Association of ventricular premature complexes with electrocardiographic-estimated left ventricular mass in a population of African-American and white men and women (The Atherosclerosis Risk in Communities

Influence of standard modifiable risk factors on ventricular tachycardia after myocardial infarction

Background

Inducible ventricular tachycardia (VT) at electrophysiology study (EPS) predicts sudden cardiac death because of ventricular tachyarrhythmia, the single greatest cause of death within 2 years after myocardial infarction (MI).

Objectives

We aimed to assess the association between standard modifiable risk factors (SMuRFs) and inducible VT at EPS early after MI.

Methods

Consecutive patients with left ventricle ejection fraction ≤40% on days 3-5 after ST elevation MI (STEMI) who underwent EPS were prospectively recruited. Positive EPS was defined as induced sustained monomorphic VT cycle length ≥200 ms for ≥10 s or shorter if hemodynamically compromised. The primary outcome was inducibility of VT at EPS, and the secondary outcome was all-cause mortality on follow-up.

Results

In 410 eligible patients undergoing EPS soon (median of 9 days) after STEMI, 126 had inducible VT. Ex-smokers experienced an increased risk of inducible VT [multivariable logistic regression adjusted odds ratio (OR) 2.0, p = 0.033] compared with current or never-smokers, with comparable risk. The presence of any SMuRFs apart from being a current smoker conferred an increased risk of inducible VT (adjusted OR 1.9, p = 0.043). Neither the number of SMuRFs nor the presence of any SMuRFs was associated with mortality at a median follow-up of 5.4 years.

Conclusions

In patients with recent STEMI and impaired left ventricular function, the presence of any SMuRFs, apart from being a current smoker, conferred an increased risk of inducible VT at EPS. These results highlight the need to modify SMuRFs in this high-risk subset of patients.

Contemporary clinical management of monomorphic idiopathic premature ventricular contractions: results of the European Heart Rhythm Association Survey

On behalf of the European Heart Rhythm Association, we designed a survey, whose aim was to understand the trend(s) in the clinical management of idiopathic monomorphic premature ventricular contractions (PVCs) among European cardiologists and cardiac electrophysiologists. A total of 202 participants in the survey answered 27 multiple-choice questions on the clinical presentation, diagnosis and treatment of idiopathic monomorphic PVCs. The most common symptom in patients with idiopathic monomorphic PVCs is palpitations, according to the majority of responders (87%), followed by fatigue (29%) and dizziness (18%). Complete blood cell count, renal function with electrolytes levels, and thyroid function are the blood tests requested by the majority of respondents (65%, 92%, and 93%, respectively). Coronary artery disease and structural heart disease needs to be ruled out, according to the vast majority of participants (99%). A 24-h Holter ECG is the preferred ECG modality to assess the burden of PVCs (86% of respondents). Among the different option treatments, beta-blockers and class I antiarrhythmic drugs are by far (81% of respondents) the preferred pharmacological option in comparison with calcium antagonists and class III antiarrhythmic drugs. Catheter ablation has also a good reputation: 99% of responders are keen to use it, especially in patients with high burden of PVCs and when signs of cardiomyopathy occur.

Hypertension and Arrhythmias

Hypertension is the most common cardiovascular risk factor and underlies heart failure, coronary artery disease, stroke, and chronic kidney disease. Hypertensive heart disease can manifest as cardiac arrhythmias. Supraventricular and ventricular arrhythmias may occur in the hypertensive patients. Atrial fibrillation and hypertension contribute to an increased risk of stroke. Some antihypertensive drugs predispose to electrolyte abnormalities, which may result in atrial and ventricular arrhythmias. A multipronged strategy involving appropriate screening, aggressive lifestyle modifications, and optimal pharmacotherapy can result in improved blood pressure control and prevent the onset or delay progression of heart failure, coronary artery disease, and cardiac arrhythmias.

Hypertension and cardiac arrhythmias: a consensus document from the European Heart Rhythm Association (EHRA) and ESC Council on Hypertension, endorsed by the Heart Rhythm Society (HRS), Asia-Pacific Heart Rhythm Society (APHRS) and Sociedad Latinoamericana de Estimulación Cardíaca y Electrofisiología (SOLEACE)

Hypertension is a common cardiovascular risk factor leading to heart failure (HF), coronary artery disease, stroke, peripheral artery disease and chronic renal insufficiency. Hypertensive heart disease can manifest as many cardiac arrhythmias, most commonly being atrial fibrillation (AF). Both supraventricular and ventricular arrhythmias may occur in hypertensive patients, especially in those with left ventricular hypertrophy (LVH) or HF. Also, some of the antihypertensive drugs commonly used to reduce blood pressure, such as thiazide diuretics, may result in electrolyte abnormalities (e.g. hypokalaemia, hypomagnesemia), further contributing to arrhythmias, whereas effective control of blood pressure may prevent the development of the arrhythmias such as AF. In recognizing this close relationship between hypertension and arrhythmias, the European Heart Rhythm Association (EHRA) and the European Society of Cardiology (ESC) Council on Hypertension convened a Task Force, with representation from the Heart Rhythm Society (HRS), Asia-Pacific Heart Rhythm Society (APHRS), and Sociedad Latinoamericana de Estimulación Cardíaca y Electrofisiología (SOLEACE), with the remit to comprehensively review the available evidence to publish a joint consensus document on hypertension and cardiac arrhythmias, and to provide up-to-date consensus recommendations for use in clinical practice. The ultimate judgment regarding care of a particular patient must be made by the healthcare provider and the patient in light of all of the circumstances presented by that patient.

The prognostic significance of frequency and morphology of premature ventricular complexes during ambulatory holter monitoring

BACKGROUND

Multiform premature ventricular complexes (PVCs) are associated with an adverse prognosis in patients with structural heart disease. Very frequent PVCs are associated with ventricular dysfunction. Our hypothesis is that multiform PVCs confer an adverse prognosis in the general population.

METHODS

We performed a retrospective cohort study of patients ≥18 years old referred to our institution for 24-hour ambulatory Holter monitoring between July 1, 2008 and December 31, 2009. Holters without PVCs or with more frequent ectopy (couplets, triplets, or nonsustained ventricular tachycardia) were excluded. Clinical and adverse event (AE) data ("major adverse cardiovascular event" or new/worsening heart failure) were gathered from chart review. Data was analyzed by PVC frequency (rare, occasional, or frequent) and pattern (uniform or multiform).

RESULTS

A total of 222 patients (43% male, mean age: 55 ± 16 years) were evaluated (median follow-up 2.3 years [IQR: 2.0-2.6]). Median frequency was 2 PVCs per hour (IQR: 1-13). Multiform PVCs were noted in 48%. Patients with multiform PVCs were older, and had a higher prevalence of comorbidities. Thirty-nine AE were noted. Patients with an AE were younger, had a higher prevalence of HTN, diabetes, CAD, CHF, and previous MI. The multiform group had a higher incidence of AE (28%) compared to the uniform group (8%) (P < 0.001). Increasing PVC frequency was associated with a higher incidence of AE (8% vs 24% vs 35%, respectively). In Cox regression analyses, the multiform pattern but not frequency predicted AE.

CONCLUSIONS

Multiform PVCs were associated with a 4-fold increase in AE in patients referred for ambulatory Holter monitoring.

Premature cardiac contractions and risk of incident ischemic stroke

BACKGROUND

The etiologies of ischemic stroke remain undetermined in 15% to 40% of patients. Apart from atrial fibrillation, other arrhythmias are less well-characterized as risk factors. Premature cardiac contractions are known to confer long-term cardiovascular risks, like myocardial infarction. Ischemic stroke as cardiovascular risk outcome remains a topic of interest. We examined the prospective relationships in the Atherosclerosis Risk in Communities (ARIC) study, to determine whether premature atrial (PAC) or ventricular (PVC) contractions are associated with increased risk for incident ischemic stroke.

METHODS AND RESULTS

We analyzed 14 493 baseline stroke-free middle-aged individuals in the ARIC public-use data. The presence of PAC or PVC at baseline was assessed from 2-minute electrocardiogram. A physician-panel confirmed and classified all stroke cases. Average follow-up time was 13 years. Proportional hazards models assessed associations between premature contractions and incident stroke. PACs and PVCs were identified in 717 (4.9%) and 793 (5.5%) participants, respectively. In all, 509(3.5%) participants developed ischemic stroke. The hazard ratio (HR) (95% confidence interval [CI]) associated with PVC was 1.77 (1.30, 2.41), attenuated to 1.25 (0.91, 1.71) after adjusting for baseline stroke risk factors. The interaction between PVC and baseline hypertension was marginally significant (P=0.08). Among normotensives, having PVCs was associated with nearly 2-fold increase in the rate of incident ischemic stroke (HR 1.69; 95% CI 1.02, 2.78), adjusting for stroke risk factors. The adjusted risk of ischemic stroke associated with PACs was 1.30 (95% CI 0.92, 1.83).

CONCLUSIONS

Presence of PVCs may indicate an increased risk of ischemic stroke, especially in normotensives. This risk approximates risk of stroke from being black, male, or obese in normotensives from this cohort.

Relation of ventricular premature complexes to heart failure (from the Atherosclerosis Risk In Communities [ARIC] Study)

Analogous to rapid ventricular pacing, frequent ventricular premature complexes (VPCs) can predispose over time to cardiomyopathy and subsequent heart failure (HF). We examined the association of frequent VPCs with HF incidence in a population-based cohort, free of HF and coronary heart disease at baseline. At study baseline (1987 to 1989), ≥1 VPC on a 2-minute rhythm electrocardiographic strip was seen in 5.5% (739 of 13,486) of the middle-age (45 to 64 years old at baseline) white and black, men and women of the Atherosclerosis Risk In Communities cohort. Incident HF was defined as the first appearance of International Classification of Diseases code 428.x in the hospital discharge record or death certificate through 2005. During an average follow-up of 15.6 years, incident HF was seen in 10% the participants (19.4% of those with VPCs vs 9.4% of those without). The age-, race-, and gender-adjusted hazard ratio of HF for VPCs was 1.89 (95% confidence interval 1.59 to 2.24). After multivariable adjustment for potential confounders, the hazard ratio of HF for those with any VPC versus no VPC was 1.63 (95% confidence interval 1.36 to 1.96). After additional adjustment for incident coronary heart disease as a time-varying covariate, the hazard ratio was 1.71 (95% confidence interval 1.42 to 2.08). Those with a greater frequency of VPCs or complex VPCs had similar rates of HF compared to those with a single VPC and all had rates greater than those with no VPC. In conclusion, in this large population-based cohort, the presence of VPCs was associated with incident HF, independent of incident coronary heart disease.

Chewing reduces sympathetic nervous response to stress and prevents poststress arrhythmias in rats

Reducing stress is important in preventing sudden death in patients with cardiovascular disease, as stressful events may cause autonomic imbalance and trigger fatal arrhythmias. Since chewing has been shown to inhibit stress-induced neuronal responses in the hypothalamus, we hypothesized that chewing could ameliorate stress-induced autonomic imbalance and prevent arrhythmias. To test this hypothesis, we analyzed changes in radiotelemetered electrocardiograms in rats that were allowed to chew a wooden stick during a 1-h period of immobilization stress. Chewing significantly reduced the occurrence of ventricular premature beats (VPBs) and complex ventricular ectopy after immobilization and prevented stress-induced prolongation of the QT interval of VPBs throughout the 10-h experimental period. It also prevented prolongation of the QRS complex and fluctuations in the QT interval in normal sinus rhythm beats preceding VPBs during both immobilization and in the poststress period. Fast Fourier transform-based spectral analysis of heart-rate variability further showed that chewing significantly inhibited the stress-induced increase in the power ratio of low-to-high frequency activity (LF/HF: a marker of sympathetic activity) during immobilization and in addition was associated with blunting of the stress-induced increase in plasma noradrenaline observed at the termination of immobilization. Similar suppressive effects on the occurrence of VPBs and the LF/HF were observed in rats that were administered the β-adrenergic blocker propranolol before immobilization. These results indicate that chewing can ameliorate sympathetic hyperactivity during stress and prevent poststress arrhythmias and suggest that chewing may provide a nonpharmacological and cost-effective treatment option for patients with a high risk of stress-induced fatal arrhythmia.

Premature ventricular complexes and the risk of incident stroke: the Atherosclerosis Risk In Communities (ARIC) Study

BACKGROUND AND PURPOSE

Premature ventricular complexes (PVCs) on a 2-minute electrocardiogram are a common, largely asymptomatic finding associated with increased risk of coronary heart disease and death. They may reflect atherosclerosis or other pathogenic pathways that predispose to arrhythmias and stroke.

METHODS

We conducted a prospective evaluation of the Atherosclerosis Risk In Communities Study cohort (n=14,783) of middle-aged men and women to assess whether the presence of PVCs at study baseline (1987 to 1989) influenced the risk of incident stroke through December 31, 2004.

RESULTS

PVCs were seen in 6.1% of the participants at baseline, and 729 (4.9%) had incident stroke. The unadjusted cumulative proportion of incident stroke in individuals with any PVC was 6.6% compared with 4.1% in those without PVC. The unadjusted hazard ratio of incident stroke in individuals with any PVC compared with those without any PVCs was 1.71 (95% CI, 1.33 to 2.20). Among individuals without hypertension and diabetes at baseline, PVCs were independently associated with incident stroke (hazard ratio: 1.72; 95% CI: 1.14 to 2.59). Among those with either diabetes or hypertension, the presence of any PVCs did not increase the risk of stroke. The association was stronger for noncarotid embolic stroke than for thrombotic stroke and its magnitude increased with higher frequency of PVCs.

CONCLUSIONS

Frequent PVCs are associated with risk of incident stroke in participants free of hypertension and diabetes. This suggests that PVCs may contribute to atrioventricular remodeling or may be a risk marker for incident stroke, particularly embolic stroke.

Association of premature ventricular complexes with central aortic pressure indices and pulse wave velocity

BACKGROUND

Although premature ventricular complex (PVC) occurs frequently, its predisposing factors have rarely been studied. We examined the connection between PVC and aortic stiffness.

METHODS

We recruited 200 consecutive patients (< 50 years, 95 men, mean age 36 +/- 10 years) who received a 24-hour ambulatory electrocardiography examination for palpitation and PVC loads. Muscular artery pulse wave velocity (PWVm) and 4 main aortic pressure indices-augmented pressure, augmentation index (AI(x)), AI(x) corrected for a steady heart rate of 75 beat/min, and the extra workload-were measured, and atherosclerosis risk was evaluated.

RESULTS

Eighty-three (42%) patients had no PVC loads; 58 (29%) patients had low loads (< 24 beat/d), and 59 (29%) had high loads (> or = 24 beat/d). Only age and hyperlipidemia were significantly associated with PVC loads. Using a multivariate logistic regression model adjusted for potential confounders, we found that AI(x) (odds ratio [OR] 1.88, 95% CI 1.20-2.91, P = .005); augmented pressure (OR 1.57, 95% CI 1.02-2.43, P = .042); AI(x) corrected for a steady heart rate of 75 beat/min (OR 1.82, 95% CI 1.18-2.82, P = .007); and PWVm (OR 1.53, 95% CI 1.07-2.19, P = .021) were independent factors for PVC loads.

CONCLUSION

Increased central aortic pressure indices as well as PWVm were associated with increased PVC loads in young patients undergoing 24-hour ambulatory electrocardiography. Central aortic properties probably contributed to the occurrence of PVC.

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

The clinical relevance of ventricular premature complexes (VPCs) in apparently healthy patients is not clear and is typically not considered when evaluating risk. We conducted a prospective longitudinal study of the population-based Atherosclerosis Risk In Communities (ARIC) study of 15,070 Caucasians and African-Americans, 45 to 64 years of age, to assess the risks of coronary heart disease (CHD) events and mortality associated with VPCs among participants with and without prevalent CHD at baseline. VPCs on a single 2-minute electrocardiogram were identified in 940 participants (6.2%). After a follow-up of >10 years, 1,762 participants died, with 366 deaths related to CHD, and 1,736 had cardiac events. The percentage of participants with CHD mortality was >3 times greater for those with VPCs compared with those without VPCs. After controlling for cardiovascular risk factors and therapy with proportional hazards regression, participants with VPCs were >2 times as likely to die due to CHD than were those without VPCs. Increased risk was found for participants with and without baseline CHD. In conclusion, a clinical finding of VPCs on electrocardiography of even apparently healthy patients may warrant a heightened awareness of and attention to cardiovascular risk assessment and management.

Gender differences in ventricular arrhythmia recurrence in patients with coronary artery disease and implantable cardioverter-defibrillators

OBJECTIVES

We sought to determine whether men and women with coronary artery disease (CAD) and implantable cardioverter-defibrillators (ICDs) differ in frequency of arrhythmia recurrence and whether gender differences are independent of clinical, electrocardiographic, and electrophysiologic characteristics.

BACKGROUND

Epidemiologic studies show that women have a lower rate of sudden cardiac death (SCD) than men, even among patients with CAD. Whether this is due to differing susceptibilities to ischemia or to arrhythmia is unknown.

METHODS

The clinical records and ICD data disks of 340 men and 59 women with CAD who received an ICD between June 1990 and June 2000 were reviewed. Ventricular tachycardia (VT) or ventricular fibrillation (VF) recurrences were compared between genders and relationship with other factors was analyzed.

RESULTS

Sustained VT/VF occurred in 52% of men and 34% of women (p < 0.01). Men experienced more total VT/VF events (p < 0.01), more shock-treated VT/VF events (p < 0.03), more electrical storms (p < 0.001), and had VT/VF on more days in follow-up (p < 0.01). Gender differences were independent of measured clinical, electrocardiographic, and electrophysiologic factors. In stratified analyses, the gender differences in VT/VF recurrence were greatest in patients presenting with sustained monomorphic VT and those with inducible VT at electrophysiology study.

CONCLUSIONS

Women were less likely to experience VT/VF, and had fewer VT/VF episodes, than men. These findings were strongest in patients with evidence of a stable anatomic VT circuit: those with clinical or electrophysiologically induced VT. This study suggests that differing susceptibility to arrhythmia triggering may underlie the known differences in SCD rates between men and women.

Hypertension, left ventricular hypertrophy, and sudden death

Left ventricular hypertrophy (LVH), a form of end-organ damage in hypertension, is associated with increased incidence of sudden cardiac death (SCD). This review explores the possible mechanisms behind this phenomenon. SCD in LVH could be thrombotic/ischemic or arrhythmic (eg, myocardial ischemia, even in the absence of significant coronary artery disease, may be one important factor). Abnormalities of flow-mediated dilatation, endothelial function, and a hypercoagulable state are well-observed abnormalities in association with hypertension and LVH, although their precise contributory role is as yet undefined in the pathogenesis of sudden death. Electrophysiologic abnormalities are also well documented in LVH, and such patients are more predisposed to arrhythmias. In the past decade, many studies have investigated the regression of LVH, and recent studies are addressing whether the latter translates into a prognostic benefit.