Usefulness of ventricular premature complexes to predict coronary heart disease events and mortality (from the Atherosclerosis Risk In Communities cohort)

Prevalence and predictors of mitral annular disjunction and ventricular ectopy in mitral valve prolapse

BACKGROUND

Mitral annular disjunction (MAD) is associated with ventricular arrhythmia in mitral valve prolapse (MVP). The proportional risk from MAD and other predictors of ventricular arrhythmia in MVP has not been well characterized.

OBJECTIVE

This study aimed to identify predictors of complex or frequent ventricular ectopy (cfVE) in MVP and to quantify risk of cfVE and mortality in MVP with MAD.

METHODS

We studied 632 adult patients with MVP on transthoracic echocardiography at the University of North Carolina Medical Center from 2016 to 2019 (median age, 64 [interquartile range, 52-74] years; 52.7% female; 16.3% African American). Resting and ambulatory electrocardiograms were used to identify cfVE.

RESULTS

MAD was present in 94 (14.9%) patients. Independent associations of MAD were bileaflet prolapse (odds ratio [95% CI], 4.25 [2.47-7.33]; P < .0001), myxomatous valve (2.17 [1.27-3.71]; P = .005), absence of hypertension (2.00 [1.21-3.32]; P = .007), electrocardiogram inferior or lateral lead T-wave inversion (2.07 [1.23-3.48]; P = .006), and female sex (1.99 [1.21-3.25]; P = .006). cfVE was frequent with MAD (39 [41.5%] vs 93 [17.3%] without; P < .0001). Independent cfVE predictors were MAD (hazard ratio [95% CI], 2.23 [1.47-3.36]; P = .0001), bileaflet prolapse (1.86 [1.25-2.76]; P = .002), heart failure (1.79 [1.16-2.77]; P = .009), lower left ventricular ejection fraction (0.14 [0.03-0.61]; P = .009), coronary artery disease (1.60 [1.05-2.43]; P = .03), and inferior or lateral lead T-wave inversion (1.51 [1.03-2.22]; P = .03). After a median of 40 (33-48) months, there was increased mortality with MAD (P = .04).

CONCLUSION

MAD in MVP is associated with bileaflet or myxomatous MVP, absence of hypertension, T-wave inversion, and female sex. There is increased cfVE and mortality with MAD, highlighting the need for closer follow-up of these patients.

Can the efficacy of a medical treatment be predicted based on the type of idiopathic premature ventricular contraction?

BACKGROUND

Premature ventricular contractions (PVCs) are common arrhythmias with diverse clinical implications. This retrospective study aimed to evaluate the efficacy of medical treatments using various clinical, imaging, and electrocardiographic parameters in patients with idiopathic PVCs.

METHODS

A total of 1051 patients with idiopathic PVCs were retrospectively analyzed. Patients were categorized into three groups based on treatment response: beta-blocker (BB) responders (479 patients), calcium-channel blocker (CCB) responders (335 patients), and class 1c antiarrhythmic (AA) responders (237 patients). Clinical, imaging, and electrocardiographic data were collected and analyzed to assess the factors influencing treatment response.

RESULTS

Age, left ventricular ejection fraction (LVEF), PVC QRS duration, CI variability, and multiple PVC morphologies were identified as significant factors affecting treatment response. Older age and lower LVEF were associated with better response to BB treatment, whereas CCB responders showed narrower QRS complexes. BB responders also exhibited higher CI variability, possibly linked to automaticity mechanisms. Moreover, the BB responder group had a higher frequency of multiple PVC morphologies.

CONCLUSION

These findings emphasize the importance of tailored treatment approaches based on individual patient characteristics.

[Ventricular tachycardia-without structural heart disease: History]

This article focuses on ventricular arrythmias without evidence for structural heart disease. There are many different reasons for this type of arrythmia and there is still a gap of knowledge. Starting with the first description of this disease, we present the diagnosis and management with medication, and finally catheter ablation procedures from the beginning to how it is currently treated and how it possibly will be treated in the near future.

Association between cardiac arrhythmia before pregnancy and gestational diabetes: a nationwide population-based study in Korea

Given the higher prevalence of cardiac arrhythmias in individuals with diabetes, we investigated the relationship between cardiac arrhythmias and the incidence of gestational diabetes (GDM). This retrospective cohort study utilized data from the Korean Health Insurance Service database, encompassing 1,113,729 women who gave birth between January 2007 and December 2015. After excluding those who did not undergo National Health Screening tests within 1 year prior to pregnancy, those with multifetal pregnancies, and those diagnosed with diabetes, we analyzed 365,880 singleton pregnancies without a history of diabetes. Of these, 3,253 (0.9%) had cardiac arrhythmias, including premature extra beats, supraventricular tachyarrhythmias, and/or atrial flutter/fibrillation. GDM occurred in 31,938 (8.7%) subjects during pregnancy, and was more prevalent in women with cardiac arrhythmia than in those without (14.9% vs. 8.7%, p<0.001). In the multivariate analysis, the association between cardiac arrhythmia and GDM remained statistically significant (adjusted odds ratio, 1.78; 95% CI, 1.615-1.970; p<0.001). Subgroup analysis revealed that the risk of GDM was consistently statistically significant in subjects with cardiac arrhythmia, regardless of age, body mass index, and the presence or absence of chronic hypertension. Therefore, cardiac arrhythmias before and during pregnancy appear to be associated with an increased risk of developing GDM.

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.

Risk of atrial fibrillation among patients with premature ventricular complexes: a systematic review and meta-analysis of cohort studies

INTRODUCTION

Atrial fibrillation (AF) is more likely found in patients with premature ventricular complexes (PVCs). Nonetheless, the outcomes of previous investigations remain inconclusive. To evaluate the link between PVCs and the risk of AF, we did a systematic review and meta-analysis.

EVIDENCE ACQUISITION

Potentially eligible studies were found by searching for published publications indexed in the MEDLINE and EMBASE databases from inception to April 13, 2021, looking for studies that assessed the risk of AF in patients with PVCs vs. those who did not have PVCs. Dersimonian and Laird's random-effect, generic inverse variance technique was used to calculate the pooled risk ratio (RR) and 95% confidence interval (CI).

EVIDENCE SYNTHESIS

The meta-analysis includes 6 cohort studies (1 prospective and 5 retrospective cohort studies) with a total of 9,662,088 individuals. We found that patients with PVCs have a significantly higher risk of AF than individuals without PVCs with the pooled RR of 1.90 (95% CI: 1.51-2.39, I²=83%).

CONCLUSIONS

PVCs are significantly related with a 1.90-fold higher incidence of AF, according to the present systematic review and meta-analysis. Nonetheless, further research is needed to determine how this connection should be treated in clinical practice if it is causal.

Relationship between premature ventricular complexes and stroke mortality in the general population

OBJECTIVES

Predictors for increased stroke mortality identify those who may need closer monitoring and better hospital care. While the link between premature ventricular complexes (PVCs) and incident ischemic stroke has been reported, studies on the association with fatal stroke are non-existent.

MATERIALS AND METHODS

We examined the association of PVCs with stroke mortality in 8047 participants (56.5 ± 0.39 years, 53% women, 80.9% Non-Hispanic Whites) without prior history of stroke from the Third National Health and Nutrition Examination Survey. National Death Index was used to identify the date and cause of death. PVCs were detected from 12‑lead standard electrocardiograms. Cox proportional hazard analysis was used to examine the association between any PVC with stroke mortality.

RESULTS

Approximately 2.1% (n = 134) participants had PVCs at baseline. Over a median follow-up of 22 years, 337 fatal strokes occurred. More strokes occurred in participants with baseline PVCs compared to those without (unadjusted cumulative incidence of stroke 9.5% vs. 2.5% respectively, p-value 0.001). In a multivariable-adjusted model, the presence of PVC was associated with an increased risk of stroke mortality (HR (95%CI): 2.50 (1.15-5.43). This association was stronger in participants with coronary heart disease (CHD) than those without it (HR (95%CI): 5.98 (2.2-16.2) vs. 1.97 (0.75-5.1) respectively; interaction-p = 0.008).

CONCLUSIONS

PVCs are associated with an increased risk of stroke mortality, especially among individuals with CHD. Whether improved hospital care or modifying PVCs could change outcomes should be examined in prospective studies.

Left and Right PVC-Induced Ventricular Dysfunction

BACKGROUND

Frequent premature ventricular complexes (PVCs) can result in a reversible form of cardiomyopathy that usually affects the left ventricle (LV).

OBJECTIVES

The objective of this study was to assess whether frequent PVCs have an impact on right ventricular (RV) function.

METHODS

Serial cardiac magnetic resonance (CMR) studies were performed in a series of 47 patients before and after ablation of frequent PVCs.

RESULTS

Patients with RV cardiomyopathy (ejection fraction [EF] <0.45) had more frequent PVCs than did patients without decreased RV function (23% ± 11% vs 15% ± 11%, P = 0.03). Likewise, patients with LV cardiomyopathy (EF <0.50) had more frequent PVCs than did patients without decreased LV function (23% ± 10% vs 14% ± 12%, P = 0.003). LV dysfunction was present in 21 patients (45%). In patients with LV dysfunction, 15 patients (32%) had biventricular dysfunction, and 6 patients (13%) had isolated LV dysfunction. A total of 19 patients (40%) had RV dysfunction, and 4 of the patients with RV dysfunction (9%) had isolated RV dysfunction. Cardiac magnetic resonance was repeated 1.9 ± 1.3 years after ablation. In patients with successful ablation, RV function improved, and in patients without successful ablation, RV function did not significantly change (before and after ablation RVEF 0.45 ± 0.09 and 0.52 ± 0.09; P < 0.001 vs. 0.46 ± 0.07 and 0.48 ± 0.04; P = 0.14, respectively).

CONCLUSIONS

Frequent PVCs can cause RV cardiomyopathy that parallels LV cardiomyopathy and is reversible with successful ablation.

Efficacy and safety of Xinmai'an tablet in treatment of premature ventricular contractions due to coronary heart disease: A protocol for systematic review and meta-analysis

BACKGROUND

Coronary heart disease (CHD) is the leading cause of human death in the world and a public health problem of global concern. As a common arrhythmia in CHD, premature ventricular contractions are very likely to progress to fatal arrhythmias, resulting in serious adverse consequences. At present, the treatment of premature ventricular contractions due to CHD mainly focuses on catheter ablation, beta-blockers and antiarrhythmics. Both require ongoing monitoring because relapses may lead to redevelopment of cardiomyopathy, and there are varying degrees of indications and side effects. Several clinical studies have shown that Xinmai'an can effectively control the occurrence of premature ventricular contractions and reduce the risk of recurrence. However, there is currently no systematic review evaluating its effectiveness. Therefore, the purpose of this study is to provide strong evidence-based medical evidence for Xinmai'an tablet in the treatment of premature ventricular contractions due to CHD.

METHODS

We will search the main Chinese and English databases from inception to June 5, 2022. And identified as the randomized controlled trials. In addition, a reference list of studies meeting the inclusion criteria will be retrieved. Two researchers will conduct literature screening and quality evaluation. And we will conduct bias risk assessment and sensitivity analysis. The analysis software uses RevMan 5.3.

RESULTS

Mainly by observing the number of ventricular premature beat attacks (24-hour holter monitoring electrocardiogram), electrocardiogram efficacy (ST segment and T wave changes) and echocardiogram assesses the structure and function of the left and right ventricular, left ventricular ejection fraction, etc. To evaluate the clinical effect of Xinmai'an on premature ventricular contractions due to CHD.

CONCLUSION

The results of this study will provide a basis for the selection of treatment options for premature ventricular contractions due to CHD.

FRONTAL QRS-T AÇISI İLE AMBULATUAR 24 SAAT HOLTERDE PREMATÜR VENTRİKÜLER KONTRAKSİYON YÜKÜ ARASINDAKİ İLİŞKİ

AMAÇ Sık prematür ventriküler kontraksiyonlar (PVK), ventriküler fonksiyonun bozulmasına veya ventriküler kavitelerin genişlemesine neden olabilir. Frontal düzlem QRS-T [f(QRS-T)] açısı, miyokardın elektrofizyolojik özelliklerindeki kararsızlığın bir göstergesidir ve aritmilerle ilişkilidir. Bu çalışma, ventriküler repolarizasyon heterojenitesinin bir belirteci olarak f(QRS-T) açısının, ambulatuar 24 saatlik holterde prematüre ventriküler kontraksiyon yükünü tahmin edip etmediğini araştırmayı amaçlamıştır. METHOD Çalışmada 100 hasta mevcuttu. Hastalar 24 saatlik Holter izleminde PVK yüklerine göre “sık PVK” ve “nadir PVK” olarak iki gruba ayrıldı. Laboratuar ve frontal plan QRS-T açısı dahil olmak üzere bazı ambulatuar elektrokardiyografi parametreleri iki grup arasında karşılaştırıldı. BULGULAR Frontal QRS-T açısı (63.34±37.86°'ye karşı 23.46±14.29° p

Ventricular Premature Complexes and Their Associated Factors in a General Population of Japanese Men

Increased ventricular premature complexes (VPCs) are associated with a higher risk of cardiac morbidities. However, little information is available on the risk factors of Western general populations. Therefore, we aimed to assess the frequency and associated factors of VPCs in healthy general Japanese men. We conducted a population-based cross-sectional study in 517 men, aged 40 to 79 years, using 24-hour Holter electrocardiography. Age, body mass index, height, low-density lipoprotein cholesterol, triglycerides, high-density lipoprotein cholesterol, resting heart rate, diabetes mellitus, hypertension, physical activity, smoking, alcohol consumption, lipid-lowering therapy were included in multivariable negative binomial regression to assess independent correlates for the number of VPCs per hour. We observed at least 1 VPC in 1 hour in 429 men (83%). In multivariable negative binomial regression adjusted for all covariates simultaneously, age (risk ratio [95% confidence interval] 1.91 [1.56 to 2.33] per 1-SD increment), height (1.17 [1.04 to 1.49] per 1-SD increment), resting heart rate(1.34 [1.02 to 1.77] per 1-SD increment), diabetes mellitus (2.36 [1.17 to 4.76] ), hypertension (1.90 [1.03 to 3.50]), physical activity (0.67 [0.47 to 0.97] ), current smoking (4.23 [1.86 to 9.60] ), past smoking (2.08 [1.03 to 4.19] ), current light alcohol consumption (0.16 [0.04 to 0.64] ), and lipid-lowering therapy (0.47 [0.23 to 0.96] ) were independently associated with VPCs frequency. In conclusion, VPCs frequency was independently associated with age, height, resting heart rate, diabetes mellitus, hypertension, physical activity, smoking, alcohol consumption, and lipid-lowering therapy.

Developing a Mechanistic Approach to Sudden Death Prevention in Mitral Valve Prolapse

Sudden cardiac death (SCD) from ventricular fibrillation (VF) can occur in mitral valve prolapse (MVP) in the absence of other comorbidities including mitral regurgitation, heart failure or coronary disease. Although only a small proportion with MVP are at risk, it can affect young, otherwise healthy adults, most commonly premenopausal women, often as the first presentation of MVP. In this review, we discuss arrhythmic mechanisms in MVP and mechanistic approaches for sudden death risk assessment and prevention. We define arrhythmogenic or arrhythmic MVP (AMVP) as MVP associated with complex and frequent ventricular ectopy, and malignant MVP (MMVP) as MVP with high risk of SCD. Factors predisposing to AMVP are myxomatous, bileaflet MVP and mitral annular disjunction (MAD). Data from autopsy, cardiac imaging and electrophysiological studies suggest that ectopy in AMVP is due to inflammation, fibrosis and scarring within the left ventricular (LV) base, LV papillary muscles and Purkinje tissue. Postulated mechanisms include repetitive injury to these regions from systolic papillary muscle stretch and abrupt mitral annular dysmotility (excursion and curling) and diastolic endocardial interaction of redundant mitral leaflets and chordae. Whereas AMVP is seen relatively commonly (up to 30%) in those with MVP, MVP-related SCD is rare (2-4%). However, the proportion at risk (i.e., with MMVP) is unknown. The clustering of cardiac morphological and electrophysiological characteristics similar to AMVP in otherwise idiopathic SCD suggests that MMVP arises when specific arrhythmia modulators allow for VF initiation and perpetuation through action potential prolongation, repolarization heterogeneity and Purkinje triggering. Adequately powered prospective studies are needed to assess strategies for identifying MMVP and the primary prevention of SCD, including ICD implantation, sympathetic modulation and early surgical mitral valve repair. Given the low event rate, a collaborative multicenter approach is essential.

Diagnostic and prognostic significance of premature ventricular complexes in community and hospital-based participants: A scoping review

BACKGROUND

While there are published studies that have examined premature ventricular complexes (PVCs) among patients with and without cardiac disease, there has not been a comprehensive review of the literature examining the diagnostic and prognostic significance of PVCs. This could help guide both community and hospital-based research and clinical practice.

METHODS

Scoping review frameworks by Arksey and O'Malley and the Joanna Briggs Institute (JBI) were used. A systematic search of the literature using four databases (CINAHL, Embase, PubMed, and Web of Science) was conducted. The review was prepared adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Extension for Scoping Review (PRISMA-ScR).

RESULTS

A total of 71 relevant articles were identified, 66 (93%) were observational, and five (7%) were secondary analyses from randomized clinical trials. Three studies (4%) examined the diagnostic importance of PVC origin (left/right ventricle) and QRS morphology in the diagnosis of acute myocardial ischemia (MI). The majority of the studies examined prognostic outcomes including left ventricular dysfunction, heart failure, arrhythmias, ischemic heart diseases, and mortality by PVCs frequency, burden, and QRS morphology.

CONCLUSIONS

Very few studies have evaluated the diagnostic significance of PVCs and all are decades old. No hospital setting only studies were identified. Community-based longitudinal studies, which make up most of the literature, show that PVCs are associated with structural and coronary heart disease, lethal arrhythmias, atrial fibrillation, stroke, all-cause and cardiac mortality. However, a causal association between PVCs and these outcomes cannot be established due to the purely observational study designs employed.

Extrasystolic arrhythmia: is it an additional risk factor of atherosclerosis?

BACKGROUND

Extrasystolic arrhythmia is not included in the list of risk factors of atherosclerosis. The aim of this investigation was to determine the relationship between atherosclerosis of main arteries and extrasystolic arrhythmia.

METHODS

We included 286 patients in our investigation. We performed 24-hours ECG monitoring, blood lipids analysis, transthoracic echocardiography, ultrasound Doppler of brachiocephalic arteries, abdominal aorta branches, lower extremities arteries, renal arteries. If prescribed we performed stress echocardiography, transesophageal echocardiography, coronary angiography, renal arteries angiography, pancerebral angiography. So, the investigation was made for the active revealing of atherosclerotic signs. The main parameters of heart biomechanics and main arteries kinetics we calculated using apexcardiography and sphygmography and included: speed, acceleration, power, work in each phase of the cardiocycle by apexcardiography, as well as in period of prevalence of inflow over outflow and in period of prevalence of outflow over inflow in sphygmography. All the patients were divided into two main groups according to the quantity of extrasystoles per 24 hours: 1 group - less than 3000, 2 group -3000 extrasystoles and more per 24 hours.

RESULTS

We determined that the atherosclerotic process was more advanced and more often the group 2. The atherosclerosis was more severe in patients with extrasystoles before the mitral valve opening and in fast ventricles' filling phase in cardiocycle. The main parameters of heart biomechanics and main arteries kinetics (speed, acceleration, power, work) calculated by apexcardiography and sphygmography increased with the further tendency: if earlier extrasystole appears in cardiocycle, than more changes were observed. Analyzing the methods of physics for fluid movement - Newton equation for liquids and Reynold number - we demonstrated that in extrasystolic arrhythmia in first post-extrasystolic wave there are the conditions for the turbulent blood flow that can cause the onset and progressing of atherosclerotic process.

CONCLUSIONS

Extrasystolic arrhythmia is an additional risk factor of main arteries atherosclerosis. Especially this thesis is fair for the extrasystoles that appear in cardiocycle before the mitral valve opening and in fast ventricles' filling phase.

Association of premature ventricular complexes and risk of ischemic stroke: A systematic review and meta-analysis

Recent studies have suggested that patients with premature ventricular complexes (PVCs) may have a higher risk of ischemic stroke. However, the data are limited and inconclusive. We conducted a systematic review and meta‐analysis to investigate the association between PVCs and the risk of ischemic stroke. A comprehensive literature review was conducted by searching for published articles indexed in MEDLINE and EMBASE databases from inception through September 25, 2020, to identify studies that compared the risk of ischemic stroke between patients with PVCs and individuals without PVCs. Pooled risk ratio (RR) and 95% confidence interval (CI) were calculated using a random‐effect, generic inverse variance method of Dersimonian and Laird. A total of four observational studies (2 prospective and 2 retrospective cohort studies) with 42 677 participants met the eligibility criteria and were included in the meta‐analysis. We found that patients with PVCs have a significantly higher risk of ischemic stroke than individuals without PVCs with the pooled RR of 1.31 (95% CI, 1.07–1.60, I² = 43%). From our systematic review and meta‐analysis, we found that PVCs are associated with a higher risk of ischemic stroke. Whether this association is causal and how it should be addressed in clinical practice require further investigations.

Using mathematics to diagnose, cure, and predict cardiac arrhythmia

Mathematics can be used to analyze and model cardiac arrhythmia. I discuss three different problems. (1) Diagnosis of atrial fibrillation based on the time intervals between subsequent beats. The probability density histograms of the differences of the intervals between consecutive beats have characteristic shapes for atrial fibrillation. (2) Curing atrial fibrillation by ablation of the core of rotors. Recent clinical studies have proposed that ablating the core of rotors in atrial tissue can cure atrial fibrillation. However, the claims are controversial. One problem that arises relates to difficulties associated with developing algorithms to identify the core of rotors. In model tissue culture systems, heterogeneity in the structure makes it difficult to unambiguously locate the core of rotors. (3) Risk stratification for sudden cardiac death (SCD). Despite numerous clinical studies, there is still a need for improved criteria to assess the risk of SCD. I discuss the possibility of using the dynamics of premature ventricular complexes to help make predictions. The development of wearable devices to record and analyze cardiac rhythms offers new prospects for the diagnosis and treatment of cardiac arrhythmia.

Establishing reference ranges for ambulatory electrocardiography parameters: meta-analysis

Objective

Despite the widespread and increasing use of ambulatory electrocardiography (ECG), there is no consensus on reference ranges for ambulatory electrocardiogram parameters to guide interpretation. We sought to determine population distribution-based reference ranges for parameters measured during ambulatory electrocardiogram in healthy adults, based on existing literature.

Methods

We searched multiple databases from 1950 to 2020. Articles reporting original data from ≥24-hour ambulatory electrocardiogram monitoring in healthy adults were included. Data extraction and synthesis were performed according to Meta-analysis of Observational Studies in Epidemiology guidelines. The prevalence/mean and SD for common parameters (sinus pauses, conduction abnormalities and ectopy) were extracted by age group (18–39, 40–59, 60–79 and 80+ years).

Results

We identified 33 studies involving 6466 patients. Sinus pauses of >3 s were rare (pooled prevalence <1%) across all ages. Supraventricular ectopy of >1000/24 hours increased with age, from 0% (95% CI 0% to 0%) in those aged 18–39 years to 6% (95% CI 0% to 17%) in those aged 60–79 years. Episodes of supraventricular tachycardia increased from 3% (95% CI 1% to 6%) in those aged 18–39 years to 28% (95% CI 9% to 52%) in those aged 60–79 years. Ventricular ectopy of >1000/24 hours also increased with age, from 1% (95% CI 0% to 2%) in those aged 18–39 years to 5% (95% CI 1% to 10%) in those aged 60–79 years. Episodes of non-sustained ventricular tachycardia ranged from 0% (95% CI 0% to 1%) in those aged 18–39 years to 2% (95% CI 0% to 5%) in those aged 60–79 years.

Conclusion

Despite the limitations of existing published data, this meta-analysis provides evidence-based reference ranges for ambulatory electrocardiogram parameters and highlights significant age-dependent differences that should be taken into account during interpretation.

Evaluation and Management of Premature Ventricular Complexes

Premature ventricular complexes (PVCs) are extremely common, found in the majority of individuals undergoing long-term ambulatory monitoring. Increasing age, a taller height, a higher blood pressure, a history of heart disease, performance of less physical activity, and smoking each predict a greater PVC frequency. Although the fundamental causes of PVCs remain largely unknown, potential mechanisms for any given PVC include triggered activity, automaticity, and reentry. PVCs are commonly asymptomatic but can also result in palpitations, dyspnea, presyncope, and fatigue. The history, physical examination, and 12-lead ECG are each critical to the diagnosis and evaluation of a PVC. An echocardiogram is indicated in the presence of symptoms or particularly frequent PVCs, and cardiac magnetic resonance imaging is helpful when the evaluation suggests the presence of associated structural heart disease. Ambulatory monitoring is required to assess PVC frequency. The prognosis of those with PVCs is variable, with ongoing uncertainty regarding the most informative predictors of adverse outcomes. An increased PVC frequency may be a risk factor for heart failure and death, and the resolution of systolic dysfunction after successful catheter ablation of PVCs demonstrates that a causal relationship can be present. Patients with no or mild symptoms, a low PVC burden, and normal ventricular function may be best served with simple reassurance. Either medical treatment or catheter ablation are considered first-line therapies in most patients with PVCs associated with symptoms or a reduced left ventricular ejection fraction, and patient preference plays a role in determining which to try first. If medical treatment is selected, either β-blockers or nondihydropyridine calcium channel blockers are reasonable drugs in patients with normal ventricular systolic function. Other antiarrhythmic drugs should be considered if those initial drugs fail and ablation has been declined, has been unsuccessful, or has been deemed inappropriate. Catheter ablation is the most efficacious approach to eradicate PVCs but may confer increased upfront risks. Original research remains necessary to identify individuals at risk for PVC-induced cardiomyopathy and to identify preventative and therapeutic approaches targeting the root causes of PVCs to maximize effectiveness while minimizing risk.

Chinese Herbal Medicine Dingji Fumai Decoction for Ventricular Premature Contraction: A Real-World Trial

Background

Chinese herbal medicine Dingji Fumai Decoction (DFD) is widely clinically used for ventricular premature contraction (VPC). This real-word trial was designed to assess the safety and effectiveness of DFD for VPC.

Methods

This was a double-blinded, randomized placebo-controlled trial. Patients with VPC were randomized (1 : 1) to treatment with DFD combined with metoprolol (DFD arm) or metoprolol combined with placebo (MET arm). A primary end point was a composite of clinical symptoms and signs determined by the traditionalChinese medicine syndrome score and the number of VPC determined by the Holter examination. Second outcomes were adverse events, medication compliance, and laboratory examination.

Results

144 patients were randomized to DFD arm (76 patients) or MET arm (68 patients), and 136 cases (71 in DFD arm and 65 in MET arm) finally completed this trial. After a 12-week follow-up, DFD arm significantly decreased traditional Chinese medicine syndrome score and the number of VPC compared with MET arm (P = 0.003 and 0.034, respectively). There was no adverse drug effect and patient medication compliance was good.

Conclusions

Superiority with DFD arm for VPC was demonstrated over MET arm for both the safety and effectiveness end points.

The Ubiquitous Premature Ventricular Complex

Premature ventricular complexes (PVCs) are one of the most commonly encountered arrhythmias and are ubiquitous in clinical practice, both in the outpatient and inpatient settings. They are often discovered incidentally in asymptomatic patients, however, can cause myriad symptoms acutely and chronically. Long thought to be completely benign, PVCs have been historically disregarded without pursuing any further evaluation. Newer data have revealed that a high burden of PVCs with specific characteristics can significantly increase a patient's risk of developing PVC-induced cardiomyopathy. The aim of this literature review is to provide further clarification on the identification of high-risk PVCs, subsequent workup, and the currently available treatment options. PVCs arise from an ectopic focus within the ventricles. Patients with PVCs can be either asymptomatic or have severe disabling symptoms. The diagnostic workup for PVCs includes electrocardiogram (ECG) and 24-h Holter monitor to assess the QRS morphology and its frequency. A transthoracic echocardiogram (TTE) is done to look for structural heart disease and cardiomyopathy. Management of PVCs should be focused on identifying and treating the underlying causes, such as electrolyte abnormalities, substance use, and underlying structural heart disease. Beta-blockers are first-line therapy for symptomatic PVCs. Nondihydropyridine calcium channel blockers, classic antiarrhythmic agents, and amiodarone can be considered as second-line agents. Patients who are unable to tolerate medical therapy should undergo catheter ablation of the PVC focus to prevent PVC-induced cardiomyopathy. PVCs are common in clinical practice, and it is vital to identify patients at higher risk for PVC-induced cardiomyopathy to facilitate early intervention. Patients with no evidence of structural heart disease and infrequent PVCs should be monitored closely, while those who are symptomatic should be treated medically. For those who have failed medical therapy, catheter ablation of the PVCs focus is recommended. Catheter ablation has been shown to reduce PVCs burden and improve left ventricular ejection fraction (LVEF) in those with PVC-induced cardiomyopathy.

Arrhythmic Risk in Elderly Patients Candidates to Transcatheter Aortic Valve Replacement: Predictive Role of Repolarization Temporal Dispersion

Background/Aim

Degenerative aortic valve stenosis (AS) is associated to ventricular arrhythmias and sudden cardiac death, as well as mental stress in specific patients. In such a context, substrate, autonomic imbalance as well as repolarization dispersion abnormalities play an undoubted role. Aim of the study was to evaluate the increase of premature ventricular contractions (PVC) and complex ventricular arrhythmias during mental stress in elderly patients candidate to the transcatheter aortic valve replacement (TAVR).

Methods

In eighty-one elderly patients with AS we calculated several short-period RR- and QT-derived variables at rest, during controlled breathing and during mild mental stress, the latter being represented by a mini-mental state evaluation (MMSE).

Results

All the myocardial repolarization dispersion markers worsened during mental stress (p < 0.05). Furthermore, during MMSE, low frequency component of the RR variability increased significantly both as absolute power (LF_RR) and normalized units (LF_{RRN U}) (p < 0.05) as well as the low-high frequency ratio (LF_RR/HF_RR) (p < 0.05). Eventually, twenty-four (30%) and twelve (15%) patients increased significantly PVC and, respectively, complex ventricular arrhythmias during the MMSE administration. At multivariate logistic regression analysis, the standard deviation of QTend (QTe_sd), obtained at rest, was predictive of increased PVC (odd ratio: 1.54, 95% CI 1.14-2.08; p = 0.005) and complex ventricular arrhythmias (odd ratio: 2.31, 95% CI 1.40-3.83; p = 0.001) during MMSE. The QTe_sd showed the widest sensitive-specificity area under the curve for the increase of PVC (AUC: 0.699, 95% CI: 0.576-0.822, p < 0.05) and complex ventricular arrhythmias (AUC: 0.801, 95% CI: 0.648-0.954, p < 0.05).

Conclusion

In elderly with AS ventricular arrhythmias worsened during a simple cognitive assessment, this events being a possible further burden on the outcome of TAVR. QTe_sd might be useful to identify those patients with the highest risk of ventricular arrhythmias. Whether the TAVR could led to a QTe_sd reduction and, hence, to a reduction of the arrhythmic burden in this setting of patients is worthy to be investigated.

[Premature ventricular contractions and tachycardia in a structurally normal heart : Idiopathic PVC and VT]

Premature ventricular contractions (PVC) are a common, often incidental and mostly benign finding. Treatment is indicated in frequent and symptomatic PVC or in cases of worsening of left ventricular function. Idiopathic ventricular tachycardia (VT) is mostly found in patients with a structurally healthy heart. These PVC/VT usually have a focal origin. The most likely mechanism is delayed post-depolarization. Localization of the origin is based on the creation of an activation map with or without combination of pace mapping. Idiopathic PVC/VT are most frequently located on the outflow tracts of the right and left ventricles, including the aortic root. Other typical locations include the annulus of the tricuspid or mitral valve, papillary muscles and Purkinje fibers. Catheter ablation is an alternative to antiarrhythmic medication in symptomatic monomorphic PVC/VT. The success rate is good whereby mapping and ablation can often represent a challenge. This article is the fifth part of a series dedicated to specific advanced training in the field of special rhythmology and invasive electrophysiology. It describes the pathophysiological principles, types and typical findings that can be obtained during an electrophysiological investigation.

Dietary intervention with a specific micronutrient combination for the treatment of patients with cardiac arrhythmias: the impact on insulin resistance and left ventricular function

Background

Cardiac arrhythmias (CA) are very common and may occur with or without heart disease. Causes of these disturbances can be components of the metabolic syndrome (MetS) or deficits of micronutrients especially magnesium, potassium, B vitamins and coenzyme Q10. Both causes may also influence each other. Insulin resistance (IR) is a risk factor for diastolic dysfunction. One exploratory outcome of the present pilot study was to assess the impact of a dietary intervention with specific micronutrients on the lowering of IR levels in patients with CA with the goal to improve the left ventricular (LV) function.

Methods

This was a post hoc analysis of the randomized double blind, placebo-controlled pilot study in patients with CA (VPBs, SVPBs, SV tachycardia), which were recruited using data from patients who were 18–75 years of age in an Outpatient Practice of Cardiology. These arrhythmias were assessed by Holter ECG and LV function by standard echocardiography. Glucose metabolism was measured by fasting glucose, fasting insulin level and the Homeostasis Model Assessment of IR (HOMA-IR) at baseline and after 6 weeks of dietary supplementation.

Results

A total of 54 randomized patients with CA received either a specific micronutrient combination or placebo. Dietary intervention led to a significant decrease in fasting insulin ≥58 pmol/l (p = 0.020), and HOMA-IR (p = 0.053) in the verum group after 6 weeks. At the same time, parameters of LV diastolic function were improved after intervention in the verum group: significant reduction of LV mass index (p = 0.003), and in tendency both a decrease of interventricular septal thickness (p = 0.053) as well as an increase of E/A ratio (p = 0.051). On the other hand, the premature beats (PBs) were unchanged under verum.

Conclusions

In this pilot study, dietary intervention with specific micronutrient combination as add-on to concomitant cardiovascular drug treatment seems to improve cardio metabolic health in patients with CA. Further studies are required.

Study registration

The study was approved by the Freiburg Ethics Commission International and was retrospectively registered with the U.S. National Institutes of Health Clinical Trials gov ID NCT 02652338 on 16 December 2015.

Prognostic significance of frequent premature ventricular complex early after implantation among patients with implantable cardioverter defibrillator

BACKGROUND

Premature ventricular complex (PVC) was mainly studied by 24-hour Holter in previous studies. However, the value of long-term Home Monitoring of PVC burden early after ICD implantation is unknown.

METHODS

The data of 416 patients with ICD were analyzed. The percentage of days with frequent PVC (≥10/h) within 30th-90th days was calculated as the continuous frequent PVC (CfPVC) percentage. ROC curve of CfPVC percentages was plotted. Kaplan-Meier survival and Cox regression were used to assess the cumulative risks.

RESULTS

Based on ROC curves, the cut-off value for the CfPVC percentage was 40%. According to Kaplan-Meier analysis and multivariate Cox regression analysis, CfPVC percentage ≥40% was an independent predictor of higher incidences of VAEs, appropriate ATP, appropriate shocks, and cardiac death.

CONCLUSION

A long-term continuous burden of frequent PVC with CfPVC percentage ≥40% can be a predictor of future VAEs, appropriate ATP, appropriate shocks and cardiac death in ICD recipients.

Coupling interval variability of premature ventricular contractions in patients with different underlying pathology: an insight into the arrhythmia mechanism

Purpose

Coupling interval (CI) variability of premature ventricular contractions (PVCs) is influenced by the underlying arrhythmia mechanism. The aim of this study was to compare CI variability of PVCs in different myocardial disease entities, in order to gain insight into their arrhythmia mechanism.

Methods

Sixty-four patients with four underlying pathologies were included: idiopathic (n = 16), non-ischemic dilated cardiomyopathy (NIDCM) (n = 16), familial cardiomyopathy (PLN/LMNA) (n = 16), and post-MI (n = 16)-associated PVCs. The post-MI group was included as a reference, on account of its known re-entry mechanism. On Holter registrations, the first 20 CIs of the dominant PVC morphology were measured manually after which median ΔCI and mean SD of CI/√R-R (= CI of PVC corrected for underlying heart rate) were obtained. Two observers independently measured PVC CIs on pre-selected Holter registrations in order to determine inter- and intra-observer reliability.

Results

The largest ΔCI was seen in the PLN/LMNA group (220 ms (120–295)), the lowest in the idiopathic group (120 ms (100–190)). The ΔCI in the PLN/LMNA group was significantly larger than the post-MI group (220 ms (120–295) vs 130 ms (105–155), p = 0.023). Mean SD of CI/√R-R in the PLN/LMNA group was also significantly higher than in the post-MI group (p = 0.044). Inter- and intra-observer reliability was good (ICC = 0.91 vs 0.86 and 0.96 vs 0.77, respectively).

Conclusions

Low ΔCI and SD of CI/√R-R of idiopathic and NIDCM PVCs suggest that the underlying arrhythmia mechanisms might be re-entry or triggered activity. Abnormal automaticity or modulated parasystole are unlikely mechanisms. High CI variability in PLN/LMNA patients suggests that the re-entry and triggered activity are less likely mechanisms in this group.

Electronic supplementary material

The online version of this article (10.1007/s10840-017-0309-8) contains supplementary material, which is available to authorized users.

Premature Ventricular Complex is More Prevalent During Acute Exacerbated than Stable States of Chronic Obstructive Pulmonary Disease, and Is Related to Cardiac Troponin T

During acute exacerbation of chronic obstructive pulmonary disease (AECOPD), myocardial stress may be aggravated. Sparse data exist concerning the prevalence and correlates of cardiac arrhythmias in the stable and exacerbated states of COPD. We hypothesized that AECOPD is associated with increased prevalence of cardiac arrhythmias independent of COPD-severity and co-morbidity, and explored possible mechanisms. A 24-hour Holter recording was obtained in 74 patients with stable COPD and 45 patients with AECOPD (mean age 54 years, 56% women). Any incidence of supraventricular tachycardia (SVT), frequent premature ventricular complex (PVC, >30/hour) and complex ventricular ectopy (bigeminy, trigeminy or non-sustained ventricular tachycardia) was recorded and compared between the two groups. Adjustments were made for by stable disease-related co-variates (demography, co-morbidity, COPD-severity) and by acute disease-related co-variates (heart rate, cardiac troponin T (cTnT), P_O2, P_CO2 and C-reactive protein (CRP)) in explorative analyses. The prevalence of SVT, frequent PVCs or complex ventricular ectopy was 40%, 27% and 33% in AECOPD, and 31%, 31% and 12% in stable COPD, respectively. Frequent PVC, but not SVT or complex ventricular ectopy, was significantly increased in AECOPD compared to stable COPD, odds ratio 3.03 (1.03-10.5, p = 0.039) when adjusted for stable disease-related co-variates. Higher heart rate, cTnT and CRP attenuated the association between AECOPD and frequent PVC to non-significant, while heart rate remained associated with frequent PVC. In conclusion, frequent PVC is more prevalent in exacerbated than in the stable states of COPD. Attenuation effects of cTnT, tachycardia and CRP suggest that cardiac stress or inflammation may be involved in mechanisms causing frequent PVC i AECOPD.

Changes in ischaemic ECG abnormalities and subsequent risk of cardiovascular disease

Objective

The prognostic importance of changes in ischaemic ECG abnormalities over time (especially ST-T abnormalities) among Asians has not been fully investigated. We examined the associations between changes in ischaemic abnormalities upon serial ECG (improvement, persistence, deterioration) and cardiovascular disease (CVD) risk.

Methods

A prospective study cohort was conducted with 9374 men and women aged 40–69 years in four communities. Participants had multiple ECGs at study entry and during the next 10 years, and were followed up for a median period of 23.0 years. Total CVD (stroke and coronary heart disease) was ascertained under systematic surveillance. ECG abnormalities were defined by the Minnesota Code, ST depression (Code4), abnormal T wave (Code5) and categorised into nine groups (no–no, no–minor, no–major, minor–no, minor–minor, minor–major, major–no, major–minor, major–major) by comparison with the point of entrance and maximum change.

Results

We documented 1196 CVD events. Compared with no–no abnormality, no–minor, minor–major and major–major in Code4, HRs (95% CI) adjusted for cardiovascular risk factors were 1.19 (1.00–1.42), 1.57 (1.15–2.12) and 1.87 (1.42–2.47). Similar results were observed in Code5.

Conclusions

Changes in ischaemic ECG abnormalities from none to minor, and minor to major, as well as persistent major abnormalities, were associated with an increased risk of CVD.

An observational study on the effect of premature ventricular complex burden on long-term outcome

The long-term clinical impact of premature ventricular complexes (PVCs) on mortality and morbidity has not been fully studied. This study aimed to investigate the association between the burden of PVCs and adverse clinical outcome.A total of 5778 subjects, who were pacemaker-free and ventricular tachycardia-free at baseline, received 24-hour electrocardiography monitoring between January 1, 2002 and December 31, 2004. Clinical event data were retrieved from the Bureau of National Health Insurance of Taiwan. Multivariate Cox hazards regression models and propensity-score matching were applied to assess the association between PVCs and adverse clinical outcome.Average follow-up time was 10[REPLACEMENT CHARACTER]± 1 year. In all, 1403 subjects expired, 1301 subjects were hospitalized in the cardiovascular (CV) ward, 3384 were hospitalized for any reason, and 631 subjects developed new-onset heart failure (HF). The optimal cut-off PVC frequency (12 beats per day) was obtained through receiver operator characteristic curves, with a sensitivity of 58.4% and specificity of 59.8%. Upon multivariate analysis, a PVC frequency >12 beats per day was an independent predictor for all mortality (hazard ratio [HR]: 1.429, 95% confidence interval [CI]: 1.284-1.590), CV hospitalization (HR: 1.127, 95% CI: 1.008-1.260), all-cause hospitalization (HR 1.094, 95% CI: 1.021-1.173), and new-onset HF (HR: 1.411, 95% CI: 1.203-1.655). Subjects with a PVC frequency >12 beats per day had an increased risk of cardiac death attributable to HF and sudden cardiac death. The incidence rates for mortality and HF were significantly increased in cases of raised PVC frequency. Propensity-score matching analysis also echoed the main findings.Increased PVC burden was associated with a higher incidence of all-cause mortality, CV hospitalization, all-cause hospitalization, and new-onset HF which was independent of other clinical risk factors.

Biomarkers of cardiovascular injury and stress are associated with increased frequency of ventricular ectopy: a population-based study

BACKGROUND

Asymptomatic ventricular arrhythmias are common and associated with increased risk of cardiovascular mortality. Cardiac troponins, natriuretic peptides and C-reactive protein (CRP) are also predictive of adverse cardiovascular events in the general population, but limited information is available on the relationship between these biomarkers and ventricular ectopy in a community-based population. The objectives were to evaluate the associations between ventricular ectopic activity and N-terminal pro-B-type natriuretic peptide (NT-proBNP), high sensitivity-troponin I (hs-TnI) and hs-CRP in a community-based setting.

METHODS

We performed a 24 h Holter-recording and blood sampling in 498 subjects. Premature ventricular complexes (PVC) were classified as frequent at >5/h and the presence of any bigeminy, trigeminy or non-sustained ventricular tachycardia were classified as complex ventricular ectopy. The associations between biomarkers and ventricular arrhythmias were investigated by univariate and multivariate logistic regression analyses.

RESULTS

Frequent PVC's and complex ventricular ectopy were detected in 46 (9%) and 47 (9%) participants respectively, and were associated with significantly (p < 0.001) higher concentrations of NT-proBNP and hs-TnI. The association between NT-proBNP and both frequent PVC's (p = 0.020) and complex ventricular ectopy (p = 0.001) remained significant after adjusting for conventional risk markers in multivariate analyses.

CONCLUSION

Increased level of NT-proBNP was independently associated with ventricular ectopy, whereas no independent association was observed between hs-TnI and hs-CRP levels and ventricular ectopy in this community-based sample.

Risk factors for premature ventricular contractions in young and healthy adults

BACKGROUND

Premature ventricular contractions (PVCs) are associated with an increased risk of morbidity and mortality. Therefore, it was aimed to assess risk factors for the frequency of PVCs in young and healthy adults.

METHODS

Our population-based study included 2048 healthy adults from the general population aged 25-41 years. PVC frequency was determined by 24-hour Holter ECG. We performed multivariable regression analysis using stepwise backward selection to identify factors independently associated with PVC frequency.

RESULTS

Median age was 37 years, 953 (46.5%) were male. At least one PVC during the 24-hour monitoring period was observed in 69% of participants. Median number of detected PVCs was 2, the 95th percentile was 193. In multivariable regression analyses, we found 17 significant risk factors for PVC frequency. Low educational status (risk ratio (RR) 3.33; 95% CI 1.98 to 5.60), body height>median (1.58, 95% CI 1.11 to 2.24) and increasing levels of waist:hip ratio (2.15, 95% CI 1.77 to 2.61), N-terminal pro brain natriuretic peptide (1.52, 95% CI 1.30 to 1.76) and Sokolow-Lyon Index (1.38, 95% CI 1.15 to 1.66) (all p≤0.01) were associated with a higher PVC frequency. Physical activity (RR fourth vs first quartile 0.51, 95% CI 0.34 to 0.76) and increasing levels of haemoglobin (0.58, 95% CI 0.47 to 0.70) and glucagon-like peptide-1 (0.72, 95% CI 0.64 to 0.82) (all p<0.001) were related to a lower PVC frequency.

CONCLUSIONS

PVC occurrence is common even in healthy low-risk individuals, and its frequency is associated with several covariates mainly related to cardiovascular risk factors, markers of cardiac structure and function and socioeconomic status.

Consumption of Caffeinated Products and Cardiac Ectopy

BACKGROUND

Premature cardiac contractions are associated with increased morbidity and mortality. Though experts associate premature atrial contractions (PACs) and premature ventricular contractions (PVCs) with caffeine, there are no data to support this relationship in the general population. As certain caffeinated products may have cardiovascular benefits, recommendations against them may be detrimental.

METHODS AND RESULTS

We studied Cardiovascular Health Study participants with a baseline food frequency assessment, 24-hour ambulatory electrocardiography (Holter) monitoring, and without persistent atrial fibrillation. Frequencies of habitual coffee, tea, and chocolate consumption were assessed using a picture-sort food frequency survey. The main outcomes were PACs/h and PVCs/hour. Among 1388 participants (46% male, mean age 72 years), 840 (61%) consumed ≥1 caffeinated product per day. The median numbers of PACs and PVCs/h and interquartile ranges were 3 (1-12) and 1 (0-7), respectively. There were no differences in the number of PACs or PVCs/h across levels of coffee, tea, and chocolate consumption. After adjustment for potential confounders, more frequent consumption of these products was not associated with ectopy. In examining combined dietary intake of coffee, tea, and chocolate as a continuous measure, no relationships were observed after multivariable adjustment: 0.48% fewer PACs/h (95% CI -4.60 to 3.64) and 2.87% fewer PVCs/h (95% CI -8.18 to 2.43) per 1-serving/week increase in consumption.

CONCLUSIONS

In the largest study to evaluate dietary patterns and quantify cardiac ectopy using 24-hour Holter monitoring, we found no relationship between chronic consumption of caffeinated products and ectopy.

Patients with exercise-associated ventricular ectopy present evidence of myocarditis

BACKGROUND

The origin and clinical relevance of exercise-induced premature ventricular beats (PVBs) in patients without coronary heart disease or cardiomyopathies is unknown. Cardiovascular magnetic resonance enables us to non-invasively assess myocardial scarring and oedema. The purpose of our study was to discover any evidence of myocardial anomalies in patients with exercise-induced ventricular premature beats.

METHODS

We examined 162 consecutive patients presenting palpitations and documented exercise-induced premature ventricular beats (PVBs) but no history or evidence of structural heart disease. Results were compared with 70 controls matched for gender and age. ECG-triggered, T2-weighted, fast spin echo triple inversion recovery sequences and late gadolinium enhancement were obtained as well as LV function and dimensions.

RESULTS

Structural anomalies in the myocardium and/or pericardium were present in 85 % of patients with exercise-induced PVBs. We observed a significant difference between patients with PVBs and controls in late gadolinium enhancement, that is 68 % presented subepicardial or midmyocardial lesions upon enhancement, whereas only 9 % of the controls did so (p < 0.0001). More patients presented pericardial enhancement (35 %) or pericardial thickening (27 %) compared to controls (21 % and 13 %, p < 0.0001). Myocardial oedema was present in 37 % of the patients and in only one control, p < 0.0001. Left ventricular ejection fraction did not differ between patients and controls (63.1 ± 7.9 vs. 64.7 ± 7.0, p = 0.13).

CONCLUSIONS

The majority of patients with exercise-associated premature ventricular beats present evidence of myocardial disease consistent with acute or previous myocarditis or myopericarditis.

Kcne2 deletion promotes atherosclerosis and diet-dependent sudden death

Coronary artery disease (CAD) is the leading cause of death worldwide. An estimated half of cases involve genetic predisposition. Sequence variants in human KCNE2, which encodes a cardiac and epithelial K(+) channel β subunit, cause inherited cardiac arrhythmias. Unexpectedly, human KCNE2 polymorphisms also associate with predisposition to atherosclerosis, with unestablished causality or mechanisms. Here, we report that germline Kcne2 deletion promotes atherosclerosis in mice, overcoming the relative resistance of this species to plaque deposition. In female western diet-fed mice, Kcne2 deletion increased plaque deposition >6-fold and also caused premature ventricular complexes and sudden death. The data establish causality for the first example of ion channel-linked atherosclerosis, and demonstrate that the severity of Kcne2-linked cardiac arrhythmias is strongly diet-dependent.

Ambulatory cardiac arrhythmias in relation to mild hypokalaemia and prognosis in community dwelling middle-aged and elderly subjects

AIMS

Severe hypokalaemia can aggravate arrhythmia tendency and prognosis, but less is known about risk of mild hypokalaemia, which is a frequent finding. We examined the associations between mild hypokalaemia and ambulatory cardiac arrhythmias and their prognosis.

METHODS AND RESULTS

Subjects from the cohort of the 'Copenhagen Holter Study' (n = 671), with no history of manifest cardiovascular (CV) disease or stroke, were studied. All had laboratory tests and 48-h ambulatory electrocardiogram (ECG) recording. The median follow-up was 6.3 years. p-Potassium was inversely associated with frequency of premature ventricular complexes (PVCs) especially in combination with diuretic treatment (r = -0.22, P = 0.015). Hypokalaemia was not associated with supraventricular arrhythmias. Subjects at lowest quintile of p-potassium (mean 3.42, range 2.7-3.6 mmol/L) were defined as hypokalaemic. Cardiovascular mortality was higher in the hypokalaemic group (hazard ratio and 95% confidence intervals: 2.62 (1.11-6.18) after relevant adjustments). Hypokalaemia in combination with excessive PVC worsened the prognosis synergistically; event rates: 83 per 1000 patient-year in subjects with both abnormalities, 10 and 15 per 1000 patient-year in those with one abnormality, and 3 per 1000 patient-year in subjects with no abnormality. One variable combining hypokalaemia with excessive supraventricular arrhythmias gave similar results in univariate analysis, but not after multivariate adjustments.

CONCLUSION

In middle-aged and elderly subjects with no manifest heart disease, mild hypokalaemia is associated with increased rate of ventricular but not supraventricular arrhythmias. Hypokalaemia interacts synergistically with increased ventricular ectopy to increase the risk of adverse events.

Prognostic Significance of Premature Ventricular Contractions without Obvious Heart Diseases Determined by Standard 12-Lead Electrocardiography Considering their Morphology

BACKGROUND

Although ventricular premature contraction (VPC) commonly arises in subjects with and without heart diseases, the prognosis of VPC has remained controversial and the effect of their morphology on mortality has not been fully determined in subjects without obvious heart diseases. The objective of this study was to assess the morphologic effect of VPC on mortality.

METHODS

Japanese atomic bomb survivors (n = 6685) underwent baseline health examinations and standard 12-lead electrocardiogram (ECG) between January 1990 and December 1991. Of these, we extracted data from 5,685 (67.1% women) subjects who had neither heart diseases nor electrocardiographic abnormalities at baseline. Among them, we identified 131 VPC cases using standard 12-lead ECG and classified them into left bundle branch block (LBBB) type (n = 74), right bundle branch block (RBBB) type (n = 21), and undetermined type (n = 36) according to their morphology. These subjects were followed up until December 2008; we compared all-cause, cardiac and coronary heart disease (CHD) mortality rates using multivariate Cox regression analysis between those with and without VPC.

RESULTS

No VPCs were associated with all-cause and cardiac mortality, but the LBBB type was significantly associated with CHD mortality (hazard ratio, 2.73; 95% confidence interval, 1.11-6.73) after controlling for age, sex, smoking status, alcohol consumption, and underlying diseases.

CONCLUSIONS

Among Japanese atomic bomb survivors without obvious heart diseases, LBBB-type VPC was associated with increased CHD mortality. Larger studies are needed to confirm the effect of morphology as it might help to predict the risk.

Premature ventricular contraction-induced cardiomyopathy

Premature ventricular contractions are of common occurrence in routine clinical practice. Though generally perceived as of benign consequence in healthy people in the absence of heart disease, their presence can be a harbinger of fatal ventricular tachyarrhythmia in individuals with structural heart disease. With some of the latest insights into the treatment of ventricular tachyarrhythmia, especially with the advent of catheter ablation, there has been renewed interest in premature ventricular contractions, not only as a predictor of arrhythmia, but also for their potential etiological association with cardiomyopathy.

Transparent Reporting of a multivariable prediction model for Individual Prognosis or Diagnosis (TRIPOD): explanation and elaboration

The TRIPOD (Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis) Statement includes a 22-item checklist, which aims to improve the reporting of studies developing, validating, or updating a prediction model, whether for diagnostic or prognostic purposes. The TRIPOD Statement aims to improve the transparency of the reporting of a prediction model study regardless of the study methods used. This explanation and elaboration document describes the rationale; clarifies the meaning of each item; and discusses why transparent reporting is important, with a view to assessing risk of bias and clinical usefulness of the prediction model. Each checklist item of the TRIPOD Statement is explained in detail and accompanied by published examples of good reporting. The document also provides a valuable reference of issues to consider when designing, conducting, and analyzing prediction model studies. To aid the editorial process and help peer reviewers and, ultimately, readers and systematic reviewers of prediction model studies, it is recommended that authors include a completed checklist in their submission. The TRIPOD checklist can also be downloaded from www.tripod-statement.org.

Long-term mortality risk in individuals with atrial or ventricular premature complexes (results from the Third National Health and Nutrition Examination Survey)

Premature ectopic beats are frequently detected on routine 12-lead screening electrocardiograms (ECGs). However, their prognostic importance in subjects without known cardiovascular disease (CVD) is not well established. We evaluated prognostic value of atrial premature complexes (APCs) and ventricular premature complexes (VPCs) detected by a single 12-lead electrocardiography. A prospective cohort of 7,504 participants selected from nationally representative community-dwelling subjects living in the United States, enrolled in the Third National Health and Nutrition Examination Survey III from 1988 to 1994 with follow-up through December 2006 without known CVD. The main outcomes were all-cause mortality, CVD-related mortality, and ischemic heart disease (IHD)-related mortality. Of 7,504 participants (mean age 60 ± 14 years, 47% women, 49% whites), 89 (1.2%) had APCs and 110 (1.5%) had VPCs on 12-lead ECGs. During a follow-up of up to 18 years, 2,386 deaths occurred, of which 963 were due to CVD and 511 were due to IHD. In a multivariate analysis adjusted for demographics, clinical variables, and electrocardiographic measures, APCs were significantly associated with all-cause mortality (hazard ratio [HR] 1.41, 95% confidence interval [CI] 1.08 to 1.80), CVD death (HR 1.78, 95% CI 1.26 to 2.44), and IHD death (HR 2.40, 95% CI 1.59 to 3.47). For VPCs, however, there were no significant associations with all-cause mortality (HR 1.05, 95% CI 0.80 to 1.36), CVD death (HR 0.96, 95% CI 0.62 to 1.43), and IHD death (HR 0.89, 95% CI 0.47 to 1.52). In conclusion, APCs, but not VPCs, on routine screening ECGs are predictive of adverse events in community-dwelling subjects without known CVD.

Lidocaine bolus may facilitate computed tomographic coronary angiography in patients with frequent premature ventricular contractions

Introduction

Heart rate irregularities are the major limitations of computed tomographic coronary angiography (CTCA) due to severe motion artifacts.

Aim

To evaluate the safety and efficacy of a lidocaine intravenous bolus in preserving good image quality by the transient suppression of premature ventricular contractions (PVC) during the CTCA scan.

Material and methods

The study group comprised 67 consecutive patients with sinus rhythm and numerous PVC scheduled for CTCA. Intravenous boluses of 25–50 mg lidocaine were given after calcium score assessment and immediately before CTCA. The control group comprised 67 patients with sinus rhythm without PVC matched according to the body mass index (BMI), age, sex, and calcium score. All coronary vessel segments were assessed for image quality and presence of significant stenosis.

Results

As compared with calcium score assessment, after administration of lidocaine and during the CTCA scan PVC were completely suppressed in 22 (40%), reduced in 10 (18%), unchanged in 18 (32%), and intensified in 5 (10%) patients. Overall, there were 32 (58%) patients with sinus rhythm during CTCA as compared with only 11 (20%) patients free from PVC during calcium score assessment (p < 0.001). Image quality in 871 coronary segments including both the study group and control patients was worse in patients with PVC (p < 0.0001). However, there was no statistically significant difference in the number of patients with at least one segment of non-diagnostic quality (6% vs. 12%, p = 0.36; respectively).

Conclusions

Single lidocaine bolus given prior to CTCA is safe, may temporarily eliminate or reduce the intensity of arrhythmia, and hence results in improved quality of CTCA in patients with numerous PVC.

Supraventricular and ventricular arrhythmias

Cardiac arrhythmias comprise of a heterogeneous group of disorders which manifest in a wide range of clinical presentations. They can be associated with underlying cardiac disease and portend a grave prognosis, with some arrhythmias being rapidly fatal. Other arrhythmias, however are relatively benign and can be asymptomatic or may be a mere inconvenience for the patient. All primary care physicians can expect to encounter some forms of arrhythmias during the course of their practice. This review article provides a brief overview of the commonly seen tachyarrhythmias for the general practitioner and provides relevant updates on the recent developments in our understanding of their mechanisms and management.