Abstract Background Studies of patients presenting for catheter ablation suggest that premature ventricular contractions (PVCs) are a modifiable risk factor for congestive heart failure (CHF). The ...relationship among PVC frequency, incident CHF, and mortality in the general population remains unknown. Objectives The goal of this study was to determine whether PVC frequency ascertained using a 24-h Holter monitor is a predictor of a decrease in the left ventricular ejection fraction (LVEF), incident CHF, and death in a population-based cohort. Methods We studied 1,139 Cardiovascular Health Study (CHS) participants who were randomly assigned to 24-h ambulatory electrocardiography (Holter) monitoring and who had a normal LVEF and no history of CHF. PVC frequency was quantified using Holter studies, and LVEF was measured from baseline and 5-year echocardiograms. Participants were followed for incident CHF and death. Results Those in the upper quartile versus the lowest quartile of PVC frequency had a multivariable-adjusted, 3-fold greater odds of a 5-year decrease in LVEF (odds ratio OR: 3.10; 95% confidence interval CI: 1.42 to 6.77; p = 0.005), a 48% increased risk of incident CHF (HR: 1.48; 95% CI: 1.08 to 2.04; p = 0.02), and a 31% increased risk of death (HR: 1.31; 95% CI: 1.06 to 1.63; p = 0.01) during a median follow-up of >13 years. Similar statistically significant results were observed for PVCs analyzed as a continuous variable. The specificity for the 15-year risk of CHF exceeded 90% when PVCs included at least 0.7% of ventricular beats. The population-level risk for incident CHF attributed to PVCs was 8.1% (95% CI: 1.2% to 14.9%). Conclusions In a population-based sample, a higher frequency of PVCs was associated with a decrease in LVEF, an increase in incident CHF, and increased mortality. Because of the capacity to prevent PVCs through medical or ablation therapy, PVCs may represent a modifiable risk factor for CHF and death.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Autonomic dysfunction represents a loss of normal autonomic control of the cardiovascular system associated with both sympathetic nervous system overdrive and reduced efficacy of the parasympathetic ...nervous system. Autonomic dysfunction is a strong predictor of future coronary heart disease, vascular disease, and sudden cardiac death. In the current review, we will discuss the clinical importance of autonomic dysfunction as a cardiovascular risk marker among breast cancer patients. We will review the effects of antineoplastic therapy on autonomic function, as well as discuss secondary exposures, such as psychological stress, sleep disturbances, weight gain/metabolic derangements, and loss of cardiorespiratory fitness, which may negatively impact autonomic function in breast cancer patients. Lastly, we review potential strategies to improve autonomic function in this population. The perspective can help guide new therapeutic interventions to promote longevity and cardiovascular health among breast cancer survivors.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Abstract Objectives This study sought to determine whether Holter-based parameters of heart rate variability (HRV) are independently associated with incident heart failure among older adults in the ...CHS (Cardiovascular Health Study) as evidenced by an improvement in the predictive power of the Health Aging and Body Composition Heart Failure (Health ABC) score. Background Abnormal HRV, a marker of autonomic dysfunction, has been associated with multiple adverse cardiovascular outcomes but not the development of congestive heart failure (CHF). Methods Asymptomatic CHS participants with interpretable 24-h baseline Holter recordings were included (n = 1,401). HRV measures and premature ventricular contraction (PVC) counts were compared between participants with (n = 260) and without (n = 1,141) incident CHF on follow-up. Significantly different parameters between groups were added to the components of the Health ABC score, a validated CHF prediction tool, using stepwise Cox regression. Results The final model included components of the Health ABC score, In PVC counts (adjusted hazard ratio aHR: 1.12; 95% confidence interval CI: 1.07 to 1.19; p < 0.001) and the following HRV measures: abnormal heart rate turbulence onset (aHR: 1.52; 95% CI: 1.11 to 2.08; p = 0.009), short-term fractal scaling exponent (aHR: 0.27; 95% CI: 0.14 to 0.53; p < 0.001), in very low frequency power (aHR: 1.28; 95% CI: 1.02 to 1.60; p = 0.037), and coefficient of variance of N-N intervals (aHR: 0.94; 95% CI: 0.90 to 0.99; p = 0.009). The C-statistic for the final model was significantly improved over the Health ABC model alone (0.77 vs. 0.73; p = 0.0002). Conclusions Abnormal HRV parameters were significantly and independently associated with incident CHF in asymptomatic, older adults. When combined with increased PVCs, HRV improved the predictive power of the Health ABC score.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Abstract Atrial fibrillation (AF) is likely secondary to multiple different pathophysiological mechanisms that are increasingly, but incompletely understood. Motivated by the hypothesis that 3 ...previously described electrocardiographic (ECG) predictors of AF identify distinct AF mechanisms, we sought to determine if these ECG findings independently predict incident disease. Among Cardiovascular Health Study participants without prevalent AF, we determined whether left anterior fascicular block (LAFB), a prolonged QTC , and atrial premature complexes (APCs) each predicted AF after adjusting for each other. We then calculated the attributable risk in the exposed for each ECG marker. LAFB and QTC intervals were assessed on baseline 12-lead ECG (n=4,696). APC count was determined using 24-hour Holter recordings obtained in a random subsample (n=1,234). After adjusting for potential confounders and each ECG marker, LAFB (hazard ratio HR. 2.1, 95% confidence interval CI. 1.1-3.9, p=0.023), a prolonged QTC (HR 2.5, 95% CI 1.4-4.3, p=0.002), and every doubling of APC count (HR 1.2, 95% CI 1.1-1.3, p<0.001) each remained independently predictive of incident AF. The attributable risk of AF in the exposed was 35% (95% CI 13-52%) for LAFB, 25% (95% CI 0.6-44%) for a prolonged QTC , and 34% (95% CI 26-42%) for APCs. In conclusion, in a community-based cohort, 3 previously established ECG-derived AF predictors were each independently associated with incident AF, suggesting they may represent distinct mechanisms underlying the disease.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Background The purposes of this study were to identify nocturnal patterns of heart rate (HR) in depressed and nondepressed patients after an acute myocardial infarction (MI) and to determine which ...patterns, if any, are associated with all-cause mortality or recurrent infarction. Methods Functional data analysis and model-based clustering methods were used to identify nocturnal HR patterns in 245 depressed and 247 nondepressed patients with a recent MI. All-cause mortality and recurrent infarctions were ascertained over a median follow-up of 24 months. Results Three HR activity patterns were identified. In the first, HR gradually declined during the nighttime and increased the next morning. The second pattern was similar, but with a higher overall HR during the recording interval. The third showed almost no decrease in HR at night (ie, “nondipping”). All-cause mortality was higher among patients with pattern 3 than pattern 1 ( P = .007), and the combined end point of recurrent MI or all-cause mortality was higher in pattern 3 than pattern 2 ( P = .05). Patterns 2 and 3 were more common in the depressed than in the nondepressed patients. Conclusions The nondipping nocturnal HR independently predicts all-cause mortality and recurrent MI. Future studies should examine the underlying causes of nondipping nocturnal HR and its association with depression and investigate the effects of treatment on survival.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Inflammation is linked to adverse cardiovascular events, but its association with sudden cardiac death (SCD) has been controversial. Older subjects, who are at particular risk for SCD, were ...underrepresented in previous studies addressing this issue.
The purpose of this study was to study the association between inflammation and SCD in a community-based population of older adults.
In the Cardiovascular Health Study, 5806 and 5382 participants had measurements of C-reactive protein (CRP) and interleukin-6 (IL6), respectively, and were followed for up to 17 years. SCD risk as a function of baseline IL-6 and CRP was assessed in the overall population and in a group of participants without known prevalent cardiac disease.
In univariate analyses, both IL-6 (hazard ratio HR 1.79 for 1+ log IL-6, 95% confidence interval CI 1.50-2.13; 5th vs 1st quintile HR 3.36, 95% CI 2.24-5.05) and CRP (HR 1.31 for 1+ log CRP, 95% CI 1.18-1.45; 5th vs 1st quintile HR 2.00, 95% CI 1.40-2.87) were associated with SCD risk. In covariate-adjusted analyses, accounting for baseline risk factors, incident myocardial infarction, and heart failure, the association with SCD risk persisted for IL-6 (HR 1.26 for 1+ log IL-6, 95% CI 1.02-1.56; 5th vs 1st quintile HR 1.63, 95% CI 1.03-2.56) but was significantly attenuated for CRP (HR 1.13 for 1+ log CRP, 95% CI 1.00-1.28; 5th vs 1st quintile HR 1.34, 95% CI 0.88-2.05). Similar findings were observed in participants without prevalent cardiac disease.
Greater burden of inflammation, assessed by IL-6 levels, is associated with SCD risk beyond traditional risk factors, incident myocardial infarction, and heart failure.
Heart rate turbulence (HRT) is a promising marker for risk of mortality after acute myocardial infarction (AMI). We investigated HRT for risk stratification in high-risk patients after MI. HRT from ...24-hour Holter monitoring in 481 hospitalized patients after AMI with heart failure and/or diabetes with left ventricular dysfunction before randomization in the Eplerenone Post-Acute Myocardial Infarction Heart Failure Efficacy and Survival Study (EPHESUS). Over a 1-year follow-up, 55 died, 49 of cardiovascular causes. HRT onset (TO) and slope (TS) were calculated using previous and cohort-optimized cutpoints and their independent contribution to risk of cardiovascular death determined. Models were tested with <5 ventricular premature complexes (PVCs) categorized as normal (n = 452) and with <5 VPCs excluded (n = 342). In EPHESUS, optimal cutpoints were TS ≤3.0 and TO ≥0.0. The strongest model for predicting cardiovascular mortality used EPHESUS cutpoints excluding subjects with <5 VPCs. On 3-category HRT model multivariate analysis (TS and TO normal, TS or TO abnormal, TS and TO abnormal), both TS and TO abnormal (relative risk 3.64, 95% confidence interval 1.55 to 8.55, p = 0.003) and left ventricular ejection fraction ≤30% (relative risk 1.97, 95% confidence interval 1.04 to 3.73, p = 0.037) independently predicted cardiovascular death. In conclusion, HRT is an independent predictor of cardiovascular death in a high-risk population after AMI, with a possibly higher optimal cutpoint for HRT slope than previously reported.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
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