CDSS) for AF rhythm management, called QRhythm, which uses both supervised and reinforcement learning to recommend either a rate control or one of 3 types of rhythm control strategies—external cardioversion, antiarrhythmic medication, or ablation—based on individual patient characteristics.

Methods

Thirty-three clinicians, including cardiology attendings and fellows and internal medicine attendings and residents, performed an assessment of QRhythm, followed by a survey to assess relative comfort with automated CDSS in rhythm management and to examine areas for future development.

Results

The 33 providers were surveyed with training levels ranging from resident to fellow to attending. Of the characteristics of the app surveyed, safety was most important to providers, with an average importance rating of 4.7 out of 5 (SD 0.72). This priority was followed by clinical integrity (a desire for the advice provided to make clinical sense; importance rating 4.5, SD 0.9), backward interpretability (transparency in the population used to create the algorithm; importance rating 4.3, SD 0.65), transparency of the algorithm (reasoning underlying the decisions made; importance rating 4.3, SD 0.88), and provider autonomy (the ability to challenge the decisions made by the model; importance rating 3.85, SD 0.83). Providers who used the app ranked the integrity of recommendations as their highest concern with ongoing clinical use of the model, followed by efficacy of the application and patient data security. Trust in the app varied; 1 (17%) provider responded that they somewhat disagreed with the statement, “I trust the recommendations provided by the QRhythm app,” 2 (33%) providers responded with neutrality to the statement, and 3 (50%) somewhat agreed with the statement.

Conclusions

Safety of ML applications was the highest priority of the providers surveyed, and trust of such models remains varied. Widespread clinical acceptance of ML in health care is dependent on how much providers trust the algorithms. Building this trust involves ensuring transparency and interpretability of the model.

Premature Ventricular Contractions Are Presaged by a Mechanically Abnormal Sinus Beat

BACKGROUND

Frequent premature ventricular contractions (PVCs) can lead to cardiomyopathy; it is unclear if there are abnormal myocardial mechanics operative in the PVC and non-PVC beats.

OBJECTIVES

The aim of this study was to investigate regional and global myocardial mechanics, including dyssynchrony, in patients with frequent PVCs.

METHODS

Fifty-six consecutive patients referred for PVC ablation were prospectively studied. During sinus rhythm (SR) and PVC beats, left ventricular (LV) global longitudinal strain (GLS), LV dyssynchrony (measured as the SD of time to peak GLS), and dyssynergy (measured as maximum regional strain minus minimum regional strain at aortic valve closure) were quantified using 2-dimensional strain echocardiography. GLS, dyssynchrony, and dyssynergy were compared in remote SR, pre-PVC SR, PVC, and post-PVC SR beats.

RESULTS

In SR beats remote from the PVC, GLS was -17.3% ± 4%, dyssynchrony was 49 ± 14 ms, and dyssynergy was 22% ± 9%. Myocardial mechanics were significantly abnormal during PVCs compared with remote SR beats (GLS -7.7% ± 3% [P < 0.001], dyssynchrony 115 ± 37 milliseconds [P < 0.001], and dyssynergy 26% ± 10% [P < 0.001]). There were significant mechanical abnormalities in the SR beat preceding the PVC, which demonstrated significantly lower LV strain (pre-PVC SR, -13% ± 4%; P < 0.001) and more dyssynchrony (pre-PVC SR, 63 ± 19 milliseconds; P < 0.001) compared with remote SR beats. Dyssynergy was significantly higher for pre-PVC SR and PVC beats compared with remote SR (pre-PVC SR, 25% ± 8% [P < 0.001]; PVC, 26% ± 10% [P < 0.001]).

CONCLUSIONS

In patients with frequent PVCs, the SR beat preceding the PVC demonstrates significant mechanical abnormalities. This finding suggests that perturbations in cellular physiological processes such as excitation-contraction coupling may underlie the generation of frequent PVCs.

Effect of Sacubitril/Valsartan on Reducing the Risk of Arrhythmia: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background and Objective

Relevant data of PARADIGM-HF reveals sacubitril/valsartan (SV) therapy led to a greater reduction in the risks of arrhythmia, and sudden cardiac death than angiotensin converting enzyme inhibitor (ACEI)/angiotensin receptor inhibitor (ARB) therapy in HFrEF, however, inconsistent results were reported in subsequent studies. Here, we conduct a meta-analysis of related randomized controlled trials (RCTs) to evaluate the protective effect of SV on reducing the risk of arrhythmias.

Methods and Results

RCTs focused on the difference in therapeutic outcomes between SV and ACEI/ARB were searched from PUBMED, EMBASE, ClinicalTrials.gov, and Cochrane Library. The results were extracted from each individual study, expressed as binary risk, 95% confidence interval (CI) and relative risk (RR). Sixteen RCTs including 22, 563 patients met the study criteria. Compared with ACEI/ARB therapy, SV therapy did significantly reduce in the risks of severe arrhythmias among patients with heart failure with reduced ejection fraction (HFrEF) (RR 0.83, 95% CI 0.73–0.95, p = 0.006), ventricular tachycardia (VT) among patients with HFrEF (RR 0.69, 95% CI 0.51–0.92, p = 0.01), cardiac arrest among patients with heart failure (HF) (RR 0.52, 95% CI 0.37–0.73, p = 0.0002), cardiac arrest among patients with HFrEF (RR 0.49, 95% CI 0.32–0.76, p = 0.001), cardiac arrest or ventricular fibrillation (VF) among patients with HF (RR 0.63, 95% CI 0.48–0.83, p = 0.001), and cardiac arrest or VF among patients with HFrEF (RR 0.65, 95% CI 0.47–0.89, p = 0.008), but reduced the risks of arrhythmias (RR 0.87, 95% CI 0.74–1.01, p = 0.07), atrial arrhythmias (RR 0.98, 95% CI 0.83–1.16, p = 0.85), and atrial fibrillation (RR 0.98, 95% CI 0.82–1.17, p = 0.82) among all patients with no significant between-group difference. The merged result was robust after sensitivity analysis, and there was no publication bias.

Conclusion

Our meta-analysis provides evidence that, compared with ACEI/ARB, SV can additionally reduce the risks of most arrhythmias, just the significant differences are revealed in reducing the risks of VT, severe arrhythmias, and cardiac arrest in patients with HFrEF. Besides, the positive effect of SV on VF according to statistical result of combining VF with cardiac arrest in patients with HFrEF is credibility.

Electrocardiogram and CMR to differentiate tachycardia-induced cardiomyopathy from dilated cardiomyopathy in patients admitted for heart failure

In patients admitted for heart failure (HF) with reduced left ventricular ejection fraction (LVEF) and a concomitant supraventricular tachyarrhythmia (SVT) it is a challenge to predict LVEF recovery and differentiate tachycardia-induced cardiomyopathy (TIC) from dilated cardiomyopathy (DCM). The role of the electrocardiogram (ECG) and cardiac magnetic resonance (CMR) and in this acute setting remains unsettled. Forty-three consecutive patients admitted for HF due to SVT and LVEF < 50% undergoing CMR in the acute phase, were retrospectively included. Those who had LVEF > 50% at follow up were classified as TIC and those with LVEF < 50% were classified as DCM. Clinical, CMR and ECG findings were analyzed to predict LVEF recovery. Twenty-five (58%) patients were classified as TIC. Patients with DCM had wider QRS (121.2 ± 26 vs 97.7 ± 17.35 ms; p = 0.003). On CRM the TIC group presented with higher LVEF (33.4 ± 11 vs 26.9 ± 6.4%; p = 0.019) whereas late gadolinium enhancement (LGE) was more frequent in DCM group (61 vs 16%; p = 0.004). On multivariate analysis, QRS duration ≥ 100 ms (p = 0.027), LVEF < 40% on CMR (p = 0.047) and presence of LGE (p = 0.03) were independent predictors of lack of LVEF recovery. Furthermore, during follow-up (median 60 months) DCM patients were admitted more frequently for HF (44 vs 0%; p < 0.001) than TIC patients. In patients with reduced LVEF admitted for HF due to SVT, QRS ≥ 100 ms, LVEF < 40% and LGE are independently associated with lack of LVEF recovery and worse clinical outcome.

Effect of Heart Rate on 1-Year Outcome for Patients With Acute Ischemic Stroke

Background Previous literature about the effect of heart rate on poststroke outcomes is limited. We attempted to elucidate (1) whether heart rate during the acute period of ischemic stroke predicts subsequent major clinical events, (2) which heart rate parameter is best for prediction, and (3) what is the estimated heart rate cutoff point for the primary outcome. Methods and Results Eight thousand thirty-one patients with acute ischemic stroke who were hospitalized within 48 hours of onset were analyzed retrospectively. Heart rates between the 4th and 7th day after onset were collected and heart rate parameters including mean, time-weighted average, maximum, and minimum heart rate were evaluated. The primary outcome was the composite of recurrent stroke, myocardial infarction, and mortality up to 1 year after stroke onset. All heart rate parameters were associated with the primary outcome (P's<0.001). Maximum heart rate had the highest predictive power. The estimated cutoff point for the primary outcome was 81 beats per minute for mean heart rate and 100 beats per minute for maximum heart rate. Patients with heart rates above these cutoff points had a higher risk of the primary outcome (adjusted hazard ratio, 1.80 [95% CI, 1.57-2.06] for maximum heart rate and 1.65 [95% CI, 1.45-1.89] for mean heart rate). The associations were replicated in a separate validation dataset (N=10 000). Conclusions These findings suggest that heart rate during the acute period of ischemic stroke is a predictor of major clinical events, and optimal heart rate control might be a target for preventing subsequent cardiovascular events.

Risk Factors and Heart Rate Variability Associated with Left Ventricular Enlargement in Patients with Frequent Premature Ventricular Contractions

INTRODUCTION

Premature ventricular contractions (PVCs) were now well recognized to carry the risk of inducing left ventricular (LV) enlargement and were closely related to the cardiac autonomic nervous activity quantified by heart rate variability (HRV) analysis. However, the relationship between LV enlargement and HRV in patients with frequent PVCs is still unclear. This study aimed to investigate the risk factors and HRV for LV enlargement in patients with frequent PVCs.

METHODS

Patients with frequent PVCs (n = 571), whose PVC burden counts >10,000/24 h or PVC burden >10%, were recruited. Patients were divided into LV enlargement group (n = 161), defined as female left ventricular end-diastolic diameter (LVEDD) >49.8 mm or male LVEDD >54.2 mm, and LV normal group (n = 410). Two groups were compared on their clinical, electrocardiographic, and HRV parameters. Logistic regression analysis was used to predict the risk factors of LV enlargement in patients with frequent PVCs. The parameters of echocardiography, Holter monitoring, and HRV were collected after ablation.

RESULTS

There were significant differences between the patients with left enlargement and with normal LV structure, in terms of sex, left ventricular ejection fraction (LVEF), level of N-terminal pro-brain natriuretic peptide (NT-proBNP), 24-h PVC burden, with nonsustained ventricular tachycardia, multifocal PVCs, QRS duration of PVC, and values of very low-frequency power of HRV parameter (all p < 0.05). Multivariate analysis showed that female gender (odds ratio [OR] = 2.753, p < 0.001), increased NT-proBNP (OR = 1.011, p = 0.022), increased LVEF (OR = 0.292, p < 0.001), increased 24-h PVC burden (OR = 1.594, p < 0.001), increased standard deviation of all NN intervals (SDNN) (OR = 1.100, p = 0.003), increased the proportion of consecutive NN intervals that differ by more than 50 ms (pNN50) (OR = 0.844, p = 0.026) were predictors for LV enlargement in patients with frequent PVCs. 84.4% (54/64) of patients with LV enlargement at baseline had normalized their LV structure after ablation. The values of SDNN, standard deviation of the averages of NN intervals in all 5-min segments, the square root of the mean of the sum of the squares of differences between adjacent NN intervals, pNN50, low-frequency power (LF), LF/high-frequency power ratio of patients were significantly decreased after ablation (all p < 0.05).

CONCLUSION

Female gender, increased level of NT-proBNP, lower LVEF, higher PVC burden, increased sympathetic parameters SDNN, and reduced parasympathetic parameters pNN50 were the independent risk factors of LV enlargement in patients with frequent PVCs. LV enlargement induced by PVCs can be reversible after PVC elimination by ablation. The activities of sympathetic and parasympathetic were reduced after ablation.

Left atrium phasic impairments in paroxysmal atrial fibrillation patients assessed by cardiovascular magnetic resonance feature tracking

Atrial fibrillation (AF) is an abnormal and irregular heartbeat caused by uncoordinated electrical impulses in the left atrium (LA), which could induce lasting changes in the heart tissue or could be a consequence of underlying cardiac disease. This study aimed to assess the left atrial phasic function and deformation in paroxysmal AF (PAF) patients—who had not received radiofrequency ablation and had no signs of permanent AF—using the cardiovascular magnetic resonance (CMR) feature-tracking (FT) technique. Fifty subjects (27 PAF patients and 23 controls) were included and examined with CMR. Their LA volume, LA function, LA longitudinal strain (LS) and LA strain rate were assessed in the LA reservoir, conduit, and contractile phases. PAF patients exhibited higher LA volumes than controls, while their LA emptying fraction and LA LS was significantly lower in all three phases. In contrast, the corresponding emptying volumes (total, passive and active) were similar in both groups. The LA volumetric rates from CMR-derived volume curves differed significantly in PAF patients vs controls in the reservoir and contractile phases. In contrast, the equivalent LV volumetric rates were similar. This study suggests that assessing the LA phasic function could offer insight into early LA impairments for PAF patients.

A biosensing system using a multiparameter nonlinear dynamic analysis of cardiomyocyte beating for drug-induced arrhythmia recognition

Cardiovascular disease is the number one cause of death in humans. Therefore, cardiotoxicity is one of the most important adverse effects assessed by arrhythmia recognition in drug development. Recently, cell-based techniques developed for arrhythmia recognition primarily employ linear methods such as time-domain analysis that detect and compare individual waveforms and thus fall short in some applications that require automated and efficient arrhythmia recognition from large datasets. We carried out the first report to develop a biosensing system that integrated impedance measurement and multiparameter nonlinear dynamic algorithm (MNDA) analysis for drug-induced arrhythmia recognition and classification. The biosensing system cultured cardiomyocytes as physiologically relevant models, used interdigitated electrodes to detect the mechanical beating of the cardiomyocytes, and employed MNDA analysis to recognize drug-induced arrhythmia from the cardiomyocyte beating recording. The best performing MNDA parameter, approximate entropy, enabled the system to recognize the appearance of sertindole- and norepinephrine-induced arrhythmia in the recording. The MNDA reconstruction in phase space enabled the system to classify the different arrhythmias and quantify the severity of arrhythmia. This new biosensing system utilizing MNDA provides a promising and alternative method for drug-induced arrhythmia recognition and classification in cardiological and pharmaceutical applications.

2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure" replaces the "2013 ACCF/AHA Guideline for the Management of Heart Failure" and the "2017 ACC/AHA/HFSA Focused Update of the 2013 ACCF/AHA Guideline for the Management of Heart Failure." The 2022 guideline is intended to provide patient-centric recommendations for clinicians to prevent, diagnose, and manage patients with heart failure.

METHODS

A comprehensive literature search was conducted from May 2020 to December 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from MEDLINE (PubMed), EMBASE, the Cochrane Collaboration, the Agency for Healthcare Research and Quality, and other relevant databases. Additional relevant clinical trials and research studies, published through September 2021, were also considered. This guideline was harmonized with other American Heart Association/American College of Cardiology guidelines published through December 2021. Structure: Heart failure remains a leading cause of morbidity and mortality globally. The 2022 heart failure guideline provides recommendations based on contemporary evidence for the treatment of these patients. The recommendations present an evidence-based approach to managing patients with heart failure, with the intent to improve quality of care and align with patients' interests. Many recommendations from the earlier heart failure guidelines have been updated with new evidence, and new recommendations have been created when supported by published data. Value statements are provided for certain treatments with high-quality published economic analyses.

Elevated Premature Ventricular Complex counts on 24-hour ECG predict incident atrial fibrillation and heart failure - A prospective population-based cohort study

Background

Objectives

Methods

Results

Conclusion

Prognostic Impact and Predictors of New-Onset Atrial Fibrillation in Heart Failure

Background: The prognostic impact and predictors of NOAF in HF patients are not fully elucidated. This study aims to determine whether new-onset atrial fibrillation (NOAF) affects patient outcome and investigate predictors of atrial fibrillation (AF) in acute heart failure (HF) patients using real-world data. Methods: The factors associated with NOAF in 2894 patients with sinus rhythm (SR) enrolled in the Korean Acute Heart Failure (KorAHF) registry were investigated. Survival was analyzed using AF as a time-dependent covariate. Relevant predictors of NOAF were analyzed using multivariate proportional hazards models. Results: Over 27.4 months, 187 patients developed AF. The median overall survival time was over 48 and 9.9 months for the SR and NOAF groups, respectively. Cox regression analysis with NOAF as a time-dependent covariate showed a higher risk of death among patients with NOAF. Multivariate Cox modeling showed that age, worsening HF, valvular heart disease (VHD), loop diuretics, lower heart rate, larger left atrium (LA) diameter, and elevated creatinine levels were independently associated with NOAF. Risk score indicated the number of independent predictors. The incidence of NOAF was 2.9%, 9.4%, and 21.8% in the low-risk, moderate-risk, and high-risk groups, respectively (p < 0.001). Conditional inference tree analysis identified worsening HF, heart rate, age, LA diameter, and VHD as discriminators. Conclusions: NOAF was associated with decreased survival in acute HF patients with SR. Age, worsening HF, VHD, loop diuretics, lower heart rate, larger LA diameter, and elevated creatinine could independently predict NOAF. This may be useful to risk-stratify HF patients at risk for AF.

Left Ventricular Remodeling in Non-syndromic Mitral Valve Prolapse: Volume Overload or Concomitant Cardiomyopathy?

Mitral valve prolapse (MVP) is a common valvular disorder that can be associated with mitral regurgitation (MR), heart failure, ventricular arrhythmias and sudden cardiac death. Given the prognostic impact of these conditions, it is important to evaluate not only mitral valve morphology and regurgitation, but also the presence of left ventricular (LV) function and remodeling. To date, several possible hypotheses have been proposed regarding the underlying mechanisms of LV remodeling in the context of non-syndromic MVP, but the exact pathophysiological explanation remains elusive. Overall, volume overload related to severe MR is considered the main cause of LV dilatation in MVP. However, significant LV remodeling has been observed in patients with MVP and no/mild MR, particularly in patients with bileaflet MVP or Barlow’s disease, generating several new hypotheses. Recently, the concept of “prolapse volume” was introduced, adding a significant volume load to the LV on top of the transvalvular MR volume. Another possible hypothesis is the existence of a concomitant cardiomyopathy, supported by the link between MVP and myocardial fibrosis. The origin of this cardiomyopathy could be either genetic, a second hit (e.g., on top of genetic predisposition) and/or frequent ventricular ectopic beats. This review provides an overview of the different mechanisms and remaining questions regarding LV remodeling in non-syndromic MVP. Since technical specifications of imaging modalities impact the evaluation of MR severity and LV remodeling, and therefore might influence clinical decision making in these patients, this review will also discuss assessment of MVP using different imaging modalities.

Selvester QRS Score Predicts Improvement of LVEF in Atrial Fibrillation Patients with Systolic Heart Failure

BACKGROUND

Left-ventricular systolic dysfunction (LVSD) comorbid with atrial fibrillation is reversible, but recovery is limited in a subset of patients. The Selvester QRS (S-QRS) score is an electrocardiogram-based assessment that reportedly reflects myocardial scar/damage. We evaluated the predictability of S-QRS score for the recovery of left-ventricular ejection fraction (LVEF) in persistent AF (PeAF) patients with LVSD undergoing catheter ablation (CA).

METHOD

CA was performed in 51 PeAF patients with reduced LVEF (<40%); S-QRS scores were measured after restoration of sinus rhythm. LVEF was re-evaluated at one year after CA; LVEF recovery was related to the S-QRS score.

RESULTS

The median [interquartile range] S-QRS score was 1 points [0-2]. LVEF increased from 32% [28-37] at baseline to 56% [49-57] at one year after CA. Thirty-seven patients achieved normalization of LVEF (≥50%, Group A); 14 patients did not (Group B). Group A had significantly lower S-QRS scores than Group B (0 point [0-2] vs. 2 points [2-3], p<0.05). In univariate/multivariate analyses, S-QRS score was an independent predictor of LVEF normalization. In the receiver operating characteristic curve, the cut-off value of S-QRS score was 2 points for prediction of the LVEF normalization (AUC = 0.75). Patients with low S-QRS score (<2 points) had greater LVEF improvement than those with high S-QRS score (≥2 points, ΔLVEF: 23% [17-28] vs. 17% [12-24], p<0.05).

CONCLUSION

S-QRS scoring non-invasively assesses the improvement of LVEF in PeAF patients with LVSD after CA. A high S-QRS score may indicate underlying myocardial scar/damage associated with unknown etiologies for LVSD other than PeAF. This article is protected by copyright. All rights reserved.

2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure

AIM

The "2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure" replaces the "2013 ACCF/AHA Guideline for the Management of Heart Failure" and the "2017 ACC/AHA/HFSA Focused Update of the 2013 ACCF/AHA Guideline for the Management of Heart Failure." The 2022 guideline is intended to provide patient-centric recommendations for clinicians to prevent, diagnose, and manage patients with heart failure.

METHODS

A comprehensive literature search was conducted from May 2020 to December 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from MEDLINE (PubMed), EMBASE, the Cochrane Collaboration, the Agency for Healthcare Research and Quality, and other relevant databases. Additional relevant clinical trials and research studies, published through September 2021, were also considered. This guideline was harmonized with other American Heart Association/American College of Cardiology guidelines published through December 2021.

STRUCTURE

Heart failure remains a leading cause of morbidity and mortality globally. The 2022 heart failure guideline provides recommendations based on contemporary evidence for the treatment of these patients. The recommendations present an evidence-based approach to managing patients with heart failure, with the intent to improve quality of care and align with patients' interests. Many recommendations from the earlier heart failure guidelines have been updated with new evidence, and new recommendations have been created when supported by published data. Value statements are provided for certain treatments with high-quality published economic analyses.