02330nas a2200229 4500008004100000022001400041245006900055210006800124260001500192300001000207490000800217520165900225100002201884700002201906700002301928700002101951700002201972700002401994700002302018700002302041856003602064 2016 eng d a1879-191300aElectrocardiographic Predictors of Incident Atrial Fibrillation.0 aElectrocardiographic Predictors of Incident Atrial Fibrillation c2016 Sep 1 a714-90 v1183 a

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 predictors of AF identify distinct AF mechanisms, we sought to determine if these electrocardiographic 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 electrocardiographic marker. LAFB and QTC intervals were assessed on baseline 12-lead electrocardiogram (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 electrocardiographic marker, LAFB (hazard ratio [HR] 2.1, 95% confidence interval [CI] 1.1 to 3.9, p = 0.023), a prolonged QTC (HR 2.5, 95% CI 1.4 to 4.3, p = 0.002), and every doubling of APC count (HR 1.2, 95% CI 1.1 to 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% to 52%) for LAFB, 25% (95% CI 0.6% to 44%) for a prolonged QTC, and 34% (95% CI 26% to 42%) for APCs. In conclusion, in a community-based cohort, 3 previously established electrocardiogram-derived AF predictors were each independently associated with incident AF, suggesting that they may represent distinct mechanisms underlying the disease.

1 aNguyen, Kaylin, T1 aVittinghoff, Eric1 aDewland, Thomas, A1 aMandyam, Mala, C1 aStein, Phyllis, K1 aSoliman, Elsayed, Z1 aHeckbert, Susan, R1 aMarcus, Gregory, M uhttps://chs-nhlbi.org/node/712902588nas a2200253 4500008004100000022001400041245008900055210006900144260001300213300001400226490000700240520182000247100002802067700002202095700002202117700002402139700002402163700002302187700002202210700002002232700002302252700002302275856003602298 2017 eng d a1556-387100aAtrial ectopy as a mediator of the association between race and atrial fibrillation.0 aAtrial ectopy as a mediator of the association between race and  c2017 Dec a1856-18610 v143 a

BACKGROUND: Blacks have a lower risk of atrial fibrillation (AF) despite having more AF risk factors, but the mechanism remains unknown. Premature atrial contraction (PAC) burden is a recently identified risk factor for AF.

OBJECTIVE: The purpose of this study was to determine whether the burden of PACs explains racial differences in AF risk.

METHODS: PAC burden (number per hour) was assessed by 24-hour ambulatory electrocardiographic (ECG) monitoring in a randomly selected subset of patients in the Cardiovascular Health Study. Participants were followed prospectively for the development of AF, diagnosed by study ECG and hospital admission records.

RESULTS: Among 938 participants (median age 73 years; 34% black; 58% female), 206 (22%) developed AF over a median follow-up of 11.0 years (interquartile range 6.1-13.4). After adjusting for age, sex, body mass index, coronary disease, congestive heart failure, diabetes, hypertension, alcohol consumption, smoking status, and study site, black race was associated with a 42% lower risk of AF (hazard ratio 0.58, 95% confidence interval [CI] 0.40-0.85; P = .005). The baseline PAC burden was 2.10 times (95% CI 1.57-2.83; P <.001) higher in whites than blacks. There was no detectable difference in premature ventricular contraction (PVC) burden by race. PAC burden mediated 19.5% (95% CI 6.3-52.5) of the adjusted association between race and AF.

CONCLUSION: On average, whites exhibited more PACs than blacks, and this difference statistically explains a modest proportion of the differential risk of AF by race. The differential PAC burden, without differences in PVCs, by race suggests that identifiable common exposures or genetic influences might be important to atrial pathophysiology.

1 aChristensen, Matthew, A1 aNguyen, Kaylin, T1 aStein, Phyllis, K1 aFohtung, Raymond, B1 aSoliman, Elsayed, Z1 aDewland, Thomas, A1 aVittinghoff, Eric1 aPsaty, Bruce, M1 aHeckbert, Susan, R1 aMarcus, Gregory, M uhttps://chs-nhlbi.org/node/755502652nas a2200265 4500008004100000022001400041245009100055210006900146260001600215490000600231520185100237100002202088700002202110700002302132700002302155700002402178700002202202700002402224700001902248700001702267700002002284700002302304700002302327856003602350 2017 eng d a2047-998000aEctopy on a Single 12-Lead ECG, Incident Cardiac Myopathy, and Death in the Community.0 aEctopy on a Single 12Lead ECG Incident Cardiac Myopathy and Deat c2017 Aug 030 v63 a

BACKGROUND: Atrial fibrillation and heart failure are 2 of the most common diseases, yet ready means to identify individuals at risk are lacking. The 12-lead ECG is one of the most accessible tests in medicine. Our objective was to determine whether a premature atrial contraction observed on a standard 12-lead ECG would predict atrial fibrillation and mortality and whether a premature ventricular contraction would predict heart failure and mortality.

METHODS AND RESULTS: We utilized the CHS (Cardiovascular Health) Study, which followed 5577 participants for a median of 12 years, as the primary cohort. The ARIC (Atherosclerosis Risk in Communities Study), the replication cohort, captured data from 15 792 participants over a median of 22 years. In the CHS, multivariable analyses revealed that a baseline 12-lead ECG premature atrial contraction predicted a 60% increased risk of atrial fibrillation (hazard ratio, 1.6; 95% CI, 1.3-2.0; P<0.001) and a premature ventricular contraction predicted a 30% increased risk of heart failure (hazard ratio, 1.3; 95% CI, 1.0-1.6; P=0.021). In the negative control analyses, neither predicted incident myocardial infarction. A premature atrial contraction was associated with a 30% increased risk of death (hazard ratio, 1.3; 95% CI, 1.1-1.5; P=0.008) and a premature ventricular contraction was associated with a 20% increased risk of death (hazard ratio, 1.2; 95% CI, 1.0-1.3; P=0.044). Similarly statistically significant results for each analysis were also observed in ARIC.

CONCLUSIONS: Based on a single standard ECG, a premature atrial contraction predicted incident atrial fibrillation and death and a premature ventricular contraction predicted incident heart failure and death, suggesting that this commonly used test may predict future disease.

1 aNguyen, Kaylin, T1 aVittinghoff, Eric1 aDewland, Thomas, A1 aDukes, Jonathan, W1 aSoliman, Elsayed, Z1 aStein, Phyllis, K1 aGottdiener, John, S1 aAlonso, Alvaro1 aChen, Lin, Y1 aPsaty, Bruce, M1 aHeckbert, Susan, R1 aMarcus, Gregory, M uhttps://chs-nhlbi.org/node/7489